Electrocatalyst-based energy storage technologies such as alkali metal–air batteries, fuel cells, and water splitting devices are the new holy grail in the next-generation energy storage landscape as they deliver higher energy densities than Li-ion/Na-ion batteries (LIBs/SIBs). The new chemistries of energy storage such as metal–air batteries under aqueous or non-aqueous conditions will complement existing LIBs/SIBs owing to the increasing requirement for batteries with high energy density in the present era. Phosphate-based polyanionic frameworks have long been known for their ability to (de)intercalate alkali metal ions. Because of their innate oxygen electrocatalytic activity, these insertion cathode materials have lately emerged as air electrodes in metal–air battery systems. In this review, the present status of phosphate-based polyanionic insertion materials for oxygen reduction and oxygen evolution reaction (ORR and OER) electrocatalysis is summarized. Factors influencing electrocatalytic activity in these materials, such as the presence of different types of alkali metal cations, transition metals, and the type of ligand/mixed anion as well as coordination around the transition metals are discussed. Finally, the development of metal–air batteries derived from phosphate-based polyanionic insertion materials as air electrodes is discussed.

中文翻译：

---

用于氧电催化的磷酸基聚阴离子插入材料

基于电催化剂的储能技术，如碱金属空气电池、燃料电池和水分解装置，是下一代储能领域的新圣杯，因为它们比锂离子/钠离子电池提供更高的能量密度。 LIB/SIB）。由于当今时代对高能量密度电池的需求不断增加，新型储能化学物质（例如水或非水条件下的金属空气电池）将补充现有的LIB/SIB。磷酸盐基聚阴离子骨架长期以来因其嵌入（脱）碱金属离子的能力而闻名。由于其固有的氧电催化活性，这些插入式阴极材料最近已成为金属-空气电池系统中的空气电极。本文综述了用于氧还原和析氧反应（ORR和OER）电催化的磷酸盐基聚阴离子插入材料的现状。讨论了影响这些材料中电催化活性的因素，例如不同类型的碱金属阳离子、过渡金属的存在、配体/混合阴离子的类型以及过渡金属周围的配位。最后，讨论了由磷酸盐基聚阴离子插入材料作为空气电极衍生的金属空气电池的发展。