Movable Busbar Assembly for Battery Pack Swelling Relief

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery packs face issues with short circuits and potential explosions due to swelling of unit cells, leading to damage of tabs and leads, and fixed busbar structures fail to provide sufficient movement distance during swelling, affecting performance and safety.

Innovation Solution

A battery pack design with movable busbar frames and busbars that allow for independent movement towards the side plates, incorporating elastic and corrugated connection busbars to accommodate swelling, reducing stress on leads and preventing short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If fixed busbar structures are used to connect battery cells, then structural stability is improved, but short circuits and lead damage occur during battery swelling

Engineering Contradiction:
Improvestructural stabilityVSAvoidrisk of short circuit
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The busbar assembly is designed with movable components that can dynamically adjust their position during battery swelling. The busbar frame includes sliding structures that allow the busbar to move along the side plates, and the connection between busbar and battery cell tabs uses flexible connectors that can deform to accommodate volume changes, transforming the fixed structure into a dynamic one that adapts to swelling conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The connection between the busbar and battery cell tabs employs flexible connector structures that can deform elastically. These flexible connections allow the busbar assembly to accommodate the volume expansion of battery cells during swelling while maintaining electrical connectivity, preventing the rigid connection from causing lead damage or short circuits

Inventive Principle:
Principle #30Flexible shells and thin films

2Ease of manufacture

If fixed busbar frames are used to support busbars, then manufacturing simplicity is improved, but insufficient movement distance is provided during swelling

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidmovement distance during swelling
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The busbar frame incorporates sliding mechanisms that enable controlled movement along the side plates of the battery pack. This dynamic structure provides sufficient movement distance to accommodate battery swelling while maintaining a relatively simple manufacturing process through the use of guide rails and sliding interfaces

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The busbar frame is divided into movable and fixed segments, with the busbar itself being movable relative to the busbar frame. This segmentation allows the busbar to move independently to accommodate swelling while the busbar frame provides structural support, balancing manufacturing simplicity with adaptability

Inventive Principle:
Principle #1Segmentation

3Strength

If busbars are fixed to side plates, then structural support is improved, but stress concentration damages leads and connections

Engineering Contradiction:
Improvestructural supportVSAvoidstress on leads
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

The connection between busbars and battery cell tabs uses flexible connector structures that can deform elastically under stress. These flexible connections distribute the stress generated during battery swelling across a larger area and through deformation, preventing stress concentration that would damage rigid leads and connections

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

Flexible connector structures serve as intermediaries between the rigid busbar assembly and the battery cell tabs. These intermediaries absorb and distribute mechanical stress, protecting the leads and焊接 connections from damage while maintaining electrical connectivity during battery volume changes

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 effectively prevents damage to tabs and leads, maintains battery performance, and enhances safety by allowing for movement of busbars and frames, reducing the risk of short circuits and explosions.

Implementation Method 1

incorporating elastic and corrugated connection busbars to accommodate swelling

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3907818B1Battery pack having movable busbar assembly and secondary battery including the same
Publication Date: 2025.11.05 LG ENERGY SOLUTION LTD
  • EP3907818B1 patent drawingFigure 1
  • EP3907818B1 patent drawingFigure 2
  • EP3907818B1 patent drawingFigure 3

AI summary

Disclosed are a battery pack having a movable busbar assembly and a secondary battery including the same, and more particularly a battery pack having a movable busbar assembly configured such that at least one of a first busbar frame located at the front surface of a pack case, a second busbar frame located at the rear surface of the pack case, a first busbar connected to the first busbar frame, and a second busbar connected to the second busbar frame is movable in a direction toward a side plate of the pack case, whereby it is possible to minimize short circuit between leads, and a secondary battery including the same.