Fluid-Filled Tube Battery Module for Pouch Cell Swelling

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Solution Overview

Problem

Existing battery modules face issues with structural stability due to swelling of pouch-type secondary batteries, which can lead to deformation of the module frame and potential damage to the separator, reducing overall performance.

Innovation Solution

Incorporating a tube filled with a fluid inside the battery module to absorb expansion displacement and apply a constant pressing force to the battery cells, minimizing damage and maintaining optimal performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple battery cells are arranged side by side and connected in parallel, then the output current capability is improved, but the current distribution uniformity deteriorates due to resistance variations

Engineering Contradiction:
Improveoutput current capabilityVSAvoidcurrent distribution uniformity
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The battery module is divided into multiple independent battery packs, each containing a series connection of battery cells. These packs are then connected in parallel to form the complete module. This segmentation approach isolates the current paths, reducing the impact of resistance variations within individual packs and improving overall current distribution uniformity while maintaining high output current capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A current equalization structure is introduced as an intermediary component between the battery packs. This structure includes current equalization wires connected to the positive and negative terminals of adjacent battery packs, which actively balance the current distribution across parallel-connected packs, thereby improving current uniformity without compromising the high power output capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If battery cells are connected in series to increase voltage, then the output voltage is improved, but the reliability deteriorates due to increased failure risk

Engineering Contradiction:
Improveoutput voltageVSAvoidfailure risk
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

Instead of using a single long series chain of battery cells, the system is segmented into multiple series-connected packs that are then connected in parallel. This segmentation reduces the voltage stress on any single series chain and provides redundancy, as failure in one pack does not necessarily cause complete system failure, thereby improving reliability while maintaining high output voltage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrical configuration parameters are changed from a simple series connection to a complex series-parallel hybrid architecture. By adjusting the number of series cells per pack and the number of parallel packs, the system achieves the desired high output voltage while distributing the failure risk across multiple independent pathways, thus improving overall reliability.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If a complex battery module structure is used to improve heat dissipation, then the heat dissipation performance is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveheat dissipation performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The current equalization structure is merged with the heat dissipation structure. The current equalization wires are integrated into the same aluminum alloy plate that serves as the heat dissipation component. This merging allows the structure to perform dual functions: electrical current equalization and thermal management, thereby improving heat dissipation performance without proportionally increasing manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The aluminum alloy plate structure is designed to serve multiple functions simultaneously: it acts as a current equalization wire, a heat dissipation component, and a structural support element. This multi-functionality reduces the total number of separate components needed, simplifying the manufacturing process while achieving effective heat dissipation performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4391154B1Battery module and manufacturing method of the same
Publication Date: 2026.04.08 LG ENERGY SOLUTION LTD
  • EP4391154B1 patent drawingFigure 1
  • EP4391154B1 patent drawingFigure 2
  • EP4391154B1 patent drawingFigure 3

AI summary

A battery module according to one embodiment of the present disclosure includes a battery cell stack in which a plurality of battery cells are stacked in one direction; a module frame that accommodates the battery cell stack therein; and a tube that is stacked on one side of the battery cells within the battery cell stack, wherein a through hole is formed in the module frame, and wherein the tube includes an injection part connected to an external fluid supply device via the through hole, and fluid flows into the inside of the tube from the fluid supply device through the injection part.