The reliable operation of lithium-ion batteries(LIBs)in low temperatures has long been hindered by severe side reactions on graphite anodes.To develop a commercially viable low-temperature electrolyte,we design a solv...The reliable operation of lithium-ion batteries(LIBs)in low temperatures has long been hindered by severe side reactions on graphite anodes.To develop a commercially viable low-temperature electrolyte,we design a solvent-resistant Nitrate-coordinated electrolyte.The practical Ah-level graphite LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) pouch cell with the newly developed electrolyte demonstrates a significant breakthrough in cycling stability,exhibiting negligible capacity fade after 250 cycles at-30℃ and 0.1 C.NO_(3)^(-),as the functional additive,compresses the electric field around Li^(+)through electrostatic interactions,mimicking the Debye-screening effect and inducing the coordinative exclusion of free ethyl acetate molecules at low temperatures.The transformation from contact ion pairs(CIPs)formed by Pto solventseparated ion pairs is significantly restrained,which mitigates the continuous reactions between the electrolyte and inevitable lithium deposition at low temperature.Additionally,this customized inert CIPs form a solid electrolyte interphase on graphite that exhibits remarkable ionic conductivity and rigidity,preventing excessive Li dendrite growth.This finding offers new insights into the relationship of microstructure-performance for low-temperature electrolytes,demonstrating that relying solely on inert CIPs can also inhibit the decomposition of the interfacial electrolyte,and inspires a unique design concept for high-performance,commercially viable LIBs that operate reliably in sub-zero environments.展开更多
Lithium-ion batteries(LIBs)have emerged as the predominant electrochemical energy storage devices in contemporary applications.However,the uncontrollable lithium(Li)plating on graphite(Gr)anodes and the structural det...Lithium-ion batteries(LIBs)have emerged as the predominant electrochemical energy storage devices in contemporary applications.However,the uncontrollable lithium(Li)plating on graphite(Gr)anodes and the structural deterioration of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)cathodes in conventional carbonate electrolytes-particularly at high operating voltages and elevated temperatures-are the primary factors contributing to capacity decay and short circuits in LIBs.Herein,we elucidate the regulation of the lithium hexafluorophosphate(LiPF_(6))decomposition pathway with a 1.15 M LiPF_(6) by incorporating trace dual-unsaturated additives,0.5 wt.% vinylene carbonate(VC)and 0.3 wt.%prop-1-ene-1,3-sultone(PES),resulting in LiF-enriched cathode electrolyte interphase and polymeric C-F and S-F species.The influences of the VC and PES serve to deactivate the Lewis acid phosphorus pentafluoride(PF5),thereby impeding the formation of the byproduct Li_(x)POF_(y).Furthermore,the radical copolymerization of VC with PES through electrochemical initiation engenders a spatially adaptable polymeric solid electrolyte interphase on the Gr anode,significantly mitigating Li plating during cycling.Consequently,Gr|NCM523 pouch cells containing 0.5% VC and 0.3% PES additives exhibit a remarkable capacity retention of 97.54% after 500 cycles at 45℃.This work offers a new insight into tuning the interphasial chemistry of anode/cathode at elevated temperatures through strategic dual-unsaturated electrolyte additives.展开更多
基金support from the Heilongjiang Touyan Innovation Team Program(HITTY-20190033)National Natural Science Foundation of China(22278096)Innovation Special Project on Science and Technology for Carbon Peaking and Carbon Neutrality in Jiangsu Province(WSSJH20230015)。
文摘The reliable operation of lithium-ion batteries(LIBs)in low temperatures has long been hindered by severe side reactions on graphite anodes.To develop a commercially viable low-temperature electrolyte,we design a solvent-resistant Nitrate-coordinated electrolyte.The practical Ah-level graphite LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) pouch cell with the newly developed electrolyte demonstrates a significant breakthrough in cycling stability,exhibiting negligible capacity fade after 250 cycles at-30℃ and 0.1 C.NO_(3)^(-),as the functional additive,compresses the electric field around Li^(+)through electrostatic interactions,mimicking the Debye-screening effect and inducing the coordinative exclusion of free ethyl acetate molecules at low temperatures.The transformation from contact ion pairs(CIPs)formed by Pto solventseparated ion pairs is significantly restrained,which mitigates the continuous reactions between the electrolyte and inevitable lithium deposition at low temperature.Additionally,this customized inert CIPs form a solid electrolyte interphase on graphite that exhibits remarkable ionic conductivity and rigidity,preventing excessive Li dendrite growth.This finding offers new insights into the relationship of microstructure-performance for low-temperature electrolytes,demonstrating that relying solely on inert CIPs can also inhibit the decomposition of the interfacial electrolyte,and inspires a unique design concept for high-performance,commercially viable LIBs that operate reliably in sub-zero environments.
基金financially supported by the National Natural Science Foundation of China(Nos.52027816 and 52231009).
文摘Lithium-ion batteries(LIBs)have emerged as the predominant electrochemical energy storage devices in contemporary applications.However,the uncontrollable lithium(Li)plating on graphite(Gr)anodes and the structural deterioration of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)cathodes in conventional carbonate electrolytes-particularly at high operating voltages and elevated temperatures-are the primary factors contributing to capacity decay and short circuits in LIBs.Herein,we elucidate the regulation of the lithium hexafluorophosphate(LiPF_(6))decomposition pathway with a 1.15 M LiPF_(6) by incorporating trace dual-unsaturated additives,0.5 wt.% vinylene carbonate(VC)and 0.3 wt.%prop-1-ene-1,3-sultone(PES),resulting in LiF-enriched cathode electrolyte interphase and polymeric C-F and S-F species.The influences of the VC and PES serve to deactivate the Lewis acid phosphorus pentafluoride(PF5),thereby impeding the formation of the byproduct Li_(x)POF_(y).Furthermore,the radical copolymerization of VC with PES through electrochemical initiation engenders a spatially adaptable polymeric solid electrolyte interphase on the Gr anode,significantly mitigating Li plating during cycling.Consequently,Gr|NCM523 pouch cells containing 0.5% VC and 0.3% PES additives exhibit a remarkable capacity retention of 97.54% after 500 cycles at 45℃.This work offers a new insight into tuning the interphasial chemistry of anode/cathode at elevated temperatures through strategic dual-unsaturated electrolyte additives.
