As battery technology evolves and demand for efficient energy storage solutions,aqueous zinc ion batteries(AZIBs)have garnered significant attention due to their safety and environmental benefits.However,the stability...As battery technology evolves and demand for efficient energy storage solutions,aqueous zinc ion batteries(AZIBs)have garnered significant attention due to their safety and environmental benefits.However,the stability of cathode materials under high-voltage conditions remains a critical challenge in improving its energy density.This review systematically explores the failure mechanisms of high-voltage cathode materials in AZIBs,including hydrogen evolution reaction,phase transformation and dissolution phenomena.To address these challenges,we propose a range of advanced strategies aimed at improving the stability of cathode materials.These strategies include surface coating and doping techniques designed to fortify the surface properties and structure integrity of the cathode materials under high-voltage conditions.Additionally,we emphasize the importance of designing antioxidant electrolytes,with a focus on understanding and optimizing electrolyte decomposition mechanisms.The review also highlights the significance of modifying conductive agents and employing innovative separators to further enhance the stability of AZIBs.By integrating these cutting-edge approaches,this review anticipates substantial advancements in the stability of high-voltage cathode materials,paving the way for the broader application and development of AZIBs in energy storage.展开更多
This article introduces a novel 20 V radiation-hardened high-voltage metal-oxide-semiconductor field-effect transistor(MOSFET)driver with an optimized input circuit and a drain-surrounding-source(DSS)structure.The inp...This article introduces a novel 20 V radiation-hardened high-voltage metal-oxide-semiconductor field-effect transistor(MOSFET)driver with an optimized input circuit and a drain-surrounding-source(DSS)structure.The input circuit of a conventional inverter consists of a thick-gate-oxide n-type MOSFET(NMOS).These conventional drivers can tolerate a total ionizing dose(TID)of up to 100 krad(Si).In contrast,the proposed comparator input circuit uses both a thick-gate-oxide p-type MOSFET(PMOS)and thin-gate-oxide NMOS to offer a high input voltage and higher TID tolerance.Because the thick-gate-oxide PMOS and thin-gate-oxide NMOS collectively provide better TID tolerance than the thick-gate-oxide NMOS,the circuit exhibits enhanced TID tolerance of>300 krad(Si).Simulations and experimental date indicate that the DSS structure reduces the probability of unwanted parasitic bipolar junction transistor activation,yielding a better single-event effect tolerance of over 81.8 MeVcm^(2)mg^(-1).The innovative strategy proposed in this study involves circuit and layout design optimization,and does not require any specialized process flow.Hence,the proposed circuit can be manufactured using common commercial 0.35μm BCD processes.展开更多
Expanding the cutoff voltage of layered oxide cathodes for sodium-ion batteries(SIBs)is crucial for overcoming their existing energy density limitations.However,cationic/anodic redox-triggered multiple phase transitio...Expanding the cutoff voltage of layered oxide cathodes for sodium-ion batteries(SIBs)is crucial for overcoming their existing energy density limitations.However,cationic/anodic redox-triggered multiple phase transitions and unfavorable interfacial side reactions accelerate capacity and voltage decay.Herein,we present a straightforward melting plus reactive wetting strategy using H_(3)BO_(3)for surface modification of O_(3)-type Na_(0.9)Cu_(0.12)Ni_(0.33)Mn_(0.4)Ti_(0.15)O_(2)(CNMT).The transformation of H_(3)BO_(3)from solid to liquid under mild heating facilitates the uniform dispersion and complete surface coverage of CNMT particles.By neutralizing the residual alkali and extracting Na^(+)from the CNMT lattice,H_(3)BO_(3)forms a multifunctional Na_(2)B_(2)O_(5)-dominated layer on the CNMT surface.This Na_(x)B_(y)O_(z)(NBO)layer plays a positive role in providing low-barrier Na^(+)transport channels,suppressing phase transitions,and minimizing the generation of O_(2)/CO_(2)gases and resistive byproducts.As a result,at a charge cutoff voltage of 4.5 V,the NBO-coated CNMT delivers a high discharge capacity of 149,1 mAh g^(-1)at 10 mA g^(-1)and exhibits excellent cycling stability at 100 mA g^(-1)over 200 cycles with a higher capacity retention than that of pristine CNMT(86,4%vs,62.1%).This study highlights the effectiveness of surface modification using lowmelting-point solid acids,with potential applications for other layered oxide cathode materials to achieve stable high-voltage cycling.This proposed strategy opens new avenues for the construction of highquality coatings for high-voltage layered oxide cathodes in SIBs.展开更多
Li/Mn-rich layered oxide(LMR)cathode active materials offer remarkably high specific discharge capacity(>250 mAh g^(-1))from both cationic and anionic redox.The latter necessitates harsh charging conditions to high...Li/Mn-rich layered oxide(LMR)cathode active materials offer remarkably high specific discharge capacity(>250 mAh g^(-1))from both cationic and anionic redox.The latter necessitates harsh charging conditions to high cathode potentials(>4.5 V vs Li|Li^(+)),which is accompanied by lattice oxygen release,phase transformation,voltage fade,and transition metal(TM)dissolution.In cells with graphite anode,TM dissolution is particularly detrimental as it initiates electrode crosstalk.Lithium difluorophosphate(LiDFP)is known for its pivotal role in suppressing electrode crosstalk through TM scavenging.In LMR‖graphite cells charged to an upper cutoff voltage(UCV)of 4.5 V,effective TM scavenging effects of LiDFP are observed.In contrast,for an UCV of 4.7 V,the scavenging effects are limited due to more severe TM dissolution compared an UCV of 4.5V.Given the saturation in solubility of the TM scavenging agents,which are LiDFP decomposition products,e.g.,PO_(4)^(3-) and PO_(3)F^(2-),higher concentrations of the LiDFP as precursor"cannot enhance the amount of scavenging species,they rather start to precipitate and damage the anode.展开更多
Thermal batteries are a type of thermally activated reserve battery,where the cathode material significantly influences the operating voltage and specific capacity.In this work,Cu_(2)O–CuO nanowires are prepared by i...Thermal batteries are a type of thermally activated reserve battery,where the cathode material significantly influences the operating voltage and specific capacity.In this work,Cu_(2)O–CuO nanowires are prepared by in-situ thermal oxidation method onto Cu foam,which are further coated with a carbon layer derived from polydopamine(PDA).The morphology of the nanowires has been examined using scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The material shows a kind of core–shell structure,with CuO as the shell and Cu_(2)O as the core.To further explore the interaction between the material and lithium-ion(Li^(+)),the Lit adsorption energies of CuO and Cu_(2)O were calculated,revealing a stronger affinity of Li^(+) for CuO.The unique core–shell nanowire structure of Cu_(2)O–CuO can provide a good Li^(+)adsorption with the outer layer CuO and excellent structural stability with the inner layer Cu_(2)O.When applied in thermal batteries,Cu_(2)O–CuO–C nanowires exhibit specific capacity and specific energy of 326 mAh g^(-1)and 697 Wh kg^(-1)at a cut-off voltage of 1.5 V both of which are higher than those of Cu_(2)O–CuO(238 mAh g^(-1)and 445 Wh kg^(-1)).The discharge process includes the insertion of lithium ions and subsequent reduction reactions,ultimately resulting in the formation of lithium oxide and copper.展开更多
