Battery Module Pressing Jig for Straight Lead Busbar Welding

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Solution Overview

Problem

The manufacturing process of battery modules is complicated by the need to bend and weld electrode leads to bus bars, which can lead to reduced bonding areas and increased product failure due to decreased electrode lead length, especially in thinner cells.

Innovation Solution

An automatic pressing jig apparatus that simultaneously presses bus bars from both sides to ensure close contact with electrode leads without bending, using a system of contacting units, pressing units, and a support frame to maintain uniform force and prevent electrode leads from protruding, allowing for a single-process welding operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If electrode leads are bent to contact bus bars, then welding can be performed, but the manufacturing process becomes complicated and bonding area decreases

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidprocess complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts the bending operation from the manufacturing process by using a pressing jig that directly presses the electrode lead against the bus bar in its original straight configuration. This removes the unnecessary bending step while achieving the same welding contact, thereby simplifying the manufacturing process and reducing complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of bending the electrode lead to achieve contact with the bus bar, the patent inverts the approach by pressing the bus bar (via the pressing jig) against the electrode lead. This reverse action achieves the same welding contact without requiring the electrode lead to be bent, thus simplifying the process.

Inventive Principle:
Principle #13The other way round (Inversion)

2Volume of moving object

If cell thickness is decreased, then battery module size is reduced, but electrode lead length decreases and bonding strength deteriorates

Engineering Contradiction:
Improvecell thicknessVSAvoidbonding strength
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The pressing jig performs preliminary pressing action on the electrode lead and bus bar assembly before welding. This pre-compression ensures maximum contact pressure and uniform distribution of force across the bonding interface, thereby compensating for the reduced electrode lead length in thinner cells and maintaining adequate bonding strength.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the pressing parameters (force, duration, distribution) using the pressing jig to optimize the bonding process. By adjusting these parameters, the system achieves sufficient bonding strength even with shorter electrode leads in thinner cells, thus resolving the contradiction between reduced cell thickness and maintained bonding strength.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If multiple electrode leads are pressed simultaneously, then productivity increases, but uniform force distribution becomes difficult

Engineering Contradiction:
Improvewelding efficiencyVSAvoidforce uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The pressing jig is segmented into multiple pressing units, each independently capable of applying force to specific electrode leads. This segmentation allows simultaneous pressing of multiple electrode leads while maintaining uniform force distribution, as each unit can be independently controlled or designed to distribute force evenly across its designated area.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pressing jig is designed as a multi-functional device that can simultaneously press multiple electrode leads of different groups. The universal design of the pressing units allows them to handle various electrode lead configurations while maintaining consistent pressing force, thereby achieving both high productivity and manufacturing precision.

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

Data Source

PatentEP3719871B1Automatic pressure jig device for bringing electrode lead into close contact with busbar, and battery module manufacturing system comprising same
Publication Date: 2024.01.10 LG ENERGY SOLUTION LTD
  • EP3719871B1 patent drawingFigure 1
  • EP3719871B1 patent drawingFigure 2
  • EP3719871B1 patent drawingFigure 3

AI summary

Provided is an automatic pressing jig apparatus that closely contacts a lead assembly and a bus bar provided in a battery module to each other, the automatic pressing jig apparatus including: a plurality of contacting units configured to simultaneously press each of a plurality of bus bars provided in the battery module and press an end of the lead assembly from a top of the plurality of bus bars to prevent the lead assembly from protruding from a surface of the plurality of bus bars; a pair of pressing units connected to the plurality of contacting units and configured to adjust a pressing force of the plurality of contacting units with respect to the plurality of bus bars; a support frame supporting the pair of pressing units; and a distance adjusting unit connected to the support frame and configured to ascend or descend the support frame to move the plurality of contacting units away from or close to the battery module.