Secondary battery including insulating tape covering positive electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-energy density secondary batteries face challenges in suppressing heat generation and short-circuit currents due to the limited effectiveness of existing insulating tapes, which fail to maintain sufficient insulation at high temperatures when exposed to large foreign materials.
Innovation Solution
A secondary battery design featuring an insulating tape with a substrate material layer and an adhesive layer containing an insulating inorganic material, providing an electric resistance of 1 kΩ/mm² or more at 500°C to prevent short-circuit current increases and heat generation, even when penetrated by large foreign materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional insulating tape (polypropylene substrate with acrylic resin adhesive) is used to cover the exposed section of the positive-electrode current collector, then the tape is inexpensive and provides basic insulation, but the tape fails to maintain sufficient insulation at temperatures of 500°C or more when large foreign materials are present
Solution Approach 1:
The patent changes the material parameters of the insulating tape by using a polyimide substrate material layer instead of polypropylene, and formulating the adhesive layer with specific inorganic materials (alumina, silica, zirconia) and organic materials (polyimide, polyamide) that maintain insulation properties at temperatures of 500°C or more, thereby resolving the contradiction between basic insulation and high-temperature insulation performance
Solution Approach 2:
The patent employs composite material structure where the adhesive layer is formulated as a composition containing both inorganic materials (alumina, silica, zirconia) and organic materials (polyimide, polyamide) in specific ratios. This composite formulation provides both adhesion and high-temperature insulation resistance, preventing short-circuit current even when penetrated by large foreign materials
2Quantity of substance
If the energy density of the battery is increased by filling more power generation elements, then the energy density improves, but the risk of internal short circuit and heat generation increases
Solution Approach 1:
The patent applies local quality enhancement by providing insulating tape coverage specifically at the exposed sections of the positive-electrode current collector where short-circuit risks are highest. The insulating tape with high-temperature resistance provides localized protection without affecting the overall energy density, allowing more power generation elements to be filled while maintaining safety
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
The solution effectively suppresses heat generation and prevents thermal runaway, ensuring high safety and maintaining high energy density in batteries with increased resistance to internal short circuits.
Implementation Method 1
the adhesive layer includes an adhesive agent and an insulating inorganic material... having an electric resistance of 1 kΩ/mm² or more at 500°C
Data Source
AI summary
A secondary battery includes: a positive electrode having a positive-electrode current collector and a positive-electrode active-material layer; a negative electrode having a negative-electrode current collector and a negative-electrode active-material layer; a electrolyte; and an insulating tape covering a portion of the positive electrode. Furthermore, the positive-electrode current collector has an exposed section that the positive-electrode active-material layer is not disposed. In addition, at least a portion of the exposed section is covered with the insulating tape; the insulating tape has a substrate material layer and an adhesive layer; and the adhesive layer includes an adhesive agent and an insulating inorganic material.