Reasonable control of cut-off voltage to achieve stable lithium metal anode

Uneven lithium deposition leading to lithium dendrite growth severely hampers the application of lithium-metal batteries. Modifying the collector with lithiophilic materials helps improve lithium deposition. For lithophilic materials to modify the collector, the choice of cut-off voltage is very important. While excessively high cut-off voltages may compromise the stability of the modified layer and consequently disrupt ordered lithium deposition, conventional approaches typically employ lower cut-off voltages (particularly 0.1 V) to maintain modification layer stability. However, the 0.1 V cut-off voltage results in incomplete lithium stripping from the lithiophilic material surface. This phenomenon significantly diminishes the lithiophilic properties of the modified layer and consequently leads to substantial nucleation overpotential. Here, we propose to use a moderate cut-voltage stimulation effect to slow down the interfacial shielding effect of residual lithium metal on lithiophilic materials. By optimizing the cut-off voltage for the Cu@Sb₂S₃ collector, the stability of the modified layer can be preserved while enabling the complete stripping of lithium metal from the surface of the lithophilic material. The asymmetric cell received the highest Coulombic efficiency (CE) when the lithium stripping cut-off voltage was set at 0.5 V relative to 0.1 and 2.0 V. At a current density of 1 mA cm⁻² and a deposition capacity of 1 mA h cm⁻², the CE remained 98.6% at a cut-off voltage of 0.5 V after 140 cycles in an ether electrolyte without lithium nitrate.