Direct Water-Cooled Battery Cell With Sacrificial Corrosion Protection

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Solution Overview

Problem

Conventional direct water-cooling battery cells face issues with corrosion due to the material characteristics of their exterior cases, leading to increased manufacturing costs and vulnerability to electrical insulation deterioration.

Innovation Solution

A battery cell design featuring a scratch region on the plating layer with a porous coating layer containing a sacrificial metal having a higher ionization tendency than the case material, which facilitates electron migration and ionization reactions to enhance corrosion resistance, allowing the use of non-insulated general cooling water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If direct water-cooling method is used to dissipate heat from battery cells, then heat dissipation efficiency is improved, but corrosion resistance deteriorates due to material characteristics of the exterior case

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidcorrosion resistance

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

A plating layer is formed on the exterior case before the direct water-cooling process begins. This plating layer serves as a preliminary protective barrier that prevents corrosion of the base material when cooling water is applied, thereby resolving the contradiction between improved heat dissipation and maintained corrosion resistance

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The exterior case is constructed as a composite structure with a base material and a plating layer having different properties. The plating layer provides corrosion resistance while the base material provides structural strength, allowing the system to simultaneously achieve good heat dissipation and corrosion resistance

Inventive Principle:

Principle #40Composite materials

2Strength

If nickel-plated iron is used for the exterior case to provide structural strength, then mechanical strength is improved, but electrical insulation deteriorates due to polar characteristics

Engineering Contradiction:

Improvemechanical strengthVSAvoidelectrical insulation

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

A plating layer is applied to the nickel-plated iron exterior case before use. This plating layer acts as a preliminary insulating barrier that prevents electrical polarization and maintains electrical insulation, while the underlying nickel-plated iron structure continues to provide mechanical strength

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The plating layer serves as an intermediary between the conductive nickel-plated iron case and the cooling water environment. It mediates the electrical properties by providing insulation while allowing the structural material to maintain its mechanical functions

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If insulating oil or special cooling water is used to prevent corrosion, then corrosion resistance is improved, but manufacturing cost increases due to expensive materials

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of using expensive insulating oil or special cooling water, a plating layer is applied to the exterior case as a durable, cost-effective protective barrier. This plating layer provides long-term corrosion resistance without requiring expensive coolant additives, thereby reducing manufacturing costs while maintaining corrosion protection

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The solution changes the approach from modifying the coolant (using expensive insulating oil or special water) to modifying the case surface (applying a plating layer). This parameter change in the protection strategy allows the use of ordinary cooling water while achieving corrosion resistance through the plated surface

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 design improves corrosion resistance and electrical stability, enabling cost-effective direct water-cooling without expensive insulating treatments, while maintaining effective heat dissipation.

Implementation Method 1

a sacrificial coating layer provided to surround the scratch region and containing a sacrificial material having a higher metal ionization tendency than that of the plating layer

Methodology Applied

Scientific EffectMetal ionization: Ionisation

Implementation Method 2

improving corrosion resistance of the battery cell by using a sacrificial metal having a higher metal ionization tendency than that of a battery cell case

Methodology Applied

Scientific EffectGalvanic corrosion protection: Redox Reactions

Data Source

PatentEP4435940B1Battery cell, manufacturing method thereof, and direct water-cooling battery module comprising the same

Publication Date: 2025.12.31 LG ENERGY SOLUTION LTD

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AI summary

The present invention relates to a battery cell, a manufacturing method thereof, and a battery module comprising the same, and a battery cell related to one example of the present invention comprises an electrode assembly, a case accommodating the electrode assembly, a plating layer formed on an outer surface of the case, a scratch region formed by removing a partial region of the plating layer, and a porous coating layer provided to surround the scratch region and containing a sacrificial material having a higher metal ionization tendency than that of the plating layer.