Improved electrochemical performance of sulphur cathodes with acylated gelatine as a binder

Abstract

Acylated gelatine has been successfully used in the sulphur cathode for a Li/S battery. The results indicated that acylated gelatine could effectively constrain the resolution of polysulphide into the electrolyte because of carbonyl groups' strong affinity for polysulphide. Meanwhile it also served as a strong dispersion and adhesion agent for the cathode materials. Cyclic voltammograms and electrochemical impedance spectroscopy experiments showed that the prepared cathodes have less polarization and lower transfer resistance compared to gelatine binder-sulphur cathode. The prepared cathode exhibited a much higher initial and reversible capacity after 100 cycles at rates of 0.1 and 0.5 C than that of gelatine binder-sulphur cathode under the same condition. Our findings have shown that acylated gelatine is a promising binder to improve Li–S performance and helpful for its future development.