Rechargeable Battery Laser Welding Light Absorber

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The manufacturing process of rechargeable lithium ion secondary batteries risks damaging separators and electrode plates due to laser beam exposure during the welding of collector plates to electrode assemblies, potentially causing internal short circuits.

Innovation Solution

Incorporating a light absorbing member, made of materials like polypropylene or ethylene propylene diene monomer, between the active material non-coating portions of the electrode assembly to prevent laser beam exposure and spatter, and welding the collector plate in a direction parallel to the electrode assembly's length to maximize the active material coating area and simplify the design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If laser beam is used to weld collector plate to electrode assembly, then welding efficiency and electrical connection are improved, but separator and electrode plates are vulnerable to damage causing internal short circuit

Engineering Contradiction:

Improvewelding efficiencyVSAvoidrisk of internal short circuit

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A light absorbing member is introduced as an intermediary component between the laser beam and the electrode assembly. This member absorbs the laser energy and prevents it from reaching the separator and electrode plates, thereby eliminating the harmful effect while preserving the beneficial welding function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The light absorbing member converts the potentially harmful laser beam into useful heat energy for welding the collector plate to the light absorbing member. The laser energy that would otherwise damage internal components is now utilized to create the electrical connection through controlled heating and melting.

Inventive Principle:

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

2Ease of manufacture

If laser beam is directed at active material non-coating portion, then collector plate welding is achieved, but spatter and laser induction cause damage to internal components

Engineering Contradiction:

Improvewelding processabilityVSAvoidlaser-induced damage and spatter

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The light absorbing member serves as a mediator that intercepts the laser beam before it can cause spatter or induce harmful effects on internal components. It provides a controlled surface for laser interaction that eliminates the harmful side effects while maintaining welding functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If collector plate is welded perpendicular to electrode assembly length, then welding stability is improved, but active material coating area is reduced

Engineering Contradiction:

Improvewelding stabilityVSAvoidactive material coating area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The welding direction is changed from perpendicular to parallel relative to the electrode assembly length. This dimensional change in the welding approach allows the laser beam to travel along the length of the assembly, maximizing the use of non-coating portions while maintaining welding stability through the light absorbing member.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Reliability

If multiple welding positions are used on electrode assembly, then electrical connection is improved, but device complexity and manufacturing steps increase

Engineering Contradiction:

Improveelectrical connection qualityVSAvoidnumber of welding positions

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The light absorbing member serves multiple functions: it acts as a laser beam absorber, a welding substrate, an electrical connector, and a protective barrier. This multi-functionality eliminates the need for multiple separate welding positions and components, simplifying the overall device structure while maintaining reliable electrical connection.

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

This approach effectively prevents damage to separators and electrode plates, avoids internal short circuits, maximizes the active material coating area, simplifies the collector plate design, and reduces manufacturing steps by shielding the battery components from laser-induced damage during welding.

Implementation Method 1

a light absorbing member coupled to the electrode assembly... preventing or substantially preventing laser beam and/or spatter from being induced into an active material non-coating portion

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a collector plate welded to the electrode assembly... when a collector plate is laser-welded to the electrode assembly

Methodology Applied

Scientific EffectLaser beam welding: Laser Beam Welding

Data Source

PatentUS9859566B2Rechargeable secondary battery

Publication Date: 2018.01.02 SAMSUNG SDI CO LTD

AI summary

A rechargeable secondary battery including: a case; an electrode assembly accommodated in the case, the electrode assembly including an active material coating portion and an active material non-coating portion; a light absorbing member coupled to the electrode assembly; and a collector plate welded to the electrode assembly and contacting the active material non-coating portion.