Preconcentration of lithium salt in nanoporous alumina on Cu foil as a concentrated lithium semi-solid layer for anode-free Li-metal batteries

Abstract

We preconcentrate 2 M LiTFSI in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide inside a nanoporous alumina (Al₂O₃) layer as a so-called concentrated lithium semi-solid layer on a Cu current collector for anode-free Li-metal NMC90 batteries. This concept lowers the activation energy for lithium-ion transport and reduces the nucleation overpotential, enhancing the cycling stability.