Crosstalk shielding of transition metal ions for long cycling lithium–metal batteries

Abstract

Lithium–metal batteries (LMBs) comprising a lithium anode and high-specific-capacity manganese (Mn)-based cathode provide a promising high-energy-density system. However, this full cell suffers from poor cycling life under practical conditions. In this contribution, the effect of transition metal ions, e.g., Mn ions, dissolved from the cathode on the failure of lithium anodes was investigated in a working cell. Mn ions are involved in the formation of the solid electrolyte interphase (SEI), inducing the emergence of Mn content and a decrease in the Li₂O and LiF components in the SEI; this results in inhomogeneous lithium nucleation. Furthermore, the direct chemical reaction between Mn ions and lithium anodes results in anode corrosion. For the crossover shielding of Mn ions, a graphene-coated separator was proposed to obstruct Mn ions by adsorption for lithium protection, prolonging the lifespan of LMBs under harsh conditions. This study not only highlights the impact of dissolved transition metal ions, such as Mn ions, on the stability of lithium anodes but also affords a practical strategy to shield the crossover of transition metal ions for anodic protection in both present lithium-ion and next-generation batteries.