Effect of sonochemistry: Li- and Mn-rich layered high specific capacity cathode materials for Li-ion batteries
P. Sivakumar, P. K. Nayak, J. Grinblat, N. Perkas, B. Markovsky, D. Aurbach, A. Gedanken
Li- and Mn-rich layered Li1.2Ni0.13Co0.13Mn0.54O2 cathode material was synthesized using sonochemical method followed by annealing at 700, 800, and 900 A degrees C for 10 h. The material was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and electrochemical techniques. Its performance as a cathode material for Li-ion batteries was examined. With the sample annealed at 900 A degrees C, an initial specific capacity of 240 mAh g(-1) was obtained, which decreased to 215 mAh g(-1) after 80 cycles, thus retaining about 90 % of its initial capacity. In contrast, samples annealed at lower temperatures exhibited lower capacity retention upon cycling. Thus, the final annealing temperature was found to have a significant effect on the electrochemical stability of this material in terms of capacity, average voltage, and rate capability. The advantage of this synthesis, which includes a sonochemical stage, compared with a conventional co-precipitation synthesis, was also confirmed.