Sodium-ion batteries are regarded as one of the potential candidates to substitute lithium ion batteries in large-scale electric energy storage applications in the near future. [1] Several forms of sodium titanates including Na₂Ti₃O₇, Na₂Ti₆O₁₃ and Na₄Ti₅O₁₂have been recently applied as anode in sodium ion batteries. [2-4]

In this study, single-crystalline Na₂Ti₃O₇ nanorods are successfully fabricated by solid-state method with the addition of some solid additives. The electrochemical performance of Na₂Ti₃O₇ nanorods is compared to conventionally synthesized Na₂Ti₃O₇ irregular particles. Na₂Ti₃O₇ nanorods outperform Na₂Ti₃O₇ irregular particles at all current rates in the range of 0.1 to 5 C. Without surface modification, the nanorods can still manifest a reversible discharge capacity of 70 mAhg^-1at a high current rate of 5 C. The enhanced electrochemical performance can be attributed to the high surface area of the nanorods as well as efficient ion transport induced in highly uniform one-dimensional nanostructure.

References

1. H. Pan, Y.-S. Hu and L. Chen, Energy & Environmental Science, 2013, 6, 2338-2360.
2. P. Senguttuvan, G. Rousse, V. Seznec, J.-M. Tarascon and M. R. Palacín, Chemistry of Materials, 2011, 23, 4109-4111.
3. A. Rudola, K. Saravanan, S. Devaraj, H. Gong and P. Balaya, Chemical Communications, 2013, 49, 7451-7453.
4. P. J. P. Naeyaert, M. Avdeev, N. Sharma, H. B. Yahia and C. D. Ling, Chemistry of Materials, 2014, 26, 7067-7072.

Acknowledgements

This project is financially supported by Research Grants Council of Hong Kong (GRF 17300014), HKU Small Project Funding (201409176115), HKU Strategic Research Theme on Clean Energy, and University Development Fund for Initiative for Clean Energy and Environment.