Enhanced High-Temperature Performances of LiFePO4 Cathode with Polyacrylic Acid as Binder

The electrochemical performance of LiFePO4 at elevated temperature (55°C) is enhanced by using polyacrylic acid (PAA) as a binder. Results show that at 55°C, it can deliver 100 cycles with 97.7% capacity retention and unchanged discharge plateau potential at the current density of 70 mA g−1 (0.5 C), which is much better than the cathode with polyvinylidene fluoride. Scanning electron microscopy studies clearly demonstrate that glue-like PAA coating on the electrodes form a protective film, which may protect the LiFePO4 matrix from the corrosive solution or suppress the dissolution of Fe.