Abstract
Rapid global electrification, including for transportation, has dramatically increased demand for long-lasting and faster-charging batteries. Titanium niobium oxide (TiNb2O7) is one of the most promising anode materials for high-power lithium-ion batteries (LIBs). However, the intrinsic low electronic conductivity of TiNb2O7 is a significant drawback. Herein, an almost 10 orders of magnitude increase in conductivity is achieved via reduction of TiNb2O7 in H2 at 900 °C. The observed dramatic increase in electron conductivity upon reduction is unprecedented and opens new possibilities to produce niobium-based conductive materials for next-generation energy storage. Upon extended reduction, TiNb2O7 converts into a distorted rutile TiNb2O6 structure, which can be reoxidized back into the crystallographic shear phase. In addition, TiNb2O7 can be thermally reduced in an inert atmosphere and reoxidized by CO2 with excellent oxygen exchange capacity. Thus, the TiNb2O7 Wadsley-Roth phase demonstrates outstanding potential for solar-driven thermochemical CO2 splitting at 1400 °C. These findings manifest that controlling defect chemistry paves the way for developing advanced materials for LIBs and solar-driven thermochemical fuel production.
| Original language | English |
|---|---|
| Pages (from-to) | 10311-10319 |
| Number of pages | 9 |
| Journal | Chemistry of Materials |
| Volume | 34 |
| Issue number | 23 |
| DOIs | |
| State | Published - Dec 13 2022 |
Funding
This work was supported by the U.S. Department of Energy Office of Basic Energy Sciences, Grant DE-SC0021987. The authors acknowledge the use of facilities within the Eyring Materials Center and John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University. The authors thank David Wright and Manuel Roldan Gutierrez for assistance in sample preparation and characterization and David J. Smith for fruitful discussions.