Lithium Manganese Composite Oxide Battery Electrode Design

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Solution Overview

Problem

Lithium ion secondary batteries face challenges in achieving voltage compatibility, output characteristics, and charge-discharge cycle characteristics when used in combination with lead-acid storage batteries, particularly in reducing the load on lead-acid batteries and maintaining performance during rapid charging and discharging.

Innovation Solution

A nonaqueous electrolyte battery is designed with a positive electrode containing lithium-manganese composite oxide (LiMn 2-x M x O 4) and a negative electrode containing lithium titanate (Li 4 Ti 5 O 12), where x is between 0.22 and 0.7, and the pore specific surface area of the positive electrode layer is between 2 and 5 m^2/g, optimizing the capacity ratio between the electrodes to enhance voltage compatibility and cycle performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the pore specific surface area of the positive electrode layer is increased to improve output characteristics, then the output characteristics are improved, but the charge-discharge cycle characteristics deteriorate

Engineering Contradiction:
Improveoutput characteristicsVSAvoidcharge-discharge cycle characteristics
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent optimizes the pore specific surface area parameter to a specific range (2-5 m²/g) to achieve the best balance between output characteristics and cycle life. This parameter optimization resolves the contradiction by finding the optimal value that satisfies both requirements simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the substitution amount x in LiMn2-xMxO4 is increased to improve voltage compatibility with lead-acid batteries, then voltage compatibility is improved, but the capacity of the positive electrode decreases

Engineering Contradiction:
Improvevoltage compatibilityVSAvoidelectrode capacity
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent optimizes the substitution amount x to a specific range (0.22 ≤ x ≤ 0.7) to achieve the best balance between voltage compatibility and electrode capacity. This parameter optimization resolves the contradiction by finding the optimal substitution level that maintains both compatibility and capacity.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The battery exhibits excellent voltage compatibility, output characteristics, and charge-discharge cycle characteristics, reducing the load on lead-acid batteries and maintaining performance even during rapid charging and discharging, thus efficiently regenerating energy and extending battery life.

Implementation Method 1

A pore specific surface area obtained by a BET method using N2-adsorption of the positive electrode layer is 2 m2

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3246972B1Nonaqueous electrolyte battery and battery system
Publication Date: 2019.06.05 KK TOSHIBA
  • EP3246972B1 patent drawingFigure 1~2
  • EP3246972B1 patent drawingFigure 3~4
  • EP3246972B1 patent drawingFigure 5

AI summary

According to one embodiment, a nonaqueous electrolyte battery is provided. The nonaqueous electrolyte battery includes a positive electrode including a positive electrode, a negative electrode including a negative electrode, and a nonaqueous electrolyte battery. The positive electrode layer contains lithium-manganese composite oxide represented by a general formula of LiMn2-xMxO4. x is within the range of 0.22 ≤ x ≤ 0.7 and M is at least one element selected from a group consisting of Mg, Ti, Cr, Fe, Co, Zn, Al, and Ga. The negative electrode layer contains lithium titanate Li4Ti5O12. A pore specific surface area of the positive electrode layer is 2 m2/g or more and less than 5 m2/g. A ratio of a capacity of the positive electrode per pore surface area of the positive electrode layer to a capacity of the negative electrode per pore surface area of the negative electrode layer is within the range of 1 or more and less than 2.4.