Ceramic-Polymer Cathode Coating for High-Temperature Resistance Control
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Solution Overview
Problem
Conventional lithium-ion batteries using coated active materials experience side reactions with the electrolytic solution at high temperatures, leading to increased internal resistance.
Innovation Solution
A coating layer containing a polymer compound, a conductive assistant, and ceramic particles with a specific BET surface area is applied to the cathode active material particles to reduce contact area and suppress side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer is applied to cathode active material particles, then side reactions with electrolytic solution are suppressed, but internal resistance increases due to contact area reduction
Solution Approach 1:
The coating layer uses a composite material system consisting of polymer compound (provides baseline protection), conductive assistant (restores electrical conductivity), and ceramic particles with specific BET surface area (enhances side reaction suppression). This composite structure resolves the contradiction by combining materials with complementary functions to simultaneously achieve protection and conductivity.
Solution Approach 2:
The patent specifies that ceramic particles should have a BET surface area of 100-300 m²/g, which is a critical parameter change. This specific surface area range optimizes the balance between suppressing side reactions (requiring sufficient surface area for interaction with electrolyte) and maintaining conductivity (requiring controlled contact area).
2Reliability
If ceramic particles with high BET surface area are used, then side reactions are better suppressed, but manufacturing complexity increases
Solution Approach 1:
By specifying a concrete parameter range for ceramic particles (BET surface area: 100-300 m²/g), the patent simplifies manufacturing by providing clear selection criteria. This transforms a complex material selection problem into a straightforward parameter-based specification, making the manufacturing process more controllable and repeatable.
3Reliability
If coating layer thickness is increased, then side reaction suppression improves, but battery energy density decreases
Solution Approach 1:
The coating layer is applied to cover at least a part of the surface of cathode active material particles, not necessarily forming a uniform thick layer over the entire surface. This local quality approach allows sufficient protection at critical areas while minimizing overall material usage and preserving energy density.
Solution Approach 2:
The multi-component composite coating (polymer + conductive assistant + ceramic particles) achieves enhanced side reaction suppression with thinner overall thickness compared to a single-material coating, because each component contributes different protective mechanisms, allowing reduced total coating mass while maintaining or improving protection effectiveness.
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 the increase in internal resistance of lithium-ion batteries and enhances their performance in high-temperature environments.
Implementation Method 1
forming a coating layer, which contains a polymer compound, a conductive assistant, and ceramic particles having a certain BET specific surface area, on the surface of the cathode active material particles
Data Source
AI summary
Coated electrode active material particles for lithium-ion batteries, that can suppress side reactions between the electrolytic solution and the coated electrode active materials, and that can prevent the internal resistance value of lithium-ion batteries from increasing, can be provided. The coated cathode active material particles for lithium-ion batteries in which at least a part of the surface of the cathode active material particles is coated with a coating layer, wherein the coating layer contains a polymer compound, a conductive assistant, and ceramic particles, and wherein the BET specific surface area of the ceramic particles is 70 to 300 m2/g.