Positive Electrode Primer Coating for Stronger Battery Adhesion
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Solution Overview
Problem
Traditional binders in lithium ion batteries, such as PVDF, exhibit poor compatibility and weak adhesive force with electrode active materials, leading to instability and molding issues in electrode plates, necessitating the development of a novel binder with improved molding quality and adhesive force to enhance cycling performance.
Innovation Solution
A positive electrode plate with a primer coating layer containing a polymer A, soluble in aqueous or oily solvents, comprising structural units derived from monomers with cyano, amide, and ester groups, which increases the adhesive force and flexibility of the electrode plate, and optimizes cycling performance by improving the compatibility and dispersibility of the active material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional binder PVDF is used, then the electrode plate can be manufactured with conventional processes, but the adhesive force with electrode active material is weak and compatibility is poor
Solution Approach 1:
The patent changes the chemical composition parameters of the binder by using polymer A with specific functional groups (cyano, amide, ester) instead of conventional PVDF. This parameter change improves adhesive force and compatibility with electrode active materials while maintaining manufacturability through established coating processes.
Solution Approach 2:
The patent employs a composite binder system where polymer A serves as the primary binder in the primer coating layer, potentially combined with other materials to achieve optimal performance. This composite approach enhances adhesive properties while allowing flexibility in manufacturing processes.
2Strength
If polymer A with high molecular weight is used to improve adhesive force, then the adhesive performance increases, but the diffusibility during slurry coating decreases
Solution Approach 1:
The patent optimizes the molecular weight parameter of polymer A to a specific range (1.5×10^5-2×10^5) that balances adhesive force and diffusibility. This parameter optimization ensures sufficient adhesion while maintaining adequate diffusion during the slurry coating process.
Solution Approach 2:
The patent uses a controlled amount of polymer A (5%-40% mass content in primer coating layer) to achieve the necessary adhesive performance without excessive polymer content that would hinder diffusibility. This partial action approach balances competing requirements.
3Strength
If the mass content of polymer A in the primer coating layer is increased to improve adhesive performance, then the adhesive force increases, but the appearance quality and brittleness are adversely affected
Solution Approach 1:
The patent optimizes the mass content parameter of polymer A within the range of 5%-40% in the primer coating layer. This optimized parameter range achieves sufficient adhesive performance while preventing excessive polymer content that would cause poor appearance quality and increased brittleness.
4Strength
If the thickness of the primer coating layer is increased to improve adhesive performance, then the adhesion increases, but the power performance and cycling performance are reduced
Solution Approach 1:
The patent optimizes the thickness parameter of the primer coating layer to a specific range that balances adhesive performance with power and cycling performance. This parameter optimization ensures sufficient adhesion without creating a overly thick layer that would impede electrochemical performance.
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 the polymer A in the primer coating layer enhances the molding quality, adhesive force, and cycling performance of the battery, reducing the growth rate of cyclic internal resistance and improving the power and charge/discharge rate performance.
Implementation Method 1
the polymer A comprises a structural unit derived from a monomer containing a cyano group, a structural unit derived from a monomer containing an amide group, and a structure unit derived from a monomer containing an ester group
Data Source
AI summary
A positive electrode plate, a secondary battery, a battery module, a battery pack and a power consuming device are described. The positive electrode plate comprises a current collector, a primer coating layer provided on at least one surface of the current collector, and a positive electrode film provided on the primer coating layer, wherein the primer coating layer contains a polymer A soluble in an aqueous solvent, and the polymer A comprises a structural unit derived from a monomer containing a cyano group, a structural unit derived from a monomer containing an amide group, and a structure unit derived from a monomer containing an ester group. The polymer A is used in the primer coating layer of the positive electrode plate, which increases the molding quality, adhesive force and flexibility of the positive electrode plate, and optimizes the cycling performance of the battery.