Cyclic Sulfone Electrolyte Additive for Stable SEI and Low Gas Generation

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Solution Overview

Problem

Existing additives for nonaqueous electrolyte solutions in lithium ion batteries do not sufficiently improve battery characteristics and resistance, and they can generate gas during charge and discharge cycles, affecting battery performance and safety.

Innovation Solution

A cyclic sulfone compound is used as an additive in the nonaqueous electrolyte solution, which forms a rigid solid electrolyte interface (SEI) through ring-opening polymerization, improving charge and resistance characteristics and suppressing gas generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional additives (1,3-propanesultone, vinylene carbonate derivatives) are added to electrolyte solution, then charge and discharge cycle characteristics are improved, but gas generation occurs and battery characteristics are not sufficiently improved

Engineering Contradiction:

Improvecharge and discharge cycle characteristicsVSAvoidgas generation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical structure parameters of the additive by introducing a cyclic sulfone compound with specific molecular formula (CnH2n-2O3S) where n=3-6. This structural parameter change enables the additive to form an SEI film with different properties compared to conventional additives, achieving both improved cycle characteristics and suppressed gas generation through modified decomposition behavior.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite SEI film structure by combining the cyclic sulfone compound with existing electrolyte components. The cyclic sulfone compound works synergistically with conventional additives like vinylene carbonate to form a multi-layered SEI structure that provides both mechanical stability (reducing gas generation) and electrochemical stability (improving cycle characteristics).

Inventive Principle:

Principle #40Composite materials

2Duration of action of stationary object

If additives are added to form SEI film during initial charge and discharge, then battery capacity is maintained over cycles, but electricity is consumed for solvent decomposition

Engineering Contradiction:

Improvebattery capacity maintenance over cyclesVSAvoidelectricity consumption for solvent decomposition

Core Design Contradiction:

Duration of action of stationary objectVSUse of energy by moving object

Solution Approach 1:

The cyclic sulfone compound is designed to undergo preliminary decomposition during initial charge cycles to form a stable SEI film. This preliminary action consumes electricity only once during formation, after which the SEI film prevents further solvent decomposition. The compound's molecular structure ensures complete SEI formation in fewer cycles compared to conventional additives, reducing total energy consumption.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If existing additives are used to improve battery characteristics, then some performance enhancement is achieved, but sufficient performance improvement cannot be obtained

Engineering Contradiction:

Improvebattery characteristicsVSAvoidperformance improvement magnitude

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent achieves superior performance by changing key parameters of the additive molecule: using cyclic sulfone structure with 3-6 carbon atoms provides optimal balance between SEI formation speed and film stability. The specific molecular weight range and functional group configuration enable faster charge acceptance and lower internal resistance compared to conventional additives, delivering the sufficient performance improvement needed.

Inventive Principle:

Principle #35Parameter changes

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 cyclic sulfone compound enhances the charge and resistance characteristics of lithium ion batteries, reducing gas generation and improving battery performance and safety by forming a stable SEI.

Implementation Method 1

which forms a rigid solid electrolyte interface (SEI) through ring-opening polymerization

Methodology Applied

Scientific EffectRing-opening polymerization:

Implementation Method 2

The additives decompose during an initial charge and discharge to form a film called a solid electrolyte interface (SEI) on the surface of an electrode

Methodology Applied

Scientific EffectDecomposition: Decomposition (biological)

Implementation Method 3

the lithium ions can transfer between the electrodes through the SEI

Methodology Applied

Scientific EffectIon transfer: Ion Exchange

Data Source

PatentUS12021191B2Additive for nonaqueous electrolyte solutions, nonaqueous electrolyte solution and electricity storage device

Publication Date: 2024.06.25 SUMITOMO SEIKA CHEM CO LTD

AI summary

Disclosed is an additive for a nonaqueous electrolyte solution, including a compound represented by the following formula (1):in formula (1), X represents a sulfonyl group or a carbonyl group, R1 represents an alkyl group having 1 to 4 carbon atoms, which may be substituted with a halogen atom, a hydroxyl group, or the like, and R2 represents a hydrocarbon group having 1 to 3 carbon atoms, which may be substituted with a halogen atom.