High-voltage solid-state lithium-ion batteries(SSLIBs)have attracted considerable research attention in recent years due to their high-energy-density and superior safety characteristics.However,the integration of high...High-voltage solid-state lithium-ion batteries(SSLIBs)have attracted considerable research attention in recent years due to their high-energy-density and superior safety characteristics.However,the integration of high-voltage cathodes with solid electrolytes(SEs)presents multiple challenges,including the formation of high-impedance layers from spontaneous chemical reactions,electrochemical instability,insufficient interfacial contact,and lattice expansion.These issues significantly impair battery performance and potentially lead to battery failure,thus impeding the commercialization of high-voltage SSLIBs.The incorporation of fluorides,known for their robust bond strength and high free energy of formation,has emerged as an effective strategy to address these challenges.Fluorinated electrolytes and electrode/electrolyte interfaces have been demonstrated to significantly influence the reaction reversibility/kinetics,safety,and stability of rechargeable batteries,particularly under high voltage.This review summarizes recent advancements in fluorination treatment for high-voltage SEs,focusing on solid polymer electrolytes(SPEs),inorganic solid electrolytes(ISEs),and composite solid electrolytes(CSEs),along with the performance enhancements these strategies afford.This review aims to provide a comprehensive understanding of the structure-property relationships,the characteristics of fluorinated interfaces,and the application of fluorinated SEs in high-voltage SSLIBs.Further,the impacts of residual moisture and the challenges of fluorinated SEs are discussed.Finally,the review explores potential future directions for the development of fluorinated SSLIBs.展开更多
Enhancing the energy density of lithium-ion batteries through high-voltage cathodes holds great pro-mise.However,traditional carbonate-based electrolytes face significant challenges due to limited oxida-tive stability...Enhancing the energy density of lithium-ion batteries through high-voltage cathodes holds great pro-mise.However,traditional carbonate-based electrolytes face significant challenges due to limited oxida-tive stability and poor compatibility with high-nickel materials.This study introduces a novel electrolyte that combines bis(triethoxysilyl)methane(DMSP)as the sole solvent with lithium bis(fluorosulfonyl)imide(LiFSI)as the lithium salt.This formulation significantly improves the stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes and graphite anodes.The capacity retention of the NCM811 elec-trode increases from 5%to 95%after 1000 cycles at 1 C(3.0-4.5 V),while that of the graphite anode is improved from 22%to 92%after 400 cycles at 0.2 C(0.005-3.0 V).The NCM811//graphite pouch cell exhibits enhanced retention,rising from 12%to 66%at 25℃and from 3%to 65%at 60℃after 300 cycles at 0.2 C.Spectroscopic characterization and theoretical calculations reveal that the steric hindrance of the Si-O-CH_(3)groups in DMSP creates a weakly solvating structure,promoting the formation of Lit^(+)-FSI^(-)ion pairs and aggregation clusters,which enriches the electrode interphase with LiF,Li_(3)N,and Li_(2)SO_(3).Furthermore,DMSP with abundant Si-O effectively enhances the elasticity of the interphase layer,scav-enging harmful substances such as HF and suppressing gas evolution and transition metal dissolution.The simplicity of the DMSP-based electrolyte formulation,coupled with its superior performance,ensures scalability for large-scale manufacturing and practical application in the high-voltage battery.This work provides critical insights into improving interfacial chemistry and addressing compatibility issues in high-voltageNi-rich cathodes.展开更多
Solid-state batteries(SSBs) are highly attractive on account of their high energy density and good safety.In high-voltage and high-current conditions,however,the interface reactions,structural changes,and decompositio...Solid-state batteries(SSBs) are highly attractive on account of their high energy density and good safety.In high-voltage and high-current conditions,however,the interface reactions,structural changes,and decomposition of the electrolyte impede the transmission of lithium ions in all-solid-state lithium batteries(ASSLBs),significantly reducing the charging and discharging capacity and cycling stability of the battery and therefore restricting its practical applications.The main content of review is to conduct an in-depth analysis of the existing problems of solid-state batteries from the aspects of interface reactions,material failure,ion migration,and dendrite growth,and points out the main factors influencing the electrochemical performance of ASSLBs.Additionally,the compatibility and ion conduction mechanisms between polymer electrolytes,inorganic solid electrolytes,and composite electrolytes and the electrode materials are discussed.Furthermore,the perspectives of electrode materials,electrolyte properties,and interface modification are summarized and prospected,providing new optimization directions for the future commercialization of high-voltage solid-state electrolytes.展开更多
P2-type layered oxide Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)(NM)is a promising cathode material for sodium-ion batteries(SIBs).However,the severe irreversible phase transition,sluggish Na+diffusion kinetics,and interfacial sid...P2-type layered oxide Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)(NM)is a promising cathode material for sodium-ion batteries(SIBs).However,the severe irreversible phase transition,sluggish Na+diffusion kinetics,and interfacial side reactions at high-voltage result in grievous capacity degradation and inferior electrochemical performance.Herein,a dual-function strategy of entropy tuning and artificial cathode electrolyte interface(CEI)layer construction is reported to generate a novel P2-type medium-entropy Na_(0.75)Li_(0.1)Mg_(0.05)Ni_(0.18)Mn_(0.66)Ta_(0.01)O_(2)with NaTaO_(3)surface modification(LMNMT)to address the aforementioned issues.In situ X-ray diffraction reveals that LMNMT exhibits a near zero-strain phase transition with a volume change of only 1.4%,which is significantly lower than that of NM(20.9%),indicating that entropy tuning effectively suppresses irreversible phase transitions and enhances ion diffusion.Kinetic analysis and post-cycling interfacial characterization further confirm that the artificial CEI layer promotes the formation of a stable,thin NaF-rich CEI and reduces interfacial side reactions,thereby further enhancing ion transport kinetics and surface/interface stability.Consequently,the LMNMT electrode exhibits outstanding rate capability(46 mA h g^(−1)at 20 C)and cycling stability(89.5%capacity retention after 200 cycles at 2 C)within the voltage range of 2–4.35 V.The LMNMT also exhibits superior all-climate performance and air stability.This study provides a novel path for the design of high-voltage cathode materials for SIBs.展开更多
Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified W...Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified WSE for fast-charging high-voltage LMBs,which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE)into the tetrahydropyran(THP)based WSE.A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP,which accelerates the de-solvation kinetics of Li~+.Besides,more anions are involved in solvation structure in the presence of TTE,yielding inorganic-rich interphases with improved stability.Li(30μm)||Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)(4.1 mAh/cm^(2))batteries with the TTE modified WSE retain over 64%capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V,much better than that with pure THP based WSE.This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.展开更多
Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the...Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the cathode side,which strictly requires the development of high voltage,high capacity,and earth-abundant cathode material.Ni-Fe-Mn ternary layered oxide has been recognized as one of the most promising standard type of cathodes.However,the composition and phase structure on high-voltage characteristics have not been well investigated.Herein,selecting the typically high-voltage cathode of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)as a parent material,we fabricate ten Ni-Fe-Mn ternary layered oxides through replacing the Ni,Mn,or both Ni and Mn by Fe.The thermodynamically stable phase diagram for those materials is presented.The electrochemical properties for all the samples are investigated in detail.Three potential Ni-Fe-Mn ternary layered oxides are picked up considering the energy density,cycle stability,kinetics,cost price,and working voltage,which demonstrate great potential for surpassing the performance of lithium iron phosphate.The related electrochemical reaction and fading mechanism are well revealed.This work provides some new foundational Ni-Fe-Mn ternary layered materials for high-voltage sodium-ion batteries.展开更多
This paper focuses on the high-voltage safety of drive motor systems in new energy vehicles and conducts standardized research on functional safety design in the concept phase. In view of the lack of high-voltage haza...This paper focuses on the high-voltage safety of drive motor systems in new energy vehicles and conducts standardized research on functional safety design in the concept phase. In view of the lack of high-voltage hazard analysis for drive motor systems in existing standards, based on theories such as GB/T 34590 and ISO 26262, the safety levels are deeply analyzed. The HAZOP method is innovatively used, and 16 types of guidewords are combined to comprehensively analyze the system functions, identifying vehicle hazards such as high-voltage electric shock caused by functional abnormalities, including high-voltage interlock function failure and abnormal active discharge. Subsequently, safety goals such as preventing high-voltage electric shock are set, functional safety requirements such as accurately obtaining collision signals and timely discharging high-voltage electricity are formulated, and requirements for external signal sources and other technologies are clearly defined, constructing a complete high-voltage safety protection system. The research results provide important technical support and standardized references for the high-voltage safety functional design of drive motor systems in new energy vehicles, and are of great significance for improving the high-voltage safety level of the new energy vehicle industry, expecting to play a key role in subsequent product development and standard improvement.展开更多
The integration of large-scale new energy and high-capacity DC transmission leads to a reduction in system inertia.Grid-forming renewable energy sources(GF-RES)has a significant improvement effect on system inertia.Co...The integration of large-scale new energy and high-capacity DC transmission leads to a reduction in system inertia.Grid-forming renewable energy sources(GF-RES)has a significant improvement effect on system inertia.Commutation failure faults may cause a short-term reactive power surplus at the sending end and trigger transient overvoltage,threatening the safe and stable operation of the power grid.However,there is a lack of research on the calculation method of transient overvoltage caused by commutation failure in high-voltage DC transmission systems with grid-forming renewable energy sources integration.Based on the existing equivalent model of highvoltage DC transmission systems at the sending end,this paper proposes to construct a model of the high-voltage DC transmission system at the sending end with grid-forming renewable energy sources.The paper first clarifies the mechanism of overvoltage generation,then considers the reactive power droop control characteristics of GF-RES,and derives the transient voltage calculation model of theDC transmission system with GF-RES integration.It also proposes a calculation method for transient overvoltage at the sending-end converter bus with GF-RES integration.Based on the PSCAD/EMTDC simulation platform,this paper builds an experimental simulation model.By constructing three different experimental scenarios,the accuracy and effectiveness of the proposed transient overvoltage calculation method are verified,with a calculation error within 5%.At the same time,this paper quantitatively analyzes the impact of grid strength,new energy proportion,and rated transmission power on transient overvoltage from three different perspectives.展开更多
Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges ...Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges to electrochemical stability.This work proposes to in-situ construct a uniform element gradient modification structure on the surface and subsurface of LiCoO_(2).The modification structure contains an Sb_(2)O_(3)&SbF_(x)composite coating layer and an Sb-F doped spinel-like transition layer,simultaneously.The modified sample maintains an initial discharge specific capacity of 221.2 mA h g^(-1)and a capacity retention of 86%after 200 cycles at 3–4.6 V and 0.5 C.Moreover,it has a discharge specific capacity of163.3 mA h g^(-1)at a high rate of 5 C.Meanwhile,combining highly electronegative Sb^(3+)&F^(-)that widen the Li^(+)transport channel with the amorphous coating of F^(-)doped Sb_(2)O_(3)with higher conductivity improves the interface transport kinetics.This breaks the stereotypical view in traditional concepts that fluorinated coatings or inert metal oxide coatings inhibit Li^(+)transport.Moreover,the inert composite coating combined with Sb–O–F with high bond energy stabilizes the surface structure.A series of characterizations confirm that the joint improvement of interface structure stability and transport kinetics significantly enhances the electrochemical performance of LiCoO_(2).展开更多
Efficient,safe,and reliable energy output from high-energy-density lithium metal batteries(LMBs)at all climates is crucial for portable electronic devices operating in complex environments.The performance of correspon...Efficient,safe,and reliable energy output from high-energy-density lithium metal batteries(LMBs)at all climates is crucial for portable electronic devices operating in complex environments.The performance of corresponding cathodes and lithium(Li)metal anodes,however,faces significant challenges under such demanding conditions.Herein,a nonflammable electrolyte for high-voltage Li‖LCO cells has been designed,including partially-fluorinated ethyl 4,4,4-trifluorobutyrate(ETFB)as the key solvent,guided by theoretical calculations.With this ETFB-based electrolyte,Li‖LCO cells exhibit enhanced reversible capacities and superior capacity retention at an elevated charge voltage of 4.5 V and a wide operating temperature range spanning from-60℃to 70℃.The cells achieve 67.1%discharge capacity at-60℃,relative to room temperature capacity,and 85.9%100th-cycle retention at 70℃.The outstanding properties are attributed to the LiF-rich interphases formed in the ETFB-based electrolyte with a finetuned solvation structure,in which the coordination environment in the vicinity of Li^(+)cations and the distance between anion and solvents are subtly adjusted by introducing ETFB.This solvation structure has been mutually elucidated through joint spectra characterizations and atomistic simulations.This work presents a new strategy for the design of electrolytes to achieve all-climate reliable and safe application of LMBs.展开更多
The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SL...The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SLMBs).Herein,we report achieving accelerated Li^(+)conduction in CSEs by a novel activation of the interfacial dipole layer.Polycationic ionic liquids and polyacrylonitrile with highly polar functional groups(-C≡N)are utilized to modulate the interfacial dipole layer in MOF-based CSEs,facilitating long-range pathways for the connectivity of Li^(+)conduction and enhancing rapid transport kinetics.The as-synthesized CSEs exhibit a high ionic conductivity of 0.59 mS cm^(-1)and a lithium transfer number of 0.85.The assembled SLMBs(Li/CSE/LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2))delivered a high-capacity retention of 88.7%with a minimal discharge voltage attenuation of 17.1 mV after 500 cycles(0.03 mV per cycle)at0.5 C.This work offers an effective approach to creating interpenetrating lithium-ion transport pathways with rapid ion transport kinetics for solid-state electrolytes,thereby advancing the development of solidstate lithium metal batteries.展开更多
