Cladded Electrode Material for Low-Temperature Dry Battery Processing
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Solution Overview
Problem
Conventional electrode manufacturing processes for lithium batteries face issues such as pinholes, cracks, and uneven solvent evaporation leading to gaps and reduced quality, while dry processes using fluorine-based binders require high temperatures causing wrinkles and reduced capacity.
Innovation Solution
An electrode material with a cladding layer comprising a conductive additive and a polymer derived from a compound with acrylate groups and ethylene-vinyl acetate copolymer, formed through spray pelletization or melt blending, allowing for solvent-free processing at lower temperatures and improved adhesion and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional electrode slurry preparation and drying process is used, then electrode can be formed, but pinholes and cracks are generated in the electrode active layer
Solution Approach 1:
The patent changes the physical and chemical parameters of the binder material from conventional fluorine-based binders to a polymer derived from compound (I) with acrylate groups. This parameter change allows the binder to achieve adequate adhesion without requiring high-temperature processing, thereby preventing pinhole and crack formation during drying while maintaining ease of manufacture.
Solution Approach 2:
The patent uses a composite polymer structure derived from compound (I) containing acrylate groups combined with ethylene-vinyl acetate copolymer. This composite material provides both adhesion functionality and flexibility, enabling defect-free electrode formation through its unique molecular structure that prevents cracking during the drying process.
2Ease of manufacture
If solvent is removed during drying process, then electrode coating is formed, but pinholes and cracks occur in the pre-formed electrode active layer
Solution Approach 1:
The patent modifies the binder's thermal and mechanical parameters by using a polymer derived from compound (I) with acrylate groups. This parameter change enables the binder to maintain film integrity during solvent evaporation, preventing pinhole and crack formation while still allowing complete drying and coating formation.
3Ease of manufacture
If high temperature processing is used for fluorine-based dry electrode materials, then thermocompression can be achieved, but wrinkles are formed and capacity is reduced
Solution Approach 1:
The patent changes the processing temperature parameter from above 200°C (required for fluorine-based binders) to a lower temperature range suitable for the polymer derived from compound (I). This parameter change enables thermocompression to be achieved without excessive heat, preventing wrinkle formation while maintaining adequate adhesion and electrode density.
4Loss of substance
If fluorine-based binders are used in dry electrode manufacturing, then solvent-free processing is achieved, but high temperature above 200°C is required causing wrinkles
Solution Approach 1:
The patent changes the thermal properties of the binder material by replacing fluorine-based binders with a polymer derived from compound (I) containing acrylate groups. This parameter change allows the binder to function effectively at lower temperatures while maintaining the solvent-free dry processing advantage, thus avoiding wrinkle formation.
Solution Approach 2:
The patent employs a composite polymer material derived from compound (I) with acrylate groups and ethylene-vinyl acetate copolymer. This composite provides both the adhesion needed for solvent-free processing and the thermal stability required at lower processing temperatures, eliminating the need for high-temperature treatment that causes wrinkles.
5Ease of manufacture
If differences in solvent evaporation rates occur during drying, then coating is formed, but gaps are created within the electrode reducing quality
Solution Approach 1:
The patent changes the binder's rheological and adhesive parameters by using a polymer derived from compound (I) with acrylate groups. This parameter change enables the binder to maintain uniform distribution and adequate adhesion during non-uniform solvent evaporation, preventing gap formation within the electrode structure while still allowing complete coating formation.
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 solution enhances electrode stability, mass loading, and energy density, improving charge-discharge performance and extending the battery's life cycle without the defects of traditional methods.
Implementation Method 1
The first polymer is a product of a compound having two acrylate groups and an ethylene-vinyl acetate copolymer via a polymerization
Implementation Method 2
subjecting the composition to a spray pelletization process or a melt blending process to obtain the electrode material
Data Source
AI summary
An electrode material, electrode, battery and method for forming the electrode material are provided. The electrode material includes an active particle and a cladding layer partially or completely covering the surface of the active particle. The cladding layer includes 5 to 70 parts by weight of a conductive additive and 30 to 95 parts by weight of a first polymer, wherein the total weight of the first polymer and the conductive additive is 100 parts by weight. The first polymer is a product of a compound having two acrylate groups and an ethylene-vinyl acetate copolymer via a polymerization. The compound having two acrylate groups has the structure as represented by Formula (I)wherein A1, R1 and R2 are disclosed in the specification.