Mechanistic Study on Artificial Stabilization of Lithium Metal Anode via Thermal Pyrolysis of Ammonium Fluoride in Lithium Metal Batteries.

ABSTRACT: The use of the "Holy Grail" lithium metal anode is pivotal to achieve superior energy density. However, the practice of a lithium metal anode faces practical challenges due to the thermodynamic instability of lithium metal and dendrite growth. Herein, an artificial stabilization of lithium metal was carried out via the thermal pyrolysis of the NH₄F salt, which generates HF(g) and NH₃(g). An exposure of lithium metal to the generated gas induces a spontaneous reaction that forms multiple solid electrolyte interface (SEI) components, such as LiF, Li₃N, Li₂NH, LiNH₂, and LiH, from a single salt. The artificially multilayered protection on lithium metal (AF-Li) sustains stable lithium stripping/plating. It suppresses the Li dendrite under the Li||Li symmetric cell. The half-cell Li||Cu and Li||MCMB systems depicted the attributions of the protective layer. We demonstrate that the desirable protective layer in AF-Li exhibited remarkable capacity retention (CR) results. LiFePO₄ (LFP) showed a CR of 90.6% at 0.5 mA cm^-2 after 280 cycles, and LiNi_0.5Mn_0.3Co_0.2O₂ (NCM523) showed 58.7% at 3 mA cm^-2 after 410 cycles. Formulating the multilayered protection, with the simultaneous formation of multiple SEI components in a facile and cost-effective approach from NH₄F as a single salt, made the system competent.

SUBMITTER: Taklu BW 

PROVIDER: S-EPMC11009921 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature