Cylindrical Cell Heat-Shrink Insulation for Tab Isolation
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Solution Overview
Problem
Existing cylindrical battery cells face insulation failures due to wrinkles in insulating tapes, which can warp and cause electrical interference and insulation breakdown over time.
Innovation Solution
The use of an insulating heat-shrinkable film with a butting area, made of materials like PET or PETG, is applied to the electrode assembly to create a smooth, thin insulation layer that prevents warping and ensures reliable electrical isolation by forming a closed loop around the tab, utilizing thermocompression or adhesive connections to secure the film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating tape is pressed down to adhere to the end surface of the tab, then insulation isolation is achieved, but wrinkles are formed that can warp and cause insulation failure
Solution Approach 1:
The patent changes the physical state and properties of the insulating material by using heat-shrinkable film instead of conventional tape. The film undergoes thermal contraction when heated, transforming from a loose state to a tightly fitted state around the tab, eliminating wrinkles while maintaining insulation reliability.
Solution Approach 2:
The patent replaces the mechanical pressing method with thermal action. Instead of mechanically pressing the insulating tape to adhere it, the heat-shrinkable film is heated to cause automatic contraction and tightening, substituting mechanical compression with thermal-mechanical transformation that eliminates wrinkle formation.
2Reliability
If insulating tape is wrapped around the electrode assembly, then tab insulation is achieved, but the tape thickness and wrinkles cause interference when entering the casing
Solution Approach 1:
The patent utilizes the parameter change of the heat-shrinkable film through thermal contraction. The film starts with a larger diameter to facilitate easy installation onto the electrode assembly, then undergoes thermal shrinkage to reduce its diameter and thickness, achieving both ease of installation and minimal interference with casing entry.
Solution Approach 2:
The patent introduces dynamic characteristics to the insulating layer by using heat-shrinkable material that can change its dimensions. The film dynamically adjusts its size from an expanded installation state to a contracted operational state, providing both ease of assembly and space efficiency.
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 solution provides a reliable and efficient insulation mechanism that prevents insulation failures and maintains electrical integrity by ensuring a smooth, thin, and stable insulation layer around the tab, reducing the risk of warping and enhancing the overall insulation reliability of the battery cell.
Implementation Method 1
an insulating heat-shrinkable film is at least wrapped on a peripheral surface of the electrode assembly close to the first end to insulate and isolate the first tab from the side wall
Implementation Method 2
an adhesive layer is provided on at least part of a contact surface between the side wall portion and the electrode assembly
Data Source
AI summary
A cell and an electrical apparatus including the cell are provided. The cell includes a casing, a first electrode terminal, an electrode assembly, and the insulating heat-shrinkable film. The casing includes an end wall and a side wall surrounding the end wall. The first electrode terminal is installed through the end wall in an insulating manner. The electrode assembly is sealed and installed in the casing, a first end of the electrode assembly includes a first tab, and the first tab is electrically connected to the first electrode terminal. The insulating heat-shrinkable film is at least wrapped on a peripheral surface of the electrode assembly close to the first end to insulate and isolate the first tab from the side wall. Herein, the insulating heat-shrinkable film is connected as a closed loop, and a butting area is provided on a peripheral surface of the insulating heat-shrinkable film.