Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles.However,fading capacity,poor cyclic stability and high p H value are still major challenges,which suppress its ...Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles.However,fading capacity,poor cyclic stability and high p H value are still major challenges,which suppress its practical application.In this study,spherical LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)powders with 0.4 wt%TiO_(2)coating layer were prepared by impregnation-hydrolysis method.Scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)results show that TiO_(2)is uniformly coated on the surface of LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particle and slightly embedded into LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particles.After 100 cycles at 2.0 C,0.4 wt%TiO_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode delivers much higher discharge capacity retention(77.0%)than the pristine LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode(63.3%).The excellent cycling performance of 0.4 wt%Ti O_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode at a high discharge ratio is due to a TiO_(2)coating layer which can effectively reduce the direct contact between cathode material and electrolyte,suppress the oxidation of electrolyte,improve electrical conductivity of the electrode and increase the stability of the structure.展开更多
The isothermal desorption kinetics of the 1.1MgH2-2LiNH2-0.1LiBH4 system were improved by addition of LaNi4.5Mn0.5 alloy. The hydrogen desorption peak temperature of the sample containing LaNi4.5Mn0.5 reduced by appro...The isothermal desorption kinetics of the 1.1MgH2-2LiNH2-0.1LiBH4 system were improved by addition of LaNi4.5Mn0.5 alloy. The hydrogen desorption peak temperature of the sample containing LaNi4.5Mn0.5 reduced by approximately 5 K and the activation energy reduced by 9%. The results of isothermal dehydrogenation kinetics analysis implied that the isothermal desorption process at initial stage was controlled by the phase boundary mechanism. Moreover, the cycle performance of the materials was extended. The growth and agglomeration of the sample particles caused the deterioration of kinetics during de-/hydrogenation cycles, and then resulted in an incomplete desorption/absorption reaction which were responsible for the capacity fading. The cracking and pulverization of LaNi4.5Mn0.5 alloy had an obvious effect on preventing the composites aggregating, and the fine alloy particles could enhance the catalytic effect of the alloy, thus effectively offsetting part of the deterioration of kinetics caused by particles growth.展开更多
Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets it...Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets itself apart from existing research by applying a novel optimization technique to a basic ideal Rankine cycle,focusing on a specific power plant that has not been previously analyzed.Currently,this cycle operates at 41%efficiency and a steam quality of 76%,constrained by fixed operational parameters.The primary objectives are to increase thermal efficiency beyond 46%and raise steam quality above 85%,while adhering to operational limits:a boiler pressure not exceeding 15 MPa,condenser pressure not dropping below 10 kPa,and turbine temperature not surpassing 500℃.This study utilizes numerical simulations to model the effects of varying boiler pressure(Pb)and condenser pressure(Pc)within the ranges of 12MPa<Pb<15 MPa and 5 kPa<Pc<10 kPa.By systematically adjusting these parameters,the proposed aimto identify optimal conditions that maximize efficiency and performance within specified constraints.The findings will provide valuable insights for power plant operators seeking to optimize performance under real-world conditions,contributing to more efficient and sustainable power generation.展开更多
Plasma spray-physical vapor deposition(PS-PVD)as a novel process was used to prepare feather-like columnar thermal barrier coatings(TBCs).This special microstructure shows good strain tolerance and non-line-of-sight(N...Plasma spray-physical vapor deposition(PS-PVD)as a novel process was used to prepare feather-like columnar thermal barrier coatings(TBCs).This special microstructure shows good strain tolerance and non-line-of-sight(NLOS)deposition,giving great potential application in aero-engine.However,due to serious service environment of aero-engine,particle erosion performance is a weakness for PS-PVD 7YSZ TBCs.As a solution,an Al-modification approach was proposed in this investigation.Through in-situ reaction of Al and ZrO2,anα-Al2O3 overlay can be formed on the surface of 7YSZ columnar coating.The results demonstrate that this approach can improve particle erosion resistance since hardness improvement of Al-modified TBCs.Meanwhile,as another important performance of thermal cycle,it has a better optimization with 350-cycle water-quenching,compared with the as-sprayed TBCs.展开更多
The effects of cycle potential window on electrochemical behaviors,structural characteristics,and surface changes in Li[Ni_(0.133)Li_(0.2)Co_(0.133)Mn_(0.533)]O_(2)(or 0.5 Li_(2)MnO_(3)·0.5 Li(Co_(0.333)Ni_(0.333...The effects of cycle potential window on electrochemical behaviors,structural characteristics,and surface changes in Li[Ni_(0.133)Li_(0.2)Co_(0.133)Mn_(0.533)]O_(2)(or 0.5 Li_(2)MnO_(3)·0.5 Li(Co_(0.333)Ni_(0.333)Mn_(0.333))O2)in lithium-ion battery were investigated.Two flat charge potential plateaus,~3.9 and~4.5 V,are observed in the initial charge curves of the cells.Sharp changes in specific capacity and columbic efficiency are presented at~4.5 V during the first cycle.XRD specific peaks show an obvious shift with the increase in charge cutoff potential.When the charge cutoff potential is above4.4 V,the cycle performance decreases with the increase in charge cutoff potentials.A film with the composition of C and O elements is observed on the cycled composite particle.展开更多
