Austrian chemists boost lithium-ion battery anodes by removing oxygen from crystal lattice
Researchers at Graz University of Technology have found a way to significantly improve the ionic conductivity of lithium titanate, a material used in anodes for fast-charging and long-lasting lithium-ion batteries. Chemists Bernhard Gademair and Martin Wilkening deliberately introduced defects into the crystal lattice to enhance the movement of lithium ions.
Lithium titanate (Li₄Ti₅O₁₂) is considered an alternative to graphite in battery anodes. It offers high safety, a long cycle life, the ability to charge quickly, and stable operation at low temperatures. Its crystal lattice undergoes almost no volume change during lithium insertion and extraction, which greatly reduces mechanical degradation over time. However, in its pristine uncharged state, the material has relatively low ionic conductivity. Conductivity typically increases only during charging, when additional lithium ions and electrons enter the structure.
The Austrian team took a fundamentally different approach. They heated lithium titanate to approximately 300 °C in an oxygen-depleted atmosphere. This process removed a small fraction of oxygen atoms from the crystal lattice, creating so-called oxygen vacancies. These microscopic defects altered the material's structure: some titanium ions were reduced to a trivalent state, while the remaining lithium ions gained more space to move.
Measurements showed that the ionic conductivity of the modified material increased by an order of magnitude — roughly ten times compared to the original. The crystal structure remained stable, and the material retained its ability to cycle without degradation. The researchers emphasize that the method does not require complex equipment and can be scaled for industrial applications.
The development could enable batteries with even faster charging and longer service life, especially in low-temperature conditions where lithium titanate already outperforms graphite. The team believes that controlled defect engineering offers a practical route to enhance electrode materials without changing their basic chemistry.
