Battery Module Busbar Routing to Cut Heat Spread and Thickness

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Solution Overview

Problem

Conventional battery modules face issues with increased thickness, interference noise, exposure to flames during thermal runaway, and potential explosions due to the long electrical connection passages of busbars, which also act as heat diffusion paths.

Innovation Solution

The battery module design alternately stacks positive and negative electrodes at the ends of battery cells, with module busbars connected to lead tabs, and includes an inner plate for electrical connection between battery cells and end plates, minimizing the length of pack busbars and preventing short circuits by positioning them below the battery modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the busbar is disposed over the battery packs to connect battery packs, then electrical connection is achieved, but the thickness of the battery increases

Engineering Contradiction:
Improveelectrical connectionVSAvoidbattery thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The busbar connection path is moved from a vertical arrangement (over the battery packs) to a horizontal arrangement (along the bottom surface), changing the spatial dimension of the connection path. This allows electrical connection while reducing the vertical thickness of the battery assembly.

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

2Reliability

If the busbar is disposed over the battery packs, then electrical connection is achieved, but interference noise is generated due to vibrations

Engineering Contradiction:
Improveelectrical connectionVSAvoidinterference noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The busbar is extracted from its position over the battery packs and relocated to the bottom surface. This separation removes the source of vibration-induced interference noise from the vicinity of the battery cells, eliminating the harmful acoustic and electromagnetic interference while preserving electrical connection functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the busbar is disposed over the battery packs, then electrical connection is achieved, but the busbar is directly exposed to flame during thermal runaway

Engineering Contradiction:
Improveelectrical connectionVSAvoidflame exposure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The busbar is extracted from the vulnerable position over the battery packs and relocated to the bottom surface. This spatial separation ensures that during thermal runaway events, the busbar is not directly exposed to flames and heat rising from the battery cells, preventing catastrophic failure of the electrical connection system.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If the busbar area is increased for connection, then electrical connection is achieved, but the busbar functions as a heat diffusion passage between modules

Engineering Contradiction:
Improveelectrical connectionVSAvoidheat diffusion
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The busbar is relocated from a position where it would create large heat diffusion paths between modules to a position along the bottom surface. This reduces the busbar's role as a thermal conduit, minimizing unwanted heat transfer between battery modules while maintaining electrical connectivity.

Inventive Principle:
Principle #2Taking out (Extraction)

5Weight of moving object

If the pack busbar length is reduced, then weight and material cost are reduced, but electrical connection between battery packs must be maintained

Engineering Contradiction:
Improveproduct weightVSAvoidelectrical connection
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The busbar connection geometry is redesigned by changing from a vertical overhead arrangement to a horizontal bottom-surface arrangement. This dimensional change enables shorter busbar lengths and reduced material usage while maintaining effective electrical connection between battery packs through optimized routing along the bottom surface.

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

Data Source

PatentEP4475322A1Battery module, battery pack, and battery system assembly
Publication Date: 2024.12.11 HYUNDAI MOBIS CO LTD
  • EP4475322A1 patent drawingFigure 1
  • EP4475322A1 patent drawingFigure 2
  • EP4475322A1 patent drawingFigure 3

AI summary

A battery module according to one embodiment of the present invention may include battery cells of which positive electrodes and negative electrodes which are formed at one end portions thereof are alternately stacked in a stacking direction, a pair of end plates coupled to both side ends of the stacked battery cells, and module busbars electrically connected to lead tabs provided on the battery cells, wherein, among the battery cells, battery cells disposed at both side ends of the battery module are disposed so that front ends and rear ends have the same electrode.