Due to its high operational voltage and energy density,P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) has become a leading cathode material for sodium-ion batteries(SIBs),which is an ideal option for large-scale energy storag...Due to its high operational voltage and energy density,P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) has become a leading cathode material for sodium-ion batteries(SIBs),which is an ideal option for large-scale energy storage.However,the practical application of P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) is limited by the capacity constraints and unwanted phase transitions,presenting significant challenges to the widespread application of SIBs.To address these challenges and optimize the electrochemical properties of the P2 phase cathode material,this study proposes a Cu and Zn co-doped strategy to improve the electrochemical performance.The incorporation of Cu/Zn can stabilize the P2-phase structure against P2-O2 phase transitions,thus enhancing its electrochemical properties.The as-obtained P2-type Na0.67[Ni_(0.3)Mn_(0.58)Cu_(0.09)Zn_(0.03)]O_(2) cathode material shows an impressive cycling stability,maintaining 80%capacity retention after 1000 cycles at 2 C.The cyclic voltammetry(CV)tests show that the Cu^(2+)/Cu^(3+)redox reaction is also involved in charge compensation during the charge/discharge process.展开更多
A new LiCoO2 recovery technology for Li-ion batteries was studied in this paper. LiCoO2 was peeled from the Al foil with dimethyl acetamide （DMAC）, and then polyvinylidene fluoride （PVDF） and carbon powders in the...A new LiCoO2 recovery technology for Li-ion batteries was studied in this paper. LiCoO2 was peeled from the Al foil with dimethyl acetamide （DMAC）, and then polyvinylidene fluoride （PVDF） and carbon powders in the active material were eliminated by high temperature calcining. Subsequently, Li2CO3, LiOH-H20 and LiAc-2H2O were added into the recycled powders to adjust the Li/Co molar ratio to 1.00. The new LiCoO2 was obtained by calcining the mixture at 850℃ for 12 h in air. The structure and morphology of the recycled powders and resulting samples were studied by XRD and SEM techniques, respectively. The layered structure of LiCoO2 synthesized by adding Li2CO3 is the best, and it is found to have the best characteristics as a cathode material in terms of charge-discharge capacity and cycling performance. The first discharge capacity is 160 mAh·g^-1 between 3.0-4.3 V. The discharge capacity after cycling for 50 times is still 145.2 mAh·g^-1.展开更多
Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the applicat...Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.展开更多
In challenging operational environments,Lithium-ion batteries(LIBs)inevitably experience mechanical stresses,including impacts and extrusion,which can lead to battery damage,failure,and even the occurrence of fire and...In challenging operational environments,Lithium-ion batteries(LIBs)inevitably experience mechanical stresses,including impacts and extrusion,which can lead to battery damage,failure,and even the occurrence of fire and explosion incidents.Consequently,it is imperative to investigate the safety performance of LIBs under mechanical loads.This study is grounded in a more realistic coupling scenario consisting of electrochemical cycling and low-velocity impact.We systematically and experimentally uncovered the mechanical,electrochemical,and thermal responses,damage behavior,and corresponding mechanisms under various conditions.Our study demonstrates that higher impact energy results in increased structural stiffness,maximum temperature,and maximum voltage drop.Furthermore,heightened impact energy significantly influences the electrical resistance parameters within the internal resistance.We also examined the effects of State of Charge(SOC)and C-rates.The methodology and experimental findings will offer insights for enhancing the safety design,conducting risk assessments,and enabling the cascading utilization of energy storage systems based on LIBs.展开更多
Tin sulfide(SnS_(2))anodes have garnered significant attention within emerging energy storage technologies.However,the application of SnS_(2)is curtailed due to its inherent limitations,including poor cyclic stability...Tin sulfide(SnS_(2))anodes have garnered significant attention within emerging energy storage technologies.However,the application of SnS_(2)is curtailed due to its inherent limitations,including poor cyclic stability and inevitable volumetric expansion upon cycling.This study reports the successful fabrication of an innovative SnS_(2)-based composite,featuring an eggshell-like structured nitrogen-doped carbon coating,referred to as SnS_(2)@NxC.This novel architecture,wherein SnS_(2)acts as the core encapsulated by a nitrogen-doped carbon shell,characterized by a void space between the shell and core,is crucial in mitigating volumetric expansion.This configuration contributes to maintaining the structural integrity of the composite materials,even under the stresses of continuous cycling.Nitrogen within the carbon matrix enhances conductivity and promotes the formation of a more robust and stable solid electrolyte interphase(SEI)layer.Experimental investigations have substantiated the electrochemical superiority of the SnS_(2)@NxC electrode,demonstrating a specific capacity of 701.8 mA·h·g^(-1)after 1000 cycles at 0.5 A·g^(-1)and maintaining a capacity of 597.2mA·h·g^(-1)after 400 cycles at a heightened current density of 2 A·g^(-1).These findings underscore the exceptional cyclic performance and durability of the SnS_(2)@NxC electrode.展开更多
