Insulated Battery Electrode Coating for Short-Circuit Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face safety issues due to short circuits, dendrite growth, and side reactions leading to capacity loss and potential explosions, which existing insulation methods like tapes and organic-inorganic mixed coatings inadequately address.
Innovation Solution
An electrode assembly with an organic-inorganic mixed insulation film containing specific inorganic particles and a binder polymer is formed on the entire electrode surface, including the tab, to prevent short circuits and maintain lithium ion mobility, using materials like BaTiO3 and polyvinylidene fluoride-co-hexafluoropropylene, ensuring thermal resistance and ion conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulation tape is attached to electrode tab to prevent short circuit, then short circuit prevention 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 through coating processes. This integrates the insulation layer into the electrode itself, eliminating the need for separate insulation tapes and reducing structural complexity while maintaining short circuit prevention capabilities.
Solution Approach 2:
The patent replaces the mechanical insulation tape attachment method with a chemical/coating-based insulation film formation process. The insulation film is applied through coating and drying processes, substituting the mechanical taping operation with a more integrated manufacturing process that reduces assembly steps and potential failure points.
2Reliability
If organic-inorganic mixed coating layer is formed on separator to prevent short circuit, then short circuit prevention is improved, but manufacturing precision and quality control become more difficult
Solution Approach 1:
The patent applies insulation treatment locally to specific areas where short circuits are most likely to occur, such as electrode tabs and edges, rather than coating the entire separator uniformly. This localized approach reduces the complexity of achieving uniform coating quality across large surfaces while maintaining effective insulation at critical locations.
Solution Approach 2:
The patent employs asymmetric insulation strategies where different insulation methods and thicknesses are applied to different regions of the electrode assembly. For example, thicker insulation may be applied to tabs while thinner or no insulation is applied to active electrode areas, optimizing both safety and manufacturing feasibility.
3Reliability
If insulation film is formed on entire electrode surface including tab, then short circuit prevention is improved, but lithium ion mobility may be hindered
Solution Approach 1:
The patent employs porous insulation materials that allow lithium ion transport through their pore structures. The insulation film is designed with controlled porosity and pore size distribution that permits lithium ion diffusion while maintaining electrical insulation properties, thus preventing short circuits without significantly hindering ion mobility.
Solution Approach 2:
The patent applies insulation films with different properties to different regions of the electrode. Areas requiring high ion transport (active material regions) use porous or thinner insulation, while areas requiring maximum insulation (tabs and edges) use denser or thicker insulation, optimizing both functions spatially.
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, maintains battery capacity, and enhances safety by inhibiting gas generation and thermal runaway, while allowing lithium ion mobility and improving nail penetration resistance.
Implementation Method 1
an organic-inorganic mixed insulation film containing specific inorganic particles and a binder polymer is formed on the entire electrode surface
Implementation Method 2
maintains lithium ion mobility, using materials like BaTiO3 and polyvinylidene fluoride-co-hexafluoropropylene, ensuring thermal resistance and ion conductivity
Implementation Method 3
ensuring thermal resistance and ion conductivity... enhances safety by inhibiting gas generation and thermal runaway
Data Source
Figure 1
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.