Sulfamide Isocyanate Electrolyte Additive for Low-Impedance Interface Films

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Solution Overview

Problem

Lithium secondary batteries face performance degradation due to the oxidation, decomposition, and high impedance of the electrolyte solution, especially at high temperatures, which affects the cycle life and stability of the battery.

Innovation Solution

An isocyanate electrolyte solution additive containing a sulfamide structural group is introduced, which forms a stable interface film on electrodes, reducing impedance and acting as a stabilizing agent to inhibit acidity and chroma increases in the electrolyte solution, thereby enhancing the battery's high-temperature performance and cycle stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional carbonic ester electrolyte solution is used to form interface film on electrodes, then a protective film is formed, but the impedance of the interface film becomes too high which attenuates electrochemical performance

Engineering Contradiction:

Improveinterface film stabilityVSAvoidinterface film impedance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the electrolyte solution by introducing specific additives (cyclic carboxylate and its derivative) to modify the interface film properties. This resolves the contradiction by adjusting the electrolyte composition to form a film with lower impedance while maintaining stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite interface film system by combining traditional carbonic ester with cyclic carboxylate additives. This composite approach allows the film to simultaneously achieve good stability and reduced impedance, resolving the contradiction between film protection and ion transport.

Inventive Principle:

Principle #40Composite materials

2Productivity

If sulfur-containing additives like ethylene sulfate (DTD) are used to reduce battery impedance, then high temperature and low temperature performance improve, but thermostability deteriorates causing degradation of acid value and chroma

Engineering Contradiction:

Improvebattery performanceVSAvoidelectrolyte solution stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent introduces cyclic carboxylate as an intermediary substance that mediates between the sulfur-containing additive and the electrolyte system. This intermediary forms a stable interface film that prevents direct degradation reactions, allowing impedance reduction while maintaining thermostability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The cyclic carboxylate additive acts as a sacrificial component that preferentially reacts to form stable films, protecting the main electrolyte solution from degradation. This disposable-like behavior of the additive resolves the stability issue while maintaining performance benefits.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If film forming additives are used to improve interface film performance, then impedance is reduced, but the comprehensive performance requirements of the battery become harder to meet due to various additive interactions

Engineering Contradiction:

Improveinterface film impedanceVSAvoidadditive system complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The cyclic carboxylate additive performs multiple functions simultaneously: it forms protective interface films, reduces impedance, and stabilizes the electrolyte solution. This multi-functionality resolves the contradiction by achieving multiple performance improvements with a single additive rather than requiring complex additive combinations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 additive improves the cycle performance and high-temperature storage capabilities of lithium-ion batteries by forming a stable interface film and reducing internal resistance, while maintaining the electrolyte solution's stability and preventing discoloration and acidity increases.

Implementation Method 1

forming a stable interface film on the surface of an electrode

Methodology Applied

Scientific EffectFilm formation: Deposition (physical)

Implementation Method 2

the electrolyte solution to oxidize, decompose and degrade the battery

Methodology Applied

Scientific EffectOxidation resistance: Oxidation

Implementation Method 3

acting as a stabilizing agent to inhibit acidity and chroma increases in the electrolyte solution

Methodology Applied

Scientific EffectStabilization:

Data Source

PatentUS12166176B2Electrolyte solution additive containing isocyanate and sulfamide structural groups and application thereof

Publication Date: 2024.12.10 VALIANT CO LTD

AI summary

An isocyanate electrolyte solution additive containing a sulfamide structural group has a structure of formula I:where R1 and R2 are identical or different, R1 and R2 are each independently selected from methyl, ethyl, butyl, methoxy, methanesulfonyl, ethanesulfonyl, fluorosulfonyl, trifluoromethanesulfonyl, perfluoroethylsulfonyl, benzenesulfonyl, alkyl-containing benzenesulfonyl, cyano/fluorobenzenesulfonyl and alkoxy-containing benzenesulfonyl, and R1 and R2 can be linked to form one of five-membered ring or six-membered ring.