Li metal is widely recognized as the desired anode for next-generation energy storage,Li metal batteries,due to its highest theoretical capacity and lowest potential.Nonetheless,it suffers from unstable electrochemica...Li metal is widely recognized as the desired anode for next-generation energy storage,Li metal batteries,due to its highest theoretical capacity and lowest potential.Nonetheless,it suffers from unstable electrochemical behaviors like dendrite growth and side reactions in practical application.Herein,we report a highly stable anode with collector,Li_(5)Mg@Cu,realized by the melting-rolling process.The Li_(5)Mg@Cu anode delivers ultrahigh cycle stability for 2000 and 1000 h at the current densities of 1 and 2 mA cm^(-2),respectively in symmetric cells.Meanwhile,the Li_(5)Mg@Cu|LFP cell exhibits a high-capacity retention of 91.8% for 1000 cycles and 78.8% for 2000 cycles at 1 C.Moreover,we investigate the suppression effects of Mg on the dendrite growth by studying the performance of Li_(x)Mg@Cu electrodes with different Mg contents(2.0-16.7 at%).The exchange current density,surface energy,Li^(+)diffusion coefficient,and chemical stability of Li_(x)Mg@Cu concretely reveal this improving suppression effect when Mg content becomes higher.In addition,a Mg-rich phase with“hollow brick”morphology forming in the high Mg content Li_(x)Mg@Cu guides the uniform deposition of Li.This study reveals the suppression effects of Mg on Li dendrites growth and offers a perspective for finding the optimal component of Li-Mg alloys.展开更多
Silicon suboxide(SiO_(x),0<x<2)is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries.Nevertheless,...Silicon suboxide(SiO_(x),0<x<2)is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries.Nevertheless,the huge volume change and rapid capacity decay of SiO_(x)electrodes during cycling pose huge challenges to their large-scale practical applications.To eliminate this bottleneck,a dragonfly wing microstructure-inspired polymer electrolyte(denoted as PPM-PE)is developed based on in-situ polymerization of bicyclic phosphate ester-and urethane motif-containing monomer and methyl methacrylate in traditional liquid electrolyte.PPM-PE delivers excellent mechanical properties,highly correlated with the formation of a micro-phase separation structure similar with dragonfly wings.By virtue of superior mechanical properties and the in-situ solidified preparation method,PPM-PE can form a 3D polymer network buffer against stress within the electrode particles gap,enabling much suppressed electrode volume expansion and more stabilized solid electrolyte interface along with evidently decreased electrolyte decomposition.Resultantly,PPM-PE shows significant improvements in both cycling and rate performance in button and soft package batteries with SiO_(x)-based electrodes,compared with the liquid electrolyte counterpart.Such a dragonfly wing microstructure-inspired design philosophy of in-situ solidified polymer electrolytes helps facilitate the practical implementation of high-energy lithium batteries with SiO_(x)-based anodes.展开更多
Effects of film-forming additive on stability of electrode and cycling performance of LiFePO4/graphite cell at elevated temperature were studied. Two 18650 cells with and without VC additive were investigated by galva...Effects of film-forming additive on stability of electrode and cycling performance of LiFePO4/graphite cell at elevated temperature were studied. Two 18650 cells with and without VC additive were investigated by galvanostatic cycling, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis and Raman spectroscopy. The results show that in the presence of VC additive, dissolution of Fe from LiFePO4 material is greatly depressed and stability of graphite structure is improved; the additive can not only reduce reaction of electrolyte on surface of LiFePO4 electrode but also suppress reduction of solvent and thickening of the solid electrolyte interface （SEI） layer on graphite surface. Electrolyte with VC is considered to be a good candidate for improving cycling performance of the LiFePOa/graphite cell at elevated temperature.展开更多
LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on th...LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature.展开更多
Na^＋ doped sample Li0.95Na0.05FePO4 was prepared through solid state method. Structure characterization shows Na^＋ is successfully introduced into the LiFePO4 matrix. Scanning electron microscopy shows the particle ...Na^＋ doped sample Li0.95Na0.05FePO4 was prepared through solid state method. Structure characterization shows Na^＋ is successfully introduced into the LiFePO4 matrix. Scanning electron microscopy shows the particle size mainly ranges in 1-3 μm. X-ray diffraction Rietveld refinement demonstrates lattice distortion with an increased cell volume. As one cathode material, it has a discharge capacity of 150 mAh/g at 0.1 C rate. The material exhibits a capacity of 109 and 107 mAh/g at 5 and 7.5 C respectively. When cycled at 1 and 5 C, the material retains 84% （after 1000 cycles） and 86% （after 350 cycles） of the initial discharge capacity respectively indicating excellent structure stability and cycling performance. Na^＋ doping enhances the electrochemical activity especially the cycle performance effectively.展开更多
Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(...Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.展开更多
To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks(ZIFs)and their derived materials,a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imid...To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks(ZIFs)and their derived materials,a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imidazolate framework(ZIF-67)polyhedrons,which are used as precursors to prepare cobalt selenide/carbon composites with different crystal phases(Co_(0.85)Se,CoSe_2).When evaluated as anode material for lithium ion batteries,Co_(0.85)Se/C composites deliver a reversible capacity of 758.7 m A·h·g^(-1)with a capacity retention rate of 90.5%at 1.0 A·g^(-1)after 500 cycles,and the superior rate capability is 620 m A·h·g^(-1)at 2.0 A·g^(-1).The addition of KOH accelerates the production of ZIF-67 crystals by boosting deprotonation of dimethylimidazole,resulting in rapid growth and structures transition from two-dimensional to three-dimensional of ZIF-67 in aqueous solution,which greatly promotes the application of MOFs in the field of energy storage and conversion.展开更多
This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other...This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...展开更多
LithiumvanadatesLiV_(3)O_(8)-LiV_(6)O_(15)(LVO)witha heterojunction structure are synthesized using a conventional high-temperature solid-state method to address the challenges of low ionic conductivity,rapid capacity...LithiumvanadatesLiV_(3)O_(8)-LiV_(6)O_(15)(LVO)witha heterojunction structure are synthesized using a conventional high-temperature solid-state method to address the challenges of low ionic conductivity,rapid capacity decay,and poor cycling performance in conventional lithium-ion battery cathode materials.The charge-discharge processes of LVO span multiple platforms,delivering an impressive specific discharge capacity of 219.4 mAh.g^(-1) at 1C.Remarkably,LVO exhibits a high-capacity retention rate of 81.3%after 800 cycles within the typical operating voltage range of lithium-ion batteries(2.8-4.3V).Rate capability tests and electrochemical impedance spectroscopy(EIS)reveal that,compared to traditional cathode materials,LVO significantly enhances Li*diffusion rates(D_(Li*))and reduces charge transfer resistance(Ret).展开更多
Solid-state batteries(SSBs) with high safety are promising for the energy fields,but the development has long been limited by machinability and interfacial problems.Hence,self-supporting,flexible Nano LLZO CSEs are pr...Solid-state batteries(SSBs) with high safety are promising for the energy fields,but the development has long been limited by machinability and interfacial problems.Hence,self-supporting,flexible Nano LLZO CSEs are prepared with a solvent-free method at 25℃.The 99.8 wt% contents of Nano LLZO particles enable the Nano LLZO CSEs to maintain good thermal stability while exhibiting a wide electrochemical window of 5.0 V and a high Li~+ transfer number of 0.8.The mean modulus reaches 4376 MPa.Benefiting from the interfacial modulation,the Li|Li symmetric batteries based on the Nano LLZO CSEs show benign stability with lithium at the current densities of 0.1 mA cm^(-2),0.2 mA cm^(-2),and 0.5 mA cm^(-2).In addition,the Li|LiFePO_(4)(LFP) SSBs achieve favorable cycling performance:the specific capacity reaches128.1 mAh g^(-1) at 0.5 C rate,with a capacity retention of about 80% after 600 cycles.In the further tests of the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) cathodes with higher energy density,the Nano LLZO CSEs also demonstrate good compatibility:the specific capacities of NCM811-based SSBs reach 177.9 mAh g^(-1) at 0.5 C rate,while the capacity retention is over 96% after 150 cycles.Furthermore,the Li|LFP soft-pack SSBs verify the safety characteristics and the potential for application,which have a desirable prospect.展开更多
基金the National Natural Science Foundation of China(No.51701173)。
文摘Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles.However,fading capacity,poor cyclic stability and high p H value are still major challenges,which suppress its practical application.In this study,spherical LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)powders with 0.4 wt%TiO_(2)coating layer were prepared by impregnation-hydrolysis method.Scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)results show that TiO_(2)is uniformly coated on the surface of LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particle and slightly embedded into LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particles.After 100 cycles at 2.0 C,0.4 wt%TiO_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode delivers much higher discharge capacity retention(77.0%)than the pristine LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode(63.3%).The excellent cycling performance of 0.4 wt%Ti O_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode at a high discharge ratio is due to a TiO_(2)coating layer which can effectively reduce the direct contact between cathode material and electrolyte,suppress the oxidation of electrolyte,improve electrical conductivity of the electrode and increase the stability of the structure.
