REDOX TARGETING OF LITHIUM-ION STORAGE MATERIAL WITH REDOX MEDIATORS — FROM MICROSCALE TO MACROSCALE

Abstract

Redox-targeting-based flow battery is a novel technology for next generation large-scale energy storage. Redox-targeting reaction — the chemical redox reaction between the battery materials and the redox species in the energy storage tank, is the key process of this system. The kinetics of the reaction not only dictates the overall device performance, but also presents itself as an interesting topic for study. In this thesis, the redox targeting reaction between the Li+-storage material LiFePO4 and redox species are scrutinized from microscale to macroscale, starting with the probing of interfacial charge transfer process and the phase transition mechanism of LiFePO4/FePO4 upon chemical delithiation and lithiation at nanoscale, towards transport of charge carriers inside the primary particles, diffusion of redox species inside the porous matrix of LiFePO4/FePO4 particles engineered into agglomerated spherical pellet, and finally transport of species through the voids of LiFePO4/FePO4 pellets in a packed-bed-reactor-based energy storage tank.