Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_...Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.展开更多
Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stab...Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs.展开更多
Transition metal fluorides(TMFs)cathode materials have shown extraordinary promises for electrochemical energy storage,but the understanding of their electrochemical reaction mechanisms is still a matter of debate due...Transition metal fluorides(TMFs)cathode materials have shown extraordinary promises for electrochemical energy storage,but the understanding of their electrochemical reaction mechanisms is still a matter of debate due to the complicated and continuous changing in the battery internal environment.Here,we design a novel iron fluoride(FeF_(2))aggregate assembled with cylindrical nanoparticles as cathode material to build FeF_(2) lithium-ion batteries(LIBs)and employ advanced in situ magnetometry to detect their intrinsic electronic structure during cycling in real time.The results show that FeF_(2) cannot be involved in complete conversion reactions when the FeF_(2) LIBs operate between the conventional voltage range of 1.0–4.0 V,and that the corresponding conversion ratio of FeF_(2) can be further estimated.Importantly,we first demonstrate that the spin-polarized surface capacitance exists in the FeF_(2) cathode by monitoring the magnetic responses over various voltage ranges.The research presents an original and insightful method to examine the conversion mechanism of TMFs and significantly provides an important reference for the future artificial design of energy systems based on spinpolarized surface capacitance.展开更多
Lithium-ion capacitors(LICs)are regarded as a good choice for next-generation energy storage devices,which are expected to exhibit high energy densities,high power densities,and ultra-long cycling stability.Neverthele...Lithium-ion capacitors(LICs)are regarded as a good choice for next-generation energy storage devices,which are expected to exhibit high energy densities,high power densities,and ultra-long cycling stability.Nevertheless,only a few battery-type cathode materials with limited kinetic properties can be employed in LICs,and their electrochemical properties need to be optimized urgently.Here,we exploit a new dendrite-structured FeF_(2) consisting of closely linked primary nanoparticles using a facile solvothermal method combined with the subsequent annealing treatment.This particular architecture has favorable transport pathways for both lithium ions and electrons and exhibits an ultrafast chargedischarge capability with high reversible capacities.Furthermore,a well-designed LIC employing the prepared dendrite-structured FeF_(2) as the battery-type cathode and commercialized activated carbon(AC)as supercapacitor-type anode was constructed in an organic electrolyte containing Li ions.The LIC operates at an optimal voltage range of 1.1-3.8 V and shows a maximum high energy density of 152 W h kg^(-1) and a high power density of 4900 W kg^(-1) based on the total mass of cathode and anode.Long-term cycling stability(85%capacity retention after 2000 cycles)was achieved at 1 A g^(-1).This work suggests that the dendrite-structured FeF_(2) is a prime candidate for high-performance LICs and accelerates the development of hybrid ion capacitor devices.展开更多
Fluoride ferrous(FeF_(2))is viewed as a promising conversion cathode material for next-generation lithiumion batteries(LIBs)due to its high theoretical specific capacity and low cost.Unfortunately,issues such as poor ...Fluoride ferrous(FeF_(2))is viewed as a promising conversion cathode material for next-generation lithiumion batteries(LIBs)due to its high theoretical specific capacity and low cost.Unfortunately,issues such as poor intrinsic conductivity,iron dissolution,and phase separation hinder the application of FeF_(2)in highenergy cathodes.Here,a pressure-induced morphology control method is designed to prepare coralloidlike FeF_(2)nanocrystals with nitrogen-rich carbon coating(c-FeF_(2)@NC).The coralloid-like interconnected crystal structure of c-FeF_(2)@NC contributes to reducing interfacial resistance and enhancing the topotactic transformation during the conversion reaction,and the nitrogen-rich carbon(NC)coating can enhance interfacial stability and kinetic performance.When used as a conversion cathode for LIBs,c-FeF_(2)@NC exhibits a high initial reversible capacity of 503.57 mA h g^(-1)and excellent cycling stability of497.61 m A h g^(-1)with a low capacity decay of 1.19%over 50 cycles at 0.1 A/g.Even at 1 A/g,a stable capacity of 263.78 mA h g^(-1)can still be retained after 200 cycles.The capability of c-FeF_(2)@NC as a conversion cathode for sodium-ion batteries(SIBs)was also evaluated to expand its field of application.Furthermore,two kinds of full batteries have been assembled by employing c-FeF_(2)@NC as cathodes and quantitative limited-Li(LLi)and pre-lithiated reduced graphene oxide(PGO)as anodes,respectively,to envisage the feasibility of practical applications of conversion materials.展开更多
