Thioamide Carbonate Electrolytes for Stable Lithium Metal Anodes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electrolytes for lithium metal batteries suffer from instability and poor cycle performance due to the decomposition of organosulfur compounds, leading to harmful byproducts, excessive gas generation, and high interfacial resistance.

Innovation Solution

Incorporation of thioamide compounds such as thioacetamide, thiourea, or thioformamide as additives in a carbonate-based electrolyte, along with lithium salts and solvents, forms a stable passivation layer on the anode surface, enhancing cycle stability and reducing interfacial resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If organosulfur compounds are used as electrolyte additives, then cycle stability is improved, but decomposition occurs leading to harmful byproducts and excessive gas generation

Engineering Contradiction:

Improvecycle stabilityVSAvoidharmful byproducts and gas generation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical structure parameters of the electrolyte additive by introducing thioamide functional groups with specific molecular weight ranges (100-500 g/mol) and structural characteristics. This parameter modification allows the additive to form stable SEI layers without decomposing into harmful byproducts, resolving the contradiction between cycle stability improvement and harmful decomposition products.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of sulfur-containing compounds decomposing into harmful byproducts by carefully selecting thioamide structures that instead promote beneficial decomposition products. These controlled decomposition products form protective SEI layers that stabilize the electrode interface, turning what could be harmful decomposition into a beneficial passivation mechanism that prevents further degradation.

Inventive Principle:

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

2Reliability

If conventional electrolyte additives are used, then passivation layer formation occurs, but interfacial resistance increases

Engineering Contradiction:

Improveelectrode stabilityVSAvoidinterfacial resistance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by designing electrolyte additives with specific local molecular structures (thioamide groups with particular R1 and R2 substituents) that interact differently with the electrode surface. This localized structural optimization enables the formation of passivation layers with low interfacial resistance, as the specific thioamide structure promotes favorable interfacial properties without the high resistance associated with conventional additives.

Inventive Principle:

Principle #3Local quality

3Reliability

If electrolyte additives are introduced to improve cycle performance, then electrode stability is enhanced, but electrolyte composition complexity increases

Engineering Contradiction:

Improveelectrode stabilityVSAvoidelectrolyte composition

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs composite material principles by combining thioamide functional groups with specific carbonate solvent systems (EC/DMC/DEC combinations). This composite electrolyte formulation achieves enhanced electrode stability through the synergistic interaction between the thioamide additive and the carbonate solvent system, while maintaining relatively simple overall composition that avoids excessive complexity.

Inventive Principle:

Principle #40Composite materials

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 thioamide additives improve cycle stability by stabilizing the anode, extending battery life, reducing dendrite growth, and maintaining ionic conductivity, achieving over 230 cycles at 90% capacity retention compared to 150 cycles without thioamide compounds.

Implementation Method 1

Electrolyte additives, typically in the amount of 5% either by weight or volume of electrolyte, can interact with the negative/positive electrode surface through diffusion (such as physical adsorption or chemical absorption) to form a passivation layer

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

Methodology Applied

Scientific EffectPhysical adsorption: Adsorption

Implementation Method 3

Methodology Applied

Scientific EffectChemical absorption: Chemisorption

Data Source

PatentUS12424664B2Electrolytes comprising thioamides for use in electrochemical batteries

Publication Date: 2025.09.23 FLORIDA INTERNATIONAL UNIVERSITY

AI summary

Electrolytes for improved electrochemical batteries are provided. A carbonate-based electrolyte can include a thioamide compound (e.g., thioacetamide (TAA), thiourea (THU), or thioformamide). The electrolyte can include a salt, a carbonate solvent, and the thioamide compound as an additive. The thioamide compound can be present in a concentration of, for example, 1 millimolar (mM) to 100 mM.