Rational Modulating Ionic Transportation via Facile ZIF-L/rGO Lamellar Interlayer toward Dendrite-Free Anode for High-Performance Li-Metal Batteries

It is still a huge challenge for lithium metal batteries (LMBs) with high energy density for practical application due to the intractable dendrite-growth issue triggered by inhomogeneous Li deposition as well as the unstable solid electrolyte interphase (SEI). For the purpose of constructing a dendrite-free Li metal anode, herein we designed and fabricated a functional separator (ZIF-L/rGO@PP) by facile vacuum infiltration in order to realize the effective regulation of ion transport. The nanochannels in ZIF-L with polar functional groups promote the uniform Li+ flux and the restricted migration of anions, while the rGO lamella endows the coating with good flexibility by reinforcing the interlayer bonding interactions. Based on the synergistic effects of ZIF-L and rGO, the functional separator exhibited superb electrolyte wettability and a high Li+ transference number of 0.66, ensuring the uniformity of Li+ transmission and thus induced a robust interface of the Li anode. Consequently, the cells with ZIF-L/rGO@PP separators delivered prolonged lifespan over 700 h with a small overpotential of less than 40 mV at 2 mA cm–2. More importantly, the employment of the separator enables Li||NCM811 full cell with enhanced cycling stability even under the limited N/P ratio of 2.5.