Doping Nano-TiO2 to Improve the Performance of Lithium Battery Cathode Materials

The experiment takes lithium cobalt oxide as an example:

Function 1: Reduce the formation of oxygen defects, and correspondingly improve the structural stability of the material.

When the battery is charged to a high pressure, a large amount of Co3+ in the LiCoO2 structure will become Co4+. The formation of Co4+ will lead to the formation of oxygen defects, which will weaken the binding force between the excessive metal and oxygen, so that Co4+ will dissolve into the electrolyte. In LiCoO2, after doping with nano-titanium dioxide (VK-T30D), the interface structure between LiCoO2 and nano-titanium dioxide will be rearranged during the charging and discharging process, thereby reducing the formation of oxygen defects and correspondingly improving the structural stability of the material .

Role 2: Improve lithium battery cycle new energy

On the other hand, if the material is in direct contact with the electrolyte, the strong oxidizing Co4+ will react with the electrolyte and cause capacity loss. Doping with nano-titanium dioxide (VK-T30D) can avoid direct contact between LiCoO2 and electrolyte and reduce capacity loss, thereby increasing the electrochemical specific capacity of LiCoO2 material and improving its cycle performance.

Function three: reduce the resistance of the battery during the cycle.

After doping with nano-titanium dioxide (VK-T30D), the resistance of the lithium battery in the first cycle is greater than that of the undoped LiCoO2; but after 10 cycles, the film resistance and charge transfer resistance of the doped material are both higher than that of the non-doped LiCoO2. The doped LiCoO2 is much smaller. This shows that the doping of nano-titanium dioxide (VK-T30D) effectively reduces the electrochemical impedance of LiCoO2 during the charge and discharge cycle, which is beneficial to improve the electrochemical performance of the material.

(The data in the experiment shows that after 10 cycles, the charge transfer impedance of the cathode material doped with nano-titanium dioxide (VK-T30D) dropped from 31.8Ω to 9.0Ω)