基金Project supported by High-Tech Research and Development Program of China(2012AA051503)
文摘The isothermal desorption kinetics of the 1.1MgH2-2LiNH2-0.1LiBH4 system were improved by addition of LaNi4.5Mn0.5 alloy. The hydrogen desorption peak temperature of the sample containing LaNi4.5Mn0.5 reduced by approximately 5 K and the activation energy reduced by 9%. The results of isothermal dehydrogenation kinetics analysis implied that the isothermal desorption process at initial stage was controlled by the phase boundary mechanism. Moreover, the cycle performance of the materials was extended. The growth and agglomeration of the sample particles caused the deterioration of kinetics during de-/hydrogenation cycles, and then resulted in an incomplete desorption/absorption reaction which were responsible for the capacity fading. The cracking and pulverization of LaNi4.5Mn0.5 alloy had an obvious effect on preventing the composites aggregating, and the fine alloy particles could enhance the catalytic effect of the alloy, thus effectively offsetting part of the deterioration of kinetics caused by particles growth.
文摘Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets itself apart from existing research by applying a novel optimization technique to a basic ideal Rankine cycle,focusing on a specific power plant that has not been previously analyzed.Currently,this cycle operates at 41%efficiency and a steam quality of 76%,constrained by fixed operational parameters.The primary objectives are to increase thermal efficiency beyond 46%and raise steam quality above 85%,while adhering to operational limits:a boiler pressure not exceeding 15 MPa,condenser pressure not dropping below 10 kPa,and turbine temperature not surpassing 500℃.This study utilizes numerical simulations to model the effects of varying boiler pressure(Pb)and condenser pressure(Pc)within the ranges of 12MPa<Pb<15 MPa and 5 kPa<Pc<10 kPa.By systematically adjusting these parameters,the proposed aimto identify optimal conditions that maximize efficiency and performance within specified constraints.The findings will provide valuable insights for power plant operators seeking to optimize performance under real-world conditions,contributing to more efficient and sustainable power generation.
基金We would like to acknowledge the financial support from the National Natural Science Foundation of China(52172067)Guangdong Province Outstanding Youth Foundation(2021B1515020038)+1 种基金Guangdong Special Support Program(2019BT02C629)Guangdong Academy of Sciences Program(2020GDASYL-20200104030).
文摘Plasma spray-physical vapor deposition(PS-PVD)as a novel process was used to prepare feather-like columnar thermal barrier coatings(TBCs).This special microstructure shows good strain tolerance and non-line-of-sight(NLOS)deposition,giving great potential application in aero-engine.However,due to serious service environment of aero-engine,particle erosion performance is a weakness for PS-PVD 7YSZ TBCs.As a solution,an Al-modification approach was proposed in this investigation.Through in-situ reaction of Al and ZrO2,anα-Al2O3 overlay can be formed on the surface of 7YSZ columnar coating.The results demonstrate that this approach can improve particle erosion resistance since hardness improvement of Al-modified TBCs.Meanwhile,as another important performance of thermal cycle,it has a better optimization with 350-cycle water-quenching,compared with the as-sprayed TBCs.
基金financially supported by the HiTech Research and Development Program of China (No. 2011AA11A254)
文摘The effects of cycle potential window on electrochemical behaviors,structural characteristics,and surface changes in Li[Ni_(0.133)Li_(0.2)Co_(0.133)Mn_(0.533)]O_(2)(or 0.5 Li_(2)MnO_(3)·0.5 Li(Co_(0.333)Ni_(0.333)Mn_(0.333))O2)in lithium-ion battery were investigated.Two flat charge potential plateaus,~3.9 and~4.5 V,are observed in the initial charge curves of the cells.Sharp changes in specific capacity and columbic efficiency are presented at~4.5 V during the first cycle.XRD specific peaks show an obvious shift with the increase in charge cutoff potential.When the charge cutoff potential is above4.4 V,the cycle performance decreases with the increase in charge cutoff potentials.A film with the composition of C and O elements is observed on the cycled composite particle.
基金supported by the National Natural Science Foundation of China(Nos.22179077,51774251,21908142)Shanghai Science and Technology Commission’s“2020 Science and Technology In-novation Action Plan”(No.20511104003)Natural Science Foundation in Shanghai(No.21ZR1424200)。
文摘Due to its high operational voltage and energy density,P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) has become a leading cathode material for sodium-ion batteries(SIBs),which is an ideal option for large-scale energy storage.However,the practical application of P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) is limited by the capacity constraints and unwanted phase transitions,presenting significant challenges to the widespread application of SIBs.To address these challenges and optimize the electrochemical properties of the P2 phase cathode material,this study proposes a Cu and Zn co-doped strategy to improve the electrochemical performance.The incorporation of Cu/Zn can stabilize the P2-phase structure against P2-O2 phase transitions,thus enhancing its electrochemical properties.The as-obtained P2-type Na0.67[Ni_(0.3)Mn_(0.58)Cu_(0.09)Zn_(0.03)]O_(2) cathode material shows an impressive cycling stability,maintaining 80%capacity retention after 1000 cycles at 2 C.The cyclic voltammetry(CV)tests show that the Cu^(2+)/Cu^(3+)redox reaction is also involved in charge compensation during the charge/discharge process.