Ni-rich LiNi0.8Mn0.1Co0.1O2(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study...Ni-rich LiNi0.8Mn0.1Co0.1O2(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study,we propose an entropy-assisted multi-element doping strategy to mitigate these issues.Specifically,two routes are designed and compared:bulk-like localized high-entropy doping(BHE-NCM)and surface-distributed high-entropy-zone doping(SHE-NCM).The surface entropy-doped NCM cathode delivers enhanced electrochemical performance,including higher capacity retention under 4.5 V cycling and superior rate capability,compared to both bulk-like and pristine counterparts.Comprehensive material characterization reveals that surface-localized doping stabilizes the layered structure with reduced microcrack formation and creates a uniform dopant-rich surface region with improved thermal and electrochemical stability.Overall,entropy-assisted doping at the near surface zone effectively alleviates structural degradation and interface reactions in Ni-rich NCM,enabling improved cycling performance at high voltage.This work highlights the significance of surface entropy engineering as a promising strategy for designing high-voltage cathodes with improved safety and longevity.展开更多
While considerable research has been conducted on the structural principles,fabrication techniques,and photoelectric properties of high-voltage light-emitting diodes(LEDs),their performance in light communication rema...While considerable research has been conducted on the structural principles,fabrication techniques,and photoelectric properties of high-voltage light-emitting diodes(LEDs),their performance in light communication remains underexplored.A high-voltage seriesconnected LED or photodetector(HVS-LED/PD)based on the gallium nitride(GaN)integrated photoelectronic chip is presented in this paper.Multi-quantum wells(MQW)diodes with identical structures are integrated onto a single chip through wafer-scale micro-fabrication techniques and connected in series to construct the HVS-LED/PD.The advantages of the HVS-LED/PD in communication are explored by testing its performance as both a light transmitter and a PD.The series connection enhances the device's 3 dB bandwidth,allowing it to increase from 1.56 MHz to a minimum of 2.16 MHz when functioning as an LED,and from 47.42 kHz to at least 85.83 kHz when operating as a PD.The results demonstrate that the light communication performance of HVS-LED/PD is better than that of a single GaN MQW diode with bandwidth and transmission quantity,which enriches the research of GaN-based high-voltage devices.展开更多
Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the...Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage,as well as the high reactivity of metallic Li.The key is the development of stable electrolytes against both highvoltage cathodes and Li with the formation of robust interphase films on the surfaces.Herein,we report a highly fluorinated ether,1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane(TTME),as a cosolvent,which not only functions as a diluent forming a localized high concentration electrolyte(LHCE),but also participates in the construction of the inner solvation structure.The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase(SEI)film,which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility.The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28%after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm^(2) and 1.0m Ah/cm^(2).In addition,lithium metal cells using LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) and Li CoO_(2) cathodes(both loadings~3.0 m Ah/cm^(2))realize capacity retentions of>85%over 240 cycles with a charge cut-off voltage of 4.4 V and 90%for 170 cycles with a charge cut-off voltage of 4.5 V,respectively.This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.展开更多
Benefited from its high process feasibility and controllable costs,binary-metal layered structured LiNi_(0.8)Mn_(0.2)O_(2)(NM)can effectively alleviate the cobalt supply crisis under the surge of global electric vehic...Benefited from its high process feasibility and controllable costs,binary-metal layered structured LiNi_(0.8)Mn_(0.2)O_(2)(NM)can effectively alleviate the cobalt supply crisis under the surge of global electric vehicles(EVs)sales,which is considered as the most promising nextgeneration cathode material for lithium-ion batteries(LIBs).However,the lack of deep understanding on the failure mechanism of NM has seriously hindered its application,especially under the harsh condition of high-voltage without sacrifices of reversible capacity.Herein,singlecrystal LiNi_(0.8)Mn_(0.2)O_(2) is selected and compared with traditional LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM),mainly focusing on the failure mechanism of Cofree cathode and illuminating the significant effect of Co element on the Li/Ni antisite defect and dynamic characteristic.Specifically,the presence of high Li/Ni antisite defect in NM cathode easily results in the extremely dramatic H2/H3 phase transition,which exacerbates the distortion of the lattice,mechanical strain changes and exhibits poor electrochemical performance,especially under the high cutoff voltage.Furthermore,the reaction kinetic of NM is impaired due to the absence of Co element,especially at the single-crystal architecture.Whereas,the negative influence of Li/Ni antisite defect is controllable at low current densities,owing to the attenuated polarization.Notably,Co-free NM can exhibit better safety performance than that of NCM cathode.These findings are beneficial for understanding the fundamental reaction mechanism of single-crystal Ni-rich Co-free cathode materials,providing new insights and great encouragements to design and develop the next generation of LIBs with low-cost and high-safety performances.展开更多
基金supported by the Exchange Program of Highend Foreign Experts of Ministry of Science and Technology of People’s Republic of China(No.G2023041003L)the Natural Science Foundation of Shaanxi Provincial Department of Education(No.23JK0367)+1 种基金the Scientific Research Startup Program for Introduced Talents of Shaanxi University of Technology(Nos.SLGRCQD2208,SLGRCQD2306,SLGRCQD2133)Contaminated Soil Remediation and Resource Utilization Innovation Team at Shaanxi University of Technology。
文摘As battery technology evolves and demand for efficient energy storage solutions,aqueous zinc ion batteries(AZIBs)have garnered significant attention due to their safety and environmental benefits.However,the stability of cathode materials under high-voltage conditions remains a critical challenge in improving its energy density.This review systematically explores the failure mechanisms of high-voltage cathode materials in AZIBs,including hydrogen evolution reaction,phase transformation and dissolution phenomena.To address these challenges,we propose a range of advanced strategies aimed at improving the stability of cathode materials.These strategies include surface coating and doping techniques designed to fortify the surface properties and structure integrity of the cathode materials under high-voltage conditions.Additionally,we emphasize the importance of designing antioxidant electrolytes,with a focus on understanding and optimizing electrolyte decomposition mechanisms.The review also highlights the significance of modifying conductive agents and employing innovative separators to further enhance the stability of AZIBs.By integrating these cutting-edge approaches,this review anticipates substantial advancements in the stability of high-voltage cathode materials,paving the way for the broader application and development of AZIBs in energy storage.
