气固流化床硅氧碳负极材料的宏量制备  

Mass production of SiO_(x)@C anode material in gas-solid fluidized bed

作　　者：肖哲熙 鲁峰 林贤清 张晨曦 白浩隆 于春辉 何姿颖 姜海容 魏飞[1] XIAO Zhexi;LU Feng;LIN Xianqing;ZHANG Chenxi;BAI Haolong;YU Chunhui;HE Ziying;JIANG Hairong;WEI Fei(Department of Chemical Engineering and Technology,Tsinghua University,Beijing 100084,China;Novusilicon Co.Ltd.,Changzhou 213000,Jiangsu,China)

机构地区：[1]清华大学化工系,北京100084 [2]硅源新能材料有限公司,江苏常州213000

出　　处：《储能科学与技术》2022年第6期1739-1748,共10页Energy Storage Science and Technology

基　　金：国家自然科学基金项目(21908125)。

摘　　要：本工作基于流化床内气固相结构调控实现了流化床化学气相沉积技术批量制备锂离子电池高性能硅氧碳负极材料。针对硅氧碳负极这一类微米级细粉颗粒,颗粒间较强的范德华力使得其存在团聚严重难以流化,进而使得化学气相沉积过程中表面呈现岛状沉积问题,显著影响电化学性能。本工作首先引入颗粒相压力构造颗粒类van derWaals状态方程,基于稳定性分析给出气固相调控相图,指导硅氧碳负极二次颗粒的设计,实现其能够在流化床中充分流化进行化学气相沉积碳包覆。稳定的流动状态在避免团聚的同时能够保证高效传质传热使得氧化硅颗粒表面碳层沉积由岛状生长转变为近层状生长,成功实现了氧化硅表面的均匀碳沉积。通过多种电化学测试表征分析,制备出的硅氧碳负极材料具有良好的循环及倍率性能。该技术目前已实现百公斤级中试生产,未来有望实现百吨级工业放大。Based on gas-solid phase regulation,this work has achieved mass production of high-performance silicon oxide carbon(SiO_(x)@C)anode materials for lithium-ion batteries using fluidized bed chemical vapor deposition(FB-CVD)technology.Ordinarily,for micron-sized silicon oxide carbon powder,significant interparticle van der Waals forces impede fluidization through severe agglomeration and island-like deposition on the surface.This behavior adversely affects the resulting electrochemical performance.To address this,first,particle phase pressure was introduced to construct the particle-like van der Waals state equation.Next,based on stability analysis,the gas-solid phase regulation diagram was used to guide secondary particle design.This allowed attainment of full fluidization in the FB for CVD carbon coating.Agglomeration was suppressed by virtue of stable fluidization.Additionally,high-efficiency mass-and heat-transfer ensured a change from island growth to near-layer growth for carbon deposition onto the surfaces of silicon oxide particles.As a result,uniform deposition of carbon onto silicon oxide was successfully accomplished.Through various electrochemical tests,characterization,and analyses,the as-prepared SiO_(x)@C anode material revealed outstanding cyclability and rate performance.This technology has achieved pilot production volumes at present,and it is expected to gain industrial scale-up to 100 tons in the near future.

关 键 词：气固相结构调控 流化床 化学气相沉积 稳定性分析 二次颗粒 硅氧碳负极 

分 类 号：O646.5[理学—物理化学]