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

This thesis has investigated a family of olivine phosphate battery materials using various spectroscopic techniques. The research has demonstrated that the surfaces of these materials display nanoscale Lithium depletion. The differentiated surface layers are responsible for many of the measured properties, which have so far been mostly attributed to the bulk of the compounds. In the case of LiFePO4, the surface layers also concentrate the dopants, which have been reported as beneficial for the electrochemical performance. The identified surface differentiation seems present in other families of battery materials. Its identification provides new insights on particle surface design for performance optimization