Abstract
High-energy-density Li-CO(2) batteries are promising candidates for large-capacity energy storage systems. However, the development of Li-CO(2) batteries has been hindered by low cycle life and high overpotential. In this study, we propose a CO(2)-based thermoplastic polyurethane (CO(2)-based TPU) with CO(2) adsorption properties and excellent self-healing performance to replace traditional polyvinylidene fluoride (PVDF) as the cathode binder. The CO(2)-based TPU enhances the interfacial concentration of CO(2) at the cathode/electrolyte interfaces, effectively increasing the discharge voltage and lowering the charge voltage of Li-CO(2) batteries. Moreover, the CO(2) fixed by urethane groups (-NH-COO-) in the CO(2)-based TPU are difficult to shuttle to and corrode the Li anode, minimizing CO(2) side reactions with lithium metal and improving the cycling performance of Li-CO(2) batteries. In this work, Li-CO(2) batteries with CO(2)-based TPU as the multifunctional binders exhibit stable cycling performance for 52 cycles at a current density of 0.2 A g(-1), with a distinctly lower polarization voltage than PVDF bound Li-CO(2) batteries.