Rational design of robust nano-Si/graphite nanocomposites anodes with strong interfacial adhesion fo

• 作 者: Yuantao Yan Xiaoli Zhao Huanglin Dou Jingjiang wei Wanyu Zhao Zhihua Sun Xiaowei Yang
• 机 构: School of Materials Science and Engineering, Tongji University, Shanghai 200123, China;School of Mat
• 出 处: 中国化学快报（英文版）
• 发表日期: 2021年2期
• 关键词: Nano-silicon Graphite Interfacial adhesion Initial Coulombic efficiency Lithium-

The nano-Si/graphite nanocomposites are the promising anodes candidates for high-energy lithium-ion batteries because of their high theoretical capacities and low volume variations.However,the nano-Si has a severe tendency to separate from the graphite substrate due to the inherently weak bonding between them,thus leading to the deteriorated cycling performance and low Coulombic efficiency.Herein,we design a robust nano-Si/graphite nanocomposite structure with strong interfacial adhesion caused by the Si-Ti and Ti-C covalent bonds.The abundant Si-Ti and Ti-C bonds formed between nano-Si and graphite greatly enhance the interfacial adhesion force,resulting in the highly stabilized and integrated electrode structure during battery cycling.Consequently,the as-obtained nano-Si/graphite anodes deliver a high capacity retention of 90.0％ after 420 cycles at 0.5 C with an average Coulombic efficiency of 99.5％;moreover,a high initial Coulombic efficiency of 90.2％ is achieved.Significantly,this work provides a novel strategy to address the poor interfacial adhesion between nano-Si and graphite,which can be applied to other nano-Si based composites anodes.