Polymeric ionic liquid as binder: A promising strategy for enhancing Li–S battery performance

The development of the most promising next-generation Li–S batteries with an improved cyclability is one of the greatest challenges nowadays. In this sense, here, a novel imidazolium-based polymeric ionic liquid (PVI₁₀Cl) was successfully synthesized and integrated into a high-performing sulfur cathode. The lithium polysulfide trapping ability of PVI₁₀Cl was confirmed, which helps to accelerate conversion kinetics. This synergetic effect leads to enhanced C-rate response, improving the discharge capacities and reducing the overpotentials even at 1C in comparison with conventional PVdF binder. These features also allow cells to be operated for 100 cycles with excellent capacity retention. All in one, while conventional binders are viewed only as a “glue” to hold the active material together, it has been shown that PVI₁₀Cl binder has additional functions and plays an active role during Li–S battery operation.