Study on the Cathode Material Composed of LiCo1/3Ni1/3Mn1/3O2 and LiMn2O4

Electric vehicles and energy storage will become the main application fields of next generation lithium-ion batteries, which require excellent performances such as high safety, large capacity and high power density for lithium-ion batteries. However, currently single cathode materials for lithium-ion batteries, such as LiCoO₂、LiMn₂O₄、LiFePO₄、LiCo_1/3Ni_1/3Mn_1/3O₂,could not meet these requests at the same time. Mixing different structures of cathode materials together is one practical way to improve performances of materials by complementary advantages of each other.

This work is to improve electronic conductivity and capacity of LiMn₂O₄ by adding LiCo_1/3Ni_1/3Mn_1/3O₂ in, and meanwhile the existence of LiMn₂O₄ could lower danger bringing from LiCo_1/3Ni_1/3Mn_1/3O₂. Different proportional mixtures with LiCo_1/3Ni_1/3Mn_1/3O₂ and LiMn₂O₄ were used as cathode materials for lithium ion battery. The results of charge-discharge tests show that the cyclic performance becomes better with the increase of LiCo_1/3Ni_1/3Mn_1/3O₂ until the proportion is higher than 5:5. The battery has better cyclic capability and kkk impedance when the proportion of LiCo_1/3Ni_1/3Mn_1/3O₂ and LiMn₂O₄ is 5:5,Itsinitial discharge specific capacity is 154.4 mAh/g, after 60 times charge-discharge, specific capacity is 143.0mAh/g, the capacity retention rate is92.62%; And the average voltage is 3.92 V(vs. Li + / Li),significantly higher than the discharge voltage platform of LiCo_1/3Ni_1/3Mn_1/3O₂ which is 3.80 V (vs. Li + / Li).