Extensible Busbar Holder for Battery Cell Expansion

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Solution Overview

Problem

Existing battery modules with elastic members or springs between battery cells suffer from reduced energy density, increased mass, and potential stress-induced deterioration and short circuits due to varying expansion and contraction of battery cells, which are not adequately addressed by extensible busbars.

Innovation Solution

A battery module design featuring extensible busbar holders and optionally elastic members that follow the displacement of battery cells in the lamination direction, absorbing expansion and contraction without occupying space, thereby preventing bending and short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastic members or springs are disposed between battery cells adjacent to each other, then expansion and contraction of battery cells can be absorbed, but energy density of the battery module declines and mass increases

Engineering Contradiction:

Improveabsorption of expansion and contractionVSAvoidenergy density

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The busbar holder is integrated with the busbar to form a unified extensible connection system. The busbar holder and busbar work together as a single extensible component that absorbs battery cell expansion and contraction, eliminating the need for separate elastic members between cells and thereby maintaining energy density while providing the necessary mechanical compliance.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The busbar holder serves multiple functions: it holds the busbar in position, provides electrical insulation, and absorbs expansion and contraction of the battery cells through its extensible portion. This multi-functionality eliminates the need for additional dedicated elastic members, maintaining energy density while providing mechanical compliance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If elastic members or springs are disposed between battery cells adjacent to each other, then expansion and contraction of battery cells can be absorbed, but mass of the battery module increases

Engineering Contradiction:

Improveabsorption of expansion and contractionVSAvoidmass of battery module

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The busbar holder is merged with the busbar to create a unified extensible connection system that eliminates the need for separate elastic members. This integration reduces the total mass of the battery module while maintaining the capability to absorb battery cell expansion and contraction.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The busbar holder performs multiple functions including mechanical support, electrical insulation, and absorption of expansion and contraction. By combining these functions into a single component, the mass of the battery module is reduced compared to using separate elastic members for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If extensible busbar is used for connecting battery cells, then connection flexibility is improved, but bending of current collection portions cannot be curbed because busbar holders are fixed

Engineering Contradiction:

Improveconnection flexibilityVSAvoidprevention of bending and short circuits

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The busbar holder includes an extensible portion that can dynamically change its length to follow the displacement of battery cells during expansion and contraction. This dynamic capability allows the busbar holder to maintain proper positioning and electrical connection while accommodating volume changes, preventing bending and short circuits of the current collection portions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The extensible portion of the busbar holder acts as an intermediary between the fixed busbar connection points and the expanding/contracting battery cells. It absorbs the mechanical stress and displacement, preventing direct transmission of bending forces to the current collection portions while maintaining electrical connectivity.

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

The design maintains high energy density and prevents deterioration and short circuits by allowing the busbar holders and optionally elastic members to extend and contract with the battery cells, reducing weight and stress on current collection portions.

Implementation Method 1

the busbar holder has a first extensible portion following displacement of the battery cells in the lamination direction

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

an elastic member may be disposed between the constraint body and a battery cell among the plurality of battery cells or between the battery cells

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS20250309485A1Battery module

Publication Date: 2025.10.02 HONDA MOTOR CO LTD

AI summary

A battery module includes: a plurality of battery cells laminated in one direction; a constraint body constraining the plurality of battery cells in a lamination direction; a busbar connecting the battery cells to each other; and a busbar holder holding the busbar, wherein the busbar holder has a first extensible portion following displacement of the battery cells in the lamination direction.