High-voltage sodium-ion batteries(SIBs)are emerging as promising candidates for large-scale energy storage systems due to their abundant sodium source and high energy density.However,the instability of the electrode e...High-voltage sodium-ion batteries(SIBs)are emerging as promising candidates for large-scale energy storage systems due to their abundant sodium source and high energy density.However,the instability of the electrode electrolyte interphase remains a critical barrier to the potential use of high-voltage SIBs.Herein,sodium difluorophosphate(NaDFP)and fluoroethylene carbonate(FEC)serve as functional electrolyte additives to stabilize the interface of the high-voltage cathode.The oxidative competition between FEC and NaDFP facilitates the robust formation of the cathode-electrolyte interface(CEI)layer,enriched with inorganic components such as NaF/NaPO_(x)F_(y).The highly conductive NaF/NaPO_(x)F_(y)and inorganics provide fast ion transport pathways and mechanical strength,thereby mitigating the decomposition of carbonates and NaPF_(6).The half-cell equipped with BE 2 F+0.5 DFP demonstrates 93.9%capacity retention at 4.3 V across 600 cycles,showcasing excellent cycling capability.Full HC||NVOPF cells exhibit sustained performance with 91.69%capacity retention and a capacity of 91.57 mA·h/g over 1000 cycles at a 5 C rate.This study is poised to garner increased scholarly interest in the domain of rational electrolyte formulation for practical applications.展开更多
基金Project(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,ChinaProject(51932011)supported by the National Natural Science Foundation of China+1 种基金Project(2023JJ10060)supported by the Natural Science Foundation of Hunan Province,ChinaProject(23A0003)supported by the Scientific Research Fund of Hunan Provincial Education Department,China。
文摘High-voltage sodium-ion batteries(SIBs)are emerging as promising candidates for large-scale energy storage systems due to their abundant sodium source and high energy density.However,the instability of the electrode electrolyte interphase remains a critical barrier to the potential use of high-voltage SIBs.Herein,sodium difluorophosphate(NaDFP)and fluoroethylene carbonate(FEC)serve as functional electrolyte additives to stabilize the interface of the high-voltage cathode.The oxidative competition between FEC and NaDFP facilitates the robust formation of the cathode-electrolyte interface(CEI)layer,enriched with inorganic components such as NaF/NaPO_(x)F_(y).The highly conductive NaF/NaPO_(x)F_(y)and inorganics provide fast ion transport pathways and mechanical strength,thereby mitigating the decomposition of carbonates and NaPF_(6).The half-cell equipped with BE 2 F+0.5 DFP demonstrates 93.9%capacity retention at 4.3 V across 600 cycles,showcasing excellent cycling capability.Full HC||NVOPF cells exhibit sustained performance with 91.69%capacity retention and a capacity of 91.57 mA·h/g over 1000 cycles at a 5 C rate.This study is poised to garner increased scholarly interest in the domain of rational electrolyte formulation for practical applications.
