Effect of particle dispersion on high rate performance of nano-sized Li4Ti5O12 anode

Nano-sized Li4Ti5O12 powders with high dispersivity were fabricated by a sol-gel process using P123 as surfactant, which exhibited much better high rate performance towards Li+ insertion/extraction as compared to the densely aggregated Li4Ti5O12 particles although the primary grain sizes of both samples were almost the same. The Li4Ti5O12 electrode prepared from the well-dispersed nanopowders can preserve 88.6% of the capacity at 0.1Ag-1 when being cycled at 1Ag-1, which is obviously higher than that of the densely aggregated sample, in which only 30% capacity can be retained. By improving the dispersivity, the specific surface area of the Li4Ti5O12 nanoparticles, hence the electrode-electrolyte contact area was increased; meanwhile, more homogeneous mixing of the active materials with carbon black was achieved. All these factors might have resulted in the better high rate performance.