Fluorinated Electrolyte Suppressing HF Gas in Li-Ion Batteries
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Solution Overview
Problem
Lithium ion secondary batteries face challenges in maintaining cycle characteristics due to gradual reaction of diols or monoalcohols with fluorine-containing electrolytes, leading to hydrogen fluoride gas generation and subsequent battery deterioration.
Innovation Solution
An electrolyte solution containing a specific fluorine-containing acyclic carbonate and fluorine-containing succinic anhydride is used, with the solvent comprising between 0.001 mass % and 90 vol % of the acyclic carbonate and 0.001 to 20 mass % of the succinic anhydride, along with a lithium salt, to suppress gas generation and enhance high-temperature storage characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diols or monoalcohols are contained in high permittivity solvents or low viscosity solvents, then battery characteristics are improved, but hydrogen fluoride gas is generated over time leading to cycle characteristic deterioration
Solution Approach 1:
The patent removes diols and monoalcohols from the electrolyte solution composition to eliminate the source of hydrogen fluoride gas generation, while maintaining other beneficial components to preserve battery characteristics
Solution Approach 2:
The patent converts the harmful interaction between diols/monoalcohols and fluorine-containing electrolytes into a beneficial outcome by eliminating the reactants, thereby preventing gas generation while maintaining the advantages of fluorine-containing compounds
2Use of energy by moving object
If fluorine-containing electrolytes are used, then high energy density is achieved, but gas generation occurs over time causing battery deterioration
Solution Approach 1:
The patent extracts and removes the problematic components (diols and monoalcohols) that react with fluorine-containing electrolytes to generate gas, while retaining the fluorine-containing electrolytes to maintain high energy density
Solution Approach 2:
The patent changes the compositional parameters of the electrolyte solution by specifying the exclusion of certain alcohol components, thereby preventing gas generation while preserving the energy density benefits of fluorine-containing electrolytes
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 solution effectively reduces gas generation and improves high-temperature storage characteristics of lithium ion secondary batteries, maintaining battery performance and cycle stability.
Implementation Method 1
a fluorine-containing succinic anhydride represented by formula (2)... 0.001 to 20 mass % of the fluorine-containing succinic anhydride
Implementation Method 2
lithium ion secondary batteries... electrolyte solution containing a solvent and an electrolyte salt
Data Source
AI summary
Provided is an electrolyte solution for secondary batteries that are less likely to generate gas and excellent in high-temperature storage characteristics; an electrochemical device using the electrolyte solution; and a module using the electrochemical device. The electrolyte solution contains a solvent and an electrolyte salt, the solvent containing a fluorine-containing acyclic carbonate represented by the formula (1) and a fluorine-containing succinic anhydride represented by the formula (2). The electrolyte solution contains not less than 0.001 mass % but less than 90 vol % of the fluorine-containing acyclic carbonate, and the electrolyte solution contains 0.001 to 20 mass % of the fluorine-containing succinic anhydride.