Lead-Acid Battery Positive Electrode Adhesion Through Fiber Porosity Control

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Solution Overview

Problem

Lead-acid batteries face issues with positive electrode material detachment from the current collector, leading to reduced life characteristics and capacity, due to inadequate adhesion and excessive pore volume.

Innovation Solution

Incorporating fibers with an average specific surface area of 0.25 m^2/g or more, measured by the BET method using krypton gas, into the positive electrode material, while maintaining a total pore volume per unit mass of 0.167 cm^3/g or less, to enhance adhesion and prevent material detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the total pore volume per unit mass of the positive electrode material is increased to improve reactivity, then the battery capacity improves, but the positive electrode material becomes loose and falls off from the current collector

Engineering Contradiction:
Improvebattery capacityVSAvoidadhesion of positive electrode material
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the total pore volume per unit mass within 0.150-0.200 cm³/g and the fiber content within 3-7 wt%. This optimization balance allows sufficient porosity for electrolyte penetration and electrochemical reactivity while maintaining adequate structural integrity and adhesion to prevent material detachment during battery operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by incorporating fibers into the positive electrode material matrix. The fiber content is controlled at 3-7 wt% to provide mechanical reinforcement and improve adhesion to the current collector, while the composite structure maintains the necessary porosity for electrochemical performance. This composite approach resolves the contradiction between structural stability and reactivity.

Inventive Principle:
Principle #40Composite materials

2Strength

If fibers are added to the positive electrode material to improve adhesion, then the material strength increases, but the total pore volume increases and reactivity decreases

Engineering Contradiction:
Improveadhesion of positive electrode materialVSAvoidbattery capacity
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent resolves this contradiction through parameter optimization by controlling both the fiber content (3-7 wt%) and total pore volume (0.150-0.200 cm³/g) within specific ranges. This dual parameter control ensures that fibers provide sufficient mechanical strength and adhesion while maintaining the porosity necessary for electrolyte access and electrochemical reactivity, preventing capacity loss.

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

This configuration effectively prevents positive electrode material from falling off, significantly improving the life characteristics and capacity of lead-acid batteries by ensuring strong adhesion and optimal reactivity.

Implementation Method 1

an average specific surface area of the fibers measured by a BET method using krypton gas as an adsorption gas is 0.25 m2/g or more

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3660960B1Lead-acid battery
Publication Date: 2024.04.17 GS YUASA INT LTD
  • EP3660960B1 patent drawingFigure 1
  • EP3660960B1 patent drawingFigure 2
  • EP3660960B1 patent drawingFigure 3

AI summary

A lead-acid battery includes a positive electrode plate having a current collector and a positive electrode material supported by the current collector, and a negative electrode plate. A total pore volume per unit mass of the positive electrode material is 0.167 cm3/g or less. The positive electrode material contains a fiber, and an average specific surface area of the fibers measured by the BET method using krypton gas as an adsorption gas is 0.25 m2/g or more.