Nickel-based positive active material of lithium ion secondary battery and preparation method thereof

• Main Authors: LI XINGCUI, IKEDA KAZUTAKA, ZHANG HAIBO, LU JIANTONG, WANG FEIFEI
• Format: Patent
• Language: Chinese; English
• Published: 23.07.2014
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention discloses a nickel-based positive active material of a lithium ion secondary battery. The nickel-based positive active material is subjected to wrapping treatment and is prepared from the following components in percentage by weight: 50%-99.5 percent of nickel-based material as a matrix and 0.05-50 percent of shell material. A general formula of the lithium ion secondary battery can be expressed as [Li(p)Ni(x)Co(y)Mn(z)O2][Li(q)Ni(a)Co(b)Mn(c)O2]. A preparation method of the nickel-based positive active material comprises the steps of preparing a precursor of the positive material of the lithium ion secondary battery; and preparing the positive material of the lithium ion secondary battery. According to the invention, as the gradient variation of nickel concentration between the matrix material and the shell material is realized by virtue of wrapping, the nickel-based positive active material has good electrochemical performance of high gram volume, high working voltage, good cycle performance a