Study of full concentration-gradient Li(Ni sub(0.8)Co sub(0.1)Mn sub(0.1))O sub(2) cathode material for lithium ion batteries

A high-energy full concentration-gradient cathode material with an average composition of Li(Ni sub(0.8)Co sub(0.1-) Mn sub(0.1))O sub(2) has been successfully synthesized by a hydroxide co-precipitation method. Ni content decreases gradually along the radius of the spherical particle, and the content of Co and Mn increases. The electrochemical properties of this concentration-gradient material are studied and compared to those of the homogeneous Li(Ni sub(0.8)Co sub(0.1)Mn sub(0.1))O sub(2) material. In the concentration-gradient material of Li(Ni sub(0.8)Co sub(0.1-) Mn sub(0.1))O sub(2), the inside part rich in Ni delivers a very high capacity, while the Mn-rich outside part improves the cycling stability and rate performance. The concentration-gradient material has superior electrochemical properties compared to the homogeneous material. The initial capacity of the concentration-gradient Li(Ni sub(0.8)Co sub(0.1)Mn sub(0.1))O sub(2) is 185.2 mA h g super(-1) at 1 C between 2.8 and 4.3 V and retains 93.2% after 100 cycles. The composite also has a good rate performance with a high capacity of about 175 mA h g super(-1) even at 2 C rate.