Lithium battery positive electrode material structure
Lithium ion batteries are widely used for energy storage in mobile and portable applications and their amount is expected to increase drastically in the near future because of transport sector electrification. Consequently, more sustainable batteries based on earth abundant elements, and having long cycle lifes and high energy densities, are needed. One promising approach is improvement of Ni rich or Co based positive electrode materials by doping with heteroatoms, which affects their critical properties, i.e. functionality and durability.
Traditionally doping has taken place during the last synthesis step i.e. lithiation, which can result in inhomogeneous distribution of dopants. We anticipate that carrying out the doping in an earlier synthesis step can affect the material structure and hence, the critical properties. Consequently, in the DOPOLI project, doping of positive electrode materials during different synthesis steps will be investigated and structure – functionality relations will be elucidate. As an outcome synthesis of positive electrode materials, with focus on the doping step, are developed and the effect of heteroatoms on their structure and electrochemical behaviour is clarified.
In DOPOLI, the positive electrode precursors are synthesised by Freeport Cobalt and lithiation is carried out jointly by Freeport and Aalto University. Synthesized materials are characterised jointly by all the participants and their electrochemical properties are investigated at Aalto and at ESRF. The aging processes of the cathode material is studied in situ at the synchrotron facilities..