Fluorinated Gel Polymer Electrolyte for High-Voltage Li-Ion Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gel polymer electrolytes suffer from low lithium-ion conductivity and mechanical strength, leading to safety issues and reduced battery performance, particularly at high voltages and temperatures.
Innovation Solution
A gel polymer electrolyte composed of a matrix polymer formed through the polymerization of an oligomer with specific chemical structures, including fluorine-substituted polyether units and acrylate groups, impregnated with inorganic particles and a nonaqueous solvent, enhancing ion conductivity and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thickness of gel polymer electrolyte is reduced to improve conductivity, then lithium-ion conductivity is improved, but mechanical strength deteriorates
Solution Approach 1:
The patent optimizes the thickness of the gel polymer electrolyte to a specific range of 10-50 μm, which balances lithium-ion conductivity and mechanical strength. Additionally, the patent controls the molecular weight of PAN (10,000-100,000) and adjusts the ratio of cyclic carbonate to chain carbonate in the solvent mixture, achieving optimal mechanical properties while maintaining high conductivity through precise parameter control.
2Temperature
If gel polymer electrolyte is used, then high-temperature safety is improved, but high-voltage stability deteriorates
Solution Approach 1:
The patent selects lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the lithium salt, which has high thermal stability and electrochemical stability window suitable for high-voltage applications. The patent also optimizes the concentration of LiTFSI (0.5-2.0 M) and chooses a specific ratio of cyclic carbonate to chain carbonate, achieving both high-temperature safety and high-voltage stability through careful parameter selection.
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 electrolyte improves lithium-ion conductivity and high-temperature durability, resulting in a lithium secondary battery with enhanced high-voltage stability and safety.
Implementation Method 1
an ion conductive liquid electrolyte containing a salt dissolved in a nonaqueous organic solvent has been used widely
Implementation Method 2
the matrix polymer is formed into a three-dimensional network structure through the polymerization of an oligomer
Data Source
AI summary
Provided is a gel polymer electrolyte including a matrix polymer including an oligomer containing a fluorine-substituted polyether unit and at least one acrylate unit at the end thereof. The gel polymer electrolyte increases a degree of freedom of Li ions through the immobilization and stabilization of anions to realize an effect of reducing the resistance of a battery, thereby realizing high lithium-ion conductivity. In addition, the matrix polymer structure in the gel polymer electrolyte provides enhanced high-temperature durability, and thus allows the manufacture of a lithium secondary battery having improved high-voltage high-temperature stability.