Electrochemically in situ formed rocksalt phase in titanium dioxide determines pseudocapacitive sodium-ion storage.

ABSTRACT: Earth-abundant TiO₂ is a promising negative electrode for low-cost sodium-ion batteries (SIBs) owing to its high capacity, rapid (dis)charging capability, safe operation potential and nonflammability. Crystalline anatase TiO₂ is not suitable for reversible Na⁺ (de)intercalation, but it displays pseudocapacitive response after repeated cycles. Herein, we find and demonstrate that ordered rocksalt (RS) NaTiO₂ nanograins are in situ formed by electrochemically cycling with Na⁺ ions in anatase and amorphous TiO₂. The in situ formed RS-NaTiO₂ follows a solid-solution reaction with small volume changes of only 2.0%, that determines the pseudocapacitive "mirror-like" cyclic voltammetry curve with a couple of broad redox

SUBMITTER: Tang D 

PROVIDER: S-EPMC11868394 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature