Battery Cell Lid Assembly With Dual Vent Walls for Thermal Event Containment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The increasing energy density and system voltages in battery systems, coupled with reduced sizes, necessitate enhanced safety features to prevent thermal events from propagating between battery cells.

Innovation Solution

A battery cell lid assembly with a carrier plate featuring first and second protection walls that create a space for thermal insulation and degassing, which opens under pressure to prevent thermal event propagation, and optionally filled with thermally insulative, intumescent, and endothermic filler materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If protection walls are added to prevent thermal event propagation, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements nested protection by placing a first protection wall inside the battery cell and a second protection wall outside the battery cell, both covering the degassing vent. This nested arrangement creates multiple barriers against thermal event propagation while maintaining a compact structure that integrates with the existing battery cell design.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The protection system is segmented into two distinct protection walls positioned at different locations (inside and outside the battery cell). This segmentation allows each wall to independently contribute to thermal event prevention, with the first wall blocking internal thermal events and the second wall blocking external thermal events, thereby improving safety without requiring a single complex barrier.

Inventive Principle:
Principle #1Segmentation

2Temperature

If a space is created between protection walls for thermal insulation, then thermal insulation is improved, but volume increases

Engineering Contradiction:
Improvethermal insulationVSAvoidvolume
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The space for thermal insulation is created by nesting the first protection wall inside the battery cell and the second protection wall outside, utilizing the existing degassing vent pathway. This nested configuration allows the insulating space to be formed within the existing structural envelope without requiring additional external volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The protection walls are arranged along the longitudinal axis of the battery cell, utilizing the length dimension rather than adding width or height. The first protection wall extends along a first longitudinal direction and the second protection wall extends along a second longitudinal direction, creating the insulating space in the longitudinal dimension while maintaining a compact transverse profile.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enhances the durability and safety of battery cells by preventing thermal event propagation and providing thermal insulation, while maintaining a compact design.

Implementation Method 1

This effect relies on the space provided between the first protection wall and the second protection wall which provides thermal insulation.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

In an example, the at least one filler material comprises an endothermic material.

Methodology Applied
Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 3

In an example, the at least one filler material comprises an intumescent material.

Methodology Applied
Scientific EffectIntumescent material swelling: Intumescent Materials

Data Source

PatentEP4661171A1Battery cell lid assembly for a battery cell of a vehicle, battery cell, filler material component, battery pack, vehicle and method
Publication Date: 2025.12.10 VOLVO CAR CORP
  • EP4661171A1 patent drawingFigure 1
  • EP4661171A1 patent drawingFigure 2
  • EP4661171A1 patent drawingFigure 3~4

AI summary

The disclosure relates to a battery cell lid assembly (20) for a battery cell of a vehicle. The battery cell lid assembly (20) comprises a carrier plate (24), a first protection wall (28), and a second protection wall (30). The carrier plate (24) comprises a first side (34), a second side (36), and a through hole (38) for a degassing vent (26). The through hole (38) extends from the first side (34) to the second side (36). The first protection wall (28) is mechanically connected to the first side (34) and covers the through hole (38). The second protection wall (30) is mechanically connected to the second side (36) and covers the through hole (38). The first protection wall (28) and the second protection wall (30) are arranged at a distance (A). Additionally, a battery cell for a vehicle is described. Furthermore, a filler material component for a battery cell lid assembly (20), a battery pack and a vehicle are shown. Also, a method for manufacturing a battery cell lid assembly (20) for a battery cell of a vehicle is described.