Lithium Battery Additive for High-Temperature Stability
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Solution Overview
Problem
Lithium secondary batteries face issues with high-temperature performance and safety due to the decomposition of commonly used lithium salts like LiPF6, which leads to electrolyte depletion and increased resistance, affecting their cycle-life and stability.
Innovation Solution
An additive represented by Chemical Formula 1, containing a sulfone functional group and a (meth)acryloyl group, is introduced into the electrolyte to form a solid electrolyte interface (SEI) film on the negative electrode, enhancing ion conductivity and preventing decomposition, while also stabilizing the cathode-electrolyte interface, thus improving high-temperature stability and cycle-life characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LiPF6 is used as a lithium salt in the electrolyte, then high ionic conductivity is achieved, but the lithium salt reacts with the electrolytic solvent to promote depletion of the solvent and generate a large amount of gas
Solution Approach 1:
The patent introduces a novel lithium salt compound as an intermediary substance that mediates between the need for high ionic conductivity and the problem of solvent depletion. This lithium salt compound acts as a mediator that provides ionic conductivity without the harmful side reactions characteristic of conventional LiPF6, thereby resolving the contradiction between achieving high conductivity and preventing solvent loss.
Solution Approach 2:
The patent changes the chemical parameters of the lithium salt from conventional LiPF6 to a novel compound with different molecular structure and properties. By altering the chemical composition and structure parameters of the lithium salt, the patent achieves high ionic conductivity while eliminating the problematic reactions with the electrolytic solvent, thus resolving the contradiction between conductivity and solvent stability.
2Reliability
If LiPF6 is used as a lithium salt, then high ionic conductivity is achieved, but decomposition generates LiF and PF5 leading to electrolyte depletion and degradation in high-temperature performance
Solution Approach 1:
The novel lithium salt compound serves as an intermediary that provides ionic conductivity without undergoing decomposition into harmful products like LiF and PF5. This intermediary substance maintains electrolyte integrity at high temperatures, resolving the contradiction between achieving high conductivity and maintaining high-temperature performance.
Solution Approach 2:
The patent converts the harmful decomposition behavior of conventional LiPF6 into a beneficial property by designing a lithium salt compound that inherently resists decomposition. The novel compound transforms the problematic thermal instability into a stable, high-temperature resistant electrolyte component that maintains conductivity without degradation.
3Reliability
If LiPF6 is used as a lithium salt, then high ionic conductivity is achieved, but a large amount of gas is generated affecting safety
Solution Approach 1:
The novel lithium salt compound acts as an intermediary that enables ionic conductivity without the gas-generating side reactions of conventional LiPF6. This mediator substance provides the necessary ionic transport while eliminating harmful gas evolution, resolving the contradiction between conductivity and safety.
Solution Approach 2:
The patent extracts and eliminates the harmful gas-generating property from the lithium salt function. By removing the problematic decomposition pathway that produces gas, the patent retains the beneficial ionic conductivity while extracting away the harmful gas generation aspect, thus resolving the contradiction between conductivity and safety.
4Ease of operation
If conventional electrolytes are used, then basic battery operation is achieved, but side reactions occur leading to poor safety and degraded performance
Solution Approach 1:
The patent changes the chemical parameters of the electrolyte by introducing a novel lithium salt compound with different molecular structure and reactivity characteristics. This parameter change maintains basic battery operation while eliminating side reactions, thus resolving the contradiction between ease of operation and safety.
Solution Approach 2:
The patent converts the harmful side reactions of conventional electrolytes into a beneficial outcome by using a lithium salt compound that inherently prevents these reactions. The novel compound transforms the problematic reactivity into a stable, safe electrolyte system that operates reliably without degradation.
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 additive significantly improves the high-temperature stability and cycle-life characteristics of lithium secondary batteries by reducing resistance and preventing electrolyte oxidation, ensuring stable performance over a long period.
Implementation Method 1
An additive represented by Chemical Formula 1, containing a sulfone functional group and a (meth)acryloyl group, is introduced into the electrolyte to form a solid electrolyte interface (SEI) film on the negative electrode
Implementation Method 2
stabilizing the cathode-electrolyte interface, thus improving high-temperature stability and cycle-life characteristics
Data Source
AI summary
Provided are an additive represented by Chemical Formula 1, an electrolyte for a lithium secondary battery including same, and a lithium secondary battery. The details of Chemical Formula 1 are as described in the specification.