Water-Soluble Polyacrylic Acid as a Binder for Sulfur Cathode in Lithium-Sulfur Battery

Abstract

Polyacrylic acid (PAA) as a binder in the aqueous solvent is applied in the preparation of sulfur cathode for lithium-sulfur battery. Electrochemical performances are investigated by a charge-discharge cycle test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV and EIS tests indicate that the PAA sulfur cathode has smaller resistance and better kinetics characteristics than that of the poly(vinylidene fluoride) (PVDF) sulfur cathode using PVDF as a binder in N-methy-2-pyrrolidone (NMP) solvent. The charge-discharge tests show that the discharge capacity and the coulombic efficiency of the PAA sulfur cathode are 325 mAh g−1 and 89.5% at the 50th cycle at the current density of 335 mA g−1. Compared with the PVDF sulfur cathode, the PAA sulfur cathode shows considerably a better cyclability. These results show that the PAA binder has great potential for lithium-sulfur battery applications.