© 2020 Elsevier Ltd Compared with traditional lithium ion anode materials, copper sulfide has received extensive attention due to its high electrical conductivity and excellent electrochemical reversibility. However, it has poor cycle stability and rate performance under certain conditions. An important factor affecting the electrochemical performance of copper sulfide, that is, the composition of the electrolyte, has been neglected. In this work, the authors studied the effect of ether-based electrolyte composition on electrochemical performance by quasi-in situ XRD combined with XPS analysis, cyclic voltammetry and GITT tests. The results show that different electrolyte components not only affect the diffusion coefficient and overcharge behavior in the electrochemical process of copper sulfide but also affect the phase transition process.