This Review addresses the technical challenges, scientific basis, recent progress, and outlook with respect to the stability and degradation of catalysts for the oxygen evolution reaction (OER) operating at electrolyzer anodes in acidic environments with an emphasis on ion exchange membrane applications. First, the term “catalyst stability” is clarified, as well as current performance targets, major catalyst degradation mechanisms, and their mitigation strategies. Suitable in situ experimental methods are then evaluated to give insight into catalyst degradation and possible pathways to tune OER catalyst stability. Finally, the importance of identifying universal figures of merit for stability is highlighted, leading to a comprehensive accelerated lifetime test that could yield comparable performance data across different laboratories and catalyst types. The aim of this Review is to help disseminate and stress the important relationships between structure, composition, and stability of OER catalysts under different operating conditions.

Highly crystalline ramsdellite MnO₂ was tested as a battery cathode material in aqueous Zn-salt (ZnSO₄ and Zn(CF₃SO₃)₂) based electrolytes for the first time. The aqueous MnO₂/Zn cell has shown excellent performance and reversibility, retaining 65% of its initial capacity for more than 1000 cycles.

The advancement of anode‐free lithium metal batteries (AFLMBs) is greatly appreciated due to their exceptional energy density. Despite considerable efforts to enhance the cycling performance of AFLMBs, the understanding of lithium corrosion, which leads to substantial capacity loss during the open circuit voltage (OCV), regardless of electrolyte chemistry, remains limited. In particular, the connection between electrolytes and lithium corrosion performance lacks clear understanding, and the impact of solid‐electrolyte interface (SEI) composition on resistance against lithium corrosion remains elusive. This study explores, for the first time, the effects of salt concentration and solvents on the lithium corrosion behavior in AFLMBs, utilizing the lithium bis(fluorosulfonyl)imide (LiFSI)‐1,2 dimethoxyethane (DME)‐1,3 dioxolane (DOL) electrolyte system. The findings reveal that increasing salt concentration leads to the suppression of chemical corrosion but exacerbation of galvanic corrosion. The key to effectively suppressing both chemical and galvanic corrosion lies in promoting the coordination of less‐soluble particles and polymers within the SEI. This conclusion is further validated by a two‐step electrolyte modification measurement. As a result, a new electrolyte formula, 0.5 M LiFSI‐0.5 M LiBF₂(C₂O₄)‐0.5 M LiNO₃(DME/fluoroethylene carbonate or FEC), is prepared and shown to have improved resistance to both chemical and galvanic corrosion, and the Coulombic efficiency loss from chemical corrosion is reduced to 0.13%.