Electrochemical performance study of novel chlorosulfonated polyethylene electrode binder for LiFePO4 cathode

Abstract

Polyvinylidene fluoride (PVDF) is a kind of traditional binder for positive or negative electrode of lithium battery. However, the high cost and moisture sensibility of PVDF are the two main drawbacks in practical application. In this work, we provided a novel binder chlorosulfonated polyethylene (CP) for positive electrode of lithium battery, which can also be used for anode. Binders for cathodes are usually the same as for anodes. In addition, this binder is much cheaper and insensitive to moisture. The superficial morphologies of electrodes with chlorosulfonated polyethylene and polyvinylidene fluoride were characterized by SEM. ATR-FTIR was used to reflect the chemical composition of the electrode with chlorosulfonated polyethylene binder. The electrochemical performances were tested by electrochemical workstation and battery tester. According to the results of electrochemical test, the half-cell with chlorosulfonated polyethylene binder presented relatively comparable electrochemical performances with the half-cell of PVDF binder, such as potential-capacity tests, discharge capacity tests of different rate and cycle charge-discharge tests. Besides, in potential-capacity tests, the half-cell with chlorosulfonated polyethylene binder exhibited 140 mAh/g capacity which is 7.7 % higher than that of the half-cell with PVDF binder. The CP binder may be the candidate for PVDF binder in future application.