Patterned Cathode Coating for Penetration-Safe Lithium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face safety issues due to heat generation and ignition when penetrated by external metal objects, and existing solutions compromise battery lifespan by reducing adhesion between electrode layers.
Innovation Solution
A positive electrode structure comprising a current collector with a first coating layer, a patterned layer with dispersed conductive material, and a second coating layer, where the patterned layer occupies 30% to 80% of the first coating layer's area, enhancing adhesion and electrical conductivity while preventing heat generation and ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an overcharge prevention layer is interposed between the positive electrode current collector and positive electrode active material layer to increase resistance during overcharge, then battery safety is improved, but adhesion between layers deteriorates causing interlayer cracks and reduced lifespan
Solution Approach 1:
The patent applies local quality by creating a patterned layer with different properties in different regions. The overcharge prevention layer is positioned only in specific areas (30-80% coverage) rather than uniformly across the entire electrode, allowing regions with high safety needs to have the protective layer while other regions maintain strong adhesion for lifespan durability.
Solution Approach 2:
The patent uses composite materials by combining the overcharge prevention layer with the positive electrode active material layer in a patterned configuration. This composite structure integrates the protective function of the prevention layer with the electrochemical function of the active material, achieving both safety improvement and adhesion maintenance through the patterned arrangement.
2Reliability
If an overcharge prevention layer is added to block charging current, then safety during overcharge is improved, but penetration resistance deteriorates
Solution Approach 1:
The patterned layer provides overcharge protection locally in specific areas while leaving other areas open to maintain structural integrity and penetration resistance. This selective positioning allows the electrode to resist external penetration forces better than a complete coverage layer would.
3Duration of action of stationary object
If the area of the patterned layer is increased to improve adhesion, then lifespan characteristics are improved, but safety during penetration may deteriorate
Solution Approach 1:
The patent optimizes the patterned layer area to 30-80% of the total electrode area, creating a balance where sufficient coverage provides adhesion for lifespan durability while adequate exposed areas maintain penetration resistance for safety. This specific range represents the optimal local quality distribution.
Solution Approach 2:
The patent applies parameter changes by precisely controlling the area ratio of the patterned layer (30-80%) to achieve the optimal balance between adhesion and penetration resistance. This quantitative parameter optimization allows simultaneous improvement of lifespan characteristics and maintenance of safety properties.
Data Source
Figure 1
AI summary
The present invention relates to a positive electrode for a lithium secondary battery and a lithium secondary battery including the same, wherein the positive electrode for a lithium secondary battery sequentially includes a first coating layer and a second coating layer on a current collector, and by introducing a patterned layer in a form in which the conductive material is dispersed in the binder between the first coating layer and the second coating layer at a specific area ratio, the safety of the battery is improved, and therefore, when a metal body penetrates the electrode from the outside, not only heat generation due to an overcurrent, ignition, and the like may not occur, but also the adhesive force between layers constituting the positive electrode may be improved, so that the life characteristics of the batteries may be improved.