Recent progress in the modification of copper current collectors for lithium metal batteries

Lithium metal batteries (LMBs) are promising candidates for next-generation high-energy-density storage devices. However, an unstable lithium metal anode poses significant issues that critically compromise battery safety and cycle life, including lithium dendrite formation, solid electrolyte interphase degradation, dead lithium accumulation, and substantial volume fluctuations during cycling. These problems can be addressed by regulating lithium deposition and suppressing side reactions through the modification of copper current collectors using three classes of materials: metal and metal oxide, carbon, and polymer materials. This review comprehensively examines recent advances in the application of these materials as current collector coatings. Particularly, their distinct roles in the lithium deposition process are analyzed to understand how they mitigate the issues associated with the lithium metal anode. Furthermore, their inherent limitations are considered to inform future research directions. While each class of materials offers specific advantages, multifunctionality is required to effectively regulate lithium deposition. In prospect, a novel composite copper current collector design that integrates the merits of the aforementioned advanced materials is proposed. The insights from this review provide valuable guidance for the rational design of modified copper current collectors, which would significantly improve the safety and cycle life of LMBs and advance their commercialization.