Electrolyte Additive Coating for High-Temperature Battery Stability

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Solution Overview

Problem

Nonaqueous electrolyte secondary batteries face challenges in achieving high-temperature continuous charging properties and storage characteristics, with existing solutions either compromising capacity or leading to safety issues due to gas generation and electrode deterioration.

Innovation Solution

Incorporating 1,2-dimethoxypropane into the electrolyte solution at specific concentrations, along with a lithium salt and suitable solvents, to form a coating film that inhibits secondary reactions and enhances lithium ion permeability, thereby improving high-temperature performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the capacity is raised by pressing the active material layer of the electrode, then the battery capacity increases, but the uniformity of the active material deteriorates and lithium precipitation occurs

Engineering Contradiction:
Improvebattery capacityVSAvoiduniformity of active material
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by modifying the electrolyte composition parameters - specifically adding 1,3-propanesultone at 0.01-5 mass% and fluoroethylene carbonate at 0.01-5 mass% to the electrolyte solution. This chemical parameter modification enables the electrode to maintain uniformity and prevent lithium precipitation even when pressed to high capacity densities, thus resolving the contradiction between capacity and uniformity.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the positive electrode utilization range is broadened to support use at higher potentials, then the battery capacity increases, but the deterioration of the positive electrode accelerates due to reactions with the electrolyte solution

Engineering Contradiction:
Improvebattery capacityVSAvoidpositive electrode stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by having 1,3-propanesultone and fluoroethylene carbonate in the electrolyte solution react first to form a stable protective coating film on the positive electrode surface before the electrode undergoes deterioration reactions. This pre-formed film acts as a barrier that prevents harmful reactions between the electrode and electrolyte, enabling high potential operation without accelerated deterioration.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent uses 1,3-propanesultone and fluoroethylene carbonate as intermediary substances that mediate between the positive electrode and the main electrolyte solution. These additives form an intermediate protective layer that allows lithium ion transport while blocking direct contact between the electrode and destabilizing components of the electrolyte, thus enabling high potential operation with improved stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If the void space within the battery is reduced to increase capacity, then the battery energy density increases, but the internal pressure increases substantially when gas is generated by electrolyte solution degradation

Engineering Contradiction:
Improveenergy densityVSAvoidinternal pressure
Core Design Contradiction:
Quantity of substanceVSStress or pressure

Solution Approach 1:

The patent converts the harmful effect of gas generation into a beneficial outcome by using 1,3-propanesultone as a gas suppression agent. This additive preferentially reacts to consume components that would otherwise generate gas, transforming the potential harm of gas generation into the benefit of reduced gas production. The result is that the battery can be densely packed with minimal void space while maintaining low internal pressure even during extended operation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 solution provides a nonaqueous electrolyte battery with high capacity and excellent high-temperature storage characteristics, reducing gas generation and maintaining performance under continuous charging conditions.

Implementation Method 1

Incorporating 1,2-dimethoxypropane into the electrolyte solution at specific concentrations, along with a lithium salt and suitable solvents, to form a coating film that inhibits secondary reactions

Methodology Applied
Scientific EffectCoating film formation: Deposition (physical)

Implementation Method 2

enhances lithium ion permeability

Methodology Applied
Scientific EffectIon permeation: Permeation

Data Source

PatentEP2830143B1Nonaqueous electrolyte solution and nonaqueous electrolyte battery
Publication Date: 2019.05.22 MITSUBISHI CHEM CORP
  • EP2830143B1 patent drawingFigure 1

AI summary

The present invention can provide a nonaqueous electrolyte battery that exhibits excellent high-temperature continuous charging properties and to provide a nonaqueous electrolyte solution that gives such a nonaqueous electrolyte battery. A nonaqueous electrolyte solution comprising a lithium salt and a nonaqueous solvent that dissolves the lithium salt, wherein the nonaqueous electrolyte solution contains from at least 0.01 ppm to not more than 100 ppm of a compound represented by the following general formula (1):         R1-CR2OR3-CR22OR3     (1) (in formula (1), R1 and R3 represent an organic group having 1 to 10 carbon atoms and optionally having a substituent; R2 represents hydrogen or an organic group having 1 to 10 carbon atoms and optionally having a substituent; and R1 to R3 may each represent the same group or may each represent different groups).