Through survey on current situation of NCMS construction in Guangxi, we analyze deep reasons for farmers' resistance to NCMS. Major reasons include inadequate propaganda and training effort; narrow compensation sc...Through survey on current situation of NCMS construction in Guangxi, we analyze deep reasons for farmers' resistance to NCMS. Major reasons include inadequate propaganda and training effort; narrow compensation scope influencing institutional functions; unreasonable reimbursement mechanism; low level of informatization management; imperfect supervision mechanism; and imperfect laws and regulations. In these situations, we put forward following countermeasures and suggestions: enhance training to ensure working efficiency; expand compensation scope to raise security level; adjust compensation standard to raise reimbursement proportion; lift level of informatization management to reduce costs for institutional operation; strengthen organizational construction to reinforce fund management; open up fund-raising channels to perfect legal system.展开更多
With the approaching of large-scale retirement of power lithium-ion batteries(LIBs),their urgent handling is required for environmental protection and resource reutilization.However,at present,substantial spent power ...With the approaching of large-scale retirement of power lithium-ion batteries(LIBs),their urgent handling is required for environmental protection and resource reutilization.However,at present,substantial spent power batteries,especially for those high recovery value cathode materials,have not been greenly,sustainably,and efficiently recycled.Compared to the traditional recovery method for cathode materials with high energy consumption and severe secondary pollution,the direct repair regeneration,as a new type of short-process and efficient treatment methods,has attracted widespread attention.However,it still faces challenges in homogenization repair,electrochemical performance decline,and scaling-up production.To promote the direct regeneration technology development of failed NCM materials,herein we deeply discuss the failure mechanism of nickel-cobalt-manganese(NCM)ternary cathode materials,including element loss,Li/Ni mixing,phase transformation,structural defects,oxygen release,and surface degradation and reconstruction.Based on this,the detailed analysis and summary of the direct regeneration method embracing solid-phase sintering,eutectic salt assistance,solvothermal synthesis,sol-gel process,spray drying,and redox mediation are provided.Further,the upcycling strategy for regeneration materials,such as single-crystallization and high-nickelization,structural regulation,ion doping,and surface engineering,are discussed in deep.Finally,the challenges faced by the direct regeneration and corresponding countermeasures are pointed out.Undoubtedly,this review provides valuable guidance for the efficient and high-value recovery of failed cathode materials.展开更多
High-voltage LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes are critical for enhancing the energy density of lithium-ion batteries(LIBs).The development of binders compatible with high-voltage NCM811 cathode material...High-voltage LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes are critical for enhancing the energy density of lithium-ion batteries(LIBs).The development of binders compatible with high-voltage NCM811 cathode materials is crucial to enhance the electrochemical performance of LIBs.However,the traditional fluoropolymer binder,poly(vinylidene difluoride)(PVDF),can potentially leach components or break down into poly(fluoroalkyl substances)(PFAS)chemicals,thereby contributing to PFAS contamination.A novel fluorine-free polymer,polysulfone-polyamide-polyimide(SPIO),was designed and synthesized as a binder for NCM811 cathodes.The SPIO binder exhibits exceptional mechanical properties and superior electrochemical characteristics.The cathode film fabricated with SPIO demonstrated a remarkable delamination force of 8 N(390 N·m^(-1)),indicating robust adhesion.The Li‖NCM811 cell incorporating the SPIO binder retained 80%of its initial capacity after 300 cycles at a current density of 0.2 C.In comparison,the control cells assem bled with the PVDF binder retained only 52%of their capacities under the same cycling conditions.Furthermore,the SPIO binder exhibited improved compatibility with the electrolyte.Transmission electron microscopy analysis of the cathode films after 100 cycles revealed the formation of a unifo rm,dense,and continuous chemical-electrochemical interface(CEI)by the SPIO binder on the surface of the NCM811 particles,which significantly contributed to the enhancement of the electrochemical performance.These results highlight the potential of SPIO as an advanced binder material for high-perfo rmance lithium-ion batteries.展开更多
Rich-nickel layered ternary NCM811 has been widely used in the field of electric vehicles ascribed to its high theoretical specific capacity.However,poor cycling stability and rate-performance hindered its further dev...Rich-nickel layered ternary NCM811 has been widely used in the field of electric vehicles ascribed to its high theoretical specific capacity.However,poor cycling stability and rate-performance hindered its further development.Herein,different amounts of nitrogen-doped carbon were wrapped on the surface of NCM811 via a facile rheological phase method by regulating the amount of dopamine hydrochloride.The effects of the coating amounts on the structure and electrochemical performance are investigated.The DFT calculation,XRD,SEM and XPS reveal that an appropriate amount of nitrogen-doped carbon coating could uniformly form a protective layer on the NCM811 surface and the introduced N could anchor Ni atoms to inhibit the Li^(+)/Ni^(2+)mixing,but excessive amount would reduce Ni^(3+)to Ni^(2+)so as to conversely aggravate Li^(+)/Ni^(2+)mixing.Among the samples,the NCM811-CN0.75 sample exhibits the most excellent electrochemical performance,delivering a high-rate capacity of 151.6 mA·h/g at 10C,and long-term cyclability with 82.2%capacity retention after 300 cycles at 5C,exhibiting remarkable rate-performance and cyclability.展开更多
Ni-rich LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.I...Ni-rich LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study,we propose an entropy-assisted multi-element doping strategy to mitigate these issues.Specifically,two routes are designed and compared:bulk-like localized high-entropy doping(BHE-NCM)and surface-distributed high-entropy-zone doping(SHE-NCM).The surface entropy-doped NCM cathode delivers enhanced electrochemical performance,including higher capacity retention under 4.5 V cycling and superior rate capability,compared to both bulk-like and pristine counterparts.Comprehensive material characterization reveals that surface-localized doping stabilizes the layered structure with reduced microcrack formation and creates a uniform dopant-rich surface region with improved thermal and electrochemical stability.Overall,entropy-assisted doping at the near surface zone effectively alleviates structural degradation and interface reactions in Ni-rich NCM,enabling improved cycling performance at high voltage.This work highlights the significance of surface entropy engineering as a promising strategy for designing high-voltage cathodes with improved safety and longevity.展开更多
Although lithium-ion batteries are widely recognized as a new generation of energy storage devices,their large-scale application is severely hampered by their low energy density and restricted cyclic stability.Herein,...Although lithium-ion batteries are widely recognized as a new generation of energy storage devices,their large-scale application is severely hampered by their low energy density and restricted cyclic stability.Herein,an ingenious dual-modified interface,where the F-doping and fluorocarbon coating co-existed on Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)surface,is rationally constructed to elevate its energy density and structural stability attributed to F-grafting between the bulk material and the coating utilizing a robust super-conformal fluorocarbon coating structural framework and more stable F-doped system under high charge/discharge cut-off voltage.In comparison with a single carbon-coated modified Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),the dual-modified sample overcomes the fatal disadvantage of carbon coating stripping during long-period cycles ascribed to the“TM-F-multifunctional coating”connector which firmly combines the bulk material with the coating with a strong interaction force,exhibiting a more stable-reversible structure and excellent comprehensive electrochemical performance under high cut-off voltage.Concomitantly,the F-transition metal bonds with stronger bond energies improve its structural reversibility during the processes of charge/discharge under high voltage.Furthermore,the fluorocarbon coating enhances its charge transfer ability and effectively restrains the interfacial side reactions.Additionally,the climbing nudged elastic band methodology is used to calculate the diffusion energy barrier of lithium-ions in the matrix material,which confirms the fundamental reason for its superior lithium-ion diffusion ability.The high pseudocapacitance contribution ratio is perfectly explained by calculating the adsorption capacity on the surface of the dual-modified sample.Consequently,experiments and theoretical calculations unequivocally confirm its distinguished electrochemical properties under high cut-off voltage.展开更多
基金Supported by Project of National Social Science Foundation(06XMZ019)
文摘Through survey on current situation of NCMS construction in Guangxi, we analyze deep reasons for farmers' resistance to NCMS. Major reasons include inadequate propaganda and training effort; narrow compensation scope influencing institutional functions; unreasonable reimbursement mechanism; low level of informatization management; imperfect supervision mechanism; and imperfect laws and regulations. In these situations, we put forward following countermeasures and suggestions: enhance training to ensure working efficiency; expand compensation scope to raise security level; adjust compensation standard to raise reimbursement proportion; lift level of informatization management to reduce costs for institutional operation; strengthen organizational construction to reinforce fund management; open up fund-raising channels to perfect legal system.
