Three-dimensional porous aerogel assembly from ultrathin rGO@SnO2 nanosheets for advanced lithium-ion batteries

High capacity, ultra-fast charge/discharge rate, and long cycling life are external targets for Lithium-ion batteries (LIBs) to satisfy modern energy storage, but it is still challenging to realize them simultaneously. Here, we report a three-dimensional (3D) porous rGO@SnO2 nanosheets aerogel (rGO@SnO2 NSA) based on in-situ growing twodimensional (2D) SnO2 nanosheets on graphene oxide (GO@SnO2 NS), subsequent controllable assembly and reduction. The 2D structure of SnO2 can shorten the electron-transfer path, and the porous architecture of the 3D aerogel endows the aerogels with external ion-transfer channels and exceptional capacitive contribution. As a result, the LIBs using our 3D aerogels as anodes can endure ultrafast charge/discharge (10 A g(-1)) rate and exhibit ultra-long cycling life with a high energy density (512.1 mAh g(-1) after 10,000 cycles). For application exploration, the LiFePO4/rGO@SnO2 NSA cell also possesses excellent energy storage performance (364.5 mAh g(-1) after 100 cycles). Our electrode design strategy of combining 2D active materials and 3D porous architecture provides a new path to develop next-generation rechargeable energy storage devices.