Cylindrical Battery Tab Insulation for Short-Circuit Prevention
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Solution Overview
Problem
Cylindrical batteries face issues with internal short circuits due to electrode movement and damage, leading to heat generation or explosion, and have complex electrical connection structures with separate insulation and sealing requirements, while conventional positive electrode active materials cause particle breakage and instability during manufacturing.
Innovation Solution
A cylindrical battery design with a positive electrode terminal and negative electrode terminal aligned in the same direction, using a single particle or pseudo-single particle positive electrode active material with specific particle size distribution and silicon-based negative electrode active material, along with an insulating gasket and conductive coating to prevent short circuits and improve thermal stability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a jelly-roll type electrode assembly with vertically extending positive and negative electrode tabs is used to maximize current collection efficiency, then current collection efficiency is improved, but the risk of electrode movement and short circuit increases
Solution Approach 1:
The patent applies insulating coatings to the positive and negative electrode tabs before assembly, and designs insulating structures at the top and bottom caps to prevent electrical contact in advance. This preliminary protective measure ensures that even if electrodes move during charging/discharging, the insulating layers prevent short circuits, thus resolving the contradiction between maintaining current collection efficiency and preventing short circuit risks.
2Ease of manufacture
If positive electrode terminal and negative electrode terminal are located on opposite sides of the cylindrical battery, then electrical connection is achieved, but the electrical connection structure becomes complicated with increased insulation and sealing parts
Solution Approach 1:
The patent merges the functions of insulation and sealing into integrated structures at the top and bottom caps. The insulating coatings on electrode tabs and the insulating structures in the caps serve both electrical insulation and sealing purposes simultaneously, reducing the number of separate components needed and simplifying the overall assembly process while maintaining opposite-side terminal configuration.
3Ease of manufacture
If conventional positive electrode active material containing secondary particles is used, then manufacturing is easier, but particle breakage occurs during electrode manufacturing and battery stability decreases
Solution Approach 1:
The patent changes the particle size parameter of the positive electrode active material from conventional secondary particles to single particles or pseudo-single particles with larger primary particle sizes (D50: 5-15 μm, D90: 15-25 μm). This parameter change prevents particle breakage during electrode manufacturing while maintaining manufacturability, and significantly improves battery stability by reducing internal cracking during charging and discharging cycles.
4Stability of the object's composition
If positive electrode active material in the form of single particle or pseudo-single particle with large primary particle size is used to prevent particle breakage, then battery stability is improved, but electrode porosity cannot be achieved to target level and resistance characteristics deteriorate
Solution Approach 1:
The patent uses composite materials consisting of single particles or pseudo-single particles of positive electrode active material combined with carefully controlled binders and conductive agents. This composite structure maintains the stability benefits of large primary particles while achieving target electrode porosity (30-45%) and good resistance characteristics through optimized material composition and distribution in the electrode slurry.
Data Source
AI summary
Disclosed is a battery, which includes an electrode assembly; a battery housing configured to accommodate the electrode assembly through an open portion and electrically connected to the electrode assembly; a battery terminal configured to penetrate a closed portion of the battery housing and electrically connected to the electrode assembly; and a cap plate configured to cover the open portion, wherein the first electrode of the electrode assembly includes at least one insulation layer configured to simultaneously cover at least a part of the first uncoated portion and at least a part of the first coated portion, and at least a part of the first uncoated portion is used as an electrode tab by itself.