Lithium storage in perovskite lithium lanthanum titanate

• Electrochemical performances of perovskite Li0.27La0.54TiO2.945 were studied.
• Lithium storage mechanism was clarified in a wide voltage range of 0.01-3.00 V.
• The formation of the SEI layer was characterized and found stable up to 3.0 V.
• The cycling performance was improved significantly by CVD carbon-coating.

Perovskite lithium lanthanum titanate (LLTO) was synthesized using sol–gel method. It shows a reversible capacity of 145 mA h g− 1 and moderate cycling performance between 0.01 and 2.00 V. Cyclic voltammetry and X-ray diffraction results demonstrate a two-step solid–solution reaction behavior in the voltage range of 0.00–3.00 V upon lithium insertion/extraction. A stable solid electrolyte interphase (SEI) layer is formed on the surface of LLTO after the initial discharge. Carbon coating by chemical vapor deposition improves its cycling performance significantly.