Lithium Battery Electrolyte Additives for Stable Electrode Protection
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Solution Overview
Problem
Lithium secondary batteries, particularly those with LiFePO4 (LFP) positive electrodes, face challenges in high-temperature storage, low-temperature output characteristics, and long-term life performance due to low electronic and ionic conductivity.
Innovation Solution
An electrolyte containing 1-vinyl-1,2,4-triazole additives is used to form protective layers on the surfaces of positive and negative electrodes, improving the battery's performance. The electrolyte also includes vinylene carbonate and 1,3-propane sultone to stabilize the protective layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If LiFePO4 positive electrode is used, then thermal stability is improved, but electronic conductivity and ionic conductivity deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing 1-vinyl-1,2,4-triazole and other additives in specific concentrations (0.05-5 wt% for 1-vinyl-1,2,4-triazole, 0.1-5 wt% for vinylene carbonate, 0.1-5 wt% for 1,3-propane sultone). This modifies the electrolyte's properties to improve ionic conductivity while maintaining thermal stability of the LiFePO4 electrode.
Solution Approach 2:
The patent creates a composite electrolyte system combining multiple components: lithium salt, cyclic carbonate, chain carbonate, 1-vinyl-1,2,4-triazole, vinylene carbonate, and 1,3-propane sultone. This composite approach synergistically improves both thermal stability and conductivity properties that single components cannot achieve alone.
2Speed
If particle size is reduced to nano-sized, then rate characteristics are improved, but capacity and voltage plateau deteriorate
Solution Approach 1:
The patent modifies electrolyte composition parameters to compensate for the reduced capacity and voltage plateau of nano-sized particles. The specific additives (1-vinyl-1,2,4-triazole, vinylene carbonate, 1,3-propane sultone) are optimized to enhance ionic transport and stabilize the electrode-electrolyte interface, thereby improving rate characteristics without sacrificing overall capacity.
3Ease of manufacture
If conventional electrolyte is used, then manufacturing simplicity is maintained, but high-temperature storage and low-temperature output characteristics deteriorate
Solution Approach 1:
The patent develops a composite electrolyte formulation combining conventional components (lithium salt, cyclic carbonate, chain carbonate) with specialized additives (1-vinyl-1,2,4-triazole, vinylene carbonate, 1,3-propane sultone). This composite approach maintains manufacturing simplicity while significantly improving high-temperature storage stability and low-temperature output characteristics through synergistic effects of the multiple components.
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 use of 1-vinyl-1,2,4-triazole in the electrolyte enhances the high-temperature durability and cycle performance of lithium secondary batteries, improving their overall long-term life and output characteristics.
Implementation Method 1
1-vinyl-1,2,4-triazole contained in an electrolyte for a lithium secondary battery may decompose on a surface of a negative electrode, may form a layer for protecting the negative electrode, and may form a nitrogen-based CEI layer excellent in high-temperature durability in a positive electrode
Implementation Method 2
1-vinyl-1,2,4-triazole contained in an electrolyte for a lithium secondary battery may decompose on a surface of a negative electrode, may form a layer for protecting the negative electrode
Implementation Method 3
the additives may further include vinylene carbonate... vinylene carbonate further contained in the additives stabilizes the protective layer on the surface of the negative electrode
Implementation Method 4
the additives may further include 1,3-propane sultone... 1,3-propane sultone further contained in the additives stabilizes the protective layer on the surface of the positive electrode
Implementation Method 5
A lithium secondary battery includes four key elements of a positive electrode, a negative electrode, a separator, and an electrolyte
Data Source
AI summary
In an electrolyte for the lithium secondary battery, which is used in forming protective layers on the surfaces of positive and negative electrodes, the electrolyte contains 1-vinyl-1,2,4-triazole additives. In the instant case, vinylene carbonate further contained in the additives stabilizes the protective layer on the surface of the negative electrode, and 1,3-propane sultone further contained in the additives stabilizes the protective layer on the surface of the positive electrode, thereby improving the long-term life performance and high-temperature life characteristics of the lithium secondary battery.