LiMn_(2)O_(4)(LMO) represents one of the most prevalent cathode materials utilized in lithium-ion batteries(LIBs), yet its broader application is often hampered by its limited achievable capacity and significant capac...LiMn_(2)O_(4)(LMO) represents one of the most prevalent cathode materials utilized in lithium-ion batteries(LIBs), yet its broader application is often hampered by its limited achievable capacity and significant capacity degradation during cycling. In this work, a novel dual-doping strategy involving Al^(3+) and Zr^(4+) ions has been employed to refine the atomic structure of LMO's spinel framework. The resultant dual-doped material, Li_(1.06)Mn_(1.97)Zr_(0.01)Al_(0.02)O_(4), exhibits enhanced electrochemical properties, boasting a discharge capacity of 124.9 m Ah/g at a rate of 0.1 C. Furthermore, the formation of stronger Al–O and Zr–O bonds contributes to the stabilization of the delithiated LMO structure. Impressively, 97.7%of its initial capacity is retained after 100 cycles at a 5 C rate. Additionally, enhancements in rate performance and hightemperature cycling stability have also been observed. This study underscores the potential of Al^(3+) and Zr^(4+) dual-doping as a promising approach to enhance LMO cathodes, providing a scalable and efficient means of improving the performance of lithium manganese oxide cathode materials through the incorporation of multiple ions.展开更多
Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental frien...Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental friendliness.However,its intrinsic low conductivity and sluggish Na^(+)diffusion restricted the fast-charge and low-temperature sodium storage.Herein,an NFPP composite encapsulated by in-situ pyrolytic carbon and coupled with expanded graphite(NFPP@C/EG)was constructed via a sol-gel method followed by a ballmill procedure.Due to the dual-carbon modified strategy,this NFPP@C/EG only enhanced the electronic conductivity,but also endowed more channels for Na^(+)diffusion.As cathode for SIBs,the optimized NFPP(M-NFPP@C/EG)delivers excellent rate capability(capacity of~80.5 mAh/g at 50 C)and outstanding cycling stability(11000 cycles at 50 C with capacity retention of 89.85%).Additionally,cyclic voltammetry(CV)confirmed that its sodium storage behavior is pseudocapacitance-controlled,with in-situ electrochemical impedance spectroscopy(EIS)further elucidating improvements in electrode reaction kinetics.At lower temperatures(0℃),M-NFPP@C/EG demonstrated exceptional cycling performance(8800 cycles at 10 C with capacity retention of 95.81%).Moreover,pouch cells also exhibited excellent stability.This research demonstrates the feasibility of a dual carbon modification strategy in enhancing NFPP and proposes a low-cost,high-rate,and ultra-stable cathode material for SIBs.展开更多
Lithium nickel oxide(Li_(2)NiO_(2)),as a sacrificial cathode prelithiation additive,has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries(LIBs).However,high-cost Li_(2)Ni...Lithium nickel oxide(Li_(2)NiO_(2)),as a sacrificial cathode prelithiation additive,has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries(LIBs).However,high-cost Li_(2)NiO_(2)suffers from inferior delithiation kinetics during the first cycle.Herein,we investigated the effects of the cost-effective copper substituted Li_(2)Ni_(1-x)Cu_(x)O_(2)(x=0,0.2,0.3,0.5,0.7)synthesized by a high-temperature solid-phase method on the structure,morphology,electrochemical performance of graphite‖LiFePO_(4)battery.The X-ray diffraction(XRD)refinement result demonstrated that Cu substitution strategy could be favorable for eliminating the NiO_(x)impurity phase and weakening Li-O bond.Analysis on density of states(DOS)indicates that Cu substitution is good for enhancing the electronic conductivity,as well as reducing the delithi-ation voltage polarization confirmed by electrochemical characterizations.Therefore,the optimal Li_(2)Ni_(0.7)Cu_(0.3)O_(2)delivered a high delithiation capacity of 437 mAh·g^(-1),around 8%above that of the pristine Li_(2)NiO_(2).Furthermore,a graphite‖LiFePO_(4)pouch cell with a nominal capacity of 3000 mAh demonstrated a notably improved reversible capacity,energy density and cycle life through introducing 2 wt%Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive,delivering a 6.2 mAh·g^(-1)higher initial discharge capacity and achieving around 5%improvement in capacity retentnion at 0.5P over 1000 cycles.Additionally,the post-mortem analyses testified that the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive could suppress solid electrolyte interphase(SEI)decomposition and homogenize the Li distribution,which benefits to stabilizing interface between graphite and electrolyte,and alleviating dendritic Li plating.In conclusion,the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive may offer advantages such as lower cost,lower delithiation voltage and higher prelithiation capacity compared with Li_(2)NiO_(2),making it a promising candidate of cathode prelithiation additive for next-generation LIBs.展开更多
Mn-based P2-type oxides are considered as promising cathodes for Na-ion batteries;however,they face significant challenges,including structural degradation when charged at high cutoff voltages and structural changes u...Mn-based P2-type oxides are considered as promising cathodes for Na-ion batteries;however,they face significant challenges,including structural degradation when charged at high cutoff voltages and structural changes upon storing in a humid atmosphere.In response to these issues,we have designed an oxide with co-doping of Cu and Al which can balance both cost and structural stability.The redox reaction of Cu^(2+/3+)can provide certain charge compensation,and the introduction of Al can further suppress the Jahn-Teller effect of Mn,thereby achieving superior long-term cycling performance.The ex-situ XRD testing indicates that Cu/Al co-doping can effectively suppress the phase transition of P2-O2 at high voltage,thereby explaining the improvement in electrochemical performance.DFT calculations reveal a high chemical tolerance to moisture,with lower adsorption energy for H_(2)O compared to pure Na_(0.67)Cu_(0.25)Mn_(0.75)O_(2).A representative Na_(0.67)Cu_(0.20)Al_(0.05)Mn_(0.75)O_(2)cathode demonstrates impressive reversible capacities of 148.7 mAh/g at 0.2 C,along with a remarkable capacity retention of 79.1%(2 C,500 cycles).展开更多
Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To o...Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To overcome this obstacle,a δ-MnO_(2)/MXene heterostructure was created using a simple one-step process under gentle condition.The ZHSC was assembled using this heterostructure as the cathode,activated carbon(AC)as the anode and 2 mol·L−1 ZnSO_(4) as the electrolyte.The resultingδ-MnO_(2)/MXene//ZnSO4//AC ZHSC shows a maximum specific capacitance of 97.4 F·g^(−1) and an energy density of 32.27 Wh·kg^(−1) at the best cathode-to-anode mass ratio.Ex situ characterizations reveal the reversible energy storage mechanism combing Zn^(2+)insertion/extraction in the cathode,ion adsorption and desorption on the anode surface,and partial reversible formation and dissolution of Zn_(4)SO_(4)(OH)_(6)·5H_(2)O(ZHS)components on both electrodes.Adding of Mn^(2+)to the electrolyte reduced Mn dissolution,improving the ZHSC’s specific capacitance and energy density to 140.4 F·g^(−1) and 49.36 Wh·kg^(−1),respectively,while also enhancing its rate performance and cyclability.The improved electrochemical reaction kinetics was verified through various tests.The results suggest that the δ-MnO_(2)/MXene heterostructure has great potential as a high-performance cathode material for ZHSCs.展开更多
The electrochemical performance of layered O3-type NaCrO_(2)cathode material is significantly affected by the side reactions between NaCrO_(2)and electrolyte during sodium storage.A uniform Cr_(2)O_(3)coating layer wa...The electrochemical performance of layered O3-type NaCrO_(2)cathode material is significantly affected by the side reactions between NaCrO_(2)and electrolyte during sodium storage.A uniform Cr_(2)O_(3)coating layer was in situ constructed on the surface of NaCrO_(2)by controlling the excess ratio of sodium source.The structure,morphology,valence and electrochemical performance of the Cr_(2)O_(3)-coated NaCrO_(2)were characterized.The results indicate that the Cr_(2)O_(3)coating layer does not alter the crystal structure and morphology of NaCrO_(2),but effectively suppresses the side reactions between NaCrO_(2)and electrolyte,and improves the surface/interfacial stability of NaCrO_(2)material.The Cr_(2)O_(3)-coated NaCrO_(2)exhibits improved electrochemical performance with a capacity retention of 66.4%after 500 cycles at 10C.展开更多
Extending the charging voltage of LiCoO_(2)(LCO)is an ongoing and promising approach to increase its energy density.However,the main challenge of the approach lies in the insuperable cathodic interfacial processes at ...Extending the charging voltage of LiCoO_(2)(LCO)is an ongoing and promising approach to increase its energy density.However,the main challenge of the approach lies in the insuperable cathodic interfacial processes at high voltage,which leads to rapid failure both in the performance and structure of the LCO cathode.Herein,a Li_(2)CO_(3)-based additive was prepared by a simple sand-milling method,enabling a low electrochemical decomposition voltage<4.6 V from commonly>4.8 V,stabilizing the interface of the LCO cathode at 4.6 V.The decomposition of Li_(2)CO_(3)provides extra Li^(+)and CO_(2)to supplement the Li consumption required in the initial irreversible interfacial reactions and rapidly form a uniform and stable cathode electrolyte interphase layer(less organic and more inorganic components)on the LCO cathode by reducing CO_(2).Thus,the phase transformation and the emergence of high-valent Co ions on the surface of LCO at 4.6 V high voltage were inhibited.Thanks to this,with 2%Li_(2)CO_(3)-based additive,the capacity retention of commercial LCO at a high voltage of 4.6 V at 0.5 C for 100 cycles was improved from 59.3%to 79.3%.This work improves the high-voltage stability of LCO and provides a new idea for realizing the high-voltage operation of batteries.展开更多
The Li-CO_(2)battery has been highly rated as an intriguing technique for balancing the carbon cycle for years,but it is still significantly challenged by the obstacles such as limited reversibility,sluggish kinetics,...The Li-CO_(2)battery has been highly rated as an intriguing technique for balancing the carbon cycle for years,but it is still significantly challenged by the obstacles such as limited reversibility,sluggish kinetics,and poor energy efficiency.Hence,the design and development of advance catalysts that can enhance the kinetics and reversibility of the CO_(2)electrochemical cycling reactions are considered the imperative tasks.Transition metal-based catalysts are widely considered appealing owing to their unfilled dorbitals,rich and adjustable valences,as well as processibility.In this review,the working mechanism and the key issues of the CO_(2)electrochemical cycling reaction are discussed first.Then the strategies for composition and structure design of different type of transition metal-based catalysts are highlighted,including their benefits,limitations,and the ways to implement these strategies.Finally,based on the pioneering research,the perspectives on the challenges and key points for the future development of cathode catalyst are proposed.展开更多
