Optimizing Zn‐Mn Flow Batteries with Aminonaphthalene Sulfonic Acid via Hydrogen Bond Disruption and Interface
Jing Cui, Zhikun Liu, Chunfeng Song, Zhendong Meng, Peng Kang
Abstract
Abstract Irreversible MnO 2 dissolution into “dead MnO 2 ” limits capacity, efficiency, and cycle life in Mn 2 ⁺/MnO 2 ‐based flow batteries. This study introduces organic additives with sulfonic acid and amino groups into an MnSO 4 electrolyte to achieve a reversible Mn 2 ⁺/MnO 2 process, with hydrogen bonding and electrode‐electrolyte interface regulation playing critical roles. Specifically, 5‐amino‐2‐naphthalenesulfonic acid adsorbs onto the electrode surface, enhancing hydrophilicity and ensuring uniform Mn 2 ⁺ deposition, while coordinating with Mn 2 ⁺ in solution to disrupt hydrogen bonds and refine solvation structure, thus optimizing both electrode interface and electrolyte dynamics. Consequently, the Zn‐Mn flow battery sustains 200 cycles at 40 mA cm⁻ 2 with an areal capacity of 15 mAh cm⁻ 2 , providing an innovative strategy for designing high‐areal‐capacity Mn‐based flow batteries.