PEDOT:PSS-assisted interfacial stabilization of Li-rich NMC cathodes for high-performance lithium-ion batteries

There is a pressing need to develop lithium and manganese-rich layered oxides (Li-rich NMCs), such as Li1.2Ni0.16Co0.08Mn0.56O2, as potential cathode materials. However, they possess disadvantages such as protracted voltage loss (voltage decay), limited rate performance, and interfacial instability. In this work, we define the synthesis and electrochemical characterization of a surface coating of PEDOT:PSS on the Li-rich NMC (PEDOT:PSS@Li-richNMC) cathode material. The PEDOT:PSS on the surface of Li-rich layered oxide enhanced interfacial electronic conductivity and the stability of CEI layers while allowing the retention of redox reversibility. The electrochemical testing of the composite cathode shows improved initial capacity (295.2 mAh g−1 at 0.1C), rate capability, and long-term cycling stability (97% capacity retention upon 200 cycles at 2C) compared to pristine Li-rich NMC. Through EIS, reduced charge transfer resistance and an increased Li+ diffusion coefficient were found for the cycled cells with the PEDOT:PSS@Li-rich NMC surface-engineered conductive polymer coatings, making them suitable as cathodes for high-energy LIBs.