Electrolyte Composition for Lithium-Ion Battery Cycling and Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face challenges in maintaining high-temperature storage performance, cycling performance, charging performance, and safety performance while maintaining high energy density, particularly due to issues with electrolyte interactions with electrode active materials and potential lithium precipitation.
Innovation Solution
The electrochemical apparatus includes a negative electrode plate with a negative electrode active material layer, a positive electrode plate, a separator, and an electrolyte composition that optimizes the mass percentage of ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, sulfur-oxygen double bond-containing compounds, lithium salts, and polynitrile compounds to form protective interfaces, enhancing the battery's performance across various conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mass percentage of ethylene carbonate in the electrolyte is increased to improve cycling performance and high-temperature storage performance, then the cycling performance and high-temperature storage performance are improved, but the energy density may be reduced
Solution Approach 1:
The patent optimizes the mass percentage of ethylene carbonate in the electrolyte to a specific range (1.6 ≤ b/a ≤ 6.4) to achieve the best balance between cycling performance, high-temperature storage performance, and energy density. This parameter optimization resolves the contradiction by finding the optimal concentration point where protective film formation is sufficient without excessive electrolyte consumption.
Solution Approach 2:
The patent uses a composite electrolyte system comprising multiple components (ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, and sulfur-oxygen double bond-containing compounds) that work synergistically. This composite approach allows the electrolyte to form comprehensive protective films on both positive and negative electrodes, improving reliability while maintaining energy density through balanced composition design.
2Reliability
If the mass percentage of ethylene carbonate in the electrolyte is increased to improve high-temperature storage performance, then the high-temperature storage performance is improved, but the capacity retention rate may be affected
Solution Approach 1:
The patent optimizes the mass percentage of ethylene carbonate to a specific range (1.6 ≤ b/a ≤ 6.4) to achieve the best balance between high-temperature storage performance and capacity retention rate. This parameter optimization resolves the contradiction by finding the optimal concentration point where protective film formation is sufficient without excessive electrolyte consumption.
Solution Approach 2:
The patent uses a composite electrolyte system comprising multiple components (ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, and sulfur-oxygen double bond-containing compounds) that work synergistically. This composite approach allows the electrolyte to form comprehensive protective films on both positive and negative electrodes, improving reliability while maintaining energy density through balanced composition design.
3Reliability
If electrolyte additives are used to form protective films on electrode interfaces to reduce side reactions, then the safety performance is improved, but the device complexity increases
Solution Approach 1:
The patent uses a composite electrolyte system comprising multiple components (ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, and sulfur-oxygen double bond-containing compounds) that work synergistically. This composite approach allows the electrolyte to form comprehensive protective films on both positive and negative electrodes, improving reliability while maintaining energy density through balanced composition design.
Solution Approach 2:
The patent optimizes the mass percentage of ethylene carbonate to a specific range (1.6 ≤ b/a ≤ 6.4) to achieve the best balance between cycling performance, high-temperature storage performance, and energy density. This parameter optimization resolves the contradiction by finding the optimal concentration point where protective film formation is sufficient without excessive electrolyte consumption.
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
This configuration significantly improves cycling performance, high-temperature storage performance, capacity retention, and safety by forming protective films on electrode interfaces, reducing side reactions and lithium precipitation, thereby enhancing the overall performance and safety of lithium-ion batteries.
Implementation Method 1
forming protective films on electrode interfaces
Implementation Method 2
electrolyte interactions with electrode active materials
Data Source
AI summary
An electrochemical apparatus includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. The negative electrode plate includes a negative electrode active material layer, and the negative electrode active material layer includes a negative electrode active material, where mass of the negative electrode active material is a g. The separator is disposed between the positive electrode plate and the negative electrode plate. The electrolyte includes ethylene carbonate, where based on a mass of the electrolyte, a mass percentage of the ethylene carbonate is b%, and 1.6 ≤ b/a ≤ 6.4. A ratio of the mass percentage of the ethylene carbonate in the electrolyte to the mass of the negative electrode active material is controlled, so that cycling performance, a thickness swelling rate after high-temperature storage, a capacity retention rate after storage, and safety performance of the electrochemical apparatus can be improved.