Synthesis and Characterization of LiAl1 / 4Ni3 / 4 O 2 ( R 3̄m ) for Lithium‐Ion (Shuttlecock) Batteries

The synthesis and characterization of were carried out in order to improve the electrochemical properties of for lithium ion batteries. Single phase of ( and in hexagonal setting) was obtained by heating a reaction mixture of , , and at 750°C under an oxygen stream for 20 h and examined in nonaqueous lithium cells. was oxidized to in the voltage range of 3.5–4.8 V. X‐ray diffraction examinations of indicated that the reaction proceeded in a single phase over the entire range. The rechargeable capacity was observed to be about 150 mAh · g −1 based on the sample weight. DSC measurements on fully charged and at 4.8 V were also done and the effects of substitution of aluminum for nickel in upon the electrochemical properties were discussed in terms of capacity, failure, and safety coupled with overcharge.