High-performance lithium-ion battery composite material was successfully developed

Recently, Professor Cao Xiaoyu of Henan University of Technology first prepared a new composite cathode material, which can improve the electrochemical properties of lithium vanadate cathode material for rechargeable lithium battery. Related research is published online in the Journal of Applied Materials and Interfaces of the American Chemical Society.

Lithium-ion batteries are considered to be one of the most promising energy storage methods because of their high energy density. They have been commercialized in the field of electric vehicles. It is still the unremitting pursuit of researchers to continue to improve the energy density of lithium-ion batteries. At present, the capacity of lithium ion batteries is mainly determined by the capacity of the cathode material. Finding a cathode material with high discharge capacity and stability is the key to improving the energy density of lithium ion batteries. The layered lithium vanadate cathode material capable of multi-electron transport has high discharge capacity, which attracts people's attention due to its low cost and good safety. However, the material has low electronic conductivity and is prone to irreversible phase during charge and discharge. The vanadium element is dissolved in the electrolyte, resulting in deterioration of the rate performance and cycle performance of the material.

The researchers prepared a high-capacity lithium vanadate cathode material by rheological phase reaction method. The lithium vanadate/polydiphenylamine composite cathode material was prepared for the first time by in-situ oxidative polymerization with diphenylamine monomer. Among them, the polydiphenylamine main chain not only has a poly-p-phenylene structure with high conductivity, but also has an aniline structure with high energy density, thereby having ultra-fast electron transfer rate, good hole transporting ability and good redox. Reversible.