Lithium Battery Electrolyte Additive for LiPF6 High-Temperature Stability
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Solution Overview
Problem
Lithium secondary batteries face challenges with high-temperature stability and safety due to the decomposition of commonly used lithium salts like LiPF6, which leads to electrolyte depletion and increased resistance.
Innovation Solution
An electrolyte solution for lithium secondary batteries is developed, comprising a non-aqueous organic solvent, a lithium salt, and an additive with a compound represented by Chemical Formula 1. This compound includes a sulfone functional group and an imidazole group, which forms a solid electrolyte interface (SEI) on the negative electrode, reducing initial resistance and high-temperature storage resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If LiPF6 is used as lithium salt in electrolyte, then battery can be manufactured with conventional electrolyte formulation, but LiPF6 decomposes at high temperature causing electrolyte depletion and safety issues
Solution Approach 1:
The patent introduces a protective film forming additive as an intermediary substance that mediates between the LiPF6 lithium salt and the electrolyte solvent. This additive forms a protective interface layer that prevents direct harmful interaction between LiPF6 and solvent at high temperatures, thereby maintaining electrolyte stability while allowing continued use of conventional LiPF6-based electrolyte formulations
Solution Approach 2:
The protective film forming additive performs preliminary protective action by forming a stable interface film before high-temperature decomposition can occur. This pre-formed protective layer prevents the harmful decomposition reactions of LiPF6 that would otherwise lead to electrolyte depletion and safety issues, enabling the battery to maintain reliability at elevated temperatures
2Ease of manufacture
If LiPF6 is used as lithium salt, then electrolyte can be formulated conventionally, but decomposition leads to electrolyte depletion and increased resistance
Solution Approach 1:
The protective film forming additive serves as an intermediary that prevents direct decomposition of LiPF6. By forming a stable protective interface, it mediates the interaction between lithium salt and solvent, preventing the decomposition pathway that leads to electrolyte depletion while maintaining conventional electrolyte formulation
Solution Approach 2:
The additive provides beforehand cushioning by creating a protective buffer layer that cushions against the harmful decomposition effects. This pre-formed protective film acts as a cushion that prevents electrolyte depletion and resistance increase, allowing conventional LiPF6-based electrolytes to maintain stability over extended periods
3Ease of manufacture
If conventional electrolyte is used, then battery can be manufactured with standard formulation, but high-temperature storage causes resistance increase and performance degradation
Solution Approach 1:
The protective film forming additive introduces a mediating protective layer between the electrolyte components and the high-temperature environment. This intermediary film stabilizes the electrolyte system during high-temperature storage, preventing resistance increase and performance degradation while maintaining ease of manufacture with standard electrolyte formulation processes
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 proposed electrolyte solution enhances the high-temperature stability and cycle-life characteristics of lithium secondary batteries by preventing resistance increases and maintaining battery performance over extended cycles.
Implementation Method 1
an additive, wherein the additive includes a compound represented by Chemical Formula 1... which forms a solid electrolyte interface (SEI) on the negative electrode
Data Source
AI summary
Provided is an electrolyte solution for a lithium secondary battery, the electrolyte solution comprising a non-aqueous organic solvent, a lithium salt, and an additive, wherein the additive includes a compound represented by Chemical Formula 1.The contents of Chemical Formula 1 are the same as described in the specification.