Lead-Acid Battery Pasting Mat Composition Against Layer Bonding

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Solution Overview

Problem

Nonwoven fabrics used in lead acid batteries face issues with delamination due to bonding between layers under severe conditions of pressure, high temperature, and humidity, which affects the battery's charging/discharging reaction and overall performance.

Innovation Solution

A nonwoven fabric with a thickness of 0.02 mm to 0.1 mm, containing microglass fibers and heat-fusible binder fibers with a core/sheath structure, specifically designed to maintain bonding strength below 0.05 N under various environmental conditions, ensuring minimal delamination and enhanced tensile strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the nonwoven fabric is made thinner to improve battery performance and reduce distance between pole plates, then the charging/discharging reaction is improved, but the tensile strength and resistance to delamination deteriorate

Engineering Contradiction:
Improvethickness of nonwoven fabricVSAvoidtensile strength and delamination resistance
Core Design Contradiction:
Length of moving objectVSStrength

Solution Approach 1:

The nonwoven fabric uses a composite structure combining microglass fibers (for chemical resistance and porosity) with heat-fusible binder fibers (for mechanical strength). This composite approach allows the fabric to achieve both thinness and sufficient tensile strength, resolving the contradiction between reduced thickness and maintained strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes specific parameters including the fineness of heat-fusible binder fibers (0.5-2.0 dtex), the blending ratio (5-30 wt%), and thickness (0.02-0.1 mm) to achieve the desired balance between thinness and strength. By carefully controlling these parameters, the fabric maintains adequate tensile strength at reduced thickness.

Inventive Principle:
Principle #35Parameter changes

2Strength

If heat-fusible binder fiber is added to improve tensile strength, then the sheet strength increases, but bonding between layers occurs under pressure and temperature leading to delamination

Engineering Contradiction:
Improvetensile strengthVSAvoidlayer bonding stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The heat-fusible binder fibers are strategically used only in specific amounts (5-30 wt%) and with specific fineness (0.5-2.0 dtex) to provide localized bonding where needed for tensile strength, while avoiding excessive bonding that would cause layer delamination. This controlled local application of binding function resolves the contradiction.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention carefully controls the fineness (0.5-2.0 dtex) and blending ratio (5-30 wt%) of heat-fusible binder fibers to optimize the balance between achieving sufficient tensile strength and preventing excessive bonding under pressure and temperature conditions.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If conventional pasting paper is used to support lead paste, then workability in battery assembly is improved, but the paper decomposes by sulfuric acid leading to electrolyte stratification

Engineering Contradiction:
Improveworkability in battery assemblyVSAvoidresistance to sulfuric acid decomposition
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention replaces the decomposable pulp-based pasting paper with a durable microglass fiber nonwoven fabric that resists sulfuric acid decomposition. This substitution maintains the supportive function during battery assembly while providing long-term reliability in the harsh electrolyte environment, eliminating the need for replacement or regeneration.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The nonwoven fabric combines microglass fibers (providing chemical resistance to sulfuric acid) with heat-fusible binder fibers (providing mechanical integrity and workability). This composite material simultaneously achieves the ease of operation needed for battery assembly and the reliability required for sulfuric acid resistance.

Inventive Principle:
Principle #40Composite materials

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 solution prevents delamination and maintains the integrity of the nonwoven fabric under severe conditions, improving the battery's performance and extending its lifespan by maintaining the desired thickness and tensile strength while inhibiting electrolyte stratification.

Implementation Method 1

a nonwoven fabric (pasting mat) for lead acid batteries containing a microglass fiber and a heat-fusible binder fiber

Methodology Applied
Scientific EffectHeat-fusible binding: Melting

Implementation Method 2

a pasting mat material (nonwoven fabric) using a microglass fiber which is resistant to sulfuric acid as an electrolyte and that is produced by a wet method

Methodology Applied
Scientific EffectPorosity: Porosity

Implementation Method 3

for enhancing the battery performance, a mat material (pasting mat) using a microglass fiber has been used in place of the pasting paper

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentUS20240243433A1Nonwoven fabric for lead acid batteries using glass fiber and heat-fusible binder fiber
Publication Date: 2024.07.18 ENTEK ASIA INC

AI summary

[Problem] To provide a nonwoven fabric (pasting mat) that does not undergo bonding between the nonwoven fabrics (pasting mats) even under severe conditions (a pressure in winding and a high temperature and a high humidity in transportation, storage, and production).[Means for Resolution] A pasting mat for lead acid batteries, containing a microglass fiber and a heat-fusible binder fiber, wherein the pasting mat has a thickness under a pressure of 20 kPa of 0.02 mm or more and less than 0.1 mm, and has a bonding strength between the pasting mats after being left for 48 hours under a pressure of 5 to 10 kPa in an environment of a temperature of 70 to 90° C. and a humidity of 75% of less than 0.05 N.