A 2D hybrid nanocomposite: a promising anode material for lithium-ion batteries at high temperature†

Abstract

Two-dimensional atomically thick materials including graphene, BN, and molybdenum disulfide (MoS₂) have been investigated as possible energy storage materials, because of their large specific surface area, potential redox activity, and mechanical stability. Unfortunately, these materials cannot reach their full potential due to their low electrical conductivity and layered structural restacking. These problems have been somewhat resolved in the past by composite electrodes composed of a graphene and MoS₂ mixture; however, insufficient mixing at the nanoscale still limits performance. Here, we examined lithium-ion battery electrodes and reported three composites made using a basic ball milling technique and sonication method. The 5% BN-G@MoS₂-50@50 composite obtained has a homogeneous distribution of MoS₂ on the graphene sheet and H-BN with high crystallinity. Compared to the other two composites (5% BN-G@MoS₂-10@90 and 5% BN-G@MoS₂-90@10), the 5% BN-G@MoS₂-50@50 composite electrode exhibits a high specific capacity of 765 mA h g⁻¹ and a current density of 100 mA g⁻¹ in batteries. Additionally, the 5% BN-G@MoS₂-50@50 composite electrode displays an excellent rate capability (453 mA h g⁻¹ at a current density of 1000 mA g⁻¹) at a high temperature of 70 °C, thanks to h-BN that allows reliable and safe operation of lithium-ion batteries. Our research may pave the way for the sensible design of different anode materials, including 2D materials (5% BN-G@MoS₂-50@50) for high-performance LIBs and other energy-related fields.