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Description
Copper is widely used as a current collector in lithium metal batteries due to its electrical conductivity and mechanical stability. However, its inherently low lithiophilicity often results in uneven lithium plating and stripping, which fosters dendrite growth and negatively impacts cell safety, cycle life, and overall performance. To mitigate these issues, surface modifications such as silver (Ag) coatings have been investigated to improve interfacial properties and promote more uniform lithium nucleation.
In this work, we employed Neutron Depth Profiling (NDP), a non-destructive and highly sensitive technique to study lithium distribution within current collector materials [1,2]. NDP provides sub-micrometer depth resolution, enabling the detection of lithium penetration and accumulation beneath the surfaces of both bare and different Ag-coated Cu collectors after electrochemical cycling. Such depth-resolved insights directly reveal irreversible lithium losses to the current collector, offering a clearer understanding of lithium inventory decay mechanisms and supporting strategies for designing more lithiophilic surfaces or protective interlayers in lithium metal batteries [3].
Our findings highlight the effectiveness of NDP in tracking lithium diffusion into the collector bulk and quantifying inactive (dead) lithium formed during cycling. Furthermore, the impact of Ag coating thickness and interfacial characteristics is discussed, underscoring the utility of NDP as a powerful tool for interfacial studies in lithium metal systems and for guiding the development of next-generation batteries with improved durability and performance.
[1] M. Trunk, M. Wetjen, L. Werner, R. Gernhäuser, B. Märkisch, Z. Révay, H.A. Gasteiger, R. Gilles, Mater. Charact., 146, 127-134 (2018)
[2] J. Vacík, J. Červená, V. Hnatowicz, V. Havránek, D. Fink , Acta Phys. Hung. 75 ,369-372 (1994)
[3] M. Wan, R. Gilles, J. Vacik, H. Liu, N. Wu, S. Passerini, D. Bresser, Small, 20, 2404437(2024)
