PEDOT:PSS coating on pristine and carbon coated LiFePO4 by one-step process: the study of electrochemical performance

The carbon coating on lithium iron phosphate (LiFePO4) is well known process to improve the electrical conductivity of non-conductive LiFePO4 (LFP). But due to complex process of carbon coating at high temperature, herein, we report study on poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) water soluble conducting polymer coated pristine LFP as well as carbon coated LFP (LFP/C) prepared by simple one step process. PEDOT:PSS coating has played very important role in enhancing the electrochemical performance of Li-ion battery as well as electrical conductivity of LFP and LFP/C samples. The electrical conductivity of PEDOT:PSS coated LiFePO4 samples is increased by many folds (10(4)-10(8)) as compared to pristine and carbon coated LFP. The study reveals that different optimum amount of PEDOT:PSS say 10 wt% and 5 wt% is required for best electrochemical performance of pristine LFP and LFP/C, and samples are designated as LFP-10P and LFP/C-5P respectively. Sample LFP-10P has shown discharge capacity of 140.8 mAhg(-1) whereas LFP/C-5P shown 154.6 mAhg(-1) at current rate of 0.1C. The same samples have shown highest capacity retention of 92% and 96% respectively after 200 cycles, in their group.