Secondary Battery Electrolyte and Separator for Swelling Control
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Solution Overview
Problem
Secondary batteries face cycling performance degradation due to interfacial side reactions and electrolyte loss, which is exacerbated by high binding forces between electrode plates and separators, reducing storage space and causing electrolyte consumption and swelling.
Innovation Solution
A secondary battery design with a separator having high binding forces with electrode plates and an electrolyte containing a compound represented by formula I, where R11 and R12 are halogen-substituted or unsubstituted C1 to C6 alkyl, and specific mass percentages and binding forces are maintained to improve oxidation resistance and interfacial stability, along with the inclusion of unsubstituted carboxylic ester compounds and other additives to enhance electrolyte wettability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separators with high binding force are disposed between electrode plates to reduce interfacial side reactions, then interfacial stability is improved, but storage space for electrolytes is reduced
Solution Approach 1:
The patent optimizes the binding force parameters of the separator to specific ranges (10-15 N/m for positive electrode, 18-25 N/m for negative electrode) to achieve the right balance between interfacial stability and electrolyte storage capacity
Solution Approach 2:
The separator is designed as a composite structure with a porous substrate layer and polymer binding layers, combining the advantages of both materials to achieve high binding force while maintaining electrolyte storage space
2Reliability
If separators with high binding force are used to reduce interfacial side reactions, then interfacial stability is improved, but electrolyte consumption increases
Solution Approach 1:
The patent controls the binding force within specific ranges and formulates the electrolyte with specific compounds and concentrations to minimize electrolyte decomposition and consumption while maintaining stable interfaces
3Reliability
If separators with high binding force are used to reduce interfacial side reactions, then interfacial stability is improved, but battery swelling increases
Solution Approach 1:
The patent optimizes the binding force parameters and electrolyte formulation to reduce gas generation and by-product accumulation, thereby minimizing battery swelling while maintaining interfacial stability
Solution Approach 2:
The patent converts the potential harm of high binding force (which could cause swelling) into a benefit by carefully controlling the binding force within specific ranges and compensating with optimized electrolyte composition to prevent by-product accumulation
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 design reduces electrolyte consumption and loss speed, improving cycling and swelling performance by minimizing interfacial reactions and electrolyte depletion, while maintaining effective ion transmission.
Implementation Method 1
The electrolyte including the compound represented by formula I and controlling the value of A within the above range can improve the oxidation resistance of the electrolyte to reduce interfacial side reactions between the positive electrode plate and the electrolyte and between the negative electrode plate and the electrolyte
Implementation Method 2
the separator includes a porous substrate layer and binding layers disposed on two surfaces of the porous substrate layer, the binding layer includes a polymer, a binding force between the separator and the positive electrode plate is F1 N/m, where 10≤F1≤15, and a binding force between the separator and the negative electrode plate is F2 N/m, where 18≤F2≤25
Implementation Method 3
a positive electrode plate, a negative electrode plate, a separator, and an electrolyte
Data Source
AI summary
A secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. The electrolyte includes a compound represented by formula I. R11 and R12 are each independently selected from halogen-substituted or unsubstituted C1 to C6 alkyl, at least one of R11 or R12 is substituted with halogen, and based on a mass of the electrolyte, a mass percentage of the compound represented by formula I is A %, where 30≤A≤80. The separator includes a porous substrate layer and binding layers disposed on two surfaces of the porous substrate layer, the binding layer includes a polymer, a binding force between the separator and the positive electrode plate is F1 N/m, where 10≤F1≤15, and a binding force between the separator and the negative electrode plate is F2 N/m, where 18≤F2≤25.