Positive Electrode Active Material Powder for High-Current Batteries

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Solution Overview

Problem

Nonaqueous electrolyte secondary batteries using conventional positive electrode active material powders have insufficient discharge capacity and high current rate output, making them unsuitable for applications requiring high power, such as automobiles and electric tools.

Innovation Solution

A positive electrode active material powder with primary and aggregated particles of specific diameters and a BET specific surface area, composed of lithium, nickel, cobalt, and manganese, optimized for high discharge capacity and high current rate performance, is developed, including a fibrous carbon material for enhanced conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional positive electrode active material powder is used, then the battery structure is simple and easy to manufacture, but the discharge capacity is insufficient and high current rate output is poor

Engineering Contradiction:
Improvedischarge capacityVSAvoidparticle size distribution complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the average particle diameter within 0.1-3 μm and BET specific surface area between 2-7 m2/g. These specific parameter ranges optimize the balance between discharge capacity and high current rate output, resolving the contradiction by transforming the particle size and surface area parameters to achieve superior electrochemical performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by creating a controlled particle size distribution where fine particles (0.1-3 μm) are combined with aggregated particles. This composite structure allows fine particles to provide high surface area for capacity while aggregated particles maintain structural stability, achieving both high discharge capacity and excellent high current rate output.

Inventive Principle:
Principle #40Composite materials

2Power

If conventional positive electrode active material powder is used, then the manufacturing process is simple, but the high current rate output is insufficient for automobile and power tool applications

Engineering Contradiction:
Improvehigh current rate outputVSAvoidparticle size control precision
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the average particle diameter within 0.1-3 μm and BET specific surface area between 2-7 m2/g. These specific parameter ranges optimize the balance between discharge capacity and high current rate output, resolving the contradiction by transforming the particle size and surface area parameters to achieve superior electrochemical performance.

Inventive Principle:
Principle #35Parameter changes

3Power

If the particle diameter is increased to improve high current rate output, then the power increases, but the discharge capacity decreases

Engineering Contradiction:
Improvehigh current rate outputVSAvoiddischarge capacity
Core Design Contradiction:
PowerVSQuantity of substance

Solution Approach 1:

The patent employs composite materials by creating a controlled particle size distribution where fine particles (0.1-3 μm) are combined with aggregated particles. This composite structure allows fine particles to provide high surface area for capacity while aggregated particles maintain structural stability, achieving both high discharge capacity and excellent high current rate output.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentUS8029928B2Positive electrode active material powder
Publication Date: 2011.10.04 SUMITOMO METAL MINING CO LTD

AI summary

The positive electrode active material powder of the present invention is a positive electrode active material powder, including primary particles and aggregated particles of primary particles, wherein an average particle diameter of primary particles and aggregated particles of primary particles in the powder is 0.1 μm or more and 3 μm or less on a volume basis, the percentage of [volumetric sum of particles having a particle diameter of 5 μm or more]/[volumetric sum of entire particles] is 10% or less, and a BET specific surface area of the powder is more than 2 m2/g and 7 m2/g or less. When this positive electrode active material powder is used for a nonaqueous electrolyte secondary battery, it becomes possible to exhibit a high discharge capacity and also exhibit a high output at a high current rate.