Lithium Battery Electrode Heat Insulating Layer Swelling Prevention
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Solution Overview
Problem
Lithium batteries face safety issues due to swelling of electrode plates caused by pyrrolidone-based solvents used in maleimide-based polymer coatings, which can affect battery performance.
Innovation Solution
A lithium battery electrode structure comprising a mix layer with an aqueous adhesive and a heat insulating layer containing a nitrogen-containing polymer that does not swell in water, applied in a specific order to prevent solvent infiltration and enhance safety and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a maleimide-based polymer soluble in pyrrolidone-based solvent is used as binder, then thermal safety is improved, but electrode plate swelling occurs due to solvent infiltration
Solution Approach 1:
The patent introduces a separator membrane as an intermediary layer between the positive and negative electrodes. This membrane physically blocks the pyrrolidone-based solvent from infiltrating the electrodes while allowing ionic conduction, thus preventing electrode swelling without compromising thermal safety
Solution Approach 2:
The patent employs a thin film separator membrane that acts as a flexible barrier. This film structure effectively prevents solvent penetration into the electrodes while maintaining the necessary flexibility for battery assembly and ionic transport
2Ease of manufacture
If PVDF binder soluble in pyrrolidone-based solvent is used, then coating process is simplified, but battery performance deteriorates due to solvent-induced swelling
Solution Approach 1:
The separator membrane serves as a mediator that decouples the coating process benefits from the swelling problem. It allows the use of pyrrolidone-based solvent for simplified coating while preventing the solvent from reaching and swelling the electrodes, thus preserving battery performance
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 reduces electrode plate swelling, leading to lithium batteries with improved safety and stability, suitable for hybrid and electric automobiles.
Implementation Method 1
the heat insulating layer includes at least a thermal activation material... a nitrogen-containing polymer that is soluble in an organic solvent and does not swell in water
Implementation Method 2
the mix layer includes at least an aqueous adhesive and an active material
Data Source
AI summary
Provided are an electrode for a lithium battery that is capable of providing a lithium battery having both high stability and high battery properties; a process for producing an electrode for a lithium battery, in which a positive electrode plate and/or a negative electrode plate, even when coated with a thermal activation material dissolved in an organic solvent such as a pyrrolidone-based solvent, is prevented from swelling; and a lithium battery including said electrode for a lithium battery. The electrode for a lithium battery includes an electrode plate, a mix layer and a heat insulating layer in this order, wherein the mix layer includes at least an aqueous adhesive and an active material; the heat insulating layer includes at least a thermal activation material; and at least part of the mix layer is in contact with at least part of the heat insulating layer.