基金supported by the National Natural Science Foundation of China (Nos. 50762004 and 50864004)
文摘A new LiCoO2 recovery technology for Li-ion batteries was studied in this paper. LiCoO2 was peeled from the Al foil with dimethyl acetamide （DMAC）, and then polyvinylidene fluoride （PVDF） and carbon powders in the active material were eliminated by high temperature calcining. Subsequently, Li2CO3, LiOH-H20 and LiAc-2H2O were added into the recycled powders to adjust the Li/Co molar ratio to 1.00. The new LiCoO2 was obtained by calcining the mixture at 850℃ for 12 h in air. The structure and morphology of the recycled powders and resulting samples were studied by XRD and SEM techniques, respectively. The layered structure of LiCoO2 synthesized by adding Li2CO3 is the best, and it is found to have the best characteristics as a cathode material in terms of charge-discharge capacity and cycling performance. The first discharge capacity is 160 mAh·g^-1 between 3.0-4.3 V. The discharge capacity after cycling for 50 times is still 145.2 mAh·g^-1.
基金the Fundamental Research Funds for the Central Universities,China(No.06500177)the National Natural Science Foundation of China Joint Fund Project(No.U1764255)。
文摘Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.
基金supported by the National Natural Science Foundation of China(Grant No.12111530222)the Fundamental Research Funds for the Central Universities(Grant No.23GH02023)+2 种基金the Taicang Basic Research Program Project(Grant No.TC2023JC15)the Shaanxi Key Research and Development Program for International Cooperation and Exchanges(Grant No.2022KWZ-23)the 111 Project of China(Grant No.BP0719007).
文摘In challenging operational environments,Lithium-ion batteries(LIBs)inevitably experience mechanical stresses,including impacts and extrusion,which can lead to battery damage,failure,and even the occurrence of fire and explosion incidents.Consequently,it is imperative to investigate the safety performance of LIBs under mechanical loads.This study is grounded in a more realistic coupling scenario consisting of electrochemical cycling and low-velocity impact.We systematically and experimentally uncovered the mechanical,electrochemical,and thermal responses,damage behavior,and corresponding mechanisms under various conditions.Our study demonstrates that higher impact energy results in increased structural stiffness,maximum temperature,and maximum voltage drop.Furthermore,heightened impact energy significantly influences the electrical resistance parameters within the internal resistance.We also examined the effects of State of Charge(SOC)and C-rates.The methodology and experimental findings will offer insights for enhancing the safety design,conducting risk assessments,and enabling the cascading utilization of energy storage systems based on LIBs.
文摘Tin sulfide(SnS_(2))anodes have garnered significant attention within emerging energy storage technologies.However,the application of SnS_(2)is curtailed due to its inherent limitations,including poor cyclic stability and inevitable volumetric expansion upon cycling.This study reports the successful fabrication of an innovative SnS_(2)-based composite,featuring an eggshell-like structured nitrogen-doped carbon coating,referred to as SnS_(2)@NxC.This novel architecture,wherein SnS_(2)acts as the core encapsulated by a nitrogen-doped carbon shell,characterized by a void space between the shell and core,is crucial in mitigating volumetric expansion.This configuration contributes to maintaining the structural integrity of the composite materials,even under the stresses of continuous cycling.Nitrogen within the carbon matrix enhances conductivity and promotes the formation of a more robust and stable solid electrolyte interphase(SEI)layer.Experimental investigations have substantiated the electrochemical superiority of the SnS_(2)@NxC electrode,demonstrating a specific capacity of 701.8 mA·h·g^(-1)after 1000 cycles at 0.5 A·g^(-1)and maintaining a capacity of 597.2mA·h·g^(-1)after 400 cycles at a heightened current density of 2 A·g^(-1).These findings underscore the exceptional cyclic performance and durability of the SnS_(2)@NxC electrode.
基金supported by the Qingdao Jiuhuanxinyue New Energy Technology Co.,Ltd.the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021B1515120071)+2 种基金the 21C Innovation Laboratory,Contemporary Amperex Technology Ltd.(Grant No.21C-OP-202112)the financial support from the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515011873)the Shenzhen Science and Technology Program(Grant No.JCYJ20220531095212027).
