Cylindrical Battery Negative Lead Insulation

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Solution Overview

Problem

Cylindrical batteries face the risk of short circuits due to the tip portion of the electrode lead moving and contacting the counter electrode under impact or vibration, as the lead is not welded to the can bottom, leading to potential contact with the positive electrode.

Innovation Solution

A cylindrical battery design with an insulating tape attached to the tip side of the electrode lead, closer to the tip than the welding point, to prevent contact between the lead and the counter electrode, even under impact or vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lead tip is not welded to the can bottom, then the lead can move freely under impact or vibration, but this movement may cause contact with the positive electrode leading to short circuit

Engineering Contradiction:
Improvelead flexibilityVSAvoidshort circuit prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

An insulating tape is introduced as an intermediary component between the lead and the positive electrode. This tape prevents direct contact and potential short circuits while allowing the lead to maintain its flexibility and movement capability under impact or vibration conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating tape is applied in advance to the lead surface to prevent the harmful effect of short circuiting. By pre-applying the insulating layer, the design proactively counteracts the potential risk of lead contact with the positive electrode before such contact can occur.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If insulating tape is applied to the lead, then short circuit risk is reduced, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveshort circuit preventionVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulating tape is a simple, inexpensive component that can be easily applied and replaced if necessary. This approach prioritizes reliability enhancement through a low-cost, simple solution rather than designing a complex permanent insulation system.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If the lead is welded closer to the tip, then structural stability is improved, but the tip portion has less freedom of movement to accommodate impact and vibration

Engineering Contradiction:
Improvelead structural stabilityVSAvoidlead movement capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The insulating tape is applied specifically to the tip portion of the lead where movement occurs, while the welded portion maintains its structural stability. This localized application allows different regions of the lead to have different properties: stability at the weld and flexibility at the tip.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4641824A1Cylindrical battery
Publication Date: 2025.10.29 PANASONIC ENERGY CO LTD
  • EP4641824A1 patent drawingFigure 1
  • EP4641824A1 patent drawingFigure 2~4
  • EP4641824A1 patent drawing

AI summary

A cylindrical battery that is one example of an embodiment comprises: an electrode body (14) that includes a positive electrode lead (20) and a negative electrode lead (21); and a bottomed cylindrical outer can (16) that accommodates the electrode body (14). The cylindrical battery has a structure in which a portion (21a) where the negative electrode lead (21) is welded to the can bottom inner surface of the outer can (16) is formed at a section of the negative electrode lead (21) separate from the leading end thereof. The cylindrical battery that is one example of an embodiment further comprises an insulation tape (50) that is affixed to at least the upper surface of the leading end portion of the negative electrode lead (21) facing toward the electrode body (14).