Cationic Metal–Organic\nFramework Arrays to\nEnable Dendrite-Free Lithium Metal Anodes

Abstract

The\nsevere safety issues caused by uncontrolled lithium (Li) dendrite\ngrowth hinder the practical application of Li metal anodes. Herein,\nwe designed cationic metal–organic framework arrays on nickel\nfoam (NF–CMOF) as a multifunctional current collector for dendrite-free\nLi metal anodes. The cationic MOF (CMOF) was synthesized by grafting\nbis(trifluoromethane)sulfonimidate (TFSI) functional groups on the\nMOF nanosheets via a facile hydrothermal method. The high surface\narea, good lithiophilicity, and positively charged properties of CMOF\nnanosheets effectively facilitate uniform Li deposition. In addition,\nthe porous array structure acts as the host to accommodate deposited\nLi at a low areal capacity. Furthermore, the CMOF with grafted TFSI\ngroups induces the formation of a LiF/Li₃N-rich solid electrolyte\ninterphase, which further guarantees uniform Li deposition at high\nareal capacity. The full cells with Li predeposited NF–CMOF\n(Li@NF–CMOF) anodes maintained a high-capacity retention over\n1000 cycles and achieved an enhanced rate capability at 10 C.