Localized Superconcentrated Electrolyte for Battery Safety

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Solution Overview

Problem

Conventional superconcentrated electrolytes used in electrochemical devices are flammable, leading to safety concerns, and suffer from high cost, high viscosity, and poor wetting issues, which hinder their practical application.

Innovation Solution

Development of low flammability and nonflammable localized superconcentrated electrolytes (LSEs) comprising an active salt, a solvent with a flame retardant compound, and a diluent where the active salt is soluble in the solvent but poorly soluble in the diluent, creating localized regions of high salt concentration while minimizing free solvent molecules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional superconcentrated electrolytes are used to achieve high salt concentration, then coulombic efficiency is improved, but flammability increases and safety deteriorates

Engineering Contradiction:

Improvecoulombic efficiencyVSAvoidflammability

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a bridge solvent as an intermediary component that is miscible with both the flame-retarded solvent and the diluent. This bridge solvent enables the formation of a homogeneous electrolyte solution while maintaining the flame-retarded properties of the solvent system and the low flammability characteristics, thus resolving the contradiction between achieving high salt concentration for coulombic efficiency and maintaining safety against flammability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite electrolyte system comprising multiple components: a flame-retarded solvent, a diluent with low salt solubility, and a bridge solvent. This composite material approach allows the electrolyte to simultaneously achieve high coulombic efficiency through localized superconcentration while maintaining low flammability through the flame-retarded solvent composition, thus resolving the safety-performance contradiction

Inventive Principle:

Principle #40Composite materials

2Reliability

If conventional superconcentrated electrolytes are used to achieve high salt concentration, then coulombic efficiency is improved, but viscosity increases and wetting performance deteriorates

Engineering Contradiction:

Improvecoulombic efficiencyVSAvoidwetting performance

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent creates localized regions of high salt concentration through the selective solubility of salt in the flame-retarded solvent versus the diluent. This local quality approach maintains high coulombic efficiency at the electrode interface where salt concentration is high, while the bulk electrolyte maintains lower viscosity and better wetting performance due to the presence of the diluent and bridge solvent components

Inventive Principle:

Principle #3Local quality

3Reliability

If conventional superconcentrated electrolytes are used to achieve high salt concentration, then coulombic efficiency is improved, but material cost increases

Engineering Contradiction:

Improvecoulombic efficiencyVSAvoidmaterial cost

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent creates a diluted electrolyte system that copies the beneficial effects of superconcentrated electrolytes (high coulombic efficiency) through localized superconcentration mechanisms, but uses lower overall salt concentrations and more cost-effective solvent combinations, thus achieving similar performance at reduced material cost

Inventive Principle:

Principle #26Copying

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 LSEs enhance safety, reduce material costs, improve wetting, and maintain high coulombic efficiency and cycling stability, comparable to or exceeding that of conventional superconcentrated electrolytes, while being less flammable and having lower viscosity.

Implementation Method 1

a solvent with a flame retardant compound

Methodology Applied

Scientific EffectFlame retardant effect:

Implementation Method 2

wherein the active salt is soluble in the solvent

Methodology Applied

Scientific EffectSolvation: Solvation

Implementation Method 3

a diluent where the active salt is soluble in the solvent but poorly soluble in the diluent, creating localized regions of high salt concentration

Methodology Applied

Scientific EffectSelective solubility:

Data Source

PatentUS10472571B2Low flammability electrolytes for stable operation of electrochemical devices

Publication Date: 2019.11.12 BATTELLE MEMORIAL INST

AI summary

Low flammability and nonflammable localized superconcentrated electrolytes (LSEs) for stable operation of electrochemical devices, such as rechargeable batteries, supercapacitors, and sensors, are disclosed. Electrochemical devices, such as rechargeable batteries, supercapacitors, and sensors, including the low flammability and nonflammable LSEs are also disclosed. The low flammability and nonflammable LSEs include an active salt, a solvent comprising a flame retardant compound, wherein the active salt is soluble in the solvent, and a diluent in which the active salt is insoluble or poorly soluble. In certain embodiments, such as when the solvent and diluent are immiscible, the LSE further includes a bridge solvent.