基金supported by the National Natural Science Foundation of China(U2241221).
文摘This article introduces a novel 20 V radiation-hardened high-voltage metal-oxide-semiconductor field-effect transistor(MOSFET)driver with an optimized input circuit and a drain-surrounding-source(DSS)structure.The input circuit of a conventional inverter consists of a thick-gate-oxide n-type MOSFET(NMOS).These conventional drivers can tolerate a total ionizing dose(TID)of up to 100 krad(Si).In contrast,the proposed comparator input circuit uses both a thick-gate-oxide p-type MOSFET(PMOS)and thin-gate-oxide NMOS to offer a high input voltage and higher TID tolerance.Because the thick-gate-oxide PMOS and thin-gate-oxide NMOS collectively provide better TID tolerance than the thick-gate-oxide NMOS,the circuit exhibits enhanced TID tolerance of>300 krad(Si).Simulations and experimental date indicate that the DSS structure reduces the probability of unwanted parasitic bipolar junction transistor activation,yielding a better single-event effect tolerance of over 81.8 MeVcm^(2)mg^(-1).The innovative strategy proposed in this study involves circuit and layout design optimization,and does not require any specialized process flow.Hence,the proposed circuit can be manufactured using common commercial 0.35μm BCD processes.
基金supported by the National Natural Science Foundation of China(22169002 and 22469003)the Chongzuo Key Research and Development Program of China(20241205 and 20231204)the Counterpart Aid Project for Discipline Construction from Guangxi University(2023M02)。
文摘Expanding the cutoff voltage of layered oxide cathodes for sodium-ion batteries(SIBs)is crucial for overcoming their existing energy density limitations.However,cationic/anodic redox-triggered multiple phase transitions and unfavorable interfacial side reactions accelerate capacity and voltage decay.Herein,we present a straightforward melting plus reactive wetting strategy using H_(3)BO_(3)for surface modification of O_(3)-type Na_(0.9)Cu_(0.12)Ni_(0.33)Mn_(0.4)Ti_(0.15)O_(2)(CNMT).The transformation of H_(3)BO_(3)from solid to liquid under mild heating facilitates the uniform dispersion and complete surface coverage of CNMT particles.By neutralizing the residual alkali and extracting Na^(+)from the CNMT lattice,H_(3)BO_(3)forms a multifunctional Na_(2)B_(2)O_(5)-dominated layer on the CNMT surface.This Na_(x)B_(y)O_(z)(NBO)layer plays a positive role in providing low-barrier Na^(+)transport channels,suppressing phase transitions,and minimizing the generation of O_(2)/CO_(2)gases and resistive byproducts.As a result,at a charge cutoff voltage of 4.5 V,the NBO-coated CNMT delivers a high discharge capacity of 149,1 mAh g^(-1)at 10 mA g^(-1)and exhibits excellent cycling stability at 100 mA g^(-1)over 200 cycles with a higher capacity retention than that of pristine CNMT(86,4%vs,62.1%).This study highlights the effectiveness of surface modification using lowmelting-point solid acids,with potential applications for other layered oxide cathode materials to achieve stable high-voltage cycling.This proposed strategy opens new avenues for the construction of highquality coatings for high-voltage layered oxide cathodes in SIBs.
基金the Ministry for Culture and Science of North Rhine Westphalia(Germany)for funding this work within the International Graduate School for Battery Chemistry,Characterization,Analysis,Recycling,and Application(BACCARA)Open Access funding enabled and organized by Projekt DEAL。
文摘Li/Mn-rich layered oxide(LMR)cathode active materials offer remarkably high specific discharge capacity(>250 mAh g^(-1))from both cationic and anionic redox.The latter necessitates harsh charging conditions to high cathode potentials(>4.5 V vs Li|Li^(+)),which is accompanied by lattice oxygen release,phase transformation,voltage fade,and transition metal(TM)dissolution.In cells with graphite anode,TM dissolution is particularly detrimental as it initiates electrode crosstalk.Lithium difluorophosphate(LiDFP)is known for its pivotal role in suppressing electrode crosstalk through TM scavenging.In LMR‖graphite cells charged to an upper cutoff voltage(UCV)of 4.5 V,effective TM scavenging effects of LiDFP are observed.In contrast,for an UCV of 4.7 V,the scavenging effects are limited due to more severe TM dissolution compared an UCV of 4.5V.Given the saturation in solubility of the TM scavenging agents,which are LiDFP decomposition products,e.g.,PO_(4)^(3-) and PO_(3)F^(2-),higher concentrations of the LiDFP as precursor"cannot enhance the amount of scavenging species,they rather start to precipitate and damage the anode.
基金supported by National Natural Science Foundation of China(Nos.52374298)National Natural Science Foundation of Chongqing(Nos.CSTB2023NSCQ-MSX0662)Beijing Natural Science Foundation(Nos.L243019).
文摘Thermal batteries are a type of thermally activated reserve battery,where the cathode material significantly influences the operating voltage and specific capacity.In this work,Cu_(2)O–CuO nanowires are prepared by in-situ thermal oxidation method onto Cu foam,which are further coated with a carbon layer derived from polydopamine(PDA).The morphology of the nanowires has been examined using scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The material shows a kind of core–shell structure,with CuO as the shell and Cu_(2)O as the core.To further explore the interaction between the material and lithium-ion(Li^(+)),the Lit adsorption energies of CuO and Cu_(2)O were calculated,revealing a stronger affinity of Li^(+) for CuO.The unique core–shell nanowire structure of Cu_(2)O–CuO can provide a good Li^(+)adsorption with the outer layer CuO and excellent structural stability with the inner layer Cu_(2)O.When applied in thermal batteries,Cu_(2)O–CuO–C nanowires exhibit specific capacity and specific energy of 326 mAh g^(-1)and 697 Wh kg^(-1)at a cut-off voltage of 1.5 V both of which are higher than those of Cu_(2)O–CuO(238 mAh g^(-1)and 445 Wh kg^(-1)).The discharge process includes the insertion of lithium ions and subsequent reduction reactions,ultimately resulting in the formation of lithium oxide and copper.
