Vehicle Battery Housing Sealing for Zero-Gap Electrolyte Protection

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Solution Overview

Problem

Existing battery housings face challenges such as increased assembly errors, reduced energy capacity, complex manufacturing processes, and corrosive infiltration due to electrolyte penetration in the zero-gap area, which are not adequately addressed by current sealing methods.

Innovation Solution

A battery housing design incorporating a liquid seal in the zero-gap area between the housing cover and sealing flange, combined with a circumferential seal, using a fluid-resistant and electrolyte-impermeable sealant to prevent electrolyte penetration and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a molded seal is used in larger battery housings, then sealing effectiveness is improved, but handling difficulty increases and assembly errors rise

Engineering Contradiction:
Improvesealing effectivenessVSAvoidhandling difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sealing system is divided into two independent parts: a molded seal for the contact edge and a liquid seal for the zero-gap area. This segmentation allows each seal to be optimized for its specific function and application method, with the liquid seal being easier to apply than handling large molded seals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The liquid seal acts as an intermediary element that fills the zero-gap area between housing components. It mediates the sealing function in regions where molded seals are difficult to apply, providing a complementary sealing solution that is easier to handle and apply.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a sealing cord is used, then sealing is achieved, but the sealing flange size increases reducing battery cell installation space

Engineering Contradiction:
ImprovesealingVSAvoidbattery cell installation space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

Different sealing methods are applied to different locations: the molded seal is applied to the contact edge where structural sealing is needed, while the liquid seal is applied to the zero-gap area where space efficiency is critical. This local differentiation optimizes both sealing effectiveness and space utilization.

Inventive Principle:
Principle #3Local quality

3Reliability

If adhesive joints are used for housing seals, then sealing is achieved, but curing time increases extending production time

Engineering Contradiction:
ImprovesealingVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The liquid seal replaces adhesive joints by using a liquid-based sealing mechanism that does not require curing time. The liquid seal sets quickly upon application, eliminating the extended curing periods associated with adhesive bonding and thereby reducing production time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If adhesive seams are used, then sealing is achieved, but process parameter control complexity increases manufacturing costs

Engineering Contradiction:
ImprovesealingVSAvoidprocess parameter control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The liquid seal is applied as a simple, quick-setting material that does not require complex process control systems. It replaces expensive adhesive systems that need precise control of temperature, humidity, and surface quality parameters, thereby simplifying the manufacturing process and reducing costs.

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

5Reliability

If adhesive seams are used, then sealing is achieved, but removability during maintenance is lost

Engineering Contradiction:
ImprovesealingVSAvoidremovability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The liquid seal is designed to be removable during maintenance and repair operations. Unlike permanent adhesive bonds, the liquid seal can be discarded or removed without causing damage to the housing components, enabling easy maintenance and recovery of the sealing system.

Inventive Principle:
Principle #34Discarding and recovering

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

Ensures a reliable, leak-free, and corrosion-resistant battery housing that reduces manufacturing complexity and assembly errors, maintaining energy capacity and extending the battery's service life.

Implementation Method 1

a liquid seal which prevents penetration of the electrolyte into the zero-gap area

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

molded seals made of plastic or rubber materials, such as EPDM (ethylene propylene diene rubber), NBR (acrylonitrile or nitrile butadiene rubber), or silicone foam

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3770989B1Battery housing for a vehicle battery
Publication Date: 2025.09.10 VOLKSWAGEN AG
  • EP3770989B1 patent drawingFigure 1~2
  • EP3770989B1 patent drawingFigure 3
  • EP3770989B1 patent drawingFigure 4

AI summary

The invention relates to a battery housing (4) for a vehicle battery (2), comprising a housing part (6) with a circumferential sealing flange (10), and a housing cover (8) which has a circumferential seal (14) which seals a contact edge (16) formed between the sealing flange (10) and the housing cover (6), wherein a zero-gap area (20) is formed radially outside to the seal (14) between the housing cover (6) and the sealing flange (10), and wherein a liquid seal (22) is introduced into the zero-gap area (20).