A “three in one” strategy realized using a fluorinated gold-doped titanium silicalite layer on a copper current collector for stable lithium metal batteries

Abstract

The challenging issues for the practical application of lithium metal batteries (LMBs) are the fragile solid-electrolyte interphase (SEI) layer and uncontrollable growth of Li dendrites induced by nonuniform Li deposition. In this work, to enable homogeneous Li deposition and a stable SEI layer, a fluorinated gold (Au) doped titanium silicalite (ATSF) is prepared by a facile synthetic process to modify the Cu current collector for a stable Li metal anode. Driven by the Li affinity of Au nanoparticles and microporous properties of titanium silicalite, uniform Li nucleation and homogeneous Li deposition can be realized on the modified Cu current collector. Simultaneously, the doping of fluorine in ATSF facilitates the formation of the LiF-rich SEI layer for a more stable Li stripping/plating process. Consequently, the ATSF-5/Cu current collector exhibits a high coulombic efficiency (CE) of 96.8% even after 600 cycles and a long-term cycling stability of 1100 h with remarkably low and stable overpotential. When paired with a high-mass-loading LiFePO₄ cathode (∼2.3 mA h cm⁻²), the Li-metal full cell demonstrates an exceptional capacity retention of 97.9% with a high CE of 99.8% after 200 cycles. Furthermore, the LFP full cell with the Li@ATSF-5/Cu anode also displays superior cycling performance under harsh test conditions. This simple current collector modification through constructing a multi-functional zeolite matrix layer provides a new choice for achieving stable cycling performance of LMBs.