Elevating the operating voltage is an effective approach to improve the reversible capacity of ultra-high nickel layered oxide cathode LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM,x≥0.8)and solve the"range anxiety"confusi...Elevating the operating voltage is an effective approach to improve the reversible capacity of ultra-high nickel layered oxide cathode LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM,x≥0.8)and solve the"range anxiety"confusion of electric vehicles.However,the undesirable surface reconstruction induced by the high cut-off voltage has a fatal impact on the thermodynamic stability of the material,inevitably leading to fast capacity degradation.Herein,a mechanical fusion aided by alcohol is suggested to create a stable olivine structure for the single-crystal(SC)ultrahigh-nickel cathode LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2).The addition of nanoparticles effectively bridges the void of SC-NCM,builds an ideal particle grading,and significantly raises the cost efficiency,as well as promotes the cycling stability and safety of the full cell.Remarkably,the layered/olivine mixture forms a perfect shield by lowering the surface area between the NCM cathode and electrolyte,hence mitigating side reactions and contributing to an incredibly thin and stable cathode/electrolyte interface.Furthermore,the thermodynamic stability of highly delithiated NCM is improved,as both the particle cracks and structural degradation are simultaneously postponed.Consequently,the maximum temperature of the single-crystal LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)@LiFePO_(4)‖graphite pouch full cell is dramatically reduced from 599.4 to 351.4℃,and the full cell achieves 88.2%capacity retention after 800 cycles,demonstrating excellent thermal stability and cycling stability.This facile strategy provides a feasible technical reference for further exploiting the ultrahigh-capacity,highsafety,and long-life Ni-rich cathode for commercial application of lithium-ion batteries(LIBs).展开更多
Congo River has abundant hydropower resources,and large-scale cascade power stations,such as the Grand Inga,can be constructed in downstream locations.However,the fragile economic foundations of the Democratic Republi...Congo River has abundant hydropower resources,and large-scale cascade power stations,such as the Grand Inga,can be constructed in downstream locations.However,the fragile economic foundations of the Democratic Republic of the Congo and neighbor!ng Central African countries,and the small-scale regional power consumption market prohibit the implementation of large-scale hydro power projects.As the high-voltage,I on g-dista nee power transmission tech no logy matures,hydropower from the Grand Inga can be delivered to load centers in other regions of Africa.This study establishes a 6 dime nsional comprehe nsive assessment model using the best-worst method to evaluate large-scale,I on g-distance,cross-border power intercon necti on projects.The model is applied to evaluate all the can didate in ter-regional power delivery schemes of the Inga III hydropower station,and the evaluation results can effectively help investment institutions and policy makers in policy making and potential market targeting.展开更多
基金the support from the Natural Science Foundation of Hunan Province,China(2024JJ7301)the science and technology innovation Program of Hunan Province(2024JK2097)+5 种基金the Project of the Scientific Research Fund of Hunan Provincial Education Department(No.22C0383)Changde Scientific and Technological Innovation Plan(CDKJJ20220517)Start-up Foundation for Doctors of Hunan University of Arts and Science(No.22BSQD22,21BSQD14 and 21BSQD15)Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Provincepartially supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(PolyU152178/20E)the Innovation and Technology Commission of Hong Kong(MHP/080/22)。
文摘Elevating the operating voltage is an effective approach to improve the reversible capacity of ultra-high nickel layered oxide cathode LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM,x≥0.8)and solve the"range anxiety"confusion of electric vehicles.However,the undesirable surface reconstruction induced by the high cut-off voltage has a fatal impact on the thermodynamic stability of the material,inevitably leading to fast capacity degradation.Herein,a mechanical fusion aided by alcohol is suggested to create a stable olivine structure for the single-crystal(SC)ultrahigh-nickel cathode LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2).The addition of nanoparticles effectively bridges the void of SC-NCM,builds an ideal particle grading,and significantly raises the cost efficiency,as well as promotes the cycling stability and safety of the full cell.Remarkably,the layered/olivine mixture forms a perfect shield by lowering the surface area between the NCM cathode and electrolyte,hence mitigating side reactions and contributing to an incredibly thin and stable cathode/electrolyte interface.Furthermore,the thermodynamic stability of highly delithiated NCM is improved,as both the particle cracks and structural degradation are simultaneously postponed.Consequently,the maximum temperature of the single-crystal LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)@LiFePO_(4)‖graphite pouch full cell is dramatically reduced from 599.4 to 351.4℃,and the full cell achieves 88.2%capacity retention after 800 cycles,demonstrating excellent thermal stability and cycling stability.This facile strategy provides a feasible technical reference for further exploiting the ultrahigh-capacity,highsafety,and long-life Ni-rich cathode for commercial application of lithium-ion batteries(LIBs).
基金National Key Reaearch and Development Program of China(2016YFB0900400).
文摘Congo River has abundant hydropower resources,and large-scale cascade power stations,such as the Grand Inga,can be constructed in downstream locations.However,the fragile economic foundations of the Democratic Republic of the Congo and neighbor!ng Central African countries,and the small-scale regional power consumption market prohibit the implementation of large-scale hydro power projects.As the high-voltage,I on g-dista nee power transmission tech no logy matures,hydropower from the Grand Inga can be delivered to load centers in other regions of Africa.This study establishes a 6 dime nsional comprehe nsive assessment model using the best-worst method to evaluate large-scale,I on g-distance,cross-border power intercon necti on projects.The model is applied to evaluate all the can didate in ter-regional power delivery schemes of the Inga III hydropower station,and the evaluation results can effectively help investment institutions and policy makers in policy making and potential market targeting.