基金supported by the A*STAR MTC Programmatic Project(No.M23L9b0052)the Indonesia-NTU Singapore Institute of Research for Sustainability and Innovation(INSPIRASI)(No.6635/E3/KL.02.02/2023)+2 种基金the Singapore NRF Singapore-China Flagship Program(No.023740-00001)the National Natural Science Foundation of China(Nos.11975043 and 11475300)the China Scholarship Council(No.202306460087)。
文摘High-voltage solid-state lithium-ion batteries(SSLIBs)have attracted considerable research attention in recent years due to their high-energy-density and superior safety characteristics.However,the integration of high-voltage cathodes with solid electrolytes(SEs)presents multiple challenges,including the formation of high-impedance layers from spontaneous chemical reactions,electrochemical instability,insufficient interfacial contact,and lattice expansion.These issues significantly impair battery performance and potentially lead to battery failure,thus impeding the commercialization of high-voltage SSLIBs.The incorporation of fluorides,known for their robust bond strength and high free energy of formation,has emerged as an effective strategy to address these challenges.Fluorinated electrolytes and electrode/electrolyte interfaces have been demonstrated to significantly influence the reaction reversibility/kinetics,safety,and stability of rechargeable batteries,particularly under high voltage.This review summarizes recent advancements in fluorination treatment for high-voltage SEs,focusing on solid polymer electrolytes(SPEs),inorganic solid electrolytes(ISEs),and composite solid electrolytes(CSEs),along with the performance enhancements these strategies afford.This review aims to provide a comprehensive understanding of the structure-property relationships,the characteristics of fluorinated interfaces,and the application of fluorinated SEs in high-voltage SSLIBs.Further,the impacts of residual moisture and the challenges of fluorinated SEs are discussed.Finally,the review explores potential future directions for the development of fluorinated SSLIBs.
基金supported by the National Natural Science Foundation of China (Grant No. 22179041)the Guangzhou Science and Technology Plan Project (Grant No. 2024A04J4354)the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2024A1515010034)
文摘Enhancing the energy density of lithium-ion batteries through high-voltage cathodes holds great pro-mise.However,traditional carbonate-based electrolytes face significant challenges due to limited oxida-tive stability and poor compatibility with high-nickel materials.This study introduces a novel electrolyte that combines bis(triethoxysilyl)methane(DMSP)as the sole solvent with lithium bis(fluorosulfonyl)imide(LiFSI)as the lithium salt.This formulation significantly improves the stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes and graphite anodes.The capacity retention of the NCM811 elec-trode increases from 5%to 95%after 1000 cycles at 1 C(3.0-4.5 V),while that of the graphite anode is improved from 22%to 92%after 400 cycles at 0.2 C(0.005-3.0 V).The NCM811//graphite pouch cell exhibits enhanced retention,rising from 12%to 66%at 25℃and from 3%to 65%at 60℃after 300 cycles at 0.2 C.Spectroscopic characterization and theoretical calculations reveal that the steric hindrance of the Si-O-CH_(3)groups in DMSP creates a weakly solvating structure,promoting the formation of Lit^(+)-FSI^(-)ion pairs and aggregation clusters,which enriches the electrode interphase with LiF,Li_(3)N,and Li_(2)SO_(3).Furthermore,DMSP with abundant Si-O effectively enhances the elasticity of the interphase layer,scav-enging harmful substances such as HF and suppressing gas evolution and transition metal dissolution.The simplicity of the DMSP-based electrolyte formulation,coupled with its superior performance,ensures scalability for large-scale manufacturing and practical application in the high-voltage battery.This work provides critical insights into improving interfacial chemistry and addressing compatibility issues in high-voltageNi-rich cathodes.
基金financial support received from the National Key R&D Program of China (2023YFB2504000)the financial support from the National Outstanding Youth Foundation of China (52125104)+2 种基金the National Natural Science Foundation of China (52071285)the Fundamental Research Funds for the Central Universities (226-2024-00075)the National Youth Top-Notch Talent Support Program。
文摘Solid-state batteries(SSBs) are highly attractive on account of their high energy density and good safety.In high-voltage and high-current conditions,however,the interface reactions,structural changes,and decomposition of the electrolyte impede the transmission of lithium ions in all-solid-state lithium batteries(ASSLBs),significantly reducing the charging and discharging capacity and cycling stability of the battery and therefore restricting its practical applications.The main content of review is to conduct an in-depth analysis of the existing problems of solid-state batteries from the aspects of interface reactions,material failure,ion migration,and dendrite growth,and points out the main factors influencing the electrochemical performance of ASSLBs.Additionally,the compatibility and ion conduction mechanisms between polymer electrolytes,inorganic solid electrolytes,and composite electrolytes and the electrode materials are discussed.Furthermore,the perspectives of electrode materials,electrolyte properties,and interface modification are summarized and prospected,providing new optimization directions for the future commercialization of high-voltage solid-state electrolytes.
基金supported by the National Natural Science Foundation of China(52272295,52071137,51977071,51802040,and 21802020)the Science and Technology Innovation Program of Hunan Province(2021RC3066 and 2021RC3067)+2 种基金the Natural Science Foundation of Hunan Province(2020JJ3004 and 2020JJ4192)Graduate Research Innovation Project of Hunan Province(CX20240456 and CX20240405)N.Zhang and X.Xie also acknowledge the financial support of the Fundamental Research Funds for the Central。
文摘P2-type layered oxide Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)(NM)is a promising cathode material for sodium-ion batteries(SIBs).However,the severe irreversible phase transition,sluggish Na+diffusion kinetics,and interfacial side reactions at high-voltage result in grievous capacity degradation and inferior electrochemical performance.Herein,a dual-function strategy of entropy tuning and artificial cathode electrolyte interface(CEI)layer construction is reported to generate a novel P2-type medium-entropy Na_(0.75)Li_(0.1)Mg_(0.05)Ni_(0.18)Mn_(0.66)Ta_(0.01)O_(2)with NaTaO_(3)surface modification(LMNMT)to address the aforementioned issues.In situ X-ray diffraction reveals that LMNMT exhibits a near zero-strain phase transition with a volume change of only 1.4%,which is significantly lower than that of NM(20.9%),indicating that entropy tuning effectively suppresses irreversible phase transitions and enhances ion diffusion.Kinetic analysis and post-cycling interfacial characterization further confirm that the artificial CEI layer promotes the formation of a stable,thin NaF-rich CEI and reduces interfacial side reactions,thereby further enhancing ion transport kinetics and surface/interface stability.Consequently,the LMNMT electrode exhibits outstanding rate capability(46 mA h g^(−1)at 20 C)and cycling stability(89.5%capacity retention after 200 cycles at 2 C)within the voltage range of 2–4.35 V.The LMNMT also exhibits superior all-climate performance and air stability.This study provides a novel path for the design of high-voltage cathode materials for SIBs.
基金supported by Hengyang City,Hunan Province Science and Technology Innovation Project(No.202250045319)the National Natural Science Foundation of China(Nos.11375084,21808125)the Scientific Research Planning Project of Jilin Provincial Education Department(No.JJKH20241249KJ)。
文摘Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified WSE for fast-charging high-voltage LMBs,which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE)into the tetrahydropyran(THP)based WSE.A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP,which accelerates the de-solvation kinetics of Li~+.Besides,more anions are involved in solvation structure in the presence of TTE,yielding inorganic-rich interphases with improved stability.Li(30μm)||Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)(4.1 mAh/cm^(2))batteries with the TTE modified WSE retain over 64%capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V,much better than that with pure THP based WSE.This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.
