Water lily seed-inspired silicon/carbon composite anode synthesis for high-performance Li-ion battery

Abstract

Alternative materials for lithium-ion batteries (LIBs) are studied due to the increasing demand for high-performance energy storage systems for electric cars. Silicon is a powerful candidate as an anode material for LIBs, and silicon-carbon composites with void space were reported to improve battery cyclability thanks to their original structure. Nonetheless, the production of silicon-carbon composite with void space needs chemical etching which contains harmful and dangerous chemicals. In this study, silicon-carbon composite with void space (Si/void/C), inspired by water lily seed is prepared with the polymer coating method instead of chemical etching. The multiple silicon particles are polymer-coated rather than individual silicon particles to achieve a more compact structure. Polymethyl methacrylate is sacrificed to form a void space, and conductive carbon acetylene black (AB) is introduced in this void space. The carbon layer is achieved from the carbonization of iodine and heat-treated polyvinyl alcohol that is also investigated step-by-step with Fourier-transform infrared spectroscopy and thermogravimetric analysis. The prepared silicon-carbon composite anode (Si/void/AB/C) presents a high reversible capacity after 400 cycles and high coulombic efficiency. This study paves the way for the industrialization of high-performance silicon-based anode for LIBs. [GRAPHICS] .