Effect of freeze-drying and self-ignition process on the microstructural and electrochemical properties of Li4Ti5O12

• Li4Ti5O12 is prepared by a method involving self-ignition of a freeze-dried gel.
• Addition of NH4NO3 modifies the self-ignition propagation mode.
• Well-crystallized Li4Ti5O12 phase is obtained after only 2 h at 800 °C.
• Li4Ti5O12 powder has 161 mAh g−1 capacity and good retention at C/4 rate.

Crystalline Li4Ti5O12 is synthesized by a method involving the freeze-drying and self-ignition of a gel prepared from titanium isopropoxide, lithium nitrate and hydroxypropylmethylcellulose (HPMC). This synthesis route yields crystalline Li4Ti5O12 particles after calcination at 800 °C for 2 h. In an alternative route, addition of ammonium nitrate shifts the self-ignition mode from wave-like propagation to simultaneous. Powders with different microstructures are thereby obtained. Electrochemical characterization shows that the best results for Li+ intercalation/desintercalation are obtained for the powder prepared without ammonium nitrate addition. These results highlight the necessity for a control of the self-ignition mode to obtain adequate properties.

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