Nonaqueous Electrolyte Composition for Fast-Charging SEI Stability

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Solution Overview

Problem

Existing secondary batteries face challenges in achieving fast charging performance, cycling performance, and safety performance, particularly in energy storage systems and electric vehicles.

Innovation Solution

A non-aqueous electrolyte solution is developed, comprising a cyclic sulfate compound and a specific solvent, which forms a stable inorganic-organic hybrid SEI film on the negative electrode, inhibiting reactions and improving conductivity, thereby enhancing fast charging, cycling, and storage performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional electrolytes are used, then the battery can operate, but fast charging performance is poor due to high viscosity and low conductivity

Engineering Contradiction:

Improvefast charging performanceVSAvoidcycling performance

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the electrolyte by introducing cyclic sulfate compounds with specific molecular structures (formula I) containing ester radicals, alkoxy groups, or haloalkoxy groups. These parameter changes in electrolyte composition reduce viscosity and improve conductivity, enabling fast charging while maintaining cycling stability through the formation of stable SEI films.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite electrolyte system combining cyclic sulfate compounds (formula I) with specific solvents (formula A and formula B). This composite approach produces an inorganic-organic hybrid SEI film on the negative electrode, which provides both the low viscosity needed for fast charging and the stability required for good cycling performance.

Inventive Principle:

Principle #40Composite materials

2Speed

If the electrolyte conductivity is improved for fast charging, then charging speed increases, but gas emissions and storage performance worsen

Engineering Contradiction:

Improveconductivity and charging speedVSAvoidgas emissions

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The cyclic sulfate compound acts as an intermediary substance that mediates between the electrolyte and the negative electrode. It forms a stable protective SEI film that serves as an intermediate layer, preventing direct contact between the high-conductivity electrolyte and the electrode, thereby blocking gas-generating reactions while maintaining ionic conductivity for fast charging.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potential harm of reactive electrolytes causing gas emissions into a benefit by using the cyclic sulfate compound to form a protective SEI film. This film transforms the harmful direct reaction into a beneficial stable interface that enables fast charging without gas generation, effectively converting the reactive nature of the electrolyte from a harmful factor to a controlled beneficial feature.

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 improves battery conductivity, reduces gas emissions, and enhances cycling and storage performance by forming a stable electron-blocking film, addressing the limitations of existing electrolytes.

Implementation Method 1

the additive forms a more stable inorganic-organic hybrid SEI film with stronger electron blocking ability on the surface of the negative electrode

Methodology Applied

Scientific EffectSEI film formation:

Implementation Method 2

the additive forms a more stable inorganic-organic hybrid SEI film with stronger electron blocking ability

Methodology Applied

Scientific EffectElectron blocking:

Implementation Method 3

the first solvent can enable the electrolyte solution to have low viscosity, thus improving the conductivity of the electrolyte solution

Methodology Applied

Scientific EffectViscosity reduction:

Implementation Method 4

improving the conductivity of the electrolyte solution

Methodology Applied

Scientific EffectConductivity improvement: Conduction (electrical)

Data Source

PatentUS20260081222A1Nonaqueous electrolyte for secondary battery, secondary battery, and electric device

Publication Date: 2026.03.19 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

AI summary

A non-aqueous electrolyte solution for a secondary battery, a secondary battery, and an electrical apparatus are described. The non-aqueous electrolyte solution for a secondary battery of the present application comprises an additive and a non-aqueous solvent, wherein the non-aqueous solvent comprises a first solvent; the additive comprises a cyclic sulfate compound as shown in formula (I); and the first solvent is selected from one or more of ethylene glycol dimethyl ether, a compound as shown in formula A, and a compound as shown in formula B;