Lithium Battery Electrolyte Additives for Dendrite and High-Voltage Stability

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Solution Overview

Problem

Rechargeable lithium batteries face issues with lithium dendrite growth and deterioration due to high charging voltages and rapid charging, which can lead to internal short circuits and battery degradation, especially when using ester-based solvents with weak oxidation resistance.

Innovation Solution

An electrolyte composition for lithium batteries comprising a non-aqueous organic solvent, lithium salt, and additives including a lithium oxalato borate-based compound and a diaryl sulfate-based compound, which stabilize lithium salts and suppress dendrite formation, even at high charging voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a low-viscosity ester-based solvent is used as electrolyte solvent, then lithium dendrite growth is suppressed, but oxidation resistance deteriorates at high voltage

Engineering Contradiction:

Improvelithium dendrite suppressionVSAvoidoxidation resistance

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses a composite electrolyte system combining ester-based solvent with cyclic carbonate solvent and specific additives (cyclic sulfate and carboxylate). This composite approach allows the ester component to suppress lithium dendrites while the cyclic carbonate and additives provide oxidation resistance at high voltage, resolving the contradiction between dendrite suppression and oxidation stability

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The cyclic carbonate solvent and additive compounds act as intermediaries that protect the ester-based solvent from oxidation at high voltage. These components form stable SEI films and protective layers that prevent direct oxidation of the ester solvent, allowing the system to maintain both low viscosity for dendrite suppression and high oxidation resistance

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If charging voltage is increased to enhance energy density, then battery energy density improves, but lithium dendrite growth increases

Engineering Contradiction:

Improveenergy densityVSAvoidlithium dendrite suppression

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the electrolyte by incorporating specific ratios of ester-based solvent, cyclic carbonate, and additive compounds. This parameter optimization allows the electrolyte to maintain stability and suppress dendrite formation even at elevated charging voltages, enabling higher energy density operation without compromising reliability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The additive compounds (cyclic sulfate and carboxylate) perform preliminary action by forming stable solid electrolyte interface (SEI) films on the electrode surfaces before dendrite formation can occur. This preliminary protective layer prevents lithium ion deposition in dendritic patterns during high-voltage charging, allowing safe operation at elevated voltages for enhanced energy density

Inventive Principle:

Principle #10Preliminary action

3Productivity

If rapid charging is performed to improve charging rate, then charging speed increases, but lithium dendrite growth and battery deterioration increase

Engineering Contradiction:

Improvecharging rateVSAvoidbattery deterioration

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The electrolyte composition maintains continuous protective action during rapid charging through the synergistic combination of ester-based solvent and additive compounds. The ester component ensures continuous lithium ion transport at high rates while the cyclic carbonate and additives continuously maintain stable SEI films, preventing dendrite formation and battery deterioration even during fast charging operations

Inventive Principle:

Principle #20Continuity of useful action

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 electrolyte effectively inhibits lithium dendrite growth and battery deterioration, allowing for higher charging voltages and faster charging without adverse effects, thereby enhancing battery performance and safety.

Implementation Method 1

a first additive represented by Chemical Formula 1, and a second additive represented by Chemical Formula 2

Methodology Applied

Scientific EffectElectrochemical reaction:

Implementation Method 2

a positive electrode including a positive electrode active material capable of intercalating/deintercalating lithium ions and a negative electrode including a negative electrode active material capable of intercalating/deintercalating lithium ions

Methodology Applied

Scientific EffectIntercalation:

Data Source

PatentUS20250300240A1Electrolytes for rechargeable lithium batteries and rechargeable lithium batteries including the same

Publication Date: 2025.09.25 SAMSUNG SDI CO LTD

AI summary

An electrolyte for a rechargeable lithium battery, the electrolyte including a non-aqueous organic solvent, a lithium salt, and an additive; wherein the additive includes a first additive represented by Chemical Formula 1 and a second additive represented by Chemical Formula 2: