Composite electrodes based on Li3V2(PO4)3, Li4Ti5O12 and carbon nanotubes: The influence of composition, thickness and surface morphology on electrochemical properties

Abstract

The influence of the composition, the thickness and the surface morphology of Li3V2(PO4)3 or Li4Ti5O12 based electrode composites with carbon nanomaterial and polyvinylidene fluoride on their electrochemical performance was examined. The thickness and the surface morphology of the electrodes were jointly controlled by rolling with different gaps and monitored using 3D laser microscopy and scanning electron microscopy. Increasing carbon nanomaterial content, the increase in the specific capacity of the electrode due to the non-Faradic component was observed up to the values of the specific capacity seemingly exceeding the theoretical capabilities of Li3V2(PO4)3 or Li4Ti5O12. When rolling the electrode with decreasing gap, we observed that Li3V2(PO4)3-based electrode composites improved their performance in terms of initial specific capacity and resistance to high current loads. As for Li4Ti5O12-based composites we observed the extremum. We concluded that not only the contact of Li4Ti5O12 or Li3V2(PO4)3 with electrolyte, but the three-phase contact of Li4Ti5O12 or Li3V2(PO4)3 with carbon nanomaterial particles and electrolyte as well was important for the electrochemical activity of electrode composites. 

Keywords

• lithium-ion battery
• li-ion
• electrode composite
• carbon nanomaterial
• carbon nanotubes
• lithium vanadium phosphate
• lithium titanate