Flexible Current Collector for Secondary Battery Short Circuit Prevention

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Solution Overview

Problem

Secondary batteries used in electric vehicles and hybrid vehicles face challenges in maximizing capacity and protecting electrode assemblies from external impacts, leading to potential short circuits and reduced reliability.

Innovation Solution

The design incorporates a flexible current collector connected between the non-coating portion of the electrode assembly and the terminal, allowing for increased flexibility in component selection and disposition, while an insulation member fixes the electrode assembly within the can to prevent movement and potential short circuits, and the use of twisted wires enhances durability and adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rigid current collectors are used to ensure electrical connection, then electrical conductivity is improved, but flexibility and impact resistance deteriorate

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidflexibility in component disposition

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by using a flexible current collector that can dynamically adjust its position and shape. The current collector is designed with flexibility to move and adapt to different positions within the battery, allowing it to maintain reliable electrical connection between the electrode assembly and terminal even when components shift due to impact or during assembly variations.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If flexible wires are used for current collection, then adaptability and space utilization are improved, but structural strength and reliability deteriorate

Engineering Contradiction:

Improveflexibility in component selectionVSAvoidstructural strength of current collector

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies composite materials principle by combining flexible wire structures with protective coatings and insulation layers. The current collector uses a composite construction that integrates conductive metal wires with insulating and protective material layers, providing both flexibility for adaptability and sufficient structural strength for reliability.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If electrode assembly is allowed to move for flexibility, then ease of assembly is improved, but risk of short circuit from impact deteriorates

Engineering Contradiction:

Improveease of assemblyVSAvoidshort circuit risk from impact

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies the intermediary principle by introducing insulation members as mediators between the electrode assembly and the can wall. These insulation members allow the electrode assembly to move freely during assembly while preventing direct contact between conductive parts and the can, thereby eliminating short circuit risk even when movement occurs.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If insulation members are added to prevent movement, then short circuit prevention is improved, but device complexity and manufacturing cost deteriorate

Engineering Contradiction:

Improveshort circuit preventionVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the universality principle by designing insulation members that perform multiple functions simultaneously. The insulation members not only prevent short circuits by electrically isolating conductive parts but also serve as mechanical guides and spacers that facilitate assembly, reducing the need for separate components and simplifying the overall device structure.

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 design efficiently utilizes internal space, reduces component costs and weight, and enhances the battery's reliability by preventing short circuits and allowing flexible component placement, thereby improving the battery's performance and durability.

Implementation Method 1

a flexible current collector electrically connected between the non-coating portion of the electrode assembly and the terminal

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The at least one wire includes a plurality of wires that are twisted together along a length of the flexible current collector

Methodology Applied

Scientific EffectMechanical flexibility through twisting:

Implementation Method 3

The flexible current collector may be coupled to the non-coating portion by ultrasonic welding

Methodology Applied

Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP2479830B1Secondary battery comprising a flexible current collector

Publication Date: 2017.10.25 SAMSUNG SDI CO LTD

AI summary

The present invention refers to a secondary battery including an electrode assembly wound about an axis extending in a first direction and including a coating portion having an active material thereon, and a non-coating portion at a first end of the electrode assembly along the first direction; a can containing the electrode assembly; a cap plate sealing an opening of the can; a terminal protruding outside the can; and a flexible current collector electrically connected between the non-coating portion of the electrode assembly and the terminal.