As a cathode material for thermal batteries,NiS_(2)has a high theoretical capacity but low thermal stability.Besides,the poor formability of NiS_(2)powders also restricts the cathode performance of thermal batteries.I...As a cathode material for thermal batteries,NiS_(2)has a high theoretical capacity but low thermal stability.Besides,the poor formability of NiS_(2)powders also restricts the cathode performance of thermal batteries.In this paper,the novel NiS_(2)/SiO_(2)composite material was developed by high temperature vulcanization to improve the thermal stability formability of NiS_(2).The good filling and lubrication of spherical SiO_(2)can improve the thermal conductivity of NiS_(2)electrode.The discharge test shows that the NiS_(2)/SiO_(2)cathode has a stable discharge voltage at a current density of 200 mA/cm^(2),and the activation time is shortened by nearly 20%compared with the NiS_(2)cathode.In addition,due to the favorable thermal insulation protection of SiO_(2),the initial decomposition temperature of NiS_(2)is increased by 30℃after the addition of SiO_(2).The incorporation of SiO_(2)not only effectively improves the thermal stability and electrochemical properties of NiS_(2),but also improves the cold pressing forming performance of the NiS_(2)powder.Therefore,the novel NiS_(2)/SiO_(2)composite material is more suitable for thermal batteries with high stability and fast response,which is of great significance for improving the maneuverability and quality reliability of weapons and equipment.展开更多
PrBaFe_(2)O_(5+δ)(PBF)is one of the promising cathode materials for intermediate-temperature solid oxide fuel cell(IT-SOFC)technology.However,as the operating temperature decreases,the electrochemical performance of ...PrBaFe_(2)O_(5+δ)(PBF)is one of the promising cathode materials for intermediate-temperature solid oxide fuel cell(IT-SOFC)technology.However,as the operating temperature decreases,the electrochemical performance of this material deteriorates rapidly.To counter this,various doping strategies have been tested and reported in order to improve the electrochemical properties of this material at intermediate-temperatures.In this study,Mg-doping to partially substitute Fe of PBF was investigated.PrBaFe_(2-x)Mg_(x)O_(5+δ)(PBFMgx,x=0.1,0.15,0.2,0.3)materials were successfully synthesized,and their electrochemical performance as IT-SOFC cathode was evaluated.It is shown that Mg-doping enhances the conductivity of PBF between 650 and 800℃,impacts little on the area-specific resistance of oxygen reduction reaction at and above 700℃,and,most significantly,improves the power density of the NiSDC/SDC/PBFMg0.15single cell by 52%compared to the un-doped PBF.This enhanced electrochemical performance is attributed to the improvement in PBF conductivity by Mg-doping.展开更多
To investigate the mechanism by which ZrO_(2)modification affects the electrochemical performance of the NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)cathode material for sodium-ion batteries,ZrO_(2)-coated NFM(ZrO_(2)@NFM)was...To investigate the mechanism by which ZrO_(2)modification affects the electrochemical performance of the NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)cathode material for sodium-ion batteries,ZrO_(2)-coated NFM(ZrO_(2)@NFM)was prepared via high-temperature calcination.XRD refinement results revealed that ZrO_(2)modification increased the Na-layer spacing in the NFM material.XPS analysis results demonstrated that ZrO_(2)modification adjusted the Mn^(3+)/Mn^(4+)ratio in NFM by reducing the Mn^(3+)content.Electrochemical test results revealed that,compared to NFM,ZrO_(2)@NFM exhibited superior rate capability and cycling stability.It also exhibited significantly enhanced Na^(+)diffusion coefficients and reduced interfacial charge transfer resistance.The ZrO_(2)coating increased Na-layer spacing,reduced electrochemical polarization,and inhibited side reactions.In summary,the synergistic effect of component regulation and surface engineering through ZrO_(2)coating improved Na^(+)diffusion kinetics and enhanced cycling stability.展开更多
The performance of solid oxide electrolysis cells(SOECs)for CO_(2) electrolysis is significantly impeded by the limited electrochemical activity and insufficient durability of the cathode.This study introduces a novel...The performance of solid oxide electrolysis cells(SOECs)for CO_(2) electrolysis is significantly impeded by the limited electrochemical activity and insufficient durability of the cathode.This study introduces a novel(LaSrPrBaCaGd)_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(LSPBCGFM)perovskite via A-site entropy engineering,to improve both activity and durability.Experimental results reveal that LSPBCGFM cathode-based SOEC achieves a current density of 1.34 A·cm^(−2) at 1.5 V and 800℃,maintaining stable operation for more than 400 h at 1.2 V with negligible degradation.Theoretical calculations suggest that the high-entropy strategy shifts the transition metal d-band center and O-2p-band center closer to the Fermi energy level simultaneously,thereby initiating more favorable CO_(2) adsorption and activation.In addition,a higher O-2p-band center promotes the formation and diffusion of oxygen vacancies.The findings of this study provide crucial insights into the role of conformational entropy strategies in CO_(2) electrolysis and offer potential pathways for the development of highly efficient and stable catalysts.展开更多
文摘Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.
基金partly supported by the National Natural Science Foundation of China(Grant No.52272225).
文摘Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs.
