PhD students

Zhang Yin

Queensland University of Technology (Principal Supervisor: Jose A. Alarco; Associated supervisors: Peter C. Talbot and Jawahar Y. Nerkar)

CSIRO External supervisors: Adam S. Best (CSIRO Manufacturing, Clayton) and Graeme A. Snook (CSIRO Mineral resources, Clayton)

PhD topic – Study on electronic structure and rate performance of olivine phosphate cathode materials

Research summary

Understanding the fundamentals of electrode materials is very important for the design of high-power energy storage devices to power light rail. As a critical factor controlling the electronic conductivity and electrochemical rate capability, the electronic structures of olivine phosphates have been thoroughly investigated in this study, both experimentally and theoretically. The surface chemistry (Li-depletion in the case of olivine phosphates) has been shown to have significant impact on the electronic band structure and conductivity of the materials. The findings provide new insights on material design for high rate devices. Besides, enhanced rate performance of LiFePO₄ electrodes has been demonstrated by optimization of the microstructure and particle size distribution in this study.

Completion date

January 2020

Key achievements

• Surface chemistry has been shown to have significant effect on the electronic conductivity and rate performance of the electrode materials.
• Enhanced rate performance has been achieved after electrode optimization.
• Successful application for use of the Soft X-ray spectroscopy beamline at the Australian Synchrotron in Melbourne in May 2019 (in-kind value ~ $98,352 AUD).
• Poster titled “Electronic structure of LiFePO₄: Theoretical and experimental investigation” has been granted poster award at The International Conference on Nanoscience and Nanotechnology 2018.
• Poster titled “Electronic structure investigations of LiFePO₄ and FePO₄: Combined theoretical and experimental perspective” has been granted poster award at International Symposium on Advanced Materials and Sustainable Technologies 2018.

Publications

Zhang, Y., Alarco, J., Nerkar, J., Best, A., Snook, G. and Talbot, P. (2019). Improving the rate capability of LiFePO4 electrode by controlling particle size distribution. Journal of the Electrochemical Society 166, A4128-A4135.

Zhang, Y., Alarco, J., Nerkar, J., Best, A., Snook, G. and Talbot, P. (2020). Nanoscale characteristics of practical LiFePO4 materials – Effects on electrical, magnetic and electrochemical properties. Materials Characterization 162, 110171.

Zhang, Y., Alarco, J., Nerkar, J., Best, A., Snook, G., Talbot, P. and Cowie, B. (2020). Spectroscopic Evidence of Surface Li-Depletion of Lithium Transition-Metal Phosphates. ACS Applied Energy Materials 3, 2856-2866.

Zhang, Y., Alarco, J., Best, A., Snook, G., Talbot, P. and Nerkar, J. (2019). Re-evaluation of experimental measurements for the validation of electronic band structure calculations for LiFePO 4 and FePO 4. RSC Advances 9, 1134-1146.