Bus Bar Wall Structure for Low-Spatter Battery Terminal Welding

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Solution Overview

Problem

Conventional energy storage apparatuses face issues with welding distortion and spatter damage during the joining of bus bars and electrode terminals, leading to potential defects and increased complexity in configuration.

Innovation Solution

The energy storage apparatus incorporates a bus bar with a joint portion, a first wall portion to suppress spatter, and a second wall portion that overlaps the bus bar body, allowing for efficient laser welding and reducing path resistance, while also serving as a terminal for electric equipment, thereby simplifying the configuration and enhancing reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ultrasonic joining is used to join the bus bar and electrode terminal, then the joining strength is improved, but the bus bar becomes distorted due to pressure applied during joining

Engineering Contradiction:

Improvejoining strengthVSAvoidbus bar distortion

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The patent replaces the mechanical ultrasonic joining system with a laser welding system. Laser welding uses optical energy (laser beam) to melt and join the bus bar and electrode terminal without applying mechanical pressure, thereby achieving strong joining while avoiding bus bar distortion. This substitution of mechanical system with optical/thermal system resolves the contradiction between joining strength and shape preservation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Shape

If laser welding is used to join the bus bar and electrode terminal, then welding distortion is reduced and dissimilar materials can be joined easily, but spatter is scattered during welding which can damage resin members

Engineering Contradiction:

Improvewelding distortionVSAvoidspatter damage

Core Design Contradiction:

ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a shield gas flow as an intermediary between the laser welding zone and the surrounding environment. The shield gas (typically argon or nitrogen) creates a protective atmosphere that captures and contains the spatter, preventing it from scattering and damaging resin members. This intermediary substance resolves the contradiction by allowing laser welding benefits while mitigating spatter harm.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful spatter into a beneficial containment mechanism. By directing shield gas flow in a specific pattern, the spatter that would normally scatter and cause damage is instead channeled and contained within a specific region. The harmful spatter is transformed into a controlled phenomenon that does not damage surrounding components, thus converting harm into benefit.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Object-affected harmful factors

If a three-dimensional structure is arranged to prevent spatter scattering, then spatter damage is reduced, but the configuration of the energy storage apparatus becomes complicated

Engineering Contradiction:

Improvespatter damageVSAvoidconfiguration complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of adding complex three-dimensional protective structures, the patent uses shield gas flow as a simple intermediary medium. The shield gas is delivered through straightforward piping and nozzles that direct gas flow over the welding zone. This approach protects against spatter damage without requiring complex structural modifications, thus resolving the contradiction between spatter protection and configuration simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration effectively suppresses spatter scattering, reduces path resistance, and improves the reliability of the joint, resulting in a higher-quality energy storage apparatus with a simpler design.

Implementation Method 1

laser welding capable of joining an object to be joined in a non-contact manner is sometimes adopted for joining a bus bar and an electrode terminal

Methodology Applied

Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 2

the first wall portion erected in the first direction from the bus bar body portion

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS20230275327A1Energy storage apparatus

Publication Date: 2023.08.31 GS YUASA INT LTD

AI summary

An energy storage apparatus includes an energy storage device including an electrode terminal disposed in a first direction, and a bus bar joined to the electrode terminal. The bus bar includes a bus bar body portion including a joint portion joined to the electrode terminal, a first wall portion, and a second wall portion. The first wall portion is erected in the first direction from the bus bar body portion. The second wall portion is disposed so that at least a part of the second wall portion overlaps the bus bar body portion when viewed from the first direction and faces the bus bar body portion.