Battery Module Bus Bar Pressing for Flush Lead Welding

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Solution Overview

Problem

Conventional battery module manufacturing involves complex processes, including electrode lead bending and reduced bonding strength due to shorter electrode leads in pouch-type cells, which increases the risk of product failure.

Innovation Solution

An automatic pressing jig apparatus that simultaneously presses bus bars and electrode lead assemblies together without bending, using a plurality of pressing units, a support plate, and a distance adjusting unit to ensure constant force and even contact, allowing for welding without protrusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If electrode lead is bent to adhere to bus bar, then electrode lead can be positioned on bus bar for welding, but the process becomes complicated and requires additional bending step

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

Solution Approach 1:

Instead of bending the electrode lead to fit the bus bar, the invention inverts the approach by pressing the bus bar to conform to the electrode lead's natural position. The pressing unit applies force to the bus bar, causing it to deform and adhere to the electrode lead assembly, thereby eliminating the need for complex bending operations on the electrode lead.

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

Solution Approach 2:

The invention changes the physical state and shape of the bus bar through controlled deformation. By applying pressing force, the bus bar transitions from a rigid straight form to a deformed configuration that matches the electrode lead assembly geometry, enabling direct adhesion without additional processing steps.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If electrode lead is shortened for pouch-type cells, then cell thickness is reduced, but bonding area between electrode lead and bus bar is reduced lowering bonding strength

Engineering Contradiction:
Improveelectrode lead lengthVSAvoidbonding strength
Core Design Contradiction:
Length of stationary objectVSStrength

Solution Approach 1:

The pressing unit applies distributed pressure that causes the bus bar to curve and conform to the electrode lead assembly's contour. This curvature allows the bus bar to wrap around and adhere to the shorter electrode lead, maximizing the bonding area despite the reduced electrode lead length, thereby maintaining strong bonding strength.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Manufacturing precision

If electrode lead is pressed toward bus bar using conventional jig, then electrode lead adheres to bus bar, but electrode lead may protrude through lead slit and contact with other components

Engineering Contradiction:
Improveadhesion precisionVSAvoidprotrusion risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention reverses the pressing direction by applying force to the bus bar instead of the electrode lead. The bus bar is pressed to conform to the electrode lead assembly and is contained within the lead slit, preventing any protrusion while ensuring complete adhesion between the two components.

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

4Productivity

If electrode lead assemblies of multiple battery cell stack groups are pressed at once, then productivity is improved, but maintaining constant pressing force at all spots becomes difficult

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidpressing force uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The pressing unit is divided into multiple independent pressing elements or segments that can apply force at different locations simultaneously. Each segment can be independently controlled or designed with varying force characteristics to ensure uniform total pressing force distribution across all electrode lead assemblies, enabling multi-point pressing with constant force at each spot.

Inventive Principle:
Principle #1Segmentation

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 solution simplifies the manufacturing process by eliminating the need for electrode lead bending, ensuring reliable contact and improved welding quality by maintaining the electrode lead assemblies flush with the bus bar surface, thus enhancing bonding strength and reducing the risk of product failure.

Implementation Method 1

a pressing unit configured to press the bus bar and the electrode lead assembly together

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3723162B1Auto-pressing jig apparatus for pressing electrode lead to busbar
Publication Date: 2023.12.20 LG ENERGY SOLUTION LTD
  • EP3723162B1 patent drawingFigure 1
  • EP3723162B1 patent drawingFigure 2
  • EP3723162B1 patent drawingFigure 3~4

AI summary

Disclosed is an automatic pressing jig apparatus for closely adhering a bus bar and a lead assembly provided in a battery module to each other. The automatic pressing jig apparatus includes: a plurality of pressing units configured to simultaneously press a plurality of bus bars provided in the battery module, the pressing units pressing an end portion of the lead assembly from an upper portion of the bus bar so that the lead assembly does not protrude through a lead slit of the bus bar; a support plate connected to one end portion of the pressing unit to support the plurality of pressing units; and a distance adjusting unit connected to the support plate to move the support plate so that the plurality of pressing units are moved away from or closer to the battery module.