Electrochemical investigation of an artificial solid electrolyte interface for improving the cycle-ability of lithium ion batteries using an atomic layer deposition on a graphite electrode

Electrochemically formed solid electrolyte interfaces (SEIs) are the crucial link between electrolytes and electrodes because they enable several functions in lithium ion batteries, including ionic diffusion, electric conduction, and the safety provided by thermal stability. However, fabricating the electrochemical formed in SEI entails accuracy regarding its architecture to create the specific electrolyte composition that is mutually compatible with the electrode materials. This process, however, is difficult and hinders the industrial application and development of lithium ion batteries. In this study, the atomic layer deposition (ALD) technique is used in artificial SEI fabrication to deposit a metal oxide on the graphite anode's surface. In addition, the effects of the artificial SEI-applied Al2O3 and TiO2 on the charge–discharge performance and cycling behavior at 55 °C were investigated. Electrochemical performance was analyzed by an impedance and cyclic voltammogram to show that an ALD coating of TiO2 provides crucial functions for graphite. The results indicated that the TiO2 coating increased the graphite capacity by 5% and limited the formation of electrochemically formed SEIs. In addition, the TiO2-coating graphite with ALD improved thermal stability and greatly enhanced long-term cycle ability at 55 °C. ► The artificial SEI layer is fabricated by atomic layer deposition (ALD). ► The artificial SEI is used to prevent the decomposition at high temperature of the electrolytes. ► The battery that used the ALD-TiO2-coated graphite showed excellent cycle retention at 55 °C.