Uniform Poly(vinyl ethylene carbonate) based metal-organic framework separator for smooth lithium-ion electrodeposition

Nanoporous feature in Metal-Organic Frameworks (MOFs) could tune Li+-solvated species and provide high potential for stabilizing lithium metal anodes. However, the inevitable voids within MOF crystallites accommodating free liquid electrolyte, which re-solvates Li+-solvated compounds and vanishes nanopores' advantage for controlling Li+-solvates. Herein, we report an in-situ carbonate photopolymerization reaction within MOF channel that constitutes a uniform nanoporous separator (PVEC-MOF) for smoothing Li+ electrodeposition. PVEC-MOF membrane exhibits accelerating lithium-ion conduction and superior electrochemical performance according to the interconnected ionic nano-channels, whose overpotential maintains at about 0.01 V after 600 cycles in Li-symmetric cell without forming lithium dendrite. Furthermore, employing PVEC-MOF separator in high-voltage cathode material (LiNi0.6Co0.2Mn0.2O2) based Li-metal batteries could effectively enhance electrochemical property and prolong cycling lifespan. This work provides a novel strategy to convert traditional MOF family into uniform nanoporous lithium-ion battery separator, which promotes Li+ smooth electrodeposition and inhibits lithium dendrites in high-energy-density lithium-metal batteries.