基金National Natural Science Foundation of China,Grant/Award Number:51804173。
文摘Transition metal fluorides(TMFs)cathode materials have shown extraordinary promises for electrochemical energy storage,but the understanding of their electrochemical reaction mechanisms is still a matter of debate due to the complicated and continuous changing in the battery internal environment.Here,we design a novel iron fluoride(FeF_(2))aggregate assembled with cylindrical nanoparticles as cathode material to build FeF_(2) lithium-ion batteries(LIBs)and employ advanced in situ magnetometry to detect their intrinsic electronic structure during cycling in real time.The results show that FeF_(2) cannot be involved in complete conversion reactions when the FeF_(2) LIBs operate between the conventional voltage range of 1.0–4.0 V,and that the corresponding conversion ratio of FeF_(2) can be further estimated.Importantly,we first demonstrate that the spin-polarized surface capacitance exists in the FeF_(2) cathode by monitoring the magnetic responses over various voltage ranges.The research presents an original and insightful method to examine the conversion mechanism of TMFs and significantly provides an important reference for the future artificial design of energy systems based on spinpolarized surface capacitance.
基金funding support from the National Natural Science Foundation of China(51804173)the Shandong Provincial Natural Science Foundation(ZR2018BB030)+1 种基金the Qingdao Science and Technology Plan Applied Basic Research(Youth Special Project,18-2-2-22-jch)the funding support from “Distinguished Taishan Scholar”project。
文摘Lithium-ion capacitors(LICs)are regarded as a good choice for next-generation energy storage devices,which are expected to exhibit high energy densities,high power densities,and ultra-long cycling stability.Nevertheless,only a few battery-type cathode materials with limited kinetic properties can be employed in LICs,and their electrochemical properties need to be optimized urgently.Here,we exploit a new dendrite-structured FeF_(2) consisting of closely linked primary nanoparticles using a facile solvothermal method combined with the subsequent annealing treatment.This particular architecture has favorable transport pathways for both lithium ions and electrons and exhibits an ultrafast chargedischarge capability with high reversible capacities.Furthermore,a well-designed LIC employing the prepared dendrite-structured FeF_(2) as the battery-type cathode and commercialized activated carbon(AC)as supercapacitor-type anode was constructed in an organic electrolyte containing Li ions.The LIC operates at an optimal voltage range of 1.1-3.8 V and shows a maximum high energy density of 152 W h kg^(-1) and a high power density of 4900 W kg^(-1) based on the total mass of cathode and anode.Long-term cycling stability(85%capacity retention after 2000 cycles)was achieved at 1 A g^(-1).This work suggests that the dendrite-structured FeF_(2) is a prime candidate for high-performance LICs and accelerates the development of hybrid ion capacitor devices.
基金supported by Foundation for the Sichuan University and Zigong City Joint research project(2021CDZG-2)the Foundation for the Sichuan University and Yibin City Strategic Cooperation Project(2020CDYB-32)the Guangxi Key Laboratory of Low Carbon Energy Material(2020GKLLCEM02)。
文摘Fluoride ferrous(FeF_(2))is viewed as a promising conversion cathode material for next-generation lithiumion batteries(LIBs)due to its high theoretical specific capacity and low cost.Unfortunately,issues such as poor intrinsic conductivity,iron dissolution,and phase separation hinder the application of FeF_(2)in highenergy cathodes.Here,a pressure-induced morphology control method is designed to prepare coralloidlike FeF_(2)nanocrystals with nitrogen-rich carbon coating(c-FeF_(2)@NC).The coralloid-like interconnected crystal structure of c-FeF_(2)@NC contributes to reducing interfacial resistance and enhancing the topotactic transformation during the conversion reaction,and the nitrogen-rich carbon(NC)coating can enhance interfacial stability and kinetic performance.When used as a conversion cathode for LIBs,c-FeF_(2)@NC exhibits a high initial reversible capacity of 503.57 mA h g^(-1)and excellent cycling stability of497.61 m A h g^(-1)with a low capacity decay of 1.19%over 50 cycles at 0.1 A/g.Even at 1 A/g,a stable capacity of 263.78 mA h g^(-1)can still be retained after 200 cycles.The capability of c-FeF_(2)@NC as a conversion cathode for sodium-ion batteries(SIBs)was also evaluated to expand its field of application.Furthermore,two kinds of full batteries have been assembled by employing c-FeF_(2)@NC as cathodes and quantitative limited-Li(LLi)and pre-lithiated reduced graphene oxide(PGO)as anodes,respectively,to envisage the feasibility of practical applications of conversion materials.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2022YFB2404400)。
文摘LiMn_(2)O_(4)(LMO) represents one of the most prevalent cathode materials utilized in lithium-ion batteries(LIBs), yet its broader application is often hampered by its limited achievable capacity and significant capacity degradation during cycling. In this work, a novel dual-doping strategy involving Al^(3+) and Zr^(4+) ions has been employed to refine the atomic structure of LMO's spinel framework. The resultant dual-doped material, Li_(1.06)Mn_(1.97)Zr_(0.01)Al_(0.02)O_(4), exhibits enhanced electrochemical properties, boasting a discharge capacity of 124.9 m Ah/g at a rate of 0.1 C. Furthermore, the formation of stronger Al–O and Zr–O bonds contributes to the stabilization of the delithiated LMO structure. Impressively, 97.7%of its initial capacity is retained after 100 cycles at a 5 C rate. Additionally, enhancements in rate performance and hightemperature cycling stability have also been observed. This study underscores the potential of Al^(3+) and Zr^(4+) dual-doping as a promising approach to enhance LMO cathodes, providing a scalable and efficient means of improving the performance of lithium manganese oxide cathode materials through the incorporation of multiple ions.
