Understanding pillar chemistry in potassium-containing polyanion materials for long-lasting sodium-ion batteries.

ABSTRACT: K-containing polyanion compounds hold great potential as anodes for sodium-ion batteries considering their large ion transport channels and stable open frameworks; however, sodium storage behavior has rarely been studied, and the mechanism remains unclear. Here, using a noninterference KTiOPO₄ thin-film model, the Na⁺ storage mechanism is comprehensively revealed by in situ/operando spectroscopy, aberration-corrected electron microscopy and density functional theory calculations. We find that incomplete K⁺/Na⁺ ion exchange occurs and eventually 0.15 K⁺ remains as a pillar to stabilize the tunnel structure. The pillar effect substantially maintains the volume change within 3.9%, much smaller than that of K⁺(Na⁺) in

SUBMITTER: Liu W 

PROVIDER: S-EPMC11564968 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature