Lead-Acid Battery Separator Coating for Lower Water Loss

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Solution Overview

Problem

Lead acid batteries experience water loss due to electrolysis, leading to reduced capacity, grid corrosion, and eventual failure, with existing zinc compound additions being difficult to implement in commercial manufacturing.

Innovation Solution

A microporous separator for lead acid batteries with a surfactant and zinc sulfate coating, enhancing additives to reduce water loss, lower float charge current, and minimize internal resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If zinc compounds are dispersed in the electrolyte to reduce water loss, then water loss is reduced, but manufacturing complexity increases due to additional process steps

Engineering Contradiction:

Improvewater lossVSAvoidmanufacturing process complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent combines the zinc compound water loss reduction function with the separator component by incorporating zinc compounds into the separator matrix or coating. This merging eliminates the need for separate electrolyte addition processes while achieving the same water loss reduction effect, thereby reducing manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The separator acts as an intermediary carrier for the zinc compounds, delivering them to the electrolyte interface where they exert their water loss reduction effect. This intermediary approach allows zinc compounds to be applied during separator manufacturing rather than requiring separate electrolyte treatment steps.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If float charge is increased to maintain battery voltage, then battery performance is improved, but water loss increases due to higher electrolysis rates

Engineering Contradiction:

Improvebattery voltageVSAvoidwater loss

Core Design Contradiction:

PowerVSLoss of substance

Solution Approach 1:

The patent converts the harmful effect of float charge (which causes electrolysis and water loss) into a beneficial outcome by using zinc compounds to suppress the electrolysis reaction. The zinc compounds inhibit hydrogen and oxygen evolution at the electrodes, allowing high float charge operation without proportional water loss increases.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Strength

If separator thickness is increased to improve mechanical strength, then separator durability is improved, but internal resistance increases

Engineering Contradiction:

Improveseparator mechanical strengthVSAvoidinternal resistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent employs composite materials in the separator construction, combining polymer matrix with zinc compound additives and potentially reinforcing fibers. This composite approach enhances mechanical strength through the reinforcing phase while the conductive zinc compounds and optimized pore structure maintain low internal resistance for ion transport.

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 separator effectively reduces water loss, float current, and internal resistance, extending battery life and improving performance.

Implementation Method 1

A microporous separator for lead acid batteries with a surfactant and zinc sulfate coating, enhancing additives to reduce water loss, lower float charge current, and minimize internal resistance

Methodology Applied

Scientific EffectSurfactant: Surfactant

Implementation Method 2

Voltage reductions are often observed over the life span of a typical lead acid battery. As a lead acid battery is cycled, water that is present in the electrolyte can be reversibly split into hydrogen and oxygen gas, especially during periods of overcharge

Methodology Applied

Scientific EffectElectrolysis: Electrolysis

Implementation Method 3

A microporous separator for lead acid batteries with a surfactant and zinc sulfate coating

Methodology Applied

Scientific EffectPorosity: Porosity

Data Source

PatentEP3417496B1Improved separators, lead acid batteries, and methods and systems associated therewith

Publication Date: 2025.10.29 DARAMIC LLC

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AI summary

Disclosed herein are novel or improved separators, battery separators, lead acid battery separators, batteries, cells, and/or methods of manufacture and/or use of such separators, battery separators, lead acid battery separators, cells, and/or batteries. In accordance with at least certain embodiments, the present disclosure or invention is directed to novel or improved battery separators for lead acid batteries. In addition, disclosed herein are methods, systems and battery separators for enhancing battery life, reducing water loss, reducing float current, minimizing internal resistance increase, reducing failure rate, reducing acid stratification and/or improving uniformity in at least lead acid batteries. In accordance with at least particular embodiments, the present disclosure or invention is directed to an improved separator for lead acid batteries wherein the separator includes improved coatings, improved configurations, and/or the like.