Battery Cell Insulation Structure for End Cap Short-Circuit Prevention

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Solution Overview

Problem

Existing battery cells face challenges in achieving complete insulation due to interference from electrode terminals and convex hull structures, leading to potential short circuits and reduced safety.

Innovation Solution

A battery cell design featuring a first and second insulating layer, where the second insulating layer is adhered to an end cap patch and folded onto the case, ensuring firm adhesion and complete coverage without warping, while avoiding terminal holes and maintaining energy density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a battery cell is designed with a large volume to achieve high output capacity, then the output capacity is improved, but the cell becomes more susceptible to internal defects and external impacts

Engineering Contradiction:
Improveoutput capacityVSAvoidcell stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The battery cell is divided into multiple stacked pouch cells (e.g., 12 pouch cells arranged in 3 stacks of 4 cells each). This segmentation allows the total output capacity to be achieved through aggregation of smaller, more reliable units, reducing the risk of internal defects affecting the entire cell while maintaining high overall capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple pouch cells are stacked and nested within a single outer packaging, forming a compact three-dimensional structure. This nesting approach maximizes space utilization, achieving high output capacity within a controlled volume while maintaining structural integrity and reliability through the organized arrangement of individual cell units.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the battery cell volume is reduced to improve portability and reduce external impact susceptibility, then the cell becomes more resistant to external impacts, but the output capacity decreases

Engineering Contradiction:
Improveimpact resistanceVSAvoidoutput capacity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The battery system uses multiple smaller pouch cells (each with dimensions such as 45mm×65mm×170mm) instead of a single large cell. Each small cell has inherent impact resistance due to its compact size, while the collective output capacity of all stacked cells meets the required power supply specifications for portable devices.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple small pouch cells are combined through electrical connection and physical stacking to achieve the total output capacity required for the portable device. The merged structure maintains the impact resistance benefits of small individual cells while collectively delivering the necessary power capacity.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If conventional battery structures are used without specialized anti-collapse designs, then the manufacturing process is simpler, but the cell cannot withstand external impacts and internal pressure

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidimpact and pressure resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The pouch cells are pre-formed with specific structural characteristics (such as predetermined folding patterns and sealing configurations) before being stacked and assembled into the final battery cell. This preliminary structuring ensures that each cell unit has inherent resistance to external impacts and internal pressure, while the overall assembly process remains relatively simple and scalable for manufacturing.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4199205B1Battery cell, battery, and electrical device
Publication Date: 2026.04.29 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4199205B1 patent drawingFigure 1~2
  • EP4199205B1 patent drawingFigure 3~4
  • EP4199205B1 patent drawingFigure 5~6

AI summary

The present application relates to a battery cell, a battery, and an electrical apparatus, the battery cell includes: a case, an outer surface thereof away from the interior of the battery cell is clad with a first insulating layer; an end cap assembly, which is disposed at an end portion of the case along the length direction of the battery cell; and an end cap patch, which is attached to a surface of the end cap assembly away from the interior of the battery cell; wherein the end cap patch is adhered with a second insulating layer, and the second insulating layer is at least partially folded to the case and is connected with the first insulating layer. In the battery cell of the present application, before the end cap patch is attached to the end cap assembly, the second insulating layer is first adhered to the end cap patch, so that the second insulating layer and the first insulating layer can be completely adhered to the case, the adhesion is firm, and no warping occurs at the folded position, so as to prevent the end cap patch from falling off, and reduce the risk of short circuit of the battery.