Novel Design and Scalable Synthesis of Silicon Anodes for High-Energy Lithium-Ion Batteries

As the world races toward achieving net-zero emissions by 2050, there will inevitably be a surge in demand for high-energy batteries. Silicon is one of the most promising anode materials for next-generation lithium-ion batteries because it possesses a theoretical specific capacity that is almost ten times higher than that of the current graphite anode. However, silicon-based anodes usually suffer from a short cycle life due to the particle pulverization caused by the substantial volume change of Si (~300%) during the lithiation and delithiation process. To improve the cyclability of silicon anodes, we developed a novel scalable process for synthesizing bulk-core, porous-shell silicon that can alleviate the detrimental effects caused by volume expansion. By precisely controlling the processing parameters, both the size of the bulk core and the thickness of the porous shell can be tailored. The silicon with novel structure exhibits excellent electrochemical performances, much greater than 3D porous and bulk silicon counterparts. To further enhance the cycling performance of silicon, carbon coating was implemented via polydopamine precursor. The resulting Si-C composites showed good cycling performance up to 500 cycles. Our research offers a novel, scalable, low-cost production route for silicon anodes for high-energy lithium-ion battery applications.