Energy Storage Device Electrolyte Saturation Control

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Solution Overview

Problem

Conventional energy storage devices face challenges with reduced performance due to insufficient electrolyte quantities leading to unsaturated electrodes and separators, high electrolyte concentrations causing salt precipitation, and safety concerns from overpressure and secondary reactions.

Innovation Solution

The use of an electrolyte with a salt concentration between 0.6 and 0.95 moles/L, specifically acetonitrile-based with quaternary ammonium salts, and a limited quantity that is at least 100% but not exceeding 104% of the saturation quantity to fully saturate electrodes and separators, along with perforated electrodes to enhance electrolyte penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a high quantity of electrolyte is used to fully saturate electrodes and separators, then energy density is improved, but device volume and weight increase

Engineering Contradiction:
Improveelectrolyte quantityVSAvoiddevice volume
Core Design Contradiction:
Quantity of substanceVSVolume of stationary object

Solution Approach 1:

The patent changes the concentration parameter of the electrolyte to 0.6-0.95M (optimal around 0.8M) and precisely controls the quantity to 100-104% of saturation amount. This parameter optimization allows achieving full electrode saturation with minimal excess electrolyte, thereby maximizing energy density while minimizing device volume expansion.

Inventive Principle:
Principle #35Parameter changes

2Power

If electrolyte salt concentration is increased to improve ionic conductivity, then power density is improved, but salt precipitation occurs reducing reliability

Engineering Contradiction:
Improvepower densityVSAvoiddevice reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent identifies and applies the optimal salt concentration range of 0.6-0.95M (with 0.8M being particularly effective) in acetonitrile-based electrolyte. This optimized concentration parameter achieves sufficient ionic conductivity for high power density while remaining below the precipitation threshold, ensuring long-term device reliability and chemical stability.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If excess electrolyte is added to ensure full saturation, then electrode saturation is improved, but overpressure and secondary reactions occur reducing safety

Engineering Contradiction:
Improveelectrolyte saturationVSAvoidoverpressure and secondary reactions
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies partial excess action by adding only 100-104% of the saturation quantity of electrolyte. This controlled minimal excess ensures complete electrode and separator saturation for optimal performance while avoiding the harmful effects of large excess electrolyte quantities, such as overpressure buildup and unwanted secondary reactions.

Inventive Principle:
Principle #16Partial or excessive action

4Volume of stationary object

If electrolyte quantity is reduced to decrease device volume, then device compactness is improved, but electrodes become unsaturated reducing energy density

Engineering Contradiction:
Improvedevice volumeVSAvoidelectrolyte saturation
Core Design Contradiction:
Volume of stationary objectVSQuantity of substance

Solution Approach 1:

The patent uses optimized electrolyte concentration (0.6-0.95M) and precise quantity control (100-104% saturation amount) to achieve maximum electrolyte efficiency. This parameter optimization ensures complete electrode saturation with minimal electrolyte volume, achieving compact device design without sacrificing energy density.

Inventive Principle:
Principle #35Parameter changes

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

This approach results in improved energy density and extended lifetime performance by preventing salt precipitation and maintaining chemical stability, achieving a greater than 25% improvement in energy density over similar products.

Implementation Method 1

a separator impregnated with an electrolyte, the electrolyte facilitating transport of ionic species between the first electrode and the second electrode

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

the ultracapacitor can store electrical charge in an electrical double layer formed at an interface between an electrolyte and an electrode

Methodology Applied
Scientific EffectElectrical double layer formation: Electrostatics

Data Source

PatentEP3008738B1Energy storage device with enhanced energy density
Publication Date: 2020.07.22 MAXWELL TECHNOLOGIES INC
  • EP3008738B1 patent drawingFigure 1
  • EP3008738B1 patent drawingFigure 2
  • EP3008738B1 patent drawingFigure 3

AI summary

An energy storage device having improved energy density performance may include an electrolyte having a salt concentration of about 0.6 moles/L (M) to about 0.95M. A final energy storage device product having a total mass of electrolyte that is at least 100% of a saturation quantity of electrolyte sufficient to fully saturate one or more electrode(s) and separator(s) of the device, and below a threshold quantity above the saturation quantity.