Highly durable 3D conductive matrixed silicon anode for lithium-ion batteries

Abstract

Silicon is a strong candidate for next generation Li-ion batteries due to its high lithium storage capacity. However, to overcome electrode degradation caused by large volumetric changes during battery cycling, prohibitively expensive nanoscale synthesis techniques are typically required. To address this challenge, a low-cost methodology using fluid-induced fracture (FIF) is developed for accelerated nanoscaling of commercial micron-sized silicon and an electrode level thermolysis process is applied for the cyclization of polyacrylonitrile (cPAN) binder to form a 3D conductive anode matrix with micro-channels. This engineered matrix sandwiches the silicon particles leading to an electrode structure with incredible mechanical robustness which can accommodate the large volumetric changes occurring during battery charging and discharging. Thus, it can deliver an excellent capacity of 3081 mAh g−1 at 0.1 A g−1 and good cycle life (1423 mAh g−1 @ 2 A g−1 after 500 cycles). Furthermore, the simplicity and scalability of this approach provides a promising path forward for the commercialization of next generation Li-ion batteries based on high capacity silicon anodes.