Enhanced Na-ion storage via creating smooth ions transportation pathways in a modified heterostructure

Abstract

Sodium-ion batteries (SIBs) have drawn evolutionary attention due to the urgent requirements for renewable energy storage. Unfortunately, the cycle stability and rate capability of promising SnO2 materials are far from satisfactory. Herein, enhanced Na-ion storage via creating smooth ion transportation pathways in a modified heterostructure has been originally demonstrated. The tuned composite of uniformly dispersed SnO2 particles anchored on the surface of graphene nanosheets was prepared via a facile hydrothermal treatment with the help of iodine. Inspiringly, an anticipated Na-ion storage can be successfully achieved, with reversible Na-ion storage of 486.1 mA h g−1 at 50 mA g−1 and rate capability of 343.8 mA h g−1 even at 800 mA g−1. The exceptional electrochemical property profited from the synergistic effect of the heterostructure with plentiful ion transportation pathways for fast Na-ion diffusion. This work opens a practical opportunity for the design of next-generation rechargeable batteries in energy storage.