Ultracapacitor Nonaqueous Electrolyte High Temperature Stability
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Solution Overview
Problem
Conventional ultracapacitors are sensitive to high temperatures, leading to electrolyte leakage and reduced capacitance and increased equivalent series resistance (ESR).
Innovation Solution
An ultracapacitor design featuring a nonaqueous electrolyte with a high boiling point solvent and ionic liquid, combined with carbonaceous coatings and current collectors, is housed in a metal container to enhance temperature stability and reduce ESR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte is used in ultracapacitor, then the device can operate at normal temperatures, but the electrolyte leaks at high temperatures causing reduced capacitance and increased ESR
Solution Approach 1:
The patent changes the physical and chemical parameters of the electrolyte by using a nonaqueous solvent with a high boiling point (150°C or more) and dissolving ionic liquid at a concentration of about 1.0 mole per liter or more. This parameter change raises the electrolyte's thermal stability threshold, preventing leakage at elevated temperatures while maintaining ionic conductivity for capacitance function.
Solution Approach 2:
The patent creates a composite electrolyte system by combining a nonaqueous solvent (such as cyclic carbonate, chain carbonate, carboxylate, or nitrile) with ionic liquid. This composite formulation leverages the high boiling point of the solvent and the stable ionic properties of the ionic liquid to achieve both thermal stability and electrical performance, resolving the contradiction between reliability and harmful factors.
2Adaptability or versatility
If high temperature operation is enabled, then the ultracapacitor can function in extreme conditions, but capacitance decreases and ESR increases
Solution Approach 1:
The patent modifies the electrolyte composition parameters to include a nonaqueous solvent with a boiling point of 150°C or more and ionic liquid at about 1.0 mole per liter or more. This parameter adjustment allows the ultracapacitor to maintain stable capacitance values across an extended temperature range by preventing electrolyte degradation and maintaining ionic mobility even at elevated temperatures.
3Adaptability or versatility
If high temperature operation is enabled, then the ultracapacitor can function in extreme conditions, but equivalent series resistance increases
Solution Approach 1:
The patent changes the electrolyte parameters by using a nonaqueous solvent with high boiling point (150°C or more) and ionic liquid at about 1.0 mole per liter or more. This formulation maintains low ESR at high temperatures by ensuring sustained ionic conductivity and preventing electrolyte viscosity increases that would otherwise raise resistance.
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 design extends the operating temperature range, maintains high capacitance and low ESR values even at elevated temperatures, and is stable under various extreme conditions.
Implementation Method 1
the nonaqueous electrolyte contains an ionic liquid that is dissolved in a nonaqueous solvent at a concentration of about 1.0 mole per liter or more
Implementation Method 2
The nonaqueous solvent has a boiling temperature of about 150° C. or more
Data Source
AI summary
An ultracapacitor that contains a first electrode, second electrode, separator, nonaqueous electrolyte, and housing is provided. The first electrode comprises a first current collector electrically coupled to a first carbonaceous coating and the second electrode comprises a second current collector electrically coupled to a second carbonaceous coating. The nonaqueous electrolyte is in ionic contact with the first electrode and the second electrode, wherein the nonaqueous electrolyte contains an ionic liquid that is dissolved in a nonaqueous solvent at a concentration of about 1.0 mole per liter or more. The nonaqueous solvent has a boiling temperature of about 150° C. or more.