Impact of polypyrrole coating on the electrochemical properties of Li1.04Fe0.3Mn0.7PO4 cathode materials

Abstract

In this work, polypyrrole (PPy) was used to modify Li_1.04Fe_0.3Mn_0.7PO₄ cathode materials and improve their conductivity. This study found that PPy could form a coating layer and conductive network on the material surface and effectively enhance the conductivity of the material as well as stability of the electrolyte interface. When the amount of PPy addition was 2%, the capacity retention rate at 0.2C and 20 °C was 98.6% after 500 cycles, and the capacity retention rate at −15 °C was 89.0% after 200 cycles. The capacity retention rate of the 2% PPy coated Li_1.04Fe_0.3Mn_0.7PO₄ sample was 20.4% higher than that of the pure Li_1.04Fe_0.3Mn_0.7PO₄ sample after 200 cycles at −15 °C.