Intercalant-induced V t2g orbital occupation in vanadium oxide cathode toward fast-charging aqueous zinc-ion batteries.
Proc Natl Acad Sci U S A
; 120(13): e2217208120, 2023 Mar 28.
Article
in En
| MEDLINE
| ID: mdl-36940337
ABSTRACT
Intercalation-type layered oxides have been widely explored as cathode materials for aqueous zinc-ion batteries (ZIBs). Although high-rate capability has been achieved based on the pillar effect of various intercalants for widening interlayer space, an in-depth understanding of atomic orbital variations induced by intercalants is still unknown. Herein, we design an NH4+-intercalated vanadium oxide (NH4+-V2O5) for high-rate ZIBs, together with deeply investigating the role of the intercalant in terms of atomic orbital. Besides extended layer spacing, our X-ray spectroscopies reveal that the insertion of NH4+ could promote electron transition to 3dxy state of V t2g orbital in V2O5, which significantly accelerates the electron transfer and Zn-ion migration, further verified by DFT calculations. As results, the NH4+-V2O5 electrode delivers a high capacity of 430.0 mA h g-1 at 0.1 A g-1, especially excellent rate capability (101.0 mA h g-1 at 200 C), enabling fast charging within 18 s. Moreover, the reversible V t2g orbital and lattice space variation during cycling are found via ex-situ soft X-ray absorption spectrum and in-situ synchrotron radiation X-ray diffraction, respectively. This work provides an insight at orbital level in advanced cathode materials.
Full text:
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Collection:
01-internacional
Database:
MEDLINE
Aspects:
Determinantes_sociais_saude
Language:
En
Journal:
Proc Natl Acad Sci U S A
Year:
2023
Document type:
Article