Physical Metallurgy of Lithium and Sodium and its Role in Electrochemical Stability of Solid-State Battery Anodes
Year: 2026
Type: preprint
Abstract: Alkali metal negative electrodes in solid-state batteries (SSBs) undergo mechanical deformation during cycling, for which an understanding of their physical metallurgy is critical. Here, we study the link between microstructure and plastic deformation in lithium and sodium. Grain size is controlled through deformation processing, and etching methods are developed to reveal grain boundaries, subgrain boundaries, and dislocation structures. Hall-Petch strengthening with decreasing grain size occurs in both metals. Creep rate in lithium is grain-size-independent above the subgrain size, but increases at small grain sizes where diffusional creep dominates. Oxide dispersion-strengthened behavior is observed in Li. At length scales below the subgrain size, strength increases and creep rates decrease due to dislocation starvation. Solid-state electrochemical cell tests in which lithium of differing foil thickness is stripped under pressure validates length-scale effects. Overall, this work provides a physical metallurgy framework for alkali metal deformation and offers design principles for advanced SSBs.
Source: ChemRxiv
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, University of Pennsylvania, Harvard University, Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Office of Science, Advanced Research Projects Agency, Materials Research Science and Engineering Center, Harvard University, National Cancer Institute, Division of Materials Research, Division of Electrical, Communications and Cyber Systems
Awards: NNCI: Center for Nanoscale Systems (CNS), G2347808973, G2360436881, G2450521733, G2976286571, Materials Research Science and Engineering Centers (MRSEC) UPENN, G4671203234, G5108852245, G5699691398, NNCI: Mid-Atlantic Nanotechnology Hub (MANTH), G6176141556, G6687462672, G8440189507, Cancer Center Support (Core) Grant
OpenAlex ID: W7211972436