Borate Additive Electrolyte for Lithium Battery Stability

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Solution Overview

Problem

Lithium secondary batteries face challenges with high-temperature safety due to volatile and flammable organic solvents, leading to reduced cycle life and high-temperature lifespan.

Innovation Solution

A non-aqueous electrolyte incorporating a borate-based compound, represented by specific chemical formulas, is used to enhance room-temperature and high-temperature stability, forming a robust solid electrolyte interface that reduces interfacial resistance and prevents electrolyte decomposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If organic solvent is used in the electrolyte, then the battery can achieve high energy density and rapid charging, but the battery exhibits reduced high-temperature safety and shortened cycle life due to volatility and flammability

Engineering Contradiction:

Improvecharging speedVSAvoidhigh-temperature safety

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A borate-based compound is introduced as an intermediary substance in the electrolyte formulation. This compound acts as a mediator that forms a protective interface layer between the electrode and the organic solvent, preventing direct harmful interactions while maintaining the beneficial electrochemical performance. The borate compound thus enables both rapid charging and high-temperature safety by mediating the interface behavior.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrolyte is formulated as a composite system combining organic solvent with borate-based compounds. This composite approach leverages the high energy density properties of organic solvents while the borate compounds provide thermal stability and safety. The synergistic combination resolves the contradiction between productivity and reliability.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If organic solvent is used in the electrolyte, then the battery can achieve high energy density, but the cycle life and high-temperature lifespan are reduced due to electrolyte decomposition

Engineering Contradiction:

Improveenergy densityVSAvoidcycle life

Core Design Contradiction:

Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The borate-based compound performs preliminary protective action by forming a stable interface layer on the electrode surface before the organic solvent can decompose. This pre-formed protective layer prevents subsequent electrolyte decomposition during cycling and high-temperature storage, thereby extending cycle life while maintaining high energy density.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The addition of borate-based compounds changes the interfacial parameters between the electrode and electrolyte. This parameter change results in improved interfacial stability and reduced decomposition reactions, allowing the battery to maintain high energy density over extended cycle life and high-temperature operation.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If conventional electrolyte formulation is used, then the battery can operate at room temperature, but the high-temperature storage stability and cycle characteristics deteriorate

Engineering Contradiction:

Improveroom-temperature operationVSAvoidhigh-temperature storage stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The borate-based compound provides multi-functional benefits: it maintains room-temperature operability while simultaneously improving high-temperature storage stability and cycle characteristics. This universal additive enhances battery performance across different temperature conditions, resolving the contradiction between ease of operation and reliability.

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 inclusion of borate-based compounds in the non-aqueous electrolyte improves cycle characteristics and high-temperature storage stability, significantly increasing battery capacity retention and recovery capacity, especially when used in combination with other borate compounds.

Implementation Method 1

forming a robust solid electrolyte interface that reduces interfacial resistance and prevents electrolyte decomposition

Methodology Applied

Scientific EffectSolid electrolyte interface formation:

Data Source

PatentUS10090559B2Non-aqueous electrolyte and lithium secondary battery including the same

Publication Date: 2018.10.02 LG ENERGY SOLUTION LTD

AI summary

Provided are a non-aqueous electrolyte including a non-aqueous organic solvent, a lithium salt, and a borate-based compound, and a lithium secondary battery using the same. According to the present invention, a lithium secondary battery having improved cycle characteristics and high-temperature storage stability may be prepared by including a non-aqueous electrolyte which includes at least one borate-based compound as an additive.