Non-Aqueous Electrolyte Composition for High-Temperature Battery Storage

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Solution Overview

Problem

Existing non-aqueous electrolyte batteries face challenges in maintaining battery characteristics, such as capacity, high-temperature storage, and cycle life, due to secondary reactions between electrodes and the electrolyte solution, particularly at high temperatures.

Innovation Solution

Incorporating a compound with at least two isocyanate groups per molecule and a compound with at least two cyano groups per molecule in the non-aqueous electrolyte solution at a specific prescribed ratio, along with other additives like monofluorophosphate salts, to inhibit deterioration and gas generation during high-temperature storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional non-aqueous electrolyte solutions are used, then the battery can operate with basic charge/discharge functionality, but capacity deteriorates and gas is generated during high-temperature storage

Engineering Contradiction:

Improvebattery characteristicsVSAvoidcapacity deterioration and gas generation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by incorporating specific compounds (isocyanate group-containing compound and cyano group-containing compound) into the electrolyte solution before battery operation. These compounds pre-form protective films on the electrodes during initial cycles, preventing secondary reactions and degradation during subsequent high-temperature storage, thereby maintaining battery characteristics without capacity deterioration or gas generation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses intermediary compounds (isocyanate group-containing compound and cyano group-containing compound) as mediators between the electrodes and the electrolyte solution. These intermediaries form protective interface layers that prevent direct harmful interactions between the active electrodes and the electrolyte, thereby inhibiting secondary reactions, capacity deterioration, and gas generation during high-temperature storage while maintaining normal battery operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the electrolyte solution composition is optimized to prevent degradation, then high-temperature storage stability improves, but the complexity of the electrolyte formulation increases

Engineering Contradiction:

Improvehigh-temperature storage stabilityVSAvoidelectrolyte formulation complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by carefully controlling the concentration ratios of the isocyanate group-containing compound and cyano group-containing compound in the electrolyte solution. By optimizing these compositional parameters within specific ranges, the patent achieves high-temperature storage stability while managing formulation complexity through quantitative control rather than qualitative complexity.

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

The proposed solution effectively inhibits capacity deterioration and gas generation during high-temperature storage, while maintaining excellent cycle characteristics and charge/discharge performance at high current densities.

Implementation Method 1

the large dipole moment due to the polarity of the cyano group results in an inhibition of oxidative degradation of the electrolyte solution at the positive electrode during high-voltage charging

Methodology Applied

Scientific EffectDipole moment:

Implementation Method 2

inhibition of oxidative degradation of the electrolyte solution at the positive electrode

Methodology Applied

Scientific EffectOxidative degradation inhibition:

Implementation Method 3

improvement in the battery cycle characteristics through the addition of an isocyanate group-containing compound to the non-aqueous electrolyte solution, thereby inhibiting solvent degradation reactions

Methodology Applied

Scientific EffectSolvent degradation inhibition:

Implementation Method 4

A carbonaceous material capable of the insertion/extraction of the lithium ion is primarily used as the negative electrode active material

Methodology Applied

Scientific EffectIon insertion/extraction:

Data Source

PatentUS12315883B2Non-aqueous electrolyte solution and non-aqueous electrolyte secondary battery employing the same

Publication Date: 2025.05.27 MITSUBISHI CHEM CORP

AI summary

An object is to provide a non-aqueous electrolyte solution that can improve the capacity deterioration and gas generation associated with the high-temperature storage of non-aqueous electrolyte batteries. A further object is to provide a non-aqueous electrolyte battery that uses this non-aqueous electrolyte solution. These objects can be achieved by using a non-aqueous electrolyte solution that incorporates, in prescribed contents, (A) a compound having at least two isocyanate groups per molecule and (B) a compound of formula (3):LiCnF2n+1SO3 (3)wherein n is an integer from 0 to 4.