文摘Li metal is widely recognized as the desired anode for next-generation energy storage,Li metal batteries,due to its highest theoretical capacity and lowest potential.Nonetheless,it suffers from unstable electrochemical behaviors like dendrite growth and side reactions in practical application.Herein,we report a highly stable anode with collector,Li_(5)Mg@Cu,realized by the melting-rolling process.The Li_(5)Mg@Cu anode delivers ultrahigh cycle stability for 2000 and 1000 h at the current densities of 1 and 2 mA cm^(-2),respectively in symmetric cells.Meanwhile,the Li_(5)Mg@Cu|LFP cell exhibits a high-capacity retention of 91.8% for 1000 cycles and 78.8% for 2000 cycles at 1 C.Moreover,we investigate the suppression effects of Mg on the dendrite growth by studying the performance of Li_(x)Mg@Cu electrodes with different Mg contents(2.0-16.7 at%).The exchange current density,surface energy,Li^(+)diffusion coefficient,and chemical stability of Li_(x)Mg@Cu concretely reveal this improving suppression effect when Mg content becomes higher.In addition,a Mg-rich phase with“hollow brick”morphology forming in the high Mg content Li_(x)Mg@Cu guides the uniform deposition of Li.This study reveals the suppression effects of Mg on Li dendrites growth and offers a perspective for finding the optimal component of Li-Mg alloys.
基金financially supported by the National Key R&D Program of China(2023YFC2812700)the Key Scientific and Technological Innovation Project of Shandong(2022CXGC020301)+6 种基金the National Natural Science Foundation of China(22279153,U22A2044,22479154,52303287)the Taishan Scholars of Shandong Province(No.ts201511063)the Shandong Energy Institute(Grant No.SEI I202108)the Postdoctoral Fellowship Program of CPSF(E31Z3F04)China Postdoctoral Science Foundation(2024 M753350)the Natural Science Foundation of Shandong Province(ZR2023QB208)Qingdao Natural Science Foundation(23-2-1-77-zyyd-jch)。
文摘Silicon suboxide(SiO_(x),0<x<2)is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries.Nevertheless,the huge volume change and rapid capacity decay of SiO_(x)electrodes during cycling pose huge challenges to their large-scale practical applications.To eliminate this bottleneck,a dragonfly wing microstructure-inspired polymer electrolyte(denoted as PPM-PE)is developed based on in-situ polymerization of bicyclic phosphate ester-and urethane motif-containing monomer and methyl methacrylate in traditional liquid electrolyte.PPM-PE delivers excellent mechanical properties,highly correlated with the formation of a micro-phase separation structure similar with dragonfly wings.By virtue of superior mechanical properties and the in-situ solidified preparation method,PPM-PE can form a 3D polymer network buffer against stress within the electrode particles gap,enabling much suppressed electrode volume expansion and more stabilized solid electrolyte interface along with evidently decreased electrolyte decomposition.Resultantly,PPM-PE shows significant improvements in both cycling and rate performance in button and soft package batteries with SiO_(x)-based electrodes,compared with the liquid electrolyte counterpart.Such a dragonfly wing microstructure-inspired design philosophy of in-situ solidified polymer electrolytes helps facilitate the practical implementation of high-energy lithium batteries with SiO_(x)-based anodes.
基金Project(2007BAE12B01)supported by the National Key Technology Research and Development Program of ChinaProject(20803095)supported by the National Natural Science Foundation of China
文摘Effects of film-forming additive on stability of electrode and cycling performance of LiFePO4/graphite cell at elevated temperature were studied. Two 18650 cells with and without VC additive were investigated by galvanostatic cycling, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis and Raman spectroscopy. The results show that in the presence of VC additive, dissolution of Fe from LiFePO4 material is greatly depressed and stability of graphite structure is improved; the additive can not only reduce reaction of electrolyte on surface of LiFePO4 electrode but also suppress reduction of solvent and thickening of the solid electrolyte interface （SEI） layer on graphite surface. Electrolyte with VC is considered to be a good candidate for improving cycling performance of the LiFePOa/graphite cell at elevated temperature.
基金Project(2014CB643406)supported by the National Basic Research Program of China
文摘LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1（OH）2 at a molar ratio of 1：1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature.
基金V. ACKNOWLEDGMENTS The work was supported by the Natural Science Foundation of Anhui province （No.90414178） and USTC-NSRL Association funding （No.KY2060030010）.
文摘Na^＋ doped sample Li0.95Na0.05FePO4 was prepared through solid state method. Structure characterization shows Na^＋ is successfully introduced into the LiFePO4 matrix. Scanning electron microscopy shows the particle size mainly ranges in 1-3 μm. X-ray diffraction Rietveld refinement demonstrates lattice distortion with an increased cell volume. As one cathode material, it has a discharge capacity of 150 mAh/g at 0.1 C rate. The material exhibits a capacity of 109 and 107 mAh/g at 5 and 7.5 C respectively. When cycled at 1 and 5 C, the material retains 84% （after 1000 cycles） and 86% （after 350 cycles） of the initial discharge capacity respectively indicating excellent structure stability and cycling performance. Na^＋ doping enhances the electrochemical activity especially the cycle performance effectively.
基金the National Natural Science Foundation of China(52103093)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2021QNRC001)+2 种基金the Jiangxi Provincial Natural Science Foundation(20212BAB214048)Science and Technology Support Project of Shangrao(2020L009,2021J006)Science and Technological Project of Education Department of Jiangxi(GJJ211704)for funding their contributions to this paper。
文摘Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.
基金financially supported by the National Key Research and Development Program of China (2017YFA0208200)the National Natural Science Foundation of China (52102100,22022505 and 21872069)+4 种基金the Natural Science Foundation of Jiangsu Province (BK20181469)Guangdong Basic and Applied Basic Research Foundation (2020A1515110035)the Fundamental Research Funds for the Central Universities (0205-14380266,0205-14380272)the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province (BK20220008)the 2021 Suzhou Gusu Leading Talents of Science and Technology Innovation and Entrepreneurship in Wujiang District。
文摘To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks(ZIFs)and their derived materials,a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imidazolate framework(ZIF-67)polyhedrons,which are used as precursors to prepare cobalt selenide/carbon composites with different crystal phases(Co_(0.85)Se,CoSe_2).When evaluated as anode material for lithium ion batteries,Co_(0.85)Se/C composites deliver a reversible capacity of 758.7 m A·h·g^(-1)with a capacity retention rate of 90.5%at 1.0 A·g^(-1)after 500 cycles,and the superior rate capability is 620 m A·h·g^(-1)at 2.0 A·g^(-1).The addition of KOH accelerates the production of ZIF-67 crystals by boosting deprotonation of dimethylimidazole,resulting in rapid growth and structures transition from two-dimensional to three-dimensional of ZIF-67 in aqueous solution,which greatly promotes the application of MOFs in the field of energy storage and conversion.
基金supported by the Innovation Foundation of BUAA for Ph. D Graduates Provided by Beihang University in China
文摘This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...
基金supported by the National Natural Science Foundation of China(Nos.52125405 and U22A20108)Thailand Science Research and Innovation Fund Chulalongkorn University,National Research Council of Thailand(NRCT)+1 种基金Chulalongkorn University(No.42A660383)the Hub of Talents:Sustainable Materials for Circular Economy,National Research Council of Thailand(NRCT).
文摘LithiumvanadatesLiV_(3)O_(8)-LiV_(6)O_(15)(LVO)witha heterojunction structure are synthesized using a conventional high-temperature solid-state method to address the challenges of low ionic conductivity,rapid capacity decay,and poor cycling performance in conventional lithium-ion battery cathode materials.The charge-discharge processes of LVO span multiple platforms,delivering an impressive specific discharge capacity of 219.4 mAh.g^(-1) at 1C.Remarkably,LVO exhibits a high-capacity retention rate of 81.3%after 800 cycles within the typical operating voltage range of lithium-ion batteries(2.8-4.3V).Rate capability tests and electrochemical impedance spectroscopy(EIS)reveal that,compared to traditional cathode materials,LVO significantly enhances Li*diffusion rates(D_(Li*))and reduces charge transfer resistance(Ret).
基金supported by Science and Technology Project of China Southern Power Grid (SZKJXM20230049/090000KC23010038)。
文摘Solid-state batteries(SSBs) with high safety are promising for the energy fields,but the development has long been limited by machinability and interfacial problems.Hence,self-supporting,flexible Nano LLZO CSEs are prepared with a solvent-free method at 25℃.The 99.8 wt% contents of Nano LLZO particles enable the Nano LLZO CSEs to maintain good thermal stability while exhibiting a wide electrochemical window of 5.0 V and a high Li~+ transfer number of 0.8.The mean modulus reaches 4376 MPa.Benefiting from the interfacial modulation,the Li|Li symmetric batteries based on the Nano LLZO CSEs show benign stability with lithium at the current densities of 0.1 mA cm^(-2),0.2 mA cm^(-2),and 0.5 mA cm^(-2).In addition,the Li|LiFePO_(4)(LFP) SSBs achieve favorable cycling performance:the specific capacity reaches128.1 mAh g^(-1) at 0.5 C rate,with a capacity retention of about 80% after 600 cycles.In the further tests of the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) cathodes with higher energy density,the Nano LLZO CSEs also demonstrate good compatibility:the specific capacities of NCM811-based SSBs reach 177.9 mAh g^(-1) at 0.5 C rate,while the capacity retention is over 96% after 150 cycles.Furthermore,the Li|LFP soft-pack SSBs verify the safety characteristics and the potential for application,which have a desirable prospect.
