Lithium Battery Electrolyte Composition for High-Temperature Cathode Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Lithium secondary batteries face degradation due to surface damage of nickel-based lithium metal oxide cathodes and side reactions with the electrolyte, leading to reduced service life and environmental pollution from waste plastics, which also contribute to greenhouse gas emissions.

Innovation Solution

An electrolyte solution for lithium secondary batteries comprising an additive with a specific chemical structure, an organic solvent, and a lithium salt, which forms a robust solid electrolyte interphase (SEI) layer on the electrodes, enhancing high-temperature stability and preventing gas generation and battery thickness increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If nickel-based lithium metal oxide is used as cathode active material to achieve high capacity, then battery capacity is improved, but surface damage occurs during charge/discharge cycles leading to reduced service life

Engineering Contradiction:
Improvebattery capacityVSAvoidservice life
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary action by introducing a fluorinated cyclic carbonate additive that proactively forms a stable protective film on the cathode surface before significant degradation can occur. This preventive mechanism addresses surface damage during charge/discharge cycles by establishing a robust interface layer that protects the nickel-based lithium metal oxide from further deterioration, thereby extending service life while maintaining high capacity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by modifying the electrolyte composition with specific fluorinated cyclic carbonate compounds (where R is hydrogen or C1-C5 alkyl, X is N or P). This chemical parameter change in the electrolyte system enables the formation of a more stable solid electrolyte interphase (SEI) layer on the cathode, which prevents surface damage and improves both capacity retention and service life under high-temperature conditions

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If conventional electrolyte is used to maintain battery operation, then battery function is maintained, but side reactions occur between cathode and electrolyte reducing service life

Engineering Contradiction:
Improvebattery operationVSAvoidservice life
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies the intermediary principle by introducing fluorinated cyclic carbonate compounds as mediator substances in the electrolyte. These compounds act as intermediaries between the cathode and the bulk electrolyte, forming a protective interface layer that prevents direct harmful interactions. The additive serves as a mediator that enables stable battery operation while simultaneously preventing side reactions that would otherwise reduce service life

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the electrolyte's chemical composition parameters by incorporating fluorinated cyclic carbonate additives at specific concentrations (0.1-5 wt%). This parameter change transforms the electrolyte's interaction characteristics with the cathode, enabling stable operation while reducing parasitic reactions through the formation of a more chemically stable interface

Inventive Principle:
Principle #35Parameter changes

3Power

If battery operates at high temperature to improve performance, then power output is improved, but capacity retention deteriorates and gas generation increases

Engineering Contradiction:
Improvepower outputVSAvoidcapacity retention
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the electrolyte composition with fluorinated cyclic carbonate additives that specifically enhance high-temperature stability. The fluorinated compounds change the thermal and chemical parameters of the electrolyte system, enabling the battery to maintain high power output while improving capacity retention and suppressing gas generation under elevated temperature conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating a specialized protective environment at the electrode-electrolyte interface through the fluorinated additive. This localized modification of the interface properties (rather than changing the entire battery system) provides enhanced stability and gas suppression specifically where needed, allowing high power operation without the typical high-temperature degradation

Inventive Principle:
Principle #3Local quality

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 solution improves high-temperature storage properties by maintaining capacity retention and preventing resistance and thickness increases, thereby extending battery life and reducing environmental impact.

Implementation Method 1

an additive which may form a robust solid electrolyte interphase (SEI) on an electrode surface

Methodology Applied
Scientific EffectSolid electrolyte interphase (SEI) formation:

Data Source

PatentEP4307426A1Electrolyte solution for lithium secondary battery and lithium secondary battery including the same
Publication Date: 2024.01.17 SK ON CO LTD
  • EP4307426A1 patent drawingFigure 1~2
  • EP4307426A1 patent drawingFigure 3~4
  • EP4307426A1 patent drawingFigure 5

AI summary

Provided is an electrolyte solution for a lithium secondary battery and a lithium secondary battery including the electrolyte solution. The electrolyte solution includes an additive represented by a specific chemical formula, an organic solvent and a lithium salt. The lithium secondary battery including the electrolyte solution provide enhanced high-temperature properties.