Water Reducer: A Highly Dispersing Binder for High‐Performance Lithium‐Sulfur Batteries†

Abstract

Main observation and conclusionSulfur has been paid close attention by the research and manufacturing as a cathode material for lithium‐sulfur batteries (LSB) in recent decade because it has high specific capacity and low cost. But the low utilization of active materials and serious shuttle phenomenon inhibit its commercialization process. In this work, for the first time, water reducers are reported as multifunctional binders to address the above problems to enhance the performance of LSB. Due to the synthetic actions of the water reducer binder, such as highly dispersing effect and good chemical trapping function, commercial sulfur powders are directly used as cathodes, and much better electrochemical performance compared to using the conventional binder polyvinylidene fluoride (PVDF) was obtained, among which the sulfur cathode with sulfonated melamine formaldehyde (SMF) water reducer binder exhibits a high reversible capacity of 625.5 mA·h·g–1 after 200 cycles at 1 C and the cathode with polycarboxylic acid (PC) water reducer binder even demonstrates a high area specific capacity of 5 mA·h·cm–2 at high sulfur loading of 5 mg·cm–2. These low‐cost water reducers are a promising binder for LSB in the future.