Lithium Complex Oxide For Lithium Secondary Battery Positive Active Material And Method Of Preparing The Same

Abstract

Disclosed is a lithium complex oxide and method of manufacturing the same, more particularly, a lithium complex oxide effective in improving the characteristics of capacity, resistance, and lifetime with reduced residual lithium and with different interplanar distances of crystalline structure between a primary particle locating in a internal part of secondary particle and a primary particle locating on the surface part of the secondary particle, and a method of preparing the same.

Description

technical field [0001] The present invention relates to a lithium composite oxide for a lithium secondary battery and a preparation method thereof. More specifically, it relates to the following lithium composite oxide and a preparation method thereof: in the conventional method of forming lithium along the a-axis and c-axis directions of the crystal In the positive electrode active material of the ion diffusion path (Li ion pathway), in order to improve the residual amount of lithium, cleaning is carried out in the production process. As a result, although the residual amount of lithium is reduced, there is a problem of deteriorating performance. Based on this situation, by Coating the surface with a heterogeneous element makes the interplanar spacing of the crystal structure different between the primary particles located inside the secondary particles and the primary particles located on the surface of the secondary particles, and has the effect of improving capacity charact...

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Problems solved by technology

[0006] However, since the Ni rich system (Ni rich system) with a Ni content of 65% or more is a low-temperature reaction, it has the ability to form LiOH, Li on the surface of the positive electrode active material 2 CO 3 The problem of high residual lithium in the form

This residual lithium, that is, unreacted LiOH and Li 2 CO 3 Reacts with the electrolyte in the battery, causing gas generation and expansion, which leads to a serious decrease in high temperature safety

In addition, when the slurry is mixed before the preparation of the plate, it will cause gelation due to the high viscosity of unreacted LiOH

[0007] In order to remove such unreacted Li, a washing process is generally performed after the preparation of the active material to greatly reduce the amount of residual lithium. However, in this case, the surface of the positive electrode active material is damaged during the washing process, resulting in a decrease in capacity and rate characteristics. , and also cause another problem, such as an increase in impedance when stored at high temperature

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