PEDOT Coating Improves Thermal Stability in Charged LiCoO2 Li-Ion Cathodes When Exposed to 1.0 M LiPF6 1:1 EC:DEC Electrolyte

Lithium-ion battery (LIB) thermal stability is conceivably improvable with various cathode surface coatings. In this study, LiCoO2 (LCO) cathode composites were coated with a thin layer of poly(3,4-ethylenedioxythiophene) (PEDOT) polymer coating, electrochemically charged, carefully transferred to differential scanning calorimetry (DSC) capsules to prevent disturbance to electrolyte and film structure, and evaluated for thermal reactivity. DSC showed that PEDOT reduces the heat release of LCO and electrolyte decomposition reactions between 150 and 400 °C by nearly 75%, and this reductivity is mostly unaffected by electrolyte content. The tendency for PEDOT to stabilize LCO thermal reactivity indicates that PEDOT may be an effective thermal runaway suppressant in full cell LIB designs.