LiFSO3 Electrolyte Composition for High-Temperature Cycle Stability
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Solution Overview
Problem
Current lithium-ion secondary batteries face challenges in achieving high capacity retention and low resistance, especially after high-temperature cycles, which is crucial for their application in various fields including automobiles.
Innovation Solution
A non-aqueous electrolyte solution containing LiFSO3 and specific compounds like LiZ, where Z is PF6, BF4, N(FSO2)2, N(CF3SO2)2, N(C2F5SO2)2, or PO2F2, with a molar content ratio of FSO3 to Z ranging from 3 to 1000, is used to enhance battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte compositions are used, then basic battery operation is achieved, but capacity retention deteriorates and resistance increases after high-temperature cycles
Solution Approach 1:
The patent applies parameter changes by optimizing the molar ratio of LiFSO3 to LiZ (where Z is PF6, BF4, N(FSO2)2, N(CF3SO2)2, N(C2F5SO2)2, or PO2F2) within the specific range of 3:1 to 1000:1. This precise compositional parameter adjustment enables the electrolyte to maintain stable battery capacity retention and low resistance even after high-temperature cycling up to 90°C, resolving the contradiction between basic operation and high-temperature reliability
Solution Approach 2:
The patent employs composite materials by combining LiFSO3 with specific LiZ compounds (where Z represents various anionic groups including PF6, BF4, N(FSO2)2, N(CF3SO2)2, N(C2F5SO2)2, or PO2F2) in a non-aqueous electrolyte system. This composite electrolyte composition synergistically improves capacity retention and reduces resistance under high-temperature conditions while maintaining overall battery performance
2Reliability
If electrolyte composition is optimized for high capacity retention, then battery durability improves, but resistance may increase
Solution Approach 1:
The patent resolves this contradiction through precise parameter changes by controlling the molar ratio of LiFSO3 to LiZ within the specific range of 3:1 to 1000:1. This optimized compositional parameter simultaneously achieves high capacity retention and low resistance, eliminating the trade-off between durability and resistance in the electrolyte system
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 provides lithium-ion secondary batteries with high capacity retention and low resistance even after high-temperature cycles, specifically at temperatures up to 90°C, thereby improving their overall performance and durability.
Implementation Method 1
a non-aqueous electrolyte solution containing LiFSO3 and a compound (1) of the formula LiZ
Implementation Method 2
a negative electrode consists mainly of a carbon material that occludes and releases lithium
Data Source
AI summary
The invention provides an electrolyte solution capable of providing an electrochemical device having a high capacity retention and low resistance even after high-temperature cycles. The electrolyte solution contains LiFSO3 and a compound (1) represented by the following formula (1) : LiZ, wherein Z is PF6, BF4, N(FSO2)2, N(CF3SO2)2, N(C2F5SO2)2, PO2F2, or B(C2O4)2. The electrolyte solution has a ratio [FSO3]/[Z] of a molar content of FSO3 [FSO3] to a molar content of Z [Z] of 3 to 1000.