The continuous lithium consumption during cycling severely reduces the energy density of the lithium battery,and thus,lithium compensation is essential.Herein,Li_(x)C_(6)O_(6)(x=2,4)was proposed as an air-stable high-...The continuous lithium consumption during cycling severely reduces the energy density of the lithium battery,and thus,lithium compensation is essential.Herein,Li_(x)C_(6)O_(6)(x=2,4)was proposed as an air-stable high-efficiency sacrificial additive in the cathode to compensate for the lost lithium ions in solid-state lithium batteries.Below a delithiation(oxidation)potential as low as 3.8 V,Li_(2)C_(6)O_(6) can release most of its Li^(+)ions(294.8 mAh g^(−1) in theory).Similarly,Li_(4)C_(6)O_(6) is also characteristic of low oxidation potential and high delithiation capacity(547.8 mAh g^(−1) in theory).The feasibility of using Li_(x)C_(6)O_(6) as the self-sacrificial additive in the cathode was verified with the marked increase of the initial charge capacity of the Li||LiFePO_(4)(half)cells and the initial discharge capacity of Cu||LiFePO_(4)(full)cells,and the improved electrolyte/cathode interface stability and interface contact,in the solid-state poly(ethylene oxide)-lithium bis(trifluoromethane)sulfonimide(PEO-LiTFSI)electrolyte.In addition,the structure and delithiation of Li_(x)C_(6)O_(6) and the impacts of its decomposition product on the PEO-LiTFSI solid electrolyte were also evaluated on the basis of the comprehensive physical characterizations and the density functional theory(DFT)calculations.These findings open a new avenue for elevating the energy density and/or elongate the lifespan of the solid-state secondary batteries.展开更多
基金financially supported by the National Natural Science Foundation of China(NSFC No.22075316,U23A20577,22005334,and 52172257)the Natural Science Foundation of Beijing(Grant No.Z200013).
文摘The continuous lithium consumption during cycling severely reduces the energy density of the lithium battery,and thus,lithium compensation is essential.Herein,Li_(x)C_(6)O_(6)(x=2,4)was proposed as an air-stable high-efficiency sacrificial additive in the cathode to compensate for the lost lithium ions in solid-state lithium batteries.Below a delithiation(oxidation)potential as low as 3.8 V,Li_(2)C_(6)O_(6) can release most of its Li^(+)ions(294.8 mAh g^(−1) in theory).Similarly,Li_(4)C_(6)O_(6) is also characteristic of low oxidation potential and high delithiation capacity(547.8 mAh g^(−1) in theory).The feasibility of using Li_(x)C_(6)O_(6) as the self-sacrificial additive in the cathode was verified with the marked increase of the initial charge capacity of the Li||LiFePO_(4)(half)cells and the initial discharge capacity of Cu||LiFePO_(4)(full)cells,and the improved electrolyte/cathode interface stability and interface contact,in the solid-state poly(ethylene oxide)-lithium bis(trifluoromethane)sulfonimide(PEO-LiTFSI)electrolyte.In addition,the structure and delithiation of Li_(x)C_(6)O_(6) and the impacts of its decomposition product on the PEO-LiTFSI solid electrolyte were also evaluated on the basis of the comprehensive physical characterizations and the density functional theory(DFT)calculations.These findings open a new avenue for elevating the energy density and/or elongate the lifespan of the solid-state secondary batteries.
