Busbar Frame Welding Slit for Jig-Free Battery Module Assembly

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Solution Overview

Problem

Existing battery modules require dedicated welding jigs for different sizes and shapes, limiting ease of welding and increasing complexity due to space and structural constraints.

Innovation Solution

A unit module design featuring a bus bar frame with a welding slit, which serves as a welding jig, allowing for easy welding of electrode leads and bus bars without the need for separate jigs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a dedicated welding jig is used for each battery module model, then welding quality is improved, but device complexity and manufacturing cost increase due to needing multiple jigs for different sizes and shapes

Engineering Contradiction:
Improvewelding qualityVSAvoidnumber of welding jigs
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The bus bar frame is designed to serve dual functions: as a structural support component and as a welding jig. The frame includes positioning protrusions that align with corresponding recesses in the battery module, enabling it to function as a welding fixture for multiple battery module models without requiring separate dedicated jigs for each model

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The welding jig function is merged with the bus bar frame structure. Instead of using a separate welding jig, the bus bar frame itself incorporates positioning features (protrusions and recesses) that enable it to serve as the welding fixture, combining structural support and welding positioning functions into a single component

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If a pressing jig is used to closely adhere electrode lead and bus bar, then welding quality is improved, but space requirements increase due to needing clearance for jig placement

Engineering Contradiction:
Improvewelding qualityVSAvoidspace for welding operation
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The pressing and positioning functions are merged into the bus bar frame structure itself. The frame's positioning protrusions and recesses enable the frame to directly position and press the electrode lead and bus bar during welding, eliminating the need for a separate pressing jig and its associated space requirements

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If different welding jigs are prepared for different battery module models, then welding precision is maintained, but manufacturing time and productivity decrease

Engineering Contradiction:
Improvewelding precisionVSAvoidwelding efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The bus bar frame is designed as a universal component that can serve as a welding jig for multiple battery module models. By incorporating standardized positioning protrusions that match corresponding recesses across different models, a single frame design can be used universally, eliminating the need to prepare different jigs for different models and significantly improving manufacturing efficiency

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables easy welding operations across various battery module sizes and shapes, reducing the need for multiple jigs and simplifying the welding process while maintaining high-quality connections.

Implementation Method 1

the bus bar frame pressing the electrode lead and the bus bar so that the electrode lead and the bus bar are closely adhered to each other

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The laser welding, which is one of the methods of connecting the electrode lead and the bus bar, is performed in a state where the electrode lead is pressed toward the bus bar

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentEP3690987B1Unit module including busbar frame structure which can facilitate welding, and battery module including same
Publication Date: 2025.04.02 LG ENERGY SOLUTION LTD
  • EP3690987B1 patent drawingFigure 1
  • EP3690987B1 patent drawingFigure 2
  • EP3690987B1 patent drawingFigure 3

AI summary

A unit module includes: a battery cell having an electrode assembly, a cell case for accommodating the electrode assembly, and an electrode lead connected to the electrode assembly and drawn out of the cell case; a bus bar attached to the electrode lead; and a bus bar frame attached to a terrace portion of the battery cell to accommodate at least a portion of the electrode lead and the bus bar therein, the bus bar frame pressing the electrode lead and the bus bar so that the electrode lead and the bus bar are closely adhered to each other, the bus bar frame having a welding slit formed at a location corresponding to the bus bar and the electrode lead so that a contact portion of the bus bar and the electrode lead is exposed out.