Laser-Induced Copper Oxidation for Improved Performance in Anode-Free Lithium Metal Batteries

Introduction

Anode-free lithium metal batteries (AFLMBs) are promising for high-energy-density applications due to their reduced manufacturing complexity. However, challenges such as lithium dendrite formation, inactive lithium accumulation, and capacity degradation hinder their practical implementation [1]. This study explores a novel reagent-free approach to address these issues by leveraging laser-induced copper oxidation to enhance the electrochemical performance of AFLMBs.

Methods

Using a Nd:YAG laser under ambient conditions, a copper current collector (CC) was oxidized to produce controlled CuOx surface layers. The surface morphology and composition were analyzed using SEM, EDS, UV-Vis spectroscopy, Raman spectroscopy, and XRD. Electrochemical performance was evaluated through cyclic voltammetry, galvanostatic cycling, and impedance spectroscopy in half-cell and full-cell configurations.

Results

Laser-induced oxidation formed a CuOx layer that electrochemically converted to Li₂O during the first charge, creating a stable, artificial solid electrolyte interphase (SEI). This SEI reduced the lithium nucleation overpotential and enhanced uniform lithium deposition [2]. Moderately oxidized samples (Cu_LS1000) demonstrated optimal electrochemical performance, achieving >97% Coulombic efficiency over 100 cycles in half-cell tests and superior capacity retention in full-cell tests compared to unprocessed copper. Excessive oxidation (Cu_LS300) reduced the cycling stability due to increased polarization and lithium consumption during activation.

Conclusion

Laser-assisted copper oxidation is a scalable, cost-effective, and environmentally friendly technique for improving AFLMBs' safety and efficiency. The findings highlight the potential of precise surface engineering in advancing anode-free lithium battery technology, providing a pathway toward industrial scalability and enhanced energy storage solutions.