Comparative Study of Water-Based LA133 and CMC/SBR Binders for Sulfur Cathode in Advanced Lithium–Sulfur Batteries

Abstract

Two most widely used commercial water-based binders, polyacrylic latex (LA133) and sodium carboxymethyl cellulose/styrene butadiene rubber (CMC/SBR), are utilized for constructing sulfur cathodes to investigate their influence on the electrochemical properties of lithium–sulfur batteries. Compared with the CMC/SBR binder, the LA133 binder is found to possess not only higher charge densities (−49.6 versus −38.9 mV) but also better chain flexibility, which promises the homogeneous dispersion of the sulfur–carbon composite cathode materials and ensures an effective conducting framework, resulting in the high utilization of active sulfur. The electrode performance of the batteries further demonstrates that the LA133 cathode with higher dispersion degree delivers lower internal resistance, faster Li-ion diffusion rate, more efficient conversion of sulfur redox, higher reversible capacity (1176.2 versus 867.3 mAh g–1), and better rate capability and electrode stability.