Electrochemical Cell Assembly With Intumescent Thermal Isolation

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Solution Overview

Problem

Existing solutions for preventing thermal runaway in electrochemical cells require expensive high-thermal-resistance materials and facilitate heat transfer due to the use of thermally conductive mechanical assembly systems, increasing battery costs and risk of propagation.

Innovation Solution

Incorporation of intumescent materials that swell upon heat exposure to prevent thermal runaway by causing the casing to rupture, eliminating the need for costly thermal insulation and reducing heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-thermal-resistance insulating layers are used to prevent thermal runaway propagation, then thermal insulation effectiveness is improved, but manufacturing cost increases

Engineering Contradiction:
Improvethermal insulation effectivenessVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the thermal insulation mechanism from passive high-thermal-resistance materials to active intumescent materials that transform their properties when exposed to heat. The insulating layer transitions from a thin, low-cost state to a thick, high-insulation state upon thermal activation, resolving the contradiction between insulation effectiveness and manufacturing cost

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The intumescent insulating layer undergoes a phase transition when exposed to heat, expanding from a compact state to a voluminous foam structure. This phase change enables the material to achieve high thermal insulation properties temporarily when needed, without requiring expensive permanent insulation materials

Inventive Principle:
Principle #36Phase transitions

2Strength

If thermally conductive mechanical assembly systems are used for battery assembly, then mechanical strength and assembly ease are improved, but heat transfer between cells increases

Engineering Contradiction:
Improvemechanical assembly strengthVSAvoidheat transfer between cells
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intumescent insulating layer as an intermediary between electrochemical cells and the mechanical assembly system. This layer acts as a thermal barrier that prevents heat transfer while allowing the mechanical assembly system to maintain its thermally conductive, high-strength properties for efficient heat dissipation during normal operation

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Effectively prevents thermal runaway propagation while reducing costs by using intumescent materials that swell and rupture the casing to isolate cells, enhancing thermal insulation and mechanical stability.

Implementation Method 1

the intumescent means 28 are capable of swelling when subjected to a temperature greater than or equal to a swelling temperature

Methodology Applied
Scientific EffectIntumescent swelling: Intumescent Materials

Implementation Method 2

the frangible part 40 is configured to break under the effect of the swelling of the intumescent means 28

Methodology Applied
Scientific EffectFracture mechanics: Fracture Mechanics

Data Source

PatentEP4376169B1Assembly comprising a plurality of electrochemical cells and electrical device comprising such an assembly
Publication Date: 2026.01.28 AUTOMOTIVE CELLS CO SE
  • EP4376169B1 patent drawingFigure 1
  • EP4376169B1 patent drawingFigure 2

AI summary

The invention relates to an assembly (12) comprising: - a stack comprising a plurality of electrochemical cells (22) arranged along a longitudinal direction (X) and a plurality of insulating layers (24), and - a housing (26) defining a cavity in which the stack (20) is received. The stack (20) further comprises intumescent means (28) arranged along the longitudinal direction (X) between two adjacent electrochemical cells (22), the intumescent means (28) being capable of swelling when subjected to a temperature above a swelling temperature. The housing (26) comprises at least one frangible portion (40) configured to rupture under the effect of the swelling of the intumescent means (28).