Cylindrical Battery Insulating Plate Locking Against Internal Shorts

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Solution Overview

Problem

Cylindrical batteries lack a fixed insulating plate between the electrode assembly and the sealing assembly, leading to potential dislocation and internal short circuits due to negative electrode plate extension during overcharging.

Innovation Solution

A cylindrical battery design that includes an insulating plate fixed between the electrode assembly and the sealing assembly, using a locking mechanism to secure the insulating plate with the outer can, preventing dislocation and internal short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If no insulating plate is provided between the electrode assembly and sealing assembly, then the structure is simpler and volume is larger, but internal short circuit may occur due to electrode dislocation

Engineering Contradiction:
Improveprevention of internal short circuitVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

An insulating plate is introduced as an intermediary component between the electrode assembly and sealing assembly. This plate prevents direct contact between the negative electrode plate and positive electrode lead, eliminating the internal short circuit risk while maintaining structural simplicity through a single added element.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing structure is segmented into multiple functional components: the sealing assembly, the insulating plate, and the locking part. This segmentation allows each component to perform its specific function independently - sealing, insulation, and fixation - thereby improving reliability without significantly increasing overall complexity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If an insulating plate is provided but not fixed, then the structure remains simple, but the insulating plate may dislocate or incline causing internal short circuit

Engineering Contradiction:
Improveposition stability of insulating plateVSAvoidfixing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fixation function is merged with the existing sealing structure by integrating the locking part into the outer can. This locking part engages with the insulating plate to prevent dislocation, combining the sealing and fixation functions into a unified structure that minimizes additional complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of fixing the insulating plate to the sealing assembly directly, the locking part of the outer can engages with the insulating plate from the outside. This inverted fixation approach allows the insulating plate to be secured without requiring additional fixing mechanisms or increasing structural complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If a locking mechanism is added to fix the insulating plate, then position stability is improved, but device complexity increases

Engineering Contradiction:
Improvefixation reliability of insulating plateVSAvoidlocking mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking part of the outer can serves multiple functions: it provides structural support for the sealing assembly and simultaneously fixes the insulating plate through engagement. This multi-functionality achieves reliable fixation without adding dedicated locking mechanisms, thereby minimizing the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4160791B1Cylindrical battery
Publication Date: 2025.07.30 PANASONIC ENERGY CO LTD
  • EP4160791B1 patent drawingFigure 1
  • EP4160791B1 patent drawingFigure 2(A)~2(B)
  • EP4160791B1 patent drawingFigure 3

AI summary

The objective of the present disclosure is to provide a cylindrical battery in which it is possible to fix an insulating plate disposed in an upper portion between an electrode body and a sealing plate. A cylindrical battery (10) is provided with: an electrode body (14) in which a positive electrode (11) and a negative electrode (12) are wound with a separator (13) interposed therebetween; an electrolyte; a bottomed cylindrical outer can (20) accommodating the electrode body (14) and the electrolyte; a sealing plate (30) blocking an opening portion (20A) of the outer can (20); a gasket (31) disposed on a peripheral edge portion of the sealing plate (30); and an upper insulating plate (15) disposed between the electrode body (14) and the sealing plate (31). The gasket (31) is compressed in the radial direction between an edge surface of the peripheral edge portion of the sealing plate (30) and the outer can (20), and the outer can (20) includes a locking portion (20D) with which a peripheral edge portion (15B) of the upper insulating plate (15) engages.