Cross-Linked Electrode Binder Composition for Battery Cycle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing secondary batteries face challenges in extending their cycle life and maintaining structural stability due to inadequate binding performance between the electrode materials, which affects their energy density and safety performance.
Innovation Solution
A binder composition comprising a cross-linkable polymer matrix and a cross-linking agent is used to enhance the bonding between the first and second substances in the secondary battery, forming a three-dimensional cross-linked network structure that improves the interaction and stability of the electrode materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional binders are used in secondary batteries, then the manufacturing process is simple, but the cycle life and structural stability are insufficient
Solution Approach 1:
The patent uses a composite binder system combining polyacrylonitrile (PAN) as the base binder with polyvinylidene fluoride (PVDF) as a secondary binder component. This composite approach leverages the strong adhesion properties of PAN and the structural stability of PVDF to achieve improved cycle life and structural integrity without excessive complexity in the formulation process.
Solution Approach 2:
The patent optimizes the molecular weight parameters of the polyacrylonitrile binder, specifically using PAN with a weight-average molecular weight of 100,000 to 500,000. This parameter control ensures adequate binding strength and flexibility while maintaining processability, thereby extending cycle life without requiring complex binder formulations.
2Strength
If conventional binders are used, then the formulation is simple, but the binding performance and cohesion of electrode materials are inadequate
Solution Approach 1:
The patent employs a composite binder formulation consisting of polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) in a specific weight ratio range. PAN provides strong polar interactions with electrode materials through its nitrile groups, while PVDF contributes to mechanical strength and structural stability, achieving superior binding performance through material composition rather than complex formulation procedures.
Solution Approach 2:
The patent utilizes the local chemical properties of polyacrylonitrile, specifically the polar nitrile groups (-C≡N) that create strong dipole-dipole interactions and hydrogen bonding with electrode material surfaces. This local chemical functionality at the binder-electrode interface significantly enhances adhesion strength without requiring the entire binder system to be complex.
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 improved binding performance significantly enhances the cohesion of the electrode materials, leading to increased cycle life, reduced volume expansion, and improved energy density and safety performance of the secondary battery.
Implementation Method 1
a binder composition comprising a cross-linkable polymer matrix and a cross-linking agent is used to enhance the bonding between the first and second substances in the secondary battery, forming a three-dimensional cross-linked network structure
Data Source
Figure 1~3
Figure 4~5
AI summary
The present application discloses a secondary battery, an apparatus comprising the secondary battery, a process for the preparation of the secondary battery, and a binder composition. The secondary battery comprises a binder for bonding a first substance and a second substance, the binder comprising a polymer obtained by crosslinking a binder composition, wherein the binder composition comprises a cross-linkable polymer matrix and a cross-linking agent, the cross-linkable polymer matrix comprises one or more of monomer units represented by formula (I), and the cross-linking agent comprises a compound represented by formula (II), in which R1, R2 and R3 are each independently selected from H and straight-chain or branched-chain alkyl groups with 1 to 8 carbon atoms; R4 is a polar group containing an active hydrogen; R5 is a reactive group to R4; R6 is selected from H and substituted or unsubstituted hydrocarbon groups with 1 to 8 carbon atoms; and n is an even number greater than or equal to 4, 2≤m≤n. The secondary battery provided by the present application has an effectively improved cycle life.