Battery Module Lead Welding With Tornado-Shaped Weld Spots

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Solution Overview

Problem

The existing welding configurations between electrode leads and bus bars in battery modules have low weldability and are vulnerable to impact and vibration, leading to reduced tensile strength and increased risk of crack propagation.

Innovation Solution

A battery module with a tornado-shaped welding configuration, where multiple spiral welding lines are used to connect electrode leads and bus bars, providing a larger welding area and improved tensile strength, and distributing stress evenly across the welding spot.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a linear welding configuration is used to connect electrode leads and bus bars, then the welding process is simple and fast, but the weldability is low and the connection is vulnerable to impact and vibration

Engineering Contradiction:
ImproveweldabilityVSAvoidwelding configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies curvature by changing the welding configuration from a linear form to a spiral form. The spiral welding line creates a curved, tornado-shaped welding spot that increases the welding area and improves weldability. This curved configuration distributes stress more effectively, making the connection more resistant to impact and vibration while maintaining manufacturing feasibility through automated laser welding processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Area of stationary object

If a linear welding configuration is used, then the welding area is small, but the manufacturing process is simple

Engineering Contradiction:
Improvewelding areaVSAvoidwelding process complexity
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The spiral welding configuration increases the welding area by creating a tornado-shaped welding spot with curved paths. This spiral form naturally expands the welding area compared to a straight line, and the curvature allows for better stress distribution. The manufacturing process remains feasible through automated laser welding systems that can follow the spiral path.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent performs preliminary action by pre-designing the spiral welding configuration before manufacturing. The tornado-shaped welding spot pattern is predetermined and can be programmed into automated welding systems, allowing for consistent reproduction of the complex spiral pattern without requiring manual intervention during the welding process itself.

Inventive Principle:
Principle #10Preliminary action

3Strength

If a linear welding configuration is used, then the welding process is fast, but the tensile strength is low and crack propagation risk is high

Engineering Contradiction:
Improvetensile strengthVSAvoidwelding time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The spiral welding configuration creates a tornado-shaped welding spot that inherently provides higher tensile strength due to the curved, interwoven structure. The spiral pattern distributes mechanical stresses more evenly across the welding area, reducing stress concentration points that would lead to crack initiation and propagation. This geometric configuration naturally enhances strength properties.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The spiral welding configuration can be viewed as segmented into multiple welding lines that form the tornado shape. These segmented spiral paths work together to create a robust connection, with each segment contributing to the overall strength and crack resistance of the welding joint.

Inventive Principle:
Principle #1Segmentation

4Reliability

If a linear welding configuration is used, then the welding process is simple, but the connection is vulnerable to impact and vibration

Engineering Contradiction:
Improveresistance to impact and vibrationVSAvoidwelding configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The curved spiral configuration of the tornado-shaped welding spot provides superior resistance to impact and vibration. The curved paths distribute dynamic loads more effectively than a straight line, and the spiral structure creates multiple load paths that enhance the connection's resilience to mechanical shocks and vibrations encountered in vehicle applications.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

The tornado-shaped welding configuration significantly enhances weldability and tensile strength, stabilizing the electric connection under impact and vibration, and preventing crack growth, thus ensuring reliable performance in applications like electric vehicles.

Implementation Method 1

at least one of the electrode leads is combined and fixed to at least one of another electrode lead and the bus bar, which are contacted by the at least one of the electrode leads, via a welding spot formed in a tornado shape

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3654411B1Battery module
Publication Date: 2024.02.21 LG ENERGY SOLUTION LTD
  • EP3654411B1 patent drawingFigure 1~2
  • EP3654411B1 patent drawingFigure 3
  • EP3654411B1 patent drawingFigure 4~5

AI summary

Provided is a battery module in which weldability between electrode leads and/or between an electrode lead and a bus bar is improved. The battery module includes: a cell assembly that includes a plurality of secondary batteries stacked in at least one direction, respectively including electrode leads, and electrically connected to each other via a connection between the electrode leads; and at least one bus bar that includes an electrically conductive material and is electrically connected by contacting the electrode leads of the plurality of secondary batteries, wherein at least one of the electrode leads is combined and fixed to at least one of another electrode lead and the at least one bus bar, which are contacted by the at least one of the electrode leads, via a welding spot formed in a tornado shape.