Composite positive electrode material for lithium ion battery and battery using the same

Abstract

Disclosed is a composite positive electrode material for lithium ion batteries, which especially enables to achieve excellent high-rate discharge characteristics in a battery. Also disclosed are a slurry, positive electrode and battery using such a composite positive electrode material. Specifically disclosed is a composite positive electrode material for lithium ion batteries, which contains a positive electrode active material (a), a conductive substance (b) having a primary particle diameter of 10-100 nm and / or a fibrous conductive substance (c) having a fiber diameter of from 1 nm to 1 [mu]m, and a conductive substance (d) having an aspect ratio of 2-50. This composite positive electrode material for lithium ion batteries is obtained by mixing the conductive substance (d) with a composition containing the positive electrode active material (a), the conductive substance (b) and / or the conductive substance (c), which composition is obtained by dispersing the positive electrode active material (a), the conductive substance (b) and / or the conductive substance (c) in a solvent to a state where they are forcibly dispersed, and then agglutinating them.

Description

technical field [0001] The present invention relates to a composite positive electrode material for a lithium ion battery containing a positive electrode active material and a conductive material, and a slurry, a positive electrode, and a battery using the material. Background technique [0002] In recent years, electric vehicles, hybrid vehicles, fuel cell vehicles, etc. have attracted attention against the background of rising prices of petroleum resources and the upsurge of the global environmental protection movement, and some of them have been put into practical use. In these drive systems, secondary batteries are indispensable as an auxiliary power source and the like, and high output secondary batteries capable of responding to sudden start and sudden acceleration of automobiles are desired. In addition, from the viewpoint of weight load on the vehicle and increase in fuel consumption, secondary batteries with high energy density are desired. From such a background, ...

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Problems solved by technology

[0016] In addition, as disclosed in Patent Document 4, although it is intended to form a conductive path between positive electrode active materials covered with spherical graphite by fibrous carbon, due to the aspect ratio of fibrous carbon (Example of Patent Document 4 In general, the aspect ratio of 75) is generally large, so it is difficult to properly arrange between positive electrode active materials (especially in dry mixing), and it will become a positive electrode active material without appropriate pore capacity, The high-speed discharge performance of the obtained positive electrode was insufficient

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