The high theoretical capacity and long shelf-life of a Li-CF_(x) system make it most promising for portable electronics.However,the inactivation ideology of-CF_(3) groups in CF_(x) hinders the development of the Li-CF...The high theoretical capacity and long shelf-life of a Li-CF_(x) system make it most promising for portable electronics.However,the inactivation ideology of-CF_(3) groups in CF_(x) hinders the development of the Li-CF_(x) system to realize ultra-high energy density.Here,we developed a unique carbon fluoride nanocapsule(CFNC)with x>1 using a simple thermal-assisted chemical reaction in a controlled environment.The high curvature 3D hollow structure and rich interfaces generated by the engineered wall structure of the CFNC enable activation of-CF and-CF_(2) groups.The resulting structure bears high mass and rich charge transfer channels which deliver a cathode capacity of 1056 mA h g^(-1) and energy density up to 2487 W h kg^(-1) beyond the theoretical limits of the Li-CF_(x) system without compromising the cell voltage.To understand the role of structural engineering,density functional theory(DFT)calculations were carried out to confirm active CF_(2) components and the effects of various fragment sizes on the voltage plateau,where a higher discharge plateau voltage is obtained with the larger fragment.The materials design presented in this study is an effective and alternative approach to realizing primary batteries with ultra-high energy densities.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51972045)the Fundamental Research Funds for the Chinese Central Universities,China(No.ZYGX2019J025)+4 种基金Sichuan Science and Technology Program(No.2020JDRC0015 and 2020JDRC0045)the Vice-Chancellor fellowship scheme at RMIT Universitythe ARC Centre of Excellence in Future Low-Energy Electronics Technologies(FLEET)(CE170100039)the RMIT Micro Nano Research Facility(MNRF)in the Victorian node of the Australian National Fabrication Facility(ANFF)the RMIT Microscopy and Microanalysis Facility(RMMF).
文摘The high theoretical capacity and long shelf-life of a Li-CF_(x) system make it most promising for portable electronics.However,the inactivation ideology of-CF_(3) groups in CF_(x) hinders the development of the Li-CF_(x) system to realize ultra-high energy density.Here,we developed a unique carbon fluoride nanocapsule(CFNC)with x>1 using a simple thermal-assisted chemical reaction in a controlled environment.The high curvature 3D hollow structure and rich interfaces generated by the engineered wall structure of the CFNC enable activation of-CF and-CF_(2) groups.The resulting structure bears high mass and rich charge transfer channels which deliver a cathode capacity of 1056 mA h g^(-1) and energy density up to 2487 W h kg^(-1) beyond the theoretical limits of the Li-CF_(x) system without compromising the cell voltage.To understand the role of structural engineering,density functional theory(DFT)calculations were carried out to confirm active CF_(2) components and the effects of various fragment sizes on the voltage plateau,where a higher discharge plateau voltage is obtained with the larger fragment.The materials design presented in this study is an effective and alternative approach to realizing primary batteries with ultra-high energy densities.
