Ionic Liquid Electrolyte for High-Temperature Lithium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic solvent electrolytes for lithium secondary batteries are unstable at high temperatures and require cooling, which reduces capacity and efficiency in large-scale systems.
Innovation Solution
A non-aqueous electrolyte for lithium secondary batteries using a salt with [C(SO2F)3] as an anion and cations such as 1-ethyl-3-methylimidazolium, N-methyl-N-propylpiperidinium, tetramethylammonium, or N-methyl-N-ethylpyrrolidinium, forming an ionic liquid or plastic crystal that maintains stability and low interfacial charge transfer resistance at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an organic solvent electrolyte is used in lithium secondary batteries, then the battery can be operated at low temperature, but the battery generates heat and requires cooling at high temperature which reduces capacity and efficiency
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by using ionic liquids with specific cation-anion combinations (e.g., imidazolium with BF4-, PF6-, or CF3SO3- anions) to achieve stable operation at temperatures up to 85°C or higher, eliminating the need for cooling systems and maximizing capacity density
Solution Approach 2:
The patent employs composite ionic liquid systems combining different cation types (imidazolium, pyridinium, ammonium, phosphonium) with various anions to create electrolytes with optimized thermal stability and conductivity properties, enabling high-temperature operation without sacrificing low-temperature performance
2Reliability
If cooling systems are added to control battery temperature, then the battery can operate safely at high temperature, but the installation area increases and overall capacity is reduced
Solution Approach 1:
The patent extracts and eliminates the cooling system from the battery assembly by using ionic liquid electrolytes that inherently resist thermal runaway and maintain stability at elevated temperatures, thereby removing the need for external cooling infrastructure and maximizing installation space
Solution Approach 2:
The ionic liquid electrolyte provides self-cooling capability through its intrinsic thermal stability and heat dissipation properties, allowing the battery to manage its own thermal conditions without external intervention or additional cooling components
3Power
If conventional organic solvent electrolytes are used, then the battery can achieve high conductivity, but the electrolyte becomes unstable and volatile at high temperature
Solution Approach 1:
The patent changes the molecular structure parameters of the electrolyte by replacing volatile organic solvents with ionic liquids composed of bulky cations (imidazolium, pyridinium, ammonium, phosphonium) and appropriate anions, which eliminates volatility while maintaining high ionic conductivity through optimized ion transport pathways
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
Enables stable operation at intermediate to high temperatures, reducing the need for cooling and enhancing storage efficiency per unit volume, particularly suitable for high-capacity batteries like those for automotive use.
Implementation Method 1
contains no solvent molecule, has thermal resistance without being vaporized by heating
Implementation Method 2
achieves higher conductivity when the temperature increases
Implementation Method 3
solids that are in a plastic crystal phase near ordinary temperature have become known
Data Source
Figure 1~2
Figure 3
Figure 4a4b
AI summary
The present invention provides an ionic liquid or plastic crystal comprising an anion and a cation, the anion comprising [C(SO2F)3]-, and the cation comprising at least one member selected from the group consisting of 1-ethyl-3-methylimidazolium ([EMI]+), N,N-diethyl-N-methyl-(2-methoxyethyl)ammonium ([DEME]+), N-methyl-N-propylpyrrolidinium ([PY13]+), N-methyl-N-propylpiperidinium ([PP13]+), tetramethylammonium ([N1111]+), tetraethylammonium ([N2222]+), trimethylhexylammonium ([N6111]+), triethylhexylammonium ([N6222]+), N-methyl-N-ethylpyrrolidinium ([Py12]+), 1-butyl-3-methylimidazolium ([C4mim]+), and 1-hexyl-3-methylimidazolium ([C6mim]+).