Long-Term Stable Hollowed Silicon for Li-Ion Batteries Based on an Improved Low-Temperature Molten Salt Strategy

Nanostructured hollow silicon has attracted tremendous attention as high-performance anode materials in Li-ion battery applications. However, the large-scale production of pure hollowed silicon with long cycling stability is still a great challenge. Here, we report an improved low-temperature molten salt strategy to synthesize nanosized hollowed silicon with a stable structure on a large scale. As an anode material for rechargeable lithium-ion batteries, it exhibits a high capacity, excellent long cycling, and steady rate performance at different current densities. Especially, a high reversible capacity of 2028.6 mA h g^-1 at 0.5 A g^-1 after 150 cycles, 994.3 mA h g^-1 at 3 A g^-1 after 500 cycles, and 538.8 mAh g^-1 at 5 A g^-1 after 1200 cycles could be obtained. This kind of nanosized hollowed silicon can be applied as a basic anode material in silicon-based composites for long-term stable Li-ion battery applications.