基金supported by the National Key Research and Development Program of China(No.2022YFB2502000)the National Natural Science Foundation of China(Nos.U21A20332,51771076,U21A200970,52301266)the Science and Technology Planning Project of Guangzhou(No.2024A04J3332)。
文摘Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental friendliness.However,its intrinsic low conductivity and sluggish Na^(+)diffusion restricted the fast-charge and low-temperature sodium storage.Herein,an NFPP composite encapsulated by in-situ pyrolytic carbon and coupled with expanded graphite(NFPP@C/EG)was constructed via a sol-gel method followed by a ballmill procedure.Due to the dual-carbon modified strategy,this NFPP@C/EG only enhanced the electronic conductivity,but also endowed more channels for Na^(+)diffusion.As cathode for SIBs,the optimized NFPP(M-NFPP@C/EG)delivers excellent rate capability(capacity of~80.5 mAh/g at 50 C)and outstanding cycling stability(11000 cycles at 50 C with capacity retention of 89.85%).Additionally,cyclic voltammetry(CV)confirmed that its sodium storage behavior is pseudocapacitance-controlled,with in-situ electrochemical impedance spectroscopy(EIS)further elucidating improvements in electrode reaction kinetics.At lower temperatures(0℃),M-NFPP@C/EG demonstrated exceptional cycling performance(8800 cycles at 10 C with capacity retention of 95.81%).Moreover,pouch cells also exhibited excellent stability.This research demonstrates the feasibility of a dual carbon modification strategy in enhancing NFPP and proposes a low-cost,high-rate,and ultra-stable cathode material for SIBs.
基金supported by the Significant Science and Technology Project in Xiamen(Future Industry Field)(Grant No.3502Z20231057).
文摘Lithium nickel oxide(Li_(2)NiO_(2)),as a sacrificial cathode prelithiation additive,has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries(LIBs).However,high-cost Li_(2)NiO_(2)suffers from inferior delithiation kinetics during the first cycle.Herein,we investigated the effects of the cost-effective copper substituted Li_(2)Ni_(1-x)Cu_(x)O_(2)(x=0,0.2,0.3,0.5,0.7)synthesized by a high-temperature solid-phase method on the structure,morphology,electrochemical performance of graphite‖LiFePO_(4)battery.The X-ray diffraction(XRD)refinement result demonstrated that Cu substitution strategy could be favorable for eliminating the NiO_(x)impurity phase and weakening Li-O bond.Analysis on density of states(DOS)indicates that Cu substitution is good for enhancing the electronic conductivity,as well as reducing the delithi-ation voltage polarization confirmed by electrochemical characterizations.Therefore,the optimal Li_(2)Ni_(0.7)Cu_(0.3)O_(2)delivered a high delithiation capacity of 437 mAh·g^(-1),around 8%above that of the pristine Li_(2)NiO_(2).Furthermore,a graphite‖LiFePO_(4)pouch cell with a nominal capacity of 3000 mAh demonstrated a notably improved reversible capacity,energy density and cycle life through introducing 2 wt%Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive,delivering a 6.2 mAh·g^(-1)higher initial discharge capacity and achieving around 5%improvement in capacity retentnion at 0.5P over 1000 cycles.Additionally,the post-mortem analyses testified that the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive could suppress solid electrolyte interphase(SEI)decomposition and homogenize the Li distribution,which benefits to stabilizing interface between graphite and electrolyte,and alleviating dendritic Li plating.In conclusion,the Li_(2)Ni_(0.7)Cu_(0.3)O_(2)additive may offer advantages such as lower cost,lower delithiation voltage and higher prelithiation capacity compared with Li_(2)NiO_(2),making it a promising candidate of cathode prelithiation additive for next-generation LIBs.
基金supported by National Natural Science Youth Foundation of China(No.22308294)National Natural Science Foundation of China(No.22179077)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_1868)Qing Lan Project of Jiangsu University and the Funding for school-level research projects of Yancheng Institute of Technology.
文摘Mn-based P2-type oxides are considered as promising cathodes for Na-ion batteries;however,they face significant challenges,including structural degradation when charged at high cutoff voltages and structural changes upon storing in a humid atmosphere.In response to these issues,we have designed an oxide with co-doping of Cu and Al which can balance both cost and structural stability.The redox reaction of Cu^(2+/3+)can provide certain charge compensation,and the introduction of Al can further suppress the Jahn-Teller effect of Mn,thereby achieving superior long-term cycling performance.The ex-situ XRD testing indicates that Cu/Al co-doping can effectively suppress the phase transition of P2-O2 at high voltage,thereby explaining the improvement in electrochemical performance.DFT calculations reveal a high chemical tolerance to moisture,with lower adsorption energy for H_(2)O compared to pure Na_(0.67)Cu_(0.25)Mn_(0.75)O_(2).A representative Na_(0.67)Cu_(0.20)Al_(0.05)Mn_(0.75)O_(2)cathode demonstrates impressive reversible capacities of 148.7 mAh/g at 0.2 C,along with a remarkable capacity retention of 79.1%(2 C,500 cycles).
