Mitigating volume expansion of silicon-based anode through interfacial engineering based on intermittent discharge strategy  

作　　者：Chunlei Li Yu Zhu Yin Quan Feifei Zong Jie Wang Dongni Zhao Ningshuang Zhang Peng Wang Xiaoling Cui Shiyou Li 

机构地区：[1]School of Petrochemical Technology,Lanzhou University of Technology,Lanzhou 730050,Gansu,China [2]Key Laboratory of Low Carbon Energy and Chemical Engineering of Gansu Province,Lanzhou 730050,Gansu,China [3]Gansu Engineering Laboratory of Cathode Material for Lithium-ion Battery,Baiyin 730900,Gansu,China

出　　处：《Journal of Energy Chemistry》2024年第11期680-691,共12页能源化学（英文版）

基　　金：Department of Education of Gansu Province: Industrial Support Plan Project (2022CYZC-23);National Natural Science Foundation of China (22269012);Gansu Key Research and Development Program (23YFGA0053)。

摘　　要：Silicon is considered to be one of the most promising anode materials for lithium-ion batteries(LIBs),but its application is limited by the large volume expansion during alloying and dealloying.The constructing of a high-performance solid electrolyte interface(SEI) film on the surface of the anode material is considered to be one of the effective strategies to mitigate volume expansion of silicon-based anode.In this study,an intermittent discharge strategy which helps to improve the utilization efficiency of electrolyte additive of lithium difluorobisoxalate phosphate(LiDFBOP) is proposed to construct a highly conductive and dense SEI film.The results of electrochemical and physical characterization and theoretical calculations show that the intermittent discharge in the voltage range from open circuit voltage(OCV) to 1.8 V facilitates the diffusion of the soluble products,creates the conditions for the repeated direct contact between Si@C anode and LiDFBOP additive,increases the decomposition of LiDFBOP additive,and thus produces a uniform,dense and inorganics-rich(Li_(2)C_(2)O_(4),LiF and Li_(x)PO_yF_z) SEI film.Subsequently,this SEI film helps to ensure the even intercalation/de-intercalation of Li^(+) in the SEI film and the homogeneous diffusion of Li^(+) inside the Si particles,decreasing the internal stresses and anisotropic phase transitions,maintaining the integrity of Si particles,inhibiting the volume expansion and thu s improving the electrochemical performance of cells.This study not only improves the utilization efficiency of expensive additives through a simply and low-cost method,but also enriches the strategy to improve the electrochemical performance of Si@C anode through interfacial engineering.

关 键 词：Si@C anode Lithium difluoro(bisoxalato)phosphate Intermittent discharge Solid electrolyte interface Volume expansion 

分 类 号：TM912[电气工程—电力电子与电力传动] O646[理学—物理化学]