Revisited Ti 2 Nb 2 O 9 as an Anode Material for Advanced Li-Ion Batteries
2021; American Chemical Society; Volume: 13; Issue: 47 Linguagem: Inglês
10.1021/acsami.1c20842
ISSN1944-8252
AutoresOleg A. Drozhzhin, V. V. Grigoryev, Anastasia M. Alekseeva, Ruslan R. Samigullin, Dmitry A. Aksyonov, Olga V. Boytsova, D. Chernyshov, В. В. Шаповалов, Alexander A. Guda, А. В. Солдатов, Keith J. Stevenson, Artem M. Abakumov, Evgeny V. Antipov,
Tópico(s)Advanced Battery Materials and Technologies
ResumoTi2Nb2O9 with a tunnel-type structure is considered as a perspective negative electrode material for Li-ion batteries (LIBs) with theoretical capacity of 252 mAh g-1 corresponding to one-electron reduction/oxidation of Ti and Nb, but only ≈160 mAh g-1 has been observed practically. In this work, highly reversible capacity of 200 mAh g-1 with the average (de)lithiation potential of 1.5 V vs Li/Li+ is achieved for Ti2Nb2O9 with pseudo-2D layered morphology obtained via thermal decomposition of the NH4TiNbO5 intermediate prepared by K+→ H+→ NH4+ cation exchange from KTiNbO5. Using operando synchrotron powder X-ray diffraction (SXPD), single-phase (de)lithiation mechanism with 4.8% unit cell volume change is observed. Operando X-ray absorption near-edge structure (XANES) experiment revealed simultaneous Ti4+/Ti3+ and Nb5+/Nb4+ reduction/oxidation within the whole voltage range. Li+ migration barriers for Ti2Nb2O9 along [010] direction derived from density functional theory (DFT) calculations are within the 0.15-0.4 eV range depending on the Li content that is reflected in excellent C-rate capacity retention. Ti2Nb2O9 synthesized via the ion-exchange route appears as a strong contender to widely commercialized Ti-based negative electrode material Li4Ti5O12 in the next generation of high-performance LIBs.
Referência(s)