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

Abstract

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@SnO 2 nanosheets aerogel (rGO@SnO 2 NSA) based on in-situ growing two-dimensional (2D) SnO 2 nanosheets on graphene oxide (GO@SnO 2 NS), subsequent controllable assembly and reduction. The 2D structure of SnO 2 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 LiFePO 4 /rGO@SnO 2 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. The rGO@SnO 2 NSA based on in-situ growing two-dimensional (2D) SnO 2 nanosheets on GO, subsequent controllable assembly and reduction realizes a combination of high capacity and long-term cycling performance even at ultrahigh current density when used as anodes in LIBs, which have rarely been achieved in previous reports. This aerogel shows great potential in applications of LIBs to obtain stable and long-term fast charge/discharge. • 3D porous aerogels assembly based on rGO and ultrathin SnO 2 nanosheets achieve high content of SnO 2 and fully help SnO 2 nanosheets to fit the 3D porous architecture. • Excellent capacity and long-cycling performances at 10 A g -1 with long cycling life (10000 cycles). • Unique construction contributes to superior capacitive contribution and the stability of the structure of the electrode during the high-rate charge/discharge.