The Influence of Silicon Anode Morphology on Energy Storage Performance in Lithium Batteries

In recent years, energy crises and environmental pollution are intensifying all the time so that traditional fossil fuels is gradually replaced by electricity energy. Therefore, lithium batteries due to their high energy density and long cycle life, have become a crucial energy storage technology in the energy transition. Among all components of lithium batteries, anode material is so important that it can directly influence the energy density and cycling performance. Researchers used to pick carbon as traditional anode material, however, it unable to meet the demands for increasingly high performance of the batteries. Therefore, silicon has become ideal next-generation anode material for its theoretical specific capacity of 36004200 mAhg, abundant resources, and low cost. The problem is that silicon exhibits 300400% volume expansion during charge-discharge cycles, leading to electrode structural damage, repeated SEI film formation, and reduced initial coulombic efficiency. This paper systematically analyzes the lithium storage mechanisms and several difficulties of the performance of silicon anodes through a literature review, focusing on comparing silicon nanomaterials with different morphologies, including silicon nanoparticles, silicon nanotubes, nano porous bulk silicon, and silicon nano films. The results indicate that nano structure and composite materials can effectively alleviate volumetric stress, stabilize interfaces, and improve rate performance, but several problems are still needed to be solved, such as initial coulombic efficiency, packing density, and preparation costs. This study integrates the relationship between morphology and energy storage performance of four common nano silicon materials and helps the researchers to develop better lithium batteries.