Positive electrode material for lithium rechargeable battery, positive electrode for lithium rechargeable battery, comprising same, and lithium rechargeable battery

Abstract

The present invention relates to a positive electrode material for a lithium rechargeable battery, the positive electrode material for a lithium rechargeable battery, according to the present invention, comprising a first positive electrode active material and a second positive electrode active material. The first positive electrode active material and the second positive electrode active materialare lithium composite transition metal oxides comprising a transition metal including nickel (Ni), cobalt (Co) and manganese (Mn). The average particle diameter (D50) of the first positive electrodeactive material is greater than the average particle diameter (D50) of the second positive electrode active material. The ratio of the number of moles of lithium (Li) to the total number of moles of the transition metal of the first positive electrode active material (Li / Me)1 is higher than 1 to 1.5 or lower. The ratio of the number of moles of lithium (Li) to the total number of moles of the transition metal of the second positive electrode active material (Li / Me)2 is 0.9 to 1. The crystal size of the second positive electrode active material is at least 180 nm.

Description

[Technical field] [0001] CROSS-REFERENCE TO RELATED APPLICATIONS [0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0058423 filed on May 23, 2018, the entire contents of which are incorporated herein by reference. [0003] technical field [0004] The present invention relates to a positive electrode material for a lithium secondary battery, and a positive electrode for a lithium secondary battery and a lithium secondary battery comprising the material. [Background technique] [0005] Recently, with the rapid spread of electronic devices using batteries, such as mobile phones, notebook computers, and electric vehicles, the demand for secondary batteries having small size and light weight and relatively high capacity has rapidly increased. In particular, since lithium secondary batteries have small size and light weight and high energy density, they are attracting attention as a driving power source for portable devices....

AI Technical Summary

Problems solved by technology

However, since lithium transition metal oxides containing excess lithium have high irreversible capacity, and in high-voltage activation utilizing excess lithium, oxygen other than lithium is released to the outside of the active material structure, there are problems that the active material structure Collapse and voltage sag occurs, thereby accelerating the deterioration of battery cells

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