Constructing crosslinked lithium polyacrylate/polyvinyl alcohol complex binder for high performance sulfur cathode in lithium-sulfur batteries

High loading sulfur cathode is a vital ingredient for the application of high-energy-density Li-S battery. However, the traditional PVDF binder with inherent defects, such as relatively weak adhesion, inferior Li+ conduction, and poor polysulfides adsorption, is not suitable for sulfur cathode, especially at high sulfur loading. Herein, the multifunctional LiPAA/PVA binder with crosslinked three-dimensional structure was proposed to substitute PVDF binder. Benefiting from the effective polysulfides adsorption and successful conduction of electron and Li+, the sulfur cathode with LiPAA/PVA binder exhibited superior rate and cycle performance. Even at high sulfur loading of 4.0 mg/cm2, the LiPAA/PVA based cathode also shows a highest areal capacity of 3.03 mA h/cm2, matching the requirement for high energy density of Li-S battery. Additionally, owing to the low price and water solubility of LiPAA and PVA, the fabrication of LiPAA/PVA based cathode could be finished through an low-cost and environmentally friendly process, demonstrating the potential of LiPAA/PVA binder to realize high loading sulfur cathode in the field of large-scale Li-S battery.