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 Li4Ti5012 electrode prepared from the well-dispersed nanopowders can preserve 88.6% of the capacity at 0.1 Ag-1 when being cycled at 1 Ag (-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 Li4Ti5012 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. (c) 2007 Elsevier Ltd. All rights reserved.