基金supported by Natural Science Foundation of Ningxia Province,China(No.2023AAC05047)Special Project for the Central-Guided Local Science and Technology Development(No.2024FRD05062)+1 种基金Graduate Student Innovation Project of North Minzu University(No.YCX24102)Ningxia Science and Technology Innovation Team for Key Materials and Devices in High-Performance Secondary Batteries(No.2024CXTD003).
文摘Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To overcome this obstacle,a δ-MnO_(2)/MXene heterostructure was created using a simple one-step process under gentle condition.The ZHSC was assembled using this heterostructure as the cathode,activated carbon(AC)as the anode and 2 mol·L−1 ZnSO_(4) as the electrolyte.The resultingδ-MnO_(2)/MXene//ZnSO4//AC ZHSC shows a maximum specific capacitance of 97.4 F·g^(−1) and an energy density of 32.27 Wh·kg^(−1) at the best cathode-to-anode mass ratio.Ex situ characterizations reveal the reversible energy storage mechanism combing Zn^(2+)insertion/extraction in the cathode,ion adsorption and desorption on the anode surface,and partial reversible formation and dissolution of Zn_(4)SO_(4)(OH)_(6)·5H_(2)O(ZHS)components on both electrodes.Adding of Mn^(2+)to the electrolyte reduced Mn dissolution,improving the ZHSC’s specific capacitance and energy density to 140.4 F·g^(−1) and 49.36 Wh·kg^(−1),respectively,while also enhancing its rate performance and cyclability.The improved electrochemical reaction kinetics was verified through various tests.The results suggest that the δ-MnO_(2)/MXene heterostructure has great potential as a high-performance cathode material for ZHSCs.
基金supported by the Scientific Research Fund of Hunan Provincial Education Department,China(No.22B0741)。
文摘The electrochemical performance of layered O3-type NaCrO_(2)cathode material is significantly affected by the side reactions between NaCrO_(2)and electrolyte during sodium storage.A uniform Cr_(2)O_(3)coating layer was in situ constructed on the surface of NaCrO_(2)by controlling the excess ratio of sodium source.The structure,morphology,valence and electrochemical performance of the Cr_(2)O_(3)-coated NaCrO_(2)were characterized.The results indicate that the Cr_(2)O_(3)coating layer does not alter the crystal structure and morphology of NaCrO_(2),but effectively suppresses the side reactions between NaCrO_(2)and electrolyte,and improves the surface/interfacial stability of NaCrO_(2)material.The Cr_(2)O_(3)-coated NaCrO_(2)exhibits improved electrochemical performance with a capacity retention of 66.4%after 500 cycles at 10C.
基金supported by the National Key Research and Development Program of China(2022YFB2502103)the Xiamen Science and Technology Project(No.3502Z20231057)+2 种基金the National Natural Science Foundation of China(No.22288102,No.22279107,No.22309153)the Fujian Provincial Natural Science Foundation of China(No.2024J01040)the Fundamental Research Funds for the Central Universities(No.20720230039)。
文摘Extending the charging voltage of LiCoO_(2)(LCO)is an ongoing and promising approach to increase its energy density.However,the main challenge of the approach lies in the insuperable cathodic interfacial processes at high voltage,which leads to rapid failure both in the performance and structure of the LCO cathode.Herein,a Li_(2)CO_(3)-based additive was prepared by a simple sand-milling method,enabling a low electrochemical decomposition voltage<4.6 V from commonly>4.8 V,stabilizing the interface of the LCO cathode at 4.6 V.The decomposition of Li_(2)CO_(3)provides extra Li^(+)and CO_(2)to supplement the Li consumption required in the initial irreversible interfacial reactions and rapidly form a uniform and stable cathode electrolyte interphase layer(less organic and more inorganic components)on the LCO cathode by reducing CO_(2).Thus,the phase transformation and the emergence of high-valent Co ions on the surface of LCO at 4.6 V high voltage were inhibited.Thanks to this,with 2%Li_(2)CO_(3)-based additive,the capacity retention of commercial LCO at a high voltage of 4.6 V at 0.5 C for 100 cycles was improved from 59.3%to 79.3%.This work improves the high-voltage stability of LCO and provides a new idea for realizing the high-voltage operation of batteries.
基金financially supported by the National Natural Science Foundation of China(52201254,52234001,52074177)the National Key Research and Development Program(2022YFC3900905)+3 种基金the Natural Science Foundation of Shandong Province(ZR2020QE012,ZR2020MB090,ZR2023ME155,ZR2023ME085)the Scientific Research Foundation for New Talents in University of Jinan(XRC2406)the project of “20 Items of University”of Jinan(202228046)the Introducing Major Universities and Research Institutions to Jointly Build Innovative Carrier Project of Jining City(2023DYDS022)。
文摘The Li-CO_(2)battery has been highly rated as an intriguing technique for balancing the carbon cycle for years,but it is still significantly challenged by the obstacles such as limited reversibility,sluggish kinetics,and poor energy efficiency.Hence,the design and development of advance catalysts that can enhance the kinetics and reversibility of the CO_(2)electrochemical cycling reactions are considered the imperative tasks.Transition metal-based catalysts are widely considered appealing owing to their unfilled dorbitals,rich and adjustable valences,as well as processibility.In this review,the working mechanism and the key issues of the CO_(2)electrochemical cycling reaction are discussed first.Then the strategies for composition and structure design of different type of transition metal-based catalysts are highlighted,including their benefits,limitations,and the ways to implement these strategies.Finally,based on the pioneering research,the perspectives on the challenges and key points for the future development of cathode catalyst are proposed.