基金financially supported by the National Natural Science Foundation of China(Grant No.52402215)the Anhui Provincial Natural Science Foundation(2408085QB036)+1 种基金the Natural Science Research Project of Anhui Province Education Department(Grant Nos.2022AH050334,2022AH030046,2023AH051119)the Scientific Research Foundation of Anhui University of Technology for Talent Introduction(DT2200001211)。
文摘Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the cathode side,which strictly requires the development of high voltage,high capacity,and earth-abundant cathode material.Ni-Fe-Mn ternary layered oxide has been recognized as one of the most promising standard type of cathodes.However,the composition and phase structure on high-voltage characteristics have not been well investigated.Herein,selecting the typically high-voltage cathode of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)as a parent material,we fabricate ten Ni-Fe-Mn ternary layered oxides through replacing the Ni,Mn,or both Ni and Mn by Fe.The thermodynamically stable phase diagram for those materials is presented.The electrochemical properties for all the samples are investigated in detail.Three potential Ni-Fe-Mn ternary layered oxides are picked up considering the energy density,cycle stability,kinetics,cost price,and working voltage,which demonstrate great potential for surpassing the performance of lithium iron phosphate.The related electrochemical reaction and fading mechanism are well revealed.This work provides some new foundational Ni-Fe-Mn ternary layered materials for high-voltage sodium-ion batteries.
文摘This paper focuses on the high-voltage safety of drive motor systems in new energy vehicles and conducts standardized research on functional safety design in the concept phase. In view of the lack of high-voltage hazard analysis for drive motor systems in existing standards, based on theories such as GB/T 34590 and ISO 26262, the safety levels are deeply analyzed. The HAZOP method is innovatively used, and 16 types of guidewords are combined to comprehensively analyze the system functions, identifying vehicle hazards such as high-voltage electric shock caused by functional abnormalities, including high-voltage interlock function failure and abnormal active discharge. Subsequently, safety goals such as preventing high-voltage electric shock are set, functional safety requirements such as accurately obtaining collision signals and timely discharging high-voltage electricity are formulated, and requirements for external signal sources and other technologies are clearly defined, constructing a complete high-voltage safety protection system. The research results provide important technical support and standardized references for the high-voltage safety functional design of drive motor systems in new energy vehicles, and are of great significance for improving the high-voltage safety level of the new energy vehicle industry, expecting to play a key role in subsequent product development and standard improvement.
基金supported by Key Natural Science Research Projects of Colleges and Universities in Anhui Province(2022AH051831).
文摘The integration of large-scale new energy and high-capacity DC transmission leads to a reduction in system inertia.Grid-forming renewable energy sources(GF-RES)has a significant improvement effect on system inertia.Commutation failure faults may cause a short-term reactive power surplus at the sending end and trigger transient overvoltage,threatening the safe and stable operation of the power grid.However,there is a lack of research on the calculation method of transient overvoltage caused by commutation failure in high-voltage DC transmission systems with grid-forming renewable energy sources integration.Based on the existing equivalent model of highvoltage DC transmission systems at the sending end,this paper proposes to construct a model of the high-voltage DC transmission system at the sending end with grid-forming renewable energy sources.The paper first clarifies the mechanism of overvoltage generation,then considers the reactive power droop control characteristics of GF-RES,and derives the transient voltage calculation model of theDC transmission system with GF-RES integration.It also proposes a calculation method for transient overvoltage at the sending-end converter bus with GF-RES integration.Based on the PSCAD/EMTDC simulation platform,this paper builds an experimental simulation model.By constructing three different experimental scenarios,the accuracy and effectiveness of the proposed transient overvoltage calculation method are verified,with a calculation error within 5%.At the same time,this paper quantitatively analyzes the impact of grid strength,new energy proportion,and rated transmission power on transient overvoltage from three different perspectives.
基金supported by the National Natural Science Foundation of China(22075170)employed resources from the BL11B station of the Shanghai Synchrotron Radiation Facility(SSRF,under contract number:2023-SSRF-PT-502681)。
文摘Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges to electrochemical stability.This work proposes to in-situ construct a uniform element gradient modification structure on the surface and subsurface of LiCoO_(2).The modification structure contains an Sb_(2)O_(3)&SbF_(x)composite coating layer and an Sb-F doped spinel-like transition layer,simultaneously.The modified sample maintains an initial discharge specific capacity of 221.2 mA h g^(-1)and a capacity retention of 86%after 200 cycles at 3–4.6 V and 0.5 C.Moreover,it has a discharge specific capacity of163.3 mA h g^(-1)at a high rate of 5 C.Meanwhile,combining highly electronegative Sb^(3+)&F^(-)that widen the Li^(+)transport channel with the amorphous coating of F^(-)doped Sb_(2)O_(3)with higher conductivity improves the interface transport kinetics.This breaks the stereotypical view in traditional concepts that fluorinated coatings or inert metal oxide coatings inhibit Li^(+)transport.Moreover,the inert composite coating combined with Sb–O–F with high bond energy stabilizes the surface structure.A series of characterizations confirm that the joint improvement of interface structure stability and transport kinetics significantly enhances the electrochemical performance of LiCoO_(2).
基金the financial support from Projects of Science&Technology Department of Sichuan Province(Grant No.22023YFG0082,Grant No.2023YFG0096,and Grant No.2023ZHJY0019)Chengdu Science and Technology Projects(Grant No.2024-YF08-00062-GX).
文摘Efficient,safe,and reliable energy output from high-energy-density lithium metal batteries(LMBs)at all climates is crucial for portable electronic devices operating in complex environments.The performance of corresponding cathodes and lithium(Li)metal anodes,however,faces significant challenges under such demanding conditions.Herein,a nonflammable electrolyte for high-voltage Li‖LCO cells has been designed,including partially-fluorinated ethyl 4,4,4-trifluorobutyrate(ETFB)as the key solvent,guided by theoretical calculations.With this ETFB-based electrolyte,Li‖LCO cells exhibit enhanced reversible capacities and superior capacity retention at an elevated charge voltage of 4.5 V and a wide operating temperature range spanning from-60℃to 70℃.The cells achieve 67.1%discharge capacity at-60℃,relative to room temperature capacity,and 85.9%100th-cycle retention at 70℃.The outstanding properties are attributed to the LiF-rich interphases formed in the ETFB-based electrolyte with a finetuned solvation structure,in which the coordination environment in the vicinity of Li^(+)cations and the distance between anion and solvents are subtly adjusted by introducing ETFB.This solvation structure has been mutually elucidated through joint spectra characterizations and atomistic simulations.This work presents a new strategy for the design of electrolytes to achieve all-climate reliable and safe application of LMBs.
