Battery Module Layout With Smaller End Cells for Thermal Runaway

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Thermal runaway in battery modules poses a significant safety risk due to rapid temperature increases and energy release, which can lead to destruction or fire, and existing technologies struggle to effectively mitigate this phenomenon.

Innovation Solution

The battery module design incorporates smaller capacity cells at the ends, connected in parallel and series with larger capacity cells in the center, utilizing thermal walls to isolate units and manage heat transfer, thereby reducing the energy release during thermal runaway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If smaller capacity cells are used at the ends of the battery module, then the energy release during thermal runaway is reduced, but the total energy storage capacity of the module is decreased

Engineering Contradiction:
Improveenergy release during thermal runawayVSAvoidtotal energy storage capacity
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The battery module is segmented into different cell configurations: end units with single smaller capacity cells and intermediate units with larger capacity cells. This segmentation allows the module to reduce energy release at thermal runaway-prone end positions while maintaining higher energy density in the intermediate sections, thus resolving the contradiction between safety and total energy storage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different cell capacities are assigned to different locations within the battery module. Smaller capacity cells are placed at the ends where thermal runaway risk is highest, while larger capacity cells are placed in the intermediate units where they contribute more to overall energy storage. This local differentiation optimizes both safety and energy storage performance.

Inventive Principle:
Principle #3Local quality

2Reliability

If thermal walls are added to separate units, then thermal runaway propagation is prevented, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvethermal runaway propagation preventionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The battery module is divided into discrete units separated by thermal walls. Each unit containing one or more cells is thermally isolated from adjacent units, preventing thermal runaway propagation. This segmentation approach provides a clear and manufacturable solution that balances safety requirements with manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

3Length of stationary object

If smaller capacity cells are placed at the ends, then thermal barrier thickness can be reduced, but the cells have lower individual capacity

Engineering Contradiction:
Improvethermal barrier thicknessVSAvoidcell capacity
Core Design Contradiction:
Length of stationary objectVSQuantity of substance

Solution Approach 1:

The thermal barrier thickness is optimized locally based on the cell capacity at each position. End units with smaller capacity cells require thinner thermal barriers, while intermediate units with larger capacity cells can accommodate thicker thermal barriers. This local optimization allows the use of smaller end cells without compromising overall safety, thereby reducing the negative impact on total energy storage.

Inventive Principle:
Principle #3Local quality

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

This design effectively mitigates thermal runaway by minimizing energy release at the ends, providing additional space for increased energy density and delaying or preventing thermal runaway, thus enhancing safety and stability.

Implementation Method 1

each unit being separated of adjacent units by respective thermal walls

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4579876A1Battery module with reduced risk of thermal runaway
Publication Date: 2025.07.02 AUTOMOTIVE CELLS CO SE
  • EP4579876A1 patent drawingFigure 1
  • EP4579876A1 patent drawingFigure 2
  • EP4579876A1 patent drawingFigure 3

AI summary

The battery module (10) comprises a plurality of units (U1, U2) aligned in an alignment direction (X). Each unit (U1, U2) is separated of adjacent units by respective thermal walls (11). The plurality of units (U1, U2) comprises two end units (U1), each arranged at a respective end of the battery module (10) in the alignment direction (X), and intermediate units (U2) aligned between the end units (U1). Each end unit (U1) comprises only one first cell (12), and each intermediate unit comprises at least one cell (12, 14), the capacity of the first cell (12) of each end unit (U1) being smaller than the total capacity of the at least one cell of at least one of the intermediate units (U2).