Sodium chloride template-assisted synthesis of silicon/carbon anode nanocomposites for lithium-ion batteries

Abstract

The rapid capacity decay of silicon anodes is a significant challenge in the effort to replace graphite in lithium-ion batteries. To address this issue, it is crucial to integrate sufficient engineered void space within the silicon composites and to effectively and uniformly coat the particles with carbon. Herein, we propose a straightforward method to address both concerns. The template synthesis approach, utilizing sodium chloride as a sacrificial template, creates an internal void network, while a double carbon coating with pyrrole enhances electrical conductivity and stabilizes the microstructure. A single pyrrole carbon coating on the silicon anode yields a delithiation capacity of 480 mAh g⁻¹. However, when an additional carbon layer is applied, the delithiation capacity increases significantly, reaching up to 670 mAh g⁻¹ after 180 cycles. This indicates that the additional carbon layer not only enhances the electrical properties but also provides structural support, resulting in improved performance and longevity of the silicon anode. The synthesis strategy presented here has the potential to significantly improve the performance of silicon-based anodes, paving the way for the development of advanced silicon materials for the next generation of lithium-ion batteries. This method offers a promising solution to one of the major challenges in battery technology, providing a pathway towards higher capacity and more stable battery systems.