Preparation of high-purity straight silicon nanowires by molten salt electrolysis  

作　　者：Jie Zhang Sheng Fang Xiaopeng Qi Zhanglong Yu Zhaohui Wu Juanyu Yang Shigang Lu 

机构地区：[1]General Research Institute for Nonferrous Metals,Beijing 100088,China [2]China Automotive Battery Research Institute Co.,Ltd,Beijing 100088,China

出　　处：《Journal of Energy Chemistry》2020年第1期171-179,I0006,共10页能源化学（英文版）

基　　金：financially supported by the National Key R&D Program of China (No. 2016YFB0100400);the National Natural Science Foundation of China (No. 51604032)

摘　　要：Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly process.Using nickel formate as a metal catalyst precursor,straight silicon nanowires(65–150 nm in diameter)were directly prepared by electrolysis from the Ni/SiO2 porous pellets with 0.8 wt%nickel content in molten CaCl2 at 900℃.Benefiting from their straight appearance and high purity,the silicon nanowires therefore offered an initial coulombic efficiency of 90.53% and specific capacity of 3377 m Ah/g.In addition,the silicon nanowire/carbon composite exhibited excellent cycle performance,retaining 90.38%of the initial capacity after 100 cycles.Whilst further study on the charge storage performance is still ongoing,these preliminary results demonstrate that nickel formate is an efficient and effective metal catalyst precursor for catalytic preparation of high purity straight silicon nanowires via the molten salt electrolysis,which is suitable for large-scale production.Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly process. Using nickel formate as a metal catalyst precursor, straight silicon nanowires（65–150 nm in diameter） were directly prepared by electrolysis from the Ni/SiO2 porous pellets with 0.8 wt% nickel content in molten CaCl2 at900 °C. Benefiting from their straight appearance and high purity, the silicon nanowires therefore offered an initial coulombic efficiency of 90.53% and specific capacity of 3377 m Ah/g. In addition, the silicon nanowire/carbon composite exhibited excellent cycle performance, retaining 90.38% of the initial capacity after 100 cycles. Whilst further study on the charge storage performance is still ongoing, these preliminary results demonstrate that nickel formate is an efficient and effective metal catalyst precursor for catalytic preparation of high purity straight silicon nanowires via the molten salt electrolysis, which is suitable for large-scale production.

关 键 词：Silicon nanowires Electrochemical reduction Silicon dioxide Nickel formate 

分 类 号：TM912[电气工程—电力电子与电力传动] TB383.1[一般工业技术—材料科学与工程]