Polyanionic Cathode Materials: A Comparison Between Na‐Ion and K‐Ion Batteries

Abstract

Sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) are considered the next‐generation candidates for future energy storage systems to partially substitute commercial lithium‐ion batteries because of their abundant sodium/potassium reserves, cost‐effectiveness, and high safety. Polyanionic cathode materials are widely used in alkali ion batteries due to their stable structural framework, high thermal stability, excellent alkali ion diffusion kinetics, and adjustable working voltage. Generally, the polyanionic cathodes used for SIBs surpass PIBs in the aspect of energy density and cycle life in most cases, however, the PIBs also have their unique advantages that are seldom reported. To this end, the polyanionic materials are classified by the valence states of active metal sites, the storage mechanism of Na+ and K+ in different crystal structures is summarized, and the electrochemical performance between SIBs and PIBs is compared. Particularly, some unique advantages of polyanionic cathodes in PIBs, such as high working voltage, superior rate capability, and excellent capacity retention are revealed, and the possible reasons are discussed in detail. Finally, various viable solutions are proposed to improve the battery performance of polyanionic compounds for future development.

Selective Adsorption of Sr(II) from Aqueous Solution by Na3FePO4CO3: Experimental and DFT Studies

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Ni-rich layered cathodes in sodium-ion batteries: perspectives or déjà vu?

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“…2 The high cost associated with lithium, coupled with its substantial consumption, presents a significant barrier to the widespread adoption of LIBs in the future. 2 In that regard, SIBs present a notable alternative to LIBs due to the comparable physicochemical properties of sodium to lithium. 3 Additionally, sodium resources are abundantly available on Earth to supplant LIBs for large-scale applications in the near future.…”