Laser-assisted copper oxidation to enhance electrochemical performances of lithium-metal anode-less batteries

Anode-less lithium metal batteries (ALLMBs) have been considered promising candidates for future energy storage applications because of their high energy density and simplified manufacturing. However, issues in lithium dendrite formation and capacity degradation prevent their practical application. This study introduces a novel, reagent-free approach for enhancing ALLMBs performance through laser-induced copper oxidation under ambient conditions to create precisely controlled CuOx surface layers on the copper current collector (CC). The oxidized surface converts to Li₂O in the first charge, forming a stable artificial solid electrolyte interphase (SEI), that enables uniform lithium deposition with reduced nucleation overpotential. Electrochemical tests show Cu_LS1000 optimally balances conductivity and oxide for better Coulombic efficiency (CE) and cycling stability. Specifically, the Cu_LS1000 exhibited higher CE in half-cells and higher capacity retention compared to unprocessed copper. Full-cell testing with lithium iron phosphate (LFP) cathodes validated improved rate capability at low to moderate current densities. Excessive oxidation (Cu_LS300) compromised cycling stability due to higher polarization and lithium consumption during initial activation. This work proves that laser-assisted copper oxidation is a scalable and environmentally friendly technique to address the critical limitations of ALLMBs. The approach underlines the potential of laser-engineered CCs, enabling safer and more efficient anode-less battery technologies.