Nano Graphene Shell for Silicon Nanoparticles: A Novel Strategy for a High Stability Rechargeable Battery Anode

Many strategies have been adapted to improve the stability of silicon (Si) based anodes, one of the widely studied methods is to make Si-graphene (Si-Gr) materials, all have adapted the sandwiched structure of Si-Gr or Si-graphene oxide (Si-GO) where Si nanoparticles (NP) are sandwiched between Gr based materials. Herein, we report a simple strategy to achieve Si-Gr based anode with a different structure than that of the intercalated structure, which is expected to provide better stability to the Si-Gr based anode, i.e. a core-shell structure. This core-shell structure based on a Si-nanographene oxide (Si-nGO) delivers an initial reversible specific capacity of similar to 2000 mAhg(-1) and stability of >= 250 cycles with 80% capacity retention at an active material (AM) AM mass loading of 1.5 mg cm(-2), and at similar to 2.0 mg cm(-2), similar to 160 cycles stability was achieved, which is one of the best reported values, meanwhile, intercalated Si-graphene oxide (Si-GO) exhibited only < 50 cycles stability at similar to 2.0 mg cm 2 mass loading. Higher current rate performance of Si-nGO was similar to 70% retention of the initial capacity at 5 C, whereas Si-GO retention was < 25% at 5 C. Thus a change in the structure of Si-Gr based anode has improved the stability remarkably and shows that it is a promising strategy towards achieving electrode material for advanced lithium-ion batteries (LIBs).