One-step in situ encapsulation of Ge nanoparticles into porous carbon network with enhanced electron/ion conductivity for lithium storage

Germanium (Ge) is considered to be one of the most promising anode materials due to the high theoretical capacity and excellent rate capability. However, its further development is hindered by the poor cycling stability caused by the severe volume change. Herein, we demonstrate a one-step in situ synthesis of Ge nanoparticles embedded into porous carbon framework (PC@Ge) using a facile sacrificial template method via the introduction of poly(methyl methacrylate) and subsequent thermal treatment. This unique nanoarchitecture not only enhances lithium-ion diffusivity and electron conductivity, but also effectively buffers the huge volume expansion and protects the Ge nanoparticles from cracking and aggregation during the cycling. Consequently, the as-prepared PC@Ge electrode exhibits superior capacity retention of 75% and 87% over 1000 cycles at 1.0 and 2.0 A.g(-1), respectively. Graphic abstract