Synthesis of heterointerfaces in NiO/SnO coated nitrogen-doped graphene for efficient lithium storage.

Currently, it remains a challenge to make comprehensive improvements to overcome the disadvantages of volume expansion, LiO irreversibility and low conductivity of SnO. Heterostructure construction has been investigated as an effective strategy to promote electron transfer and surface reaction kinetics, leading to high electrochemical performance. Herein, NiO/SnO heterojunction modified nitrogen doped graphene (NiO/SnO@NG) anode materials were prepared using hydrothermal and carbonization techniques. Based on the excellent structural advantages, sufficiently small NiO/SnO heterojunction nanoparticles increase the interfacial density to promote LiO decomposition, and the built-in electric field accelerates the charge transport rate to improve the conductivity. The three-dimensional porous graphene framework effectively mitigates volume expansion during cycling and stabilizes the reactive interface of electrode materials. The results show that the NiO/SnO@NG mixture has high reversible specific capacity (938.8 mA h g after 450 cycles at 0.1 A g), superior multiplicity performance (374.5 mA h g at 3.0 A g) and long cycle life (685.3 mA h g after 1000 cycles at 0.5 A g). Thus, this design of introducing NiO to form heterostructures with SnO is directly related to enhancing the electrochemical performance of lithium-ion batteries (LIBs).