基金financially supported by the National Natural Science Foundation of China(22408239)the National Natural Science Foundation of China(51904193)+3 种基金the Sichuan Science and Technology Program(2024NSFSC0987)the Fundamental Research Funds for the Central Universities(No.YJ202280)support from the Australian Research Council(ARC)through the ARC Linkage project(LP200200926)ARC Discover project(DP240102176)。
文摘The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SLMBs).Herein,we report achieving accelerated Li^(+)conduction in CSEs by a novel activation of the interfacial dipole layer.Polycationic ionic liquids and polyacrylonitrile with highly polar functional groups(-C≡N)are utilized to modulate the interfacial dipole layer in MOF-based CSEs,facilitating long-range pathways for the connectivity of Li^(+)conduction and enhancing rapid transport kinetics.The as-synthesized CSEs exhibit a high ionic conductivity of 0.59 mS cm^(-1)and a lithium transfer number of 0.85.The assembled SLMBs(Li/CSE/LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2))delivered a high-capacity retention of 88.7%with a minimal discharge voltage attenuation of 17.1 mV after 500 cycles(0.03 mV per cycle)at0.5 C.This work offers an effective approach to creating interpenetrating lithium-ion transport pathways with rapid ion transport kinetics for solid-state electrolytes,thereby advancing the development of solidstate lithium metal batteries.
基金supported by the Australian Research Council via Discovery Projects(Nos.DP200103315,DP200103332 and DP230100685)Linkage Projects(No.LP220200920)+1 种基金support from the IONTOF M6 ToF-SIMS(funded by ARC LIEF,LE190100053)the Kratos Axis Ultra XPS(ARC LIEF,LE120100026)。
文摘Ni-rich LiNi0.8Mn0.1Co0.1O2(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study,we propose an entropy-assisted multi-element doping strategy to mitigate these issues.Specifically,two routes are designed and compared:bulk-like localized high-entropy doping(BHE-NCM)and surface-distributed high-entropy-zone doping(SHE-NCM).The surface entropy-doped NCM cathode delivers enhanced electrochemical performance,including higher capacity retention under 4.5 V cycling and superior rate capability,compared to both bulk-like and pristine counterparts.Comprehensive material characterization reveals that surface-localized doping stabilizes the layered structure with reduced microcrack formation and creates a uniform dopant-rich surface region with improved thermal and electrochemical stability.Overall,entropy-assisted doping at the near surface zone effectively alleviates structural degradation and interface reactions in Ni-rich NCM,enabling improved cycling performance at high voltage.This work highlights the significance of surface entropy engineering as a promising strategy for designing high-voltage cathodes with improved safety and longevity.
基金This work is jointly supported by the National Natural Science Foundation of China under Grant Nos.62004103,62105162,62005130,61827804,62274096,and 61904086the Natural Science Foundation of Jiangsu Province under Grant No.BK20200743+3 种基金the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province under Grant No.22KJA510003the Natural Science Foundation of Nanjing University of Posts and Telecommunications under Grant No.NY223084the“111”project under Grant No.D17018the Postgraduate Research&Practice Innovation Program of Jiangsu Province under Grant No.SJCX230257.
文摘While considerable research has been conducted on the structural principles,fabrication techniques,and photoelectric properties of high-voltage light-emitting diodes(LEDs),their performance in light communication remains underexplored.A high-voltage seriesconnected LED or photodetector(HVS-LED/PD)based on the gallium nitride(GaN)integrated photoelectronic chip is presented in this paper.Multi-quantum wells(MQW)diodes with identical structures are integrated onto a single chip through wafer-scale micro-fabrication techniques and connected in series to construct the HVS-LED/PD.The advantages of the HVS-LED/PD in communication are explored by testing its performance as both a light transmitter and a PD.The series connection enhances the device's 3 dB bandwidth,allowing it to increase from 1.56 MHz to a minimum of 2.16 MHz when functioning as an LED,and from 47.42 kHz to at least 85.83 kHz when operating as a PD.The results demonstrate that the light communication performance of HVS-LED/PD is better than that of a single GaN MQW diode with bandwidth and transmission quantity,which enriches the research of GaN-based high-voltage devices.
基金the financial supports from the KeyArea Research and Development Program of Guangdong Province (2020B090919001)the National Natural Science Foundation of China (22078144)the Guangdong Natural Science Foundation for Basic and Applied Basic Research (2021A1515010138 and 2023A1515010686)。
文摘Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage,as well as the high reactivity of metallic Li.The key is the development of stable electrolytes against both highvoltage cathodes and Li with the formation of robust interphase films on the surfaces.Herein,we report a highly fluorinated ether,1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane(TTME),as a cosolvent,which not only functions as a diluent forming a localized high concentration electrolyte(LHCE),but also participates in the construction of the inner solvation structure.The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase(SEI)film,which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility.The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28%after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm^(2) and 1.0m Ah/cm^(2).In addition,lithium metal cells using LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) and Li CoO_(2) cathodes(both loadings~3.0 m Ah/cm^(2))realize capacity retentions of>85%over 240 cycles with a charge cut-off voltage of 4.4 V and 90%for 170 cycles with a charge cut-off voltage of 4.5 V,respectively.This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.
基金the National Natural Science Foundation of China(52070194,52073309,51902347,51908555)Natural Science Foundation of Hunan Province(2022JJ20069,2020JJ5741).
文摘Benefited from its high process feasibility and controllable costs,binary-metal layered structured LiNi_(0.8)Mn_(0.2)O_(2)(NM)can effectively alleviate the cobalt supply crisis under the surge of global electric vehicles(EVs)sales,which is considered as the most promising nextgeneration cathode material for lithium-ion batteries(LIBs).However,the lack of deep understanding on the failure mechanism of NM has seriously hindered its application,especially under the harsh condition of high-voltage without sacrifices of reversible capacity.Herein,singlecrystal LiNi_(0.8)Mn_(0.2)O_(2) is selected and compared with traditional LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM),mainly focusing on the failure mechanism of Cofree cathode and illuminating the significant effect of Co element on the Li/Ni antisite defect and dynamic characteristic.Specifically,the presence of high Li/Ni antisite defect in NM cathode easily results in the extremely dramatic H2/H3 phase transition,which exacerbates the distortion of the lattice,mechanical strain changes and exhibits poor electrochemical performance,especially under the high cutoff voltage.Furthermore,the reaction kinetic of NM is impaired due to the absence of Co element,especially at the single-crystal architecture.Whereas,the negative influence of Li/Ni antisite defect is controllable at low current densities,owing to the attenuated polarization.Notably,Co-free NM can exhibit better safety performance than that of NCM cathode.These findings are beneficial for understanding the fundamental reaction mechanism of single-crystal Ni-rich Co-free cathode materials,providing new insights and great encouragements to design and develop the next generation of LIBs with low-cost and high-safety performances.
