Extrusion Head Geometry for Uniform Special-Shaped Electrode Sheets
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Solution Overview
Problem
Existing methods for molding electrode sheets, such as stamping and roller pressing, result in non-uniform thickness, high powder drop rates, and structural weaknesses, which can lead to assembly issues and safety risks.
Innovation Solution
An extrusion head with a transition cavity of gradually reduced diameter and a molding cavity of adjustable cross-section, used in a screw extruder, ensures uniform thickness and reduces powder drop by kneading the mixture thoroughly, allowing for special-shaped electrode sheets with improved strength and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If stamping molding is used to prepare electrode sheets, then the molding process is simple, but the electrode sheet has low strength and high powder drop rate
Solution Approach 1:
The invention changes the molding parameters from simple stamping pressure to a multi-stage process involving pressing pressure (5-20 MPa), heating temperature (60-100°C), and heating time (5-30 minutes). This transforms the electrode material properties in-situ, creating a denser structure with higher strength and lower powder drop rate while maintaining manufacturing feasibility
2Ease of manufacture
If stamping molding is used, then the manufacturing process is straightforward, but the electrode sheet thickness is uneven
Solution Approach 1:
The invention performs preliminary spreading of the slurry on the current collector to ensure uniform distribution before pressing. This preliminary action prevents thickness unevenness during the subsequent pressing stage, achieving both manufacturing simplicity and precision
3Strength
If roller pressing molding is used, then the electrode sheet can be formed with binder, but a large amount of organic solvent is consumed
Solution Approach 1:
The invention changes the solvent removal approach from evaporation during roller pressing to controlled heating after pressing. By applying heat (60-100°C) for a specific duration (5-30 minutes), the organic solvent is efficiently evaporated with better control, reducing solvent consumption and improving safety while maintaining electrode sheet strength
4Strength
If roller pressing molding is used, then the electrode sheet can be formed, but the thickness uniformity is difficult to guarantee
Solution Approach 1:
The invention performs preliminary spreading of the slurry to ensure uniform thickness distribution before the pressing and drying stages. This preliminary action guarantees that the final electrode sheet achieves uniform thickness while maintaining structural integrity
Solution Approach 2:
The invention implements a controlled drying process with specific temperature (60-100°C) and time (5-30 minutes) parameters that allow uniform solvent evaporation. This controlled feedback mechanism prevents localized thickness variations that would occur with rapid or uncontrolled drying
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 method achieves uniform thickness, low powder loss, and high electrical conductivity, enabling efficient production of special-shaped electrode sheets suitable for various battery designs with reduced assembly risks and enhanced discharge capacity.
Implementation Method 1
a screw extruder, including an extrusion device housing and a screw coaxially arranged inside the extrusion device housing
Implementation Method 2
The extrusion channel is divided into a transition cavity and a molding cavity which are joined and communicated in sequence along the extrusion direction, and an inner wall annular surface of the transition cavity has a gradually reduced diameter along the extrusion direction
Implementation Method 3
The molding cavity can be designed into different cross section shapes according to the requirements, so as to obtain special-shaped electrode sheets with different cross section shapes
Implementation Method 4
The mixed electrode sheet mixture is extruded into an electrode sheet with a certain thickness by a screw, and after drying, the electrode sheets of special batteries with different models can be manufactured
Data Source
AI summary
An extrusion head (1) for molding a pole piece and a molding device comprising same, and a molding method and a preparation method therefor. The extrusion head (1) comprises an extrusion head (1) housing, and a through extrusion channel (6) is provided inside the extrusion head (1) housing in an extrusion direction; and the extrusion channel (6) is divided into a transition cavity (61) and a molding cavity (62) that are in sequential butt joint and communication in the extrusion direction, and the diameter of the annular surface of the inner wall of the transition cavity (61) is gradually reduced in the extrusion direction.