Microwave-assisted synthesis and electrochemical characterization of TiNb2O7 microspheres as anode materials for lithium-ion batteries

TiNb2O7 microspheres are prepared via a microwave-assisted solvothermal method. The microwave irradiation lowers the compound formation temperature to 600 degrees C, and highly crystalline TiNb2O7 powders are obtained upon calcination at 800 degrees C. Morphological analysis of the sample shows uniformly distributed microspheres with a particle size of around 1 mu m. The Li+-ion diffusion coefficient calculated from the electrochemical impedance result is around 1.21 x 10(-13) cm(2) s(-1), which is 1.5 times higher than the sample obtained from the conventional solvothermal method. The TiNb2O7 sample derived from microwave yields a high discharge capacity of 299 mA h g(-1) at 0.1 C, whereas the sample synthesized via the conventional solvothermal process yields only 278 mA h g(-1) at 0.1 C. Excellent rate capabilities such as 220 mA h g(-1) at 5 C and 180 mA h g(-1) at 10 C are also observed for the microwave-assisted solvothermal sample. Moreover, the sample exhibits a large capacity retention of 95.5% after 100 discharge-charge cycles at 5 C. These results reveal the appropriateness of the microwave-assisted solvothermal process to prepare TiNb2O7 powders with superior properties for battery applications.

Automated summary

TiNb2O7 microspheres are successfully prepared using a microwave-assisted solvothermal method, resulting in highly crystalline powders with uniformly distributed microspheres. The microwave irradiation reduces the compound formation temperature and enhances the Li+-ion diffusion coefficient, leading to improved battery performance. The microwave-assisted solvothermal TiNb2O7 sample exhibits higher discharge capacity, excellent rate capabilities, and superior capacity retention compared to samples prepared via conventional solvothermal methods.