基金Project(23JCYBJC01870)supported by the Natural Science Foundation of Tianjin,ChinaProject(U22A20119)supported by the National Natural Science Foundation of China。
文摘As a cathode material for thermal batteries,NiS_(2)has a high theoretical capacity but low thermal stability.Besides,the poor formability of NiS_(2)powders also restricts the cathode performance of thermal batteries.In this paper,the novel NiS_(2)/SiO_(2)composite material was developed by high temperature vulcanization to improve the thermal stability formability of NiS_(2).The good filling and lubrication of spherical SiO_(2)can improve the thermal conductivity of NiS_(2)electrode.The discharge test shows that the NiS_(2)/SiO_(2)cathode has a stable discharge voltage at a current density of 200 mA/cm^(2),and the activation time is shortened by nearly 20%compared with the NiS_(2)cathode.In addition,due to the favorable thermal insulation protection of SiO_(2),the initial decomposition temperature of NiS_(2)is increased by 30℃after the addition of SiO_(2).The incorporation of SiO_(2)not only effectively improves the thermal stability and electrochemical properties of NiS_(2),but also improves the cold pressing forming performance of the NiS_(2)powder.Therefore,the novel NiS_(2)/SiO_(2)composite material is more suitable for thermal batteries with high stability and fast response,which is of great significance for improving the maneuverability and quality reliability of weapons and equipment.
基金supported by the National Natural Science Foundation of China(51974167)Natural Science Foundation Youth Foundation of Inner Mongolia(2023QN05038)Higher Education Carbon Peak Carbon Neutral Research Project of Inner Mongolia Autonomous Region(STZX202210)。
文摘PrBaFe_(2)O_(5+δ)(PBF)is one of the promising cathode materials for intermediate-temperature solid oxide fuel cell(IT-SOFC)technology.However,as the operating temperature decreases,the electrochemical performance of this material deteriorates rapidly.To counter this,various doping strategies have been tested and reported in order to improve the electrochemical properties of this material at intermediate-temperatures.In this study,Mg-doping to partially substitute Fe of PBF was investigated.PrBaFe_(2-x)Mg_(x)O_(5+δ)(PBFMgx,x=0.1,0.15,0.2,0.3)materials were successfully synthesized,and their electrochemical performance as IT-SOFC cathode was evaluated.It is shown that Mg-doping enhances the conductivity of PBF between 650 and 800℃,impacts little on the area-specific resistance of oxygen reduction reaction at and above 700℃,and,most significantly,improves the power density of the NiSDC/SDC/PBFMg0.15single cell by 52%compared to the un-doped PBF.This enhanced electrochemical performance is attributed to the improvement in PBF conductivity by Mg-doping.
基金supported by the Central South University Innovation-Driven Research Programme,China(No.2023CXQD053)the National Natural Science Foundation of China(No.52274310)financial support from the Government of Chongzuo,Guangxi Zhuang Autonomous Region,China(No.FA20210713).
文摘To investigate the mechanism by which ZrO_(2)modification affects the electrochemical performance of the NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)cathode material for sodium-ion batteries,ZrO_(2)-coated NFM(ZrO_(2)@NFM)was prepared via high-temperature calcination.XRD refinement results revealed that ZrO_(2)modification increased the Na-layer spacing in the NFM material.XPS analysis results demonstrated that ZrO_(2)modification adjusted the Mn^(3+)/Mn^(4+)ratio in NFM by reducing the Mn^(3+)content.Electrochemical test results revealed that,compared to NFM,ZrO_(2)@NFM exhibited superior rate capability and cycling stability.It also exhibited significantly enhanced Na^(+)diffusion coefficients and reduced interfacial charge transfer resistance.The ZrO_(2)coating increased Na-layer spacing,reduced electrochemical polarization,and inhibited side reactions.In summary,the synergistic effect of component regulation and surface engineering through ZrO_(2)coating improved Na^(+)diffusion kinetics and enhanced cycling stability.
基金supported by the National Natural Science Foundation of China(Nos.22379133,22075256,and 52072350)the Natural Science Foundation of Guangdong Province(No.2024A1515012235).
文摘The performance of solid oxide electrolysis cells(SOECs)for CO_(2) electrolysis is significantly impeded by the limited electrochemical activity and insufficient durability of the cathode.This study introduces a novel(LaSrPrBaCaGd)_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(LSPBCGFM)perovskite via A-site entropy engineering,to improve both activity and durability.Experimental results reveal that LSPBCGFM cathode-based SOEC achieves a current density of 1.34 A·cm^(−2) at 1.5 V and 800℃,maintaining stable operation for more than 400 h at 1.2 V with negligible degradation.Theoretical calculations suggest that the high-entropy strategy shifts the transition metal d-band center and O-2p-band center closer to the Fermi energy level simultaneously,thereby initiating more favorable CO_(2) adsorption and activation.In addition,a higher O-2p-band center promotes the formation and diffusion of oxygen vacancies.The findings of this study provide crucial insights into the role of conformational entropy strategies in CO_(2) electrolysis and offer potential pathways for the development of highly efficient and stable catalysts.
