Stable Li storage in micron-sized SiOx particles with rigid-flexible coating

• 作者: Ming-Yan Yan Zhu Liu Zhuo-Ya Lu Lin-Bo Huang Ke-Cheng Jiang Hong-Liang Li Sen Xin Quan Xu Yu-Guo Guo
• 来源期刊: 能源化学
• 年，卷（期）: 2022,（1）
• 页码范围: 309-314
• 页数: 6页
• 语种: 英文

摘要

Micrometre-sized electrode materials have distinct advantages for battery applications in terms of energy density,processability,safety and cost.For the silicon monoxide anode that undergoes electro-chemical alloying reaction with Li,the Li (de)intercalation by micron-sized active particles usually accompanies with a large volume variation,which pulverizes the particle structure and leads to rapidly faded storage performance.In this work,we proposed to stabilize the electrochemistry vs.Li of the micron-SiOx anode by forming a rigid-flexible bi-layer coating on the particle surface.The coating con-sists of pyrolysis carbon as the inner layer and polydopamine as the outer layer.While the inner layer guarantees high structural rigidity at particle surface and provides efficient pathway for electron conduc-tion,the outer layer shows high flexibility for maintaining the integrity of micrometre-sized particles against drastic volume variation,and together they facilitate formation of stable solid electrolyte inter-face on the SiOx particles.A composite anode prepared by mixing the coated micron-SiOx with graphite delivered improved Li storage performance,and promised a high-capacity,long-life LiFePO4/SiOx-graphite pouch cell.Our strategy provides a general and feasible solution for building high-energy rechargeable batteries from micrometre-sized electrode materials with significant volume variation.