Revisited Ti2Nb2O9 as an Anode Material for Advanced Li-Ion Batteries

Oleg A Drozhzhin; Vladislav V Grigoryev; Anastasia M Alekseeva; Ruslan R Samigullin; Dmitry A Aksyonov; Olga V Boytsova; Dmitry Chernyshov; Victor V Shapovalov; Alexander A Guda; Alexander V Soldatov; Keith J Stevenson; Artem M Abakumov; Evgeny V Antipov

doi:10.1021/acsami.1c20842

Revisited Ti₂Nb₂O₉ as an Anode Material for Advanced Li-Ion Batteries

ACS Appl Mater Interfaces. 2021 Dec 1;13(47):56366-56374. doi: 10.1021/acsami.1c20842. Epub 2021 Nov 16.

Authors

Oleg A Drozhzhin^{1

2}, Vladislav V Grigoryev¹, Anastasia M Alekseeva¹, Ruslan R Samigullin¹, Dmitry A Aksyonov², Olga V Boytsova^{1

3}, Dmitry Chernyshov^{4

5}, Victor V Shapovalov⁶, Alexander A Guda⁶, Alexander V Soldatov⁶, Keith J Stevenson², Artem M Abakumov², Evgeny V Antipov^{1

2}

Affiliations

¹ Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russian Federation.
² Skoltech Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Nobel Str. 3, 143026 Moscow, Russian Federation.
³ Kurnakov Institute of General and Inorganic Chemistry RAS, Moscow, 119071, Russia.
⁴ Swiss-Norwegian Beamlines, European Synchrotron, 71 Rue des Martyrs, Grenoble, 38043, France.
⁵ Peter the Great St. Petersburg Polytechnic University, 29 Polytekhnicheskaya St, Saint-Petersburg, 195251, Russia.
⁶ The Smart Materials Research Institute, Southern Federal University, 178/24 A. Sladkova street, Rostov-on-Don, 344090, Russia.

PMID: 34784712
DOI: 10.1021/acsami.1c20842

Abstract

Ti₂Nb₂O₉ 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.

Keywords: Li-ion batteries; Ti2Nb2O9; anode material; intercalation; operando XANES; operando synchrotron diffraction.