Insight into the Mechanism of Improved Interfacial Properties between Electrodes and Electrolyte in the Graphite/LiNi0.6Mn0.2Co0.2O2 Cell via Incorporation of 4-Propyl-[1,3,2]dioxathiolane-2,2-dioxide (PDTD).

4-Propyl-[1,3,2]dioxathiolane-2,2-dioxide (PDTD) has been investigated as an electrolyte additive for the graphite/LiNi0.6Mn0.2Co0.2O2 pouch cell. A significant improvement on the initial Coulombic efficiency and cycling stability has been achieved by incorporating 1.0 wt % PDTD additive. Specifically, initial Coulombic efficiency increased from 83.7% (baseline) to 87.8% (w/w, 1.0 wt % PDTD), and from 75.7% to 83.7% for capacity retention after 500 cycles upon cycling at room temperature. Improvements in the interfacial properties between cathode and electrolyte as well as between anode and electrolyte through incorporation of 1.0 wt % PDTD are believed to account for the observed enhanced cell performance. Insight into the mechanism of improved interfacial properties between electrodes and electrolyte in the graphite/LiNi0.6Mn0.2Co0.2O2 system has been addressed with a combination of theoretical computation and experimental techniques, including electrochemical methods and spectroscopic characterization.