Disultone Additive for Lithium Battery SEI Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic electrolyte solutions for lithium batteries suffer from poor stability of the solid electrolyte interface (SEI) layer and protection layer at high temperatures, leading to reduced battery life due to irreversible reactions and passivation.
Innovation Solution
Incorporating a disultone-based compound as an additive in the organic electrolyte solution, which forms a more stable SEI layer on the anode and protection layer on the cathode, enhancing their durability and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional additives are used to stabilize the SEI layer and protection layer, then the battery can operate, but the SEI layer and protection layer have poor stability at high temperatures
Solution Approach 1:
The patent introduces a novel sultone-based additive with specific molecular structure parameters (Formula 1) that changes the chemical composition parameters of the SEI layer and protection layer. This additive contains a sultone ring structure with specific substituents that enable formation of stable interfacial layers at high temperatures, resolving the contradiction between operational functionality and thermal stability.
Solution Approach 2:
The patent creates a composite interfacial layer by introducing a new additive component (sultone-based compound) that works synergistically with existing electrolyte components. The composite SEI layer and protection layer formed by this additive exhibit enhanced thermal stability compared to conventional single-component additives, achieving both reliability and high-temperature stability.
2Ease of operation
If carbonate-based polar or non-aqueous solvent is used in lithium battery, then the battery can function, but side reactions occur between anode/cathode and electrolyte solution during initial charging
Solution Approach 1:
The sultone-based additive performs preliminary action by preferentially reacting with lithium ions during initial charging to form a stable SEI layer on the anode and protection layer on the cathode before the carbonate solvents can undergo harmful side reactions. This preliminary formation process prevents subsequent irreversible reactions and reduces charge loss.
Solution Approach 2:
The additive acts as an intermediary substance that mediates between the lithium ions and the carbonate solvents. By forming a stable interfacial layer first, the additive prevents direct harmful interactions between carbonate solvents and electrode surfaces, reducing irreversible reactions while maintaining battery functionality.
3Productivity
If the SEI layer and protection layer have poor stability at high temperatures, then the battery may operate short-term, but the lithium battery life is reduced
Solution Approach 1:
The patent modifies the chemical composition parameters of the interfacial layers by introducing the sultone-based additive, which changes the thermal degradation parameters of the SEI layer and protection layer. This results in layers that maintain structural integrity at high temperatures, extending battery life while preserving operational capacity.
Solution Approach 2:
The additive acts as a sacrificial component that is consumed during initial charging to form a stable, long-lasting protective layer. This disposable-like behavior of the additive (forming irreversible stable layers) protects the main battery components, extending overall battery life while maintaining productivity.
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 disultone-based additive improves the stability and reversibility of lithium ion intercalation, leading to extended battery life and improved discharge capacity, especially at high temperatures.
Implementation Method 1
Using a carbonate-based polar or non-aqueous solvent in a lithium battery may cause a side reaction between an anode (and/or a cathode) and an electrolyte solution during initial charging, and consequentially lead to an irreversible reaction using excess charges. The irreversible reaction may result in a passivation layer such as a solid electrolyte interface (SEI) layer on a surface of the anode.
Implementation Method 2
The SEI layer may prevent decomposition of the electrolyte and also serve as an ion channel. The higher the stability of the SEI layer and the lower the resistance of the SEI layer, the longer the lithium battery life may be.
Implementation Method 3
The irreversible reaction may also form a protection layer on a surface of the cathode. The protection layer may prevent decomposition of the electrolyte solution and also serve as an ion channel.
Implementation Method 4
a lithium battery operating at a high driving voltage is incompatible with an aqueous electrolyte solution highly reactive to lithium. For this reason, the lithium battery normally uses an organic electrolyte solution.
Data Source
Figure 1~2
Figure 3
AI summary
An organic electrolytic solution comprising an additive comprising a disultone-based compound represented by Formula 1 below: wherein, in Formula 1, A1, A2, A3, and A4 are each independently a substituted or unsubstituted C1-C5 alkylene group; a carbonyl group; or a sulfinyl group and a lithium battery including the organic electrolytic solution are provided