基金financially supported by the National Key Research and Development Program of China(2023YFB3809300)。
文摘With the approaching of large-scale retirement of power lithium-ion batteries(LIBs),their urgent handling is required for environmental protection and resource reutilization.However,at present,substantial spent power batteries,especially for those high recovery value cathode materials,have not been greenly,sustainably,and efficiently recycled.Compared to the traditional recovery method for cathode materials with high energy consumption and severe secondary pollution,the direct repair regeneration,as a new type of short-process and efficient treatment methods,has attracted widespread attention.However,it still faces challenges in homogenization repair,electrochemical performance decline,and scaling-up production.To promote the direct regeneration technology development of failed NCM materials,herein we deeply discuss the failure mechanism of nickel-cobalt-manganese(NCM)ternary cathode materials,including element loss,Li/Ni mixing,phase transformation,structural defects,oxygen release,and surface degradation and reconstruction.Based on this,the detailed analysis and summary of the direct regeneration method embracing solid-phase sintering,eutectic salt assistance,solvothermal synthesis,sol-gel process,spray drying,and redox mediation are provided.Further,the upcycling strategy for regeneration materials,such as single-crystallization and high-nickelization,structural regulation,ion doping,and surface engineering,are discussed in deep.Finally,the challenges faced by the direct regeneration and corresponding countermeasures are pointed out.Undoubtedly,this review provides valuable guidance for the efficient and high-value recovery of failed cathode materials.
基金supported by the Shenzhen Science and Technology Program(No.JCYJ20220818100407016)the National Natural Science Foundation of China(No.22275059)+1 种基金Guangdong Special Support Program(No.2021TX06L775)high-level special funds(No.G03050K002)。
文摘High-voltage LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes are critical for enhancing the energy density of lithium-ion batteries(LIBs).The development of binders compatible with high-voltage NCM811 cathode materials is crucial to enhance the electrochemical performance of LIBs.However,the traditional fluoropolymer binder,poly(vinylidene difluoride)(PVDF),can potentially leach components or break down into poly(fluoroalkyl substances)(PFAS)chemicals,thereby contributing to PFAS contamination.A novel fluorine-free polymer,polysulfone-polyamide-polyimide(SPIO),was designed and synthesized as a binder for NCM811 cathodes.The SPIO binder exhibits exceptional mechanical properties and superior electrochemical characteristics.The cathode film fabricated with SPIO demonstrated a remarkable delamination force of 8 N(390 N·m^(-1)),indicating robust adhesion.The Li‖NCM811 cell incorporating the SPIO binder retained 80%of its initial capacity after 300 cycles at a current density of 0.2 C.In comparison,the control cells assem bled with the PVDF binder retained only 52%of their capacities under the same cycling conditions.Furthermore,the SPIO binder exhibited improved compatibility with the electrolyte.Transmission electron microscopy analysis of the cathode films after 100 cycles revealed the formation of a unifo rm,dense,and continuous chemical-electrochemical interface(CEI)by the SPIO binder on the surface of the NCM811 particles,which significantly contributed to the enhancement of the electrochemical performance.These results highlight the potential of SPIO as an advanced binder material for high-perfo rmance lithium-ion batteries.
