Bridge-Ring Electrolyte Additive for Li-Ion SEI Gas Suppression

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Solution Overview

Problem

Lithium-ion batteries face challenges in energy density, high-temperature safety, and service life due to unstable solid electrolyte interface films (SEI) rich in Li2CO3 components, which decompose and produce gas, affecting cycling and storage performance.

Innovation Solution

Incorporating a compound of Formula (I) with a rigid bridge ring structure in the electrolyte to form a stable SEI film, reducing Li2CO3 content and promoting lithium ion transport, while an anhydride/amide group captures water and acid to inhibit decomposition and gas production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fluorocarbonate compound is used to form SEI film, then cycling performance is improved, but high-temperature storage performance deteriorates due to Li2CO3 decomposition and gas production

Engineering Contradiction:

Improvecycling performanceVSAvoidgas production at high temperature

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The compound of Formula (I) acts as an intermediary substance that reacts with Li2CO3 components in the SEI film to suppress their decomposition. It mediates between the fluorocarbonate compound and the unstable Li2CO3, capturing water and acid to prevent gas production while maintaining cycling performance benefits.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention converts the harmful effect of Li2CO3 decomposition into a beneficial outcome by using the compound of Formula (I) to capture the decomposition products (water and acid). This transforms the harmful gas production into a controlled chemical reaction that stabilizes the SEI film and improves high-temperature storage performance.

Inventive Principle:

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

2Ease of manufacture

If conventional electrolyte is used, then manufacturing is simple, but coulombic efficiency and cycling performance are insufficient

Engineering Contradiction:

Improveelectrolyte preparationVSAvoidcoulombic efficiency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention creates a composite electrolyte system by combining the compound of Formula (I) with conventional fluorocarbonate compounds. This composite approach maintains the ease of manufacture of conventional electrolytes while significantly improving coulombic efficiency and cycling performance through the synergistic effects of the new compound.

Inventive Principle:

Principle #40Composite materials

3Strength

If SEI film is formed with Li2CO3 components, then film-forming reaction is strong, but film stability at high temperature deteriorates

Engineering Contradiction:

Improvefilm-forming capabilityVSAvoidSEI film thermal stability

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The compound of Formula (I) captures the harmful decomposition products (water and acid) from Li2CO3, converting the unstable SEI film into a more stable structure. This transforms the inherent instability of Li2CO3-rich SEI into a beneficial stable film that maintains both strength and thermal stability.

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

Enhances first-cycle coulombic efficiency, improves cycling and high-temperature storage performance by stabilizing the SEI film and reducing film-forming impedance, thus improving the electrochemical device's overall performance.

Implementation Method 1

The compound of Formula (I) is introduced and can have a polymerization reaction at a film-forming stage to introduce a rigid bridge ring structure in the SEI film

Methodology Applied

Scientific EffectPolymerization reaction: Photopolymerisation

Implementation Method 2

an anhydride/amide group in the compound of Formula (I) synchronously forms a film on a surface of an active material, and minor amounts of water and acid in the electrolyte can be captured

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

transport of lithium ions between the active material and the electrolyte can be promoted

Methodology Applied

Scientific EffectIon transport: Ion Exchange

Data Source

PatentUS20250316762A1Electrolyte, electrochemical device, and electronic device

Publication Date: 2025.10.09 DONGGUAN AMPEREX TECH

AI summary

An electrolyte includes a Formula (I) compound and a fluorocarbonate compound. X is an oxygen atom or N—R8. R1, R2, R3, R4, R5, R6, and R5 are each independently H; a halogen; substituted or unsubstituted: C1 to C10 alkyl, C2 to C10 alkenyl, C2 to C10 alkynyl, C6 to C10 aryl, C1 to C10 alkoxy, C2 to C10 enyloxy, C2 to C10 alkynyloxy, C6 to C10 aryloxy, C1 to C10 alkoxyalkyl, C1 to C10 carboxyl, C2 to C10 carboxylate, or C2 to C10 carbonate, C1 to C10 nitrogen-containing group, C1 to C10 sulfur-containing group, C1 to C10 boron-containing group, C1 to C10 silicone-containing group, or C1 to C10 phosphorus-containing group; cyano, or amino. R7 is a substituted or unsubstituted: C1 to C10 alkylene, C3 to C10 cycloalkylene, C1 to C10 oxygen-containing group, or C1 to C10 nitrogen-containing group. Where substituent group is a halogen or cyano.