In situ designing an implanted hetero-interface of high adsorption energy in composite lithium anode towards high−rate lithium metal batteries

Abstract

Lithium metal is considered as the ultimate anode material for next-generation Li based battery chemistries. The constituted lithium metal batteries (LMBs) specialize in high energy density, but the inherent dendritic lithium growth as well as the serious proliferation of native solid electrolyte interphase (SEI) have been impeding their practical application, in particular under the high-rate conditions of a more concentrated Li+ flux. Herein, we report a composite anode design, in which LiF/LiC as the products of the in situ spontaneous reductive defluorination between Li and poly(tetrafluoroethylene) (PTFE) are uniformly implanted in bulk metallic Li via facile mechanical kneading. The macroscopical composite anode creates a dispersion of lithiophilic nanodomains microscopically in bulk. The built-in LiF/LiC doping of high Li adsorption energy improves the affinity towards Li+ flux and avoids the Li+-adhesion-induced Li aggregation. The construction facilitates a dense while large granular plating as well as the generation of a thin, inorganic-rich SEI to synergistically ensure a dendrite-free Li deposition behavior. The improved plating reversibility and cycling stability are verified in forms of both symmetric cell under harsh conditions up to 30 mA cm−2@30 mAh cm−2 and high-areal-capacity Li||LiFeO4 full cell for 500 cycles at 3 C. This not only expands the state-of-the-art LMBs under high-loading and power-intensive scenarios, but also preliminarily evidences its scalable and industry-adaptable potential.