LiPF6 Battery Electrolyte Additives for High-Temperature Gas Suppression
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Solution Overview
Problem
Rechargeable lithium batteries face issues with high-temperature performance degradation and safety due to gas generation and resistance increase, particularly when using LiPF6 as a lithium salt, which leads to electrolyte depletion and poor safety characteristics.
Innovation Solution
An electrolyte composition for rechargeable lithium batteries is introduced, comprising a non-aqueous organic solvent, a lithium salt, and an additive mixture of specific compounds (represented by Chemical Formulas 1 and 2) that suppresses gas generation and resistance increase, enhancing thermal stability and high-temperature safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LiPF6 is used as a lithium salt in the electrolyte, then the battery can achieve good electrochemical performance, but gas generation and resistance increase occur at high temperatures leading to poor safety and performance degradation
Solution Approach 1:
The patent introduces a mediator substance (lithium difluoromalonate or lithium fluoromalonate) that acts as an intermediary between the lithium salt and the organic solvent. This mediator suppresses the decomposition reaction between LiPF6 and the solvent, thereby reducing gas generation and resistance increase at high temperatures without compromising electrochemical performance
Solution Approach 2:
The patent changes the chemical composition parameters of the electrolyte by incorporating specific lithium malonate compounds with fluorine substituents. This parameter change (adding F-substituted lithium malonate) fundamentally alters the chemical stability profile of the electrolyte system, preventing harmful reactions at elevated temperatures
2Reliability
If LiPF6 is used as a lithium salt in the electrolyte, then the battery can achieve good electrochemical performance, but electrolyte depletion occurs leading to high-temperature performance degradation
Solution Approach 1:
The F-substituted lithium malonate acts as a protective intermediary that prevents the decomposition of LiPF6. By suppressing the reaction between lithium salt and solvent, it prevents electrolyte depletion and maintains stable performance at high temperatures
Solution Approach 2:
The patent applies preliminary protection by adding the stabilizer compound before any harmful decomposition can occur. The stabilizer pre-establishes a protective chemical environment that prevents electrolyte depletion during high-temperature operation
3Reliability
If conventional electrolyte composition is used, then the battery can be manufactured with standard components, but swelling characteristics deteriorate during high-temperature storage
Solution Approach 1:
The patent modifies the chemical composition parameters of the electrolyte by incorporating F-substituted lithium malonate compounds. This parameter change suppresses gas generation during high-temperature storage, thereby preventing swelling and maintaining proper battery shape and dimensions
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 composition significantly improves high-temperature storage characteristics and swelling characteristics by reducing gas generation and resistance increase, ensuring improved safety and performance stability at elevated temperatures.
Implementation Method 1
the additive is a composition including a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2... significantly improves high-temperature storage characteristics and swelling characteristics by reducing gas generation and resistance increase
Data Source
AI summary
Provided are an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including same, the electrolyte including a non-aqueous organic solvent, a lithium salt, and an additive, wherein the additive is a composition including a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2.Details of Chemical Formulas 1 and 2 are the same as those described in the specification.