Battery Module Bus Bar Structure for Bend-Free Electrode Lead Welding

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Solution Overview

Problem

Conventional battery modules require manual bending of electrode leads to connect with bus bars, leading to poor adhesion due to elastic recovery forces and decreased weldability, and lack automation in the production process.

Innovation Solution

A battery module design where electrode leads are coupled to bus bars without bending, using an inclined and horizontal portion configuration on the bus bars and an elastic member to ensure secure contact, eliminating the need for manual bending and improving production line automation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrode leads are bent to contact the bus bar surface, then electrical connection is achieved, but adhesion is poor due to elastic recovery force

Engineering Contradiction:
Improveelectrical connectionVSAvoidadhesion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The bus bar surface is designed with an inclined curved surface instead of a flat surface. The electrode lead is bent to match this curvature, creating a conformal contact that distributes contact pressure and eliminates elastic recovery issues. The curved geometry ensures continuous contact between the electrode lead and bus bar during welding and operation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The bus bar features an asymmetric inclined surface on one side, allowing the electrode lead to be bent in a specific direction to match this asymmetry. This asymmetric design enables the electrode lead to contact the bus bar at an optimal angle, improving both adhesion and weldability while maintaining electrical connection reliability.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If multiple electrode leads are overlapped at one point on the bus bar, then electrical connection is achieved, but weldability deteriorates

Engineering Contradiction:
Improveelectrical connectionVSAvoidweldability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The bus bar is divided into multiple inclined surfaces along its length, with each inclined surface dedicated to receiving and welding a specific electrode lead. This segmentation distributes the electrode leads along different sections of the bus bar instead of overlapping them at one point, enabling each lead to be welded separately with optimal access for welding tools and improved weld quality.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If manual bending of electrode leads is performed, then contact with bus bar is achieved, but production automation is reduced

Engineering Contradiction:
Improvecontact alignmentVSAvoidproduction automation
Core Design Contradiction:
Ease of operationVSExtent of automation

Solution Approach 1:

The bus bar is pre-formed with inclined surfaces during manufacturing, creating a geometry that guides the electrode leads into proper contact positions. This preliminary preparation of the bus bar structure eliminates the need for manual bending operations during assembly, as the inclined surfaces automatically align the electrode leads with the bus bar contact points, enabling fully automated welding processes.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3547394B1Battery module, battery pack comprising same
Publication Date: 2024.03.06 LG ENERGY SOLUTION LTD
  • EP3547394B1 patent drawingFigure 1~2
  • EP3547394B1 patent drawingFigure 3
  • EP3547394B1 patent drawingFigure 4(a)~4(d)

AI summary

Disclosed is a battery module. The battery module includes: a battery cell stack having a plurality of battery cells stacked; and a plurality of bus bars respectively disposed adjacent to electrode leads respectively provided at the plurality of battery cells, wherein the electrode leads respectively provided at the plurality of battery cells are electrically connected to the plurality of bus bars, respectively.