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

Abstract

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.

Si anode with high initial Coulombic efficiency, long cycle life, and superior rate capability by integrated utilization of graphene and pitch-based carbon

“…The results exhibit typical type-IV isotherm, which is indicative of the porous structure. BET analysis indicates the SSA of Si@C/G is only 11.33 m 2 g −1 , which is much smaller than other Si-based anode materials [12][13][14]41]. The smaller SSA of Si@C/G is attributed to the existence of pitch-based carbon, which usually has lesser SSA than hard carbons derived from resins, biomasses, coal as well as small molecular organic compounds.…”