Xiaochao Wu

 

Lithium ion batteries with high voltage inverse spinel cathodes

LiNiVO4 Copyright: Phys. Chem. Chem. Phys., 2013, 15, 6486-6498

In recent years, the need for a lithium ion battery with high voltage and high energy density has become more urgent because of the proliferation of advanced portable electronic devices and hybrid vehicles. Spinel materials are considered as a promising candidate for cathode due to their inexpensive and environmental feature and high operating voltage. LiNiVO4 has an inverse spinel structure which the Li and Ni atoms are thought to equally and randomly occupy the octahedrally coordinated interstices and the V atoms are thought to occupy the tetrahedrally coordinated interstices. Compared to normal spinel LiMn­2O4, Li and Ni atoms in LiNiVO4 substitute the place of two Mn atoms, and V atoms replace the Li atom. Owing to the cubic close-packed structure, the inverse spinel offers a 3D lattice for insertion and extraction of Li ions, and the mix degree of the cations in LiNiVO4 is up to 100%. The material exhibits a very high voltage.

This PhD thesis consists of design and synthesis of inverse spinel materials by different routes. The characterization of the inverse spinel materials system by means of electrochemical investigations will be performed as well. Research will also focus on the modification by dopant cations and the optimization of a series of conditions.