High energy density lithium-ion pouch cell with modified high voltage lithium cobalt oxide cathode and graphite anode: Prototype stabilization, electrochemical and thermal study

Abstract

5G capable smart, lightweight, big-screen portable devices with a long standby time have growing demand as information and network technology developed. Lithium cobalt oxide, LiCoO2 (LCO) cathode material is extensively utilized in the portable electronics industry and needs further improvement. Here, a strategy to develop a high energy and high voltage 2 Ah (Amp-hour) LIBs (lithium-ion batteries) pouch cell is planned and excecated. The observed energy density of the designed cell is ∼248 Wh/kg (∼740 Wh/L) using graphite as a negative electrode and modified high voltage LCO (i.e., Li2CoMn3O8 (lithium cobalt manganese oxide) coated LCO), as a cathode with an areal capacity of ∼4.9 mAh/cm2. The developed pouch cells have cycled at a high rate (1C; up to 1000 cycles) and showed a minimum self-discharge rate (∼0.05% decay per day). An in-situ thermal mapping experiment and corresponding simulation analysis have been performed on the pouch cells at different charge and discharge stages to compare the thermal behavior. Furthermore, the effect of temperature on the SEI/CEI (solid electrolyte interface/cathode electrolyte interface) formation has been investigated by electrochemical impedance spectra (EIS) through MATLAB-based distribution of relaxation times (DRT) tool and understand different micro phenomena. The current approach may help in future generation LCO-based battery development.