Battery Bus Bar Assembly With Extended Current Path Cooling

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Solution Overview

Problem

In battery modules, heat generation on the current path of the bus bar assembly leads to deformation and damage due to high electric resistance, especially in high-power environments, and increasing the cross-sectional area is costly and inefficient.

Innovation Solution

A bus bar assembly with a frame that includes a penetrating hole for electrode leads, a depressed structure for wide contact, a spring for pressurization, and a hook structure for stable fixation, which increases the current path area and reduces resistance, and uses laser welding for reliable bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cross-sectional area of the bus bar current path is increased to reduce heat generation, then heat resistance decreases and reliability improves, but manufacturing cost increases due to thicker members or additional connecting components

Engineering Contradiction:
Improveheat resistanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extends the bus bar structure in the longitudinal direction by adding a connection extending portion that protrudes from the main body. This dimensional extension increases the effective current path area without requiring increased thickness, thereby reducing electrical resistance and heat generation while maintaining cost-effective manufacturing with standard gauge bus bar materials.

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

2Ease of manufacture

If the bus bar structure is simplified to reduce manufacturing complexity, then ease of manufacture improves, but the current path area decreases leading to increased heat generation

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidheat generation
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The bus bar is segmented into distinct functional portions: a main body for structural support and terminal connections, and a connection extending portion for optimized current flow. This segmentation allows each part to be designed for its specific function, with the extending portion specifically optimized to increase current path area and reduce heat generation, while the overall structure remains simple and manufacturable.

Inventive Principle:
Principle #1Segmentation

3Power

If high current is applied in high power environment, then power output increases, but the bus bar deforms or connected components are damaged due to heating

Engineering Contradiction:
Improvepower outputVSAvoidstructural integrity
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent converts the harmful effect of high current into a beneficial design feature by extending the connection portion. This extension creates a larger current path area that actively dissipates the heat generated by high current flow, transforming the potential harmful thermal effect into a managed thermal characteristic that maintains structural integrity during high power operation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This configuration reduces heat generation, prevents deformation and damage, increases the life and stability of the battery module, and enhances the reliability and efficiency of the welding process while maintaining low manufacturing costs.

Implementation Method 1

a spring configured to pressurize the pressurizing bus bar in a direction where the end portions of the plurality of electrode leads are located

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

uses laser welding for reliable bonding

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 3

heat generation on a current path of a module bus bar mounted on a bus bar assembly is reduced

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

heat generation on a current path of a module bus bar mounted on a bus bar assembly is reduced

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3671903B1Battery module having bus bar assembly
Publication Date: 2024.06.05 LG ENERGY SOLUTION LTD
  • EP3671903B1 patent drawingFigure 1
  • EP3671903B1 patent drawingFigure 2
  • EP3671903B1 patent drawingFigure 3

AI summary

Provided is a battery module in which heat generation of a current path of a module bus bar mounted on a bus bar assembly is reduced. The battery module includes: a cell assembly including a plurality of secondary batteries that each include a plurality of electrode leads and are stacked in at least one direction; and a bus bar assembly including: a module bus bar including an upper plate portion and a lower plate portion that electrically connect the plurality of secondary batteries and the module terminal and each have at least one region separated from each other, a connection extending portion that extends to one side end portion of each of the upper plate portion and the lower plate portion, and a bent connecting portion that is combined to the module terminal provided at a top of the upper plate portion; and a pressurizing bus bar pressurizing the plurality of electrode leads such that end portions of the plurality of electrode leads closely contact the lower plate portion.