Shicheng Yu

 

Design and synthesis of nanostructure LiFePO4 for lithium-ion batteries with high capacity, high power density and long cycle life

Different heterogeneous nanostructured materials based on structural complexity Copyright: Ref. Chem. Commun., 2011, 47, 1384. Copyright 2011, The Royal Society of Chemistry.

Lithium-ion batteries have dominated the portable electronic markets during the past two decades because of their much higher energy per unit weight or volume compared to other rechargeable battery systems. The LiFePO4 as a cathode material has already achieved commercial utilization and showed good performance. However, for to be considered for stationary storage of intermittent renewable energies like solar and wind energy, it should be improved in many aspects.

Improvements of both, lithium ion conductivity and electronic conductivity of LiFePO4 are remaining two of the most leading directions. In addition, the limits of cell lifetimes are rooted mainly in side reactions occurring at the electrode-electrolyte interface. Thus, exploration and mastering of the surface chemistry between electrolyte and electrode are also need to be considered. The ultimate aim is to develop high-energy, long cycle life and fast charging and discharging lithium batteries.

Contributing to achieve this target, my PhD research will concerned with the following aspects:

  1. Design and preparation of nanostructure LiFePO4 (include of Li1-x M x FePO4, LiM x Fe1-x PO4 or LiFe(PO)1-x M y ) with different particle size. Clearly understand the mechanism of the morphology (Figure), particle size and ion doping influence on the electrochemical performance.
  2. Design and synthesize a series of coating materials, such as carbon or metal-oxide, for improvement of the electrochemical performance of LiFePO4 cathode, as well as for the exploration of high efficiency and low energy consumption coating methods.