Synthesis and performance of Al 3+ -doped cathode materials 0.6Li[Li 1/3 Mn 2/3 ]O 2 · 0.4Li[Ni 1/3 Mn 1/3 Co( 1/3- y ) Al y ]O 2 by high temperature solid-state method

0.6Li[Li 1/3 Mn 2/3 ]O 2 · 0.4Li[Ni 1/3 Mn 1/3 Co (1/3- y ) Al y ]O 2 ( y = 0, 0.03, 0.08, 0.13) was prepared by a high-temperature solid-state method as cathode material for lithium-ion batteries. X-ray diffraction and scanning electron microscopy were used to assess the structure and morphology of the samples. Electrochemical performance testing, AC impedance testing, and cyclic voltammetry testing were performed to study various aspects of the cathode materials. The results showed that the addition of Al 3+ had little effect on the charge–discharge performance, but the cycling performance and stability of the material were significantly enhanced. When the doping fraction of Al 3+ was 0.08, the cathode material 0.6Li[Li 1/3 Mn 2/3 ]O 2 · 0.4Li[Ni 1/3 Mn 1/3 Co (19/75) Al 0.08 ]O 2 had good electrochemical performance. The first discharge specific capacity reached 161.1 mAh · g −1 in the charge and discharge test at 0.1 C rate. After 20 cycles, the discharge capacity was still 159.7 mAh · g −1 . The charge–discharge specific capacity had almost no attenuation.