Hierarchically porous Li₄Ti₅O₁₂ anode materials for Li- and Na-ion batteries: Effects of nanoarchitectural design and temperature dependence of the rate capability

Integrated design of both porous structure and crystalline morphology is expected to open up the way to a new class of materials. This report demonstrates new nanostructured Li₄Ti₅O₁₂ materials with hierarchically porous structures and flower-like morphologies. Electrochemical studies of the electrodes of Li-ion and Na-ion batteries clearly reveal the advantage of nanoarchitectural design of active materials. In addition, the temperature dependence of Na⁺-insertion/extraction capacity in relation to Li₄Ti₅O₁₂ electrodes is for the first time evaluated and it is found that elevation of the cell operating temperature effectively improves the rate capability of the Na-ion batteries. Based on the new findings, it is suggested that specially designed Li₄Ti₅O₁₂ materials allow for high-performance Na-ion batteries that are available as large-scale storage devices for applications such as automotive and stationary energy storage.