Deciphering Mn ²⁺ Solvation and Interfacial Chemistry for Rechargeable Nonaqueous Mn‐Metal Batteries

Abstract

Abstract Manganese emerges as a compelling metal anode for multivalent ion batteries given its favorable redox potential (−1.18 V vs standard hydrogen electrode), high theoretical specific capacity (976 mAh g −1 ), and large abundance. However, its practical deployment is hindered by kinetic challenges, including strong Mn 2+ solvation effects, electron repulsion from the half‐filled 3d orbital, and surface passivation of oxide layer, which collectively contribute to excessive overpotential during the Mn plating/stripping process. To address these challenges, herein, we propose a synergistic strategy integrating Mn 2+ solvation regulation using 2‐methoxyethylamine (MOEA) and electrode interfacial engineering with indium nitride (InN). Spectroscopic and theoretical analyses reveal that MOEA‐regulated Mn 2+ solvation sheath reduces the energy barrier associated with charge transfer, while InN‐coated Mn anode leverages abundant nucleation sites to facilitate Mn deposition. These concerted effects enable remarkable plating/stripping stability of Mn||Mn symmetric cells over 3400 h under 0.2 mA cm −2 and 0.2 mAh cm −2 . Full cells pairing Mn anodes with pyrene–4,5,9,10–tetraone (PTO) cathodes further validate the strategy's efficacy, delivering a specific capacity of 144 mAh g −1 at 100 mA g −1 and a stable cycling for 400 cycles. This work provides fundamental insights into Mn 2+ solvation and interfacial chemistry for rechargeable Mn‐metal batteries.