Abstract
Due to higher packing density, lower working potential, and area specific impedance, the MLi2Ti6O14(M = 2Na, Sr, Ba, and Pb) titanate family is a potential alternative to zero-strain Li4Ti5O12anodes used commercially in Li-ion batteries. However, the exact lithiation mechanism in these compounds remains unclear. Despite its structural similarity, MLi2Ti6O14behaves differently depending on charge and size of the metal ion, hosting 1.3, 2.7, 2.9, and 4.4 Li per formula unit, giving charge capacity values from 60 to 160 mAh/g in contrast to the theoretical capacity trend. However, high-temperature oxide melt solution calorimetry measurements confirm strong correlation between thermodynamic stability and the observed capacity. The main factors controlling energetics are strong acid-base interactions between basic oxides MO, Li2O and acidic TiO2, size of the cation, and compressive strain. Accordingly, the energetic stability diminishes in the order Na2Li2Ti6O14> BaLi2Ti6O14> SrLi2Ti6O14> PbLi2Ti6O14. This sequence is similar to that in many other oxide systems. This work exhibits that thermodynamic systematics can serve as guidelines for the choice of composition for building better batteries.
| Original language | English |
|---|---|
| Pages (from-to) | 42482-42488 |
| Number of pages | 7 |
| Journal | ACS Omega |
| Volume | 7 |
| Issue number | 46 |
| DOIs | |
| State | Published - Nov 22 2022 |
Funding
K.J. and A.N. acknowledge the U.S. Department of Energy Office of Basic Energy Sciences, grant DE-SC0021987 for calorimetric measurements and thermodynamic analysis. P.B. is grateful to the Alexander von Humboldt Foundation (Bonn, Germany) for a 2022 Humboldt fellowship for experienced researchers. A.C. is grateful to the Ministry of Human Resource Development (MHRD) and Raman-Charpak Fellowship-2019 by Centre Franco-Indien pour la Promotion de la Recherche Avancee (CEFIPRA) for financial support and Prof. Jean-Marie Tarascon for hosting him at Collège de France, Paris. This manuscript has been authored by UT-Battelle, LLC under Contract No. DEAC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).