Developing high-energy tellurium/selenium redox-amphoteric conversion cathode chemistry for aqueous aluminum batteries

Rechargeable aqueous aluminum battery (AAB) system is potential candidate for sustainable energy storage systems at a grid-scale, owing to their high safety, sustainability and low cost.

However, the existing cathode chemistry (intercalation/deintercalation mechanism) exhibits poor kinetics caused by extremely high charge density of Al3+ ion due to the small ionic radius of Al3+ ion (0.39 Å versus 0.59 Å of Li+) and trivalent nature, leading to a restricted energy density and fast capacity fade.

Those drawbacks hinder their extensive applications.

In this project, we will aim to develop high-performance and innovative aqueous Al-Te and Al-Se batteries by creative redox-amphoteric conversion electrochemistry which means Te or Se will undergo positive and negative valance state during charging and discharging.

To realize this goal, we will firstly screen the aqueous based electrolyte and create the appropriate electrolyte which can realize the redox-amphoteric conversion electrochemistry of Te and Se.

And further we will explore the underlying specific mechanism of the whole electrochemistry by combining in-situ characterization technologies and molecular dynamics simulation. Moreover, the performance will be optimized by adjusting host materials, separator and anode. Finally, the device on pouch cell level will be demonstrated to clear as practical application.

This project will enable the researcher to broaden her knowledge and have more comprehensive knowledge frame which is vital for her future career.

Upon successful implementation of this project, due to the dual-ion charge storage mechanism and multi-electron transfer, the well-designed AAB could exhibit state-of-the-art performance among AABs and even approach the energy density of commercial lithium batteries.

Meanwhile, this novel redox-amphoteric conversion electrochemistry will be an important extension of battery knowledge, and the proposed mechanism will be milestone in this direction.