Nonflammable Liquid Electrolyte for High-Voltage Lithium Batteries
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Solution Overview
Problem
Lithium secondary batteries face safety risks due to their flammable nature, leading to potential fires and explosions, and existing solutions either compromise battery performance or increase costs.
Innovation Solution
A non-flammable liquid electrolyte is developed using a mixture of specific solvents, such as linear ester-based and cyclic carbonate-based compounds, combined with a lithium salt, which provides a self-extinguishing property and maintains high battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional flammable liquid electrolytes are used, then battery performance and energy density are maintained, but safety is compromised due to fire and explosion risks
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing fluorinated cyclic carbonate compounds with specific molecular structures (Formula 1 and Formula 2) where n and m are integers from 0 to 5. This chemical parameter modification reduces flammability while maintaining ionic conductivity and battery performance
Solution Approach 2:
The patent creates a composite electrolyte system by combining fluorinated cyclic carbonate compounds (Formula 1 and Formula 2) with lithium salts (such as LiPF6, LiBF4, LiClO4) in specific ratios. This composite approach integrates the flame-retardant properties of the fluorinated cyclic carbonates with the ionic conductivity of lithium salts, achieving both safety and performance
2Reliability
If flame retardant additives such as phosphazene, phosphate, or ionic liquids are used, then safety is improved, but battery performance degrades and manufacturing cost increases
Solution Approach 1:
Instead of using conventional flame retardant additives, the patent changes the fundamental structure of the cyclic carbonate solvent by introducing fluorine atoms at specific positions (Formula 1 and Formula 2). This structural parameter change inherently provides flame retardancy without the performance-degrading effects of traditional additives
Solution Approach 2:
The patent extracts the flame-retardant function from separate additive molecules (such as phosphazene or ionic liquids) and integrates it directly into the cyclic carbonate solvent structure itself. This eliminates the need for additional flame retardant additives that would otherwise degrade performance or increase cost
3Reliability
If solid electrolytes are used to improve safety, then fire risk is reduced, but interfacial resistance increases leading to poor charge-discharge performance and high manufacturing cost
Solution Approach 1:
The patent uses a liquid electrolyte system (fluorinated cyclic carbonate compounds) rather than solid electrolytes, maintaining the fluid state that enables good wetting of electrode surfaces and low interfacial resistance. The liquid state allows efficient ion transport across interfaces while the fluorinated structure provides inherent flame retardancy
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 solution effectively prevents battery performance degradation while enhancing safety by ensuring the electrolyte is non-flammable, allowing for rapid charging and high energy density without the risks of fire or explosion.
Implementation Method 1
a non-aqueous organic liquid electrolyte having lithium ion conductivity
Implementation Method 2
a flame retardant or non-flammable liquid electrolyte including a lithium salt; a first solvent including a compound represented by the following Chemical Formula 1
Data Source
AI summary
The present disclosure relates to a flame retardant or non-flammable liquid electrolyte and a lithium secondary battery including the same, wherein the liquid electrolyte is flame retardant or non-flammable and capable of preventing accidents such as a lithium secondary battery being on fire, catching fire, or exploding from occurring, thereby significantly improving battery safety, is capable of obtaining increased battery energy density by allowing high-voltage charge, is capable of rapid charge, and is capable of maintaining excellent battery performance for a long period of time.