基金Project(2021H0028) supported by the Natural Scienceof Fujian Province,ChinaProject(JAT200455) supported by the Fujian Provincial Young and Middle-aged Teacher Education Project,ChinaProject(fma2023003) supported by the Open Fund of Fujian Provincial Key Laboratory of Functional Materials and Applications,China。
文摘Rich-nickel layered ternary NCM811 has been widely used in the field of electric vehicles ascribed to its high theoretical specific capacity.However,poor cycling stability and rate-performance hindered its further development.Herein,different amounts of nitrogen-doped carbon were wrapped on the surface of NCM811 via a facile rheological phase method by regulating the amount of dopamine hydrochloride.The effects of the coating amounts on the structure and electrochemical performance are investigated.The DFT calculation,XRD,SEM and XPS reveal that an appropriate amount of nitrogen-doped carbon coating could uniformly form a protective layer on the NCM811 surface and the introduced N could anchor Ni atoms to inhibit the Li^(+)/Ni^(2+)mixing,but excessive amount would reduce Ni^(3+)to Ni^(2+)so as to conversely aggravate Li^(+)/Ni^(2+)mixing.Among the samples,the NCM811-CN0.75 sample exhibits the most excellent electrochemical performance,delivering a high-rate capacity of 151.6 mA·h/g at 10C,and long-term cyclability with 82.2%capacity retention after 300 cycles at 5C,exhibiting remarkable rate-performance and cyclability.
基金supported by the Australian Research Council via Discovery Projects(Nos.DP200103315,DP200103332 and DP230100685)Linkage Projects(No.LP220200920)+1 种基金support from the IONTOF M6 ToF-SIMS(funded by ARC LIEF,LE190100053)the Kratos Axis Ultra XPS(ARC LIEF,LE120100026)。
文摘Ni-rich LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study,we propose an entropy-assisted multi-element doping strategy to mitigate these issues.Specifically,two routes are designed and compared:bulk-like localized high-entropy doping(BHE-NCM)and surface-distributed high-entropy-zone doping(SHE-NCM).The surface entropy-doped NCM cathode delivers enhanced electrochemical performance,including higher capacity retention under 4.5 V cycling and superior rate capability,compared to both bulk-like and pristine counterparts.Comprehensive material characterization reveals that surface-localized doping stabilizes the layered structure with reduced microcrack formation and creates a uniform dopant-rich surface region with improved thermal and electrochemical stability.Overall,entropy-assisted doping at the near surface zone effectively alleviates structural degradation and interface reactions in Ni-rich NCM,enabling improved cycling performance at high voltage.This work highlights the significance of surface entropy engineering as a promising strategy for designing high-voltage cathodes with improved safety and longevity.
基金support from the Natural Science Foundation of Fujian Province,China(No.2021H0028)the Natural Science Foundation of China(No.21975212)+1 种基金Open Fund of Fujian Provincial Key Laboratory of Functional Materials and Applications(No.fma2023003)the Science and Technology Planning Project of Xiamen City(No.2022CXY0409).
文摘Although lithium-ion batteries are widely recognized as a new generation of energy storage devices,their large-scale application is severely hampered by their low energy density and restricted cyclic stability.Herein,an ingenious dual-modified interface,where the F-doping and fluorocarbon coating co-existed on Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)surface,is rationally constructed to elevate its energy density and structural stability attributed to F-grafting between the bulk material and the coating utilizing a robust super-conformal fluorocarbon coating structural framework and more stable F-doped system under high charge/discharge cut-off voltage.In comparison with a single carbon-coated modified Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),the dual-modified sample overcomes the fatal disadvantage of carbon coating stripping during long-period cycles ascribed to the“TM-F-multifunctional coating”connector which firmly combines the bulk material with the coating with a strong interaction force,exhibiting a more stable-reversible structure and excellent comprehensive electrochemical performance under high cut-off voltage.Concomitantly,the F-transition metal bonds with stronger bond energies improve its structural reversibility during the processes of charge/discharge under high voltage.Furthermore,the fluorocarbon coating enhances its charge transfer ability and effectively restrains the interfacial side reactions.Additionally,the climbing nudged elastic band methodology is used to calculate the diffusion energy barrier of lithium-ions in the matrix material,which confirms the fundamental reason for its superior lithium-ion diffusion ability.The high pseudocapacitance contribution ratio is perfectly explained by calculating the adsorption capacity on the surface of the dual-modified sample.Consequently,experiments and theoretical calculations unequivocally confirm its distinguished electrochemical properties under high cut-off voltage.
