MOF in Polymer Electrolytes Raising Ion Transport for Breakthrough Lithium Metal Batteries

SPEs have gained significant attention in lithium metal batteries for enhanced safety. However, low ionic conductivity and dendrite formation limit the performance. To address these limitations, a novel composite-type SPE was developed by incorporating phytic acid(PA)-functionalized ZIF-67 (ZIFP) into （N-Methyl-2-Pyrrolidone）NMP-modified （Poly(vinylidenefluoride-co-vinylchloride-co-vinylidenefluoride)_PVDF-HFP Solid polmer electrolyte(SPE). The 2D HETCOR Nuclear magnetic resonance(NMR) reveals that the oxygen-rich functional groups of PA not only improve the filler-polymer interfacial affinity for the uniform dispersion of ZIFP, but also promote the formation of a hydrogen-bond network with the PVDF-HFP chains, resulting in a consistent, high Li⁺ flux. Moreover, the inherent hierarchical sites and anionic confinement effect of ZIFP, in combination with the solvent-regulating role of NMP, collaboratively enhance the lithium salt dissociation and enable selective Li⁺ transport. Conclusively, the PTN-ZIFP SPE achieves superior ionic conductivity (8.4 × 10^-4 S cm^-1), outstanding critical current density (1.7 mA cm^{- 2}) and stable SEI suppressing lithium dendrites (Li||Li cells exhibit stable cycling for over 2000 h at the current density of 0.1 mA cm^-2). The assembled LFP|PTN-ZIFP|Li cell possesses capacity retentional that achieves 93.2% at 0.5 C after 1000 cycles. This work presents an innovative approach for designing safe and durable solid-state lithium metal batteries.