Development of novel cathode materials for Li-ion batteries

New CrOx modified positive electrodes and quaternary spinels LiCryMn2-yO4 (y=0.05 to y=0.5) and LixCryMn2-yO4+delta(y=0.02 to 0.1) were synthesized and electrochemically characterized. An increase of O/Cr ratio and the subsequent modification of the oxide increases the capacity of m-CrOx, to 250 mA/g. The average values of these cells is 3.0 V which gives an average power density for m-CrOx of approximately 650 Wh/g. The CrOx doped LiCr0.1Mn1.9O4.132 that was synthesized using high oxygen pressure showed the best capacity retention. Using seven times higher discharge rate than that for the pure spinel or Cr3+ doped spinel (LiCr0.1Mn1.9O4), the capacity of LiCr0.1Mn1.9O4.132 remained almost unchanged after 200 cycles.