Self-assembling, nanophase-separated multi-block copoly(arylene sulfone)s, selectively swelled with ethylene carbonate, provide excellent single-ion conductivity and cycling stability for high-energy lithium/Li[Ni _1/3 Co _1/3 Mn _1/3 ]O ₂ batteries.

This perspective reviews current strategies to decouple segmental motion and ionic conductivity for lithium polymer battery electrolytes, including an outlook for potential future improvements.

High‐energy Ni‐rich lithium transition metal oxides such as Li[Ni_0.8Co_0.1Mn_0.1]O₂ (NCM₈₁₁) are appealing positive electrode materials for next‐generation lithium batteries. However, the high sensitivity toward moist air during storage and the high reactivity with common organic electrolytes, especially at elevated temperatures, are hindering their commercial use. Herein, an effective strategy is reported to overcome these issues by coating the NCM₈₁₁ particles with a lithium phosphonate functionalized poly(aryl ether sulfone). The application of this coating allows for a substantial reduction of lithium‐based surface impurities (e.g., LiOH, Li₂CO₃) and, generally, the suppression of detrimental side reactions upon both storage and cycling. As a result, the coated NCM₈₁₁‐based cathodes reveal superior Coulombic efficiency and cycling stability at ambient and, particularly, at elevated temperatures up to 60 °C (a temperature at which the non‐coated NCM₈₁₁ electrodes rapidly fail) owing to the formation of a stable cathode electrolyte interphase with enhanced Li⁺ transport kinetics and the well‐retained layered crystal structure. These results render the herein presented coating strategy generally applicable for high‐performance lithium battery cathodes.

Rechargeable alkali metal–air batteries have enormous potential in energy storage applications due to their high energy densities, low cost, and environmental friendliness. Membrane separators determine the performance and economic viability of these batteries. Usually, porous membrane separators taken from lithium-based batteries are used. Moreover, composite and cation-exchange membranes have been tested. However, crossover of unwanted species (such as zincate ions in zinc–air flow batteries) and/or low hydroxide ions conductivity are major issues to be overcome. On the other hand, state-of-art anion-exchange membranes (AEMs) have been applied to meet the current challenges with regard to rechargeable zinc–air batteries, which have received the most attention among alkali metal–air batteries. The recent advances and remaining challenges of AEMs for these batteries are critically discussed in this review. Correlation between the properties of the AEMs and performance and cyclability of the batteries is discussed. Finally, strategies for overcoming the remaining challenges and future outlooks on the topic are briefly provided. We believe this paper will play a significant role in promoting R&D on developing suitable AEMs with potential applications in alkali metal–air flow batteries.