Lithium titanate (LTO, Li4Ti5O12) is a well-established battery material that in its pristine state is a poor conductor of lithium ions. It develops high ionic conductivity only during charging, when additional lithium ions and electrons are incorporated into the material.
Source: [Phys.org](https://phys.org/news/2026-08-oxygen-vacancies-fast-lithium-ion.html)