Copper-nickel MOF-coated electrospun polyacrylonitrile membranes for Li-S batteries: Mitigating the shuttle effect and enhancing stability

Cu-Ni MOF nanoparticles were synthesized as coating materials for lithium-sulfur battery membranes, and the performance of batteries employing Cu-Ni MOF/PAN (CNMP) electrospinning membranes were examined. The modified membrane efficiently suppresses the shuttle effect, leveraging the synergistic catalysis and adsorption capabilities of the Cu-Ni MOF nanoparticles. The modified membrane exhibited relatively high porosity and outstanding electrolyte absorption capacity. The CNMP membrane battery demonstrated a remarkable first-cycle discharge capacity of 1529 mA h g(-1). The battery maintained an exceptional discharge capacity with 85.2 % retention and a minimal capacity decay rate of just 0.074 % per cycle after 200 cycles at 0.5 C. The capacity retention of the modified membrane battery remained at 74.6 % even after 2000 cycles at 2 C. The excellent performance of the modified membrane battery was due to the physical entrapment and strong chemical adsorption of lithium polysulfides by Cu-Ni MOF nanoparticles, significantly preventing the shuttle effect and facilitating rapid oxidation-reduction kinetics based on strong catalytic conversion.