Fluorinated Separator Coating for Battery Thermal Safety and Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrochemical apparatuses face challenges in maintaining puncture resistance, thermal safety, and electrochemical performance under high-temperature and low-temperature conditions, particularly in applications requiring excellent electrochemical performance and overcharge protection.
Innovation Solution
A separator with specific atomic ratios of aluminum and fluorine atoms, spaced stripes, and optimized coating design to enhance structural strength, liquid retention, and interface bonding, combined with an electrolyte solution containing nitrile additives and triphenylphosphine oxide to improve thermal safety and cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the atomic percentage of aluminum atoms is increased to improve puncture resistance, then the puncture resistance improves, but the risk of separator puncture increases when the ratio is excessively high
Solution Approach 1:
The patent optimizes the atomic percentage ratio of aluminum atoms to fluorine atoms (1:4 to 4:1) on the separator surface to achieve optimal puncture resistance while preventing short-circuit risks. This parameter optimization resolves the contradiction by finding the precise compositional range that maximizes strength without compromising reliability.
Solution Approach 2:
The patent uses a composite coating containing both aluminum atoms and fluorine atoms on the separator surface. This composite material approach allows the synergistic combination of aluminum's puncture resistance enhancement and fluorine's protective and affinity properties, resolving the contradiction between strength improvement and reliability maintenance.
2Reliability
If the atomic percentage of fluorine atoms is increased to improve thermal safety performance, then the protective effect on separator surface improves, but the manufacturing complexity increases
Solution Approach 1:
The patent specifies an optimal atomic percentage range for fluorine atoms (5% to 20%) to achieve thermal safety performance improvement while avoiding excessive complexity in coating formulation and manufacturing processes.
Solution Approach 2:
The patent applies fluorine-containing coating materials specifically on the separator surface where thermal safety protection is most needed, rather than uniformly throughout the entire separator structure. This localized application optimizes thermal safety performance while minimizing manufacturing complexity.
3Quantity of substance
If the spacing between stripes is reduced to improve liquid retention capacity, then the liquid retention capacity improves, but the interface bonding force may be affected
Solution Approach 1:
The patent optimizes the spacing between stripes (1 mm to 3 mm) to achieve the right balance between liquid retention capacity and interface bonding force. This parameter optimization ensures that stripes are close enough to retain liquid effectively but not so close that they compromise the bonding strength with electrode plates.
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 separator enhances puncture resistance, reduces short-circuit risk, improves thermal safety, and increases cycle performance and overcharge protection, ensuring stable operation under varying temperatures.
Implementation Method 1
The separator includes aluminum atoms and fluorine atoms... can effectively improve the puncture resistance of the separator... can effectively reduce the short-circuit risk... improve the thermal safety performance
Implementation Method 2
the fluorine atoms can effectively improve the affinity between the surface of the separator and the electrolyte solution, which is more conducive to improving the liquid retention capability of the electrochemical apparatus during cycling
Implementation Method 3
the average spacing between two adjacent stripes falls within an appropriate range, it is conducive to improving the interface bonding force between the separator and the positive/negative electrode plates
Data Source
AI summary
A separator comprises aluminum atoms and fluorine atoms, and in a 2 µm × 2 µm region, a ratio A of atomic percentages of the aluminum atoms to the fluorine atoms satisfies 1 ≤ A ≤ 4. The separator includes a substrate, and the surface of the substrate is provided with a coating. The coating includes a plurality of spaced stripes, and an average spacing between two adjacent stripes is 1 mm to 3 mm. The separator provided in this application can improve the high-temperature cycle performance, low-temperature intermittent cycle performance, and thermal safety performance of the electrochemical apparatus.