Full-Surface Electrode Insulation Film for Short-Circuit Safety
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Solution Overview
Problem
Lithium secondary batteries face safety issues due to short circuits, dendrite growth, and side reactions, which can lead to explosions and capacity loss, and existing solutions like insulation tapes and organic-inorganic mixed coating layers are insufficient in addressing these problems.
Innovation Solution
An electrode assembly with an organic-inorganic mixed insulation film containing inorganic particles and a binder polymer is formed on the entire surface of the electrodes, including tabs, to prevent short circuits and maintain lithium ion mobility, while also using thermally conductive inorganic particles to enhance safety and prevent thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulation tape is attached to prevent short circuits, then safety against short circuits is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the insulation function with the electrode structure by forming an insulation film directly on the electrode surface during the coating process. This integrates two previously separate components (electrode and insulation layer) into a single integrated structure, eliminating the need for separate insulation tape attachment and reducing overall device complexity.
Solution Approach 2:
The insulation film is formed preliminarily during the electrode manufacturing process before assembly. By applying the insulation coating to the current collector before electrode material deposition, the insulation function is built-in from the start, avoiding subsequent insulation tape attachment steps and simplifying manufacturing.
2Reliability
If organic-inorganic mixed coating layer is formed to prevent short circuits, then safety is improved, but manufacturing precision and process complexity increase
Solution Approach 1:
The patent optimizes the insulation film thickness to a specific range (1-10 μm) to balance insulation performance with manufacturing feasibility. By controlling the thickness parameter within this range, the film provides adequate insulation while remaining thin enough to be applied uniformly during the coating process without requiring excessive manufacturing precision.
Solution Approach 2:
The patent uses a composite insulation film containing both organic binder and inorganic particles. This composite structure provides effective insulation properties while maintaining a relatively simple coating process, as the organic-inorganic combination offers both adhesion and insulation functionality in a single layer.
3Reliability
If insulation film is formed on entire electrode surface including tabs, then short circuit prevention is improved, but lithium ion mobility may be reduced
Solution Approach 1:
The patent applies different treatments to different regions of the electrode. The insulation film is formed on the active electrode surface where short circuit prevention is critical, while the tab region receives different handling to maintain conductivity. This localized approach ensures insulation where needed without impeding lithium ion transport in active regions.
Solution Approach 2:
The patent uses a thin insulation film (1-10 μm) that provides adequate insulation while being thin enough to allow lithium ion penetration. The thin film structure maintains porosity and ion transport pathways, ensuring that lithium ion mobility is not significantly reduced despite the presence of the insulation layer.
4Reliability
If thicker insulation film is used to prevent dendrite penetration, then safety against dendrites is improved, but battery capacity and ion mobility deteriorate
Solution Approach 1:
The patent optimizes the insulation film thickness to a specific range (1-10 μm) that balances dendrite prevention with ion mobility. This parameter optimization ensures the film is thick enough to provide insulation and resist dendrite penetration while remaining thin enough to allow adequate lithium ion transport, thus maintaining battery capacity.
Solution Approach 2:
The patent employs a composite insulation film with organic binder and inorganic particles that provides enhanced mechanical strength and dendrite resistance at reduced thickness. The inorganic particles provide structural rigidity for dendrite prevention while the organic matrix maintains porosity for ion transport, achieving both safety and performance goals at optimal thickness.
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 prevents short circuits, reduces gas generation, and maintains battery capacity and output performance, while providing improved safety against thermal runaway and nail penetration, outperforming traditional coating methods and insulation tapes.
Implementation Method 1
an insulation film is formed on the entire surface of one or both sides of the electrode, and the insulation film is an organic-inorganic mixed film containing inorganic particles and a binder polymer
Implementation Method 2
using thermally conductive inorganic particles to enhance safety and prevent thermal runaway
Data Source
AI summary
The present disclosure relates to an electrode assembly for a lithium secondary battery including an electrode, a separator and a counter electrode, wherein an insulation film is formed on the entire surface of one or both sides of the electrode, and the insulation film is an organic-inorganic mixed film containing inorganic particles and a binder polymer. The present disclosure also relates to a manufacturing method thereof, and a lithium secondary battery including the same.