An integrated device for pre-pressing and forming aqueous sodium ion battery electrodes

Abstract

The utility model discloses an integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries, comprising a press head and a material tray located below the press head, wherein the lower surface of the press head and the upper surface of the material tray are both non-flat surfaces; the non-flat surfaces contain 10 to 50 extension spaces. The integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries of the utility model can demulsify the PTFE emulsion to exert the excellent ductility of polytetrafluoroethylene, and mix with powder to form a fibrous network, so that irregular and unformed materials can be preformed.

Description

Technical Field

[0001] The utility model relates to an integrated device for pre-pressing and forming electrodes of aqueous sodium ion batteries. Background Art

[0002] The patent with application number CN202210160505.9 discloses a method for preparing an aqueous sodium ion battery electrode, including the following steps: 1) using ceramic powder and conductive agent used in aqueous ion battery electrodes as raw material powders, mixing them evenly in a high-speed mixer, and mixing the evenly mixed powder; 2) adding a certain amount of binder to the obtained uniform slurry, stirring for 0-2h after mixing evenly, and obtaining a uniform flocculent; 3) forming the prepared flocculent by roller pressing to obtain a continuous electrode blank membrane; and 4) further placing the membrane after roller pressing in an oven for drying. In the production process of aqueous sodium ion battery electrodes, it is necessary to form the flocculent obtained in step 2 by roller pressing to realize the process characteristics of the electrode. In the process of material forming, the material of the previous process is a loose mass material, and the material is difficult to form in the first few times during the forming process. Therefore, it is necessary to preform the material of the previous process first. After the mass material is preformed, it is easy to form a continuous electrode membrane by forming the material.

[0003] The binder of aqueous sodium-ion battery electrodes is polytetrafluoroethylene (PTFE). After the PTFE emulsion is added as a binder, it must be demulsified to exert the excellent ductility of polytetrafluoroethylene and mix with the powder to form a fibrous network. Under normal circumstances, the best way to accelerate demulsification is to apply shear force to the material, and at the same time ensure the retention of the internal solution without affecting the material properties. If the front-end floc material is placed in a conventional flat-bottomed material tray and directly pressed into shape with a flat press head, it is found that the material has poor ductility, the mixed solution inside the material is directly pressed out, and the material cannot be formed and becomes hard. Utility Model Content

[0004] The purpose of the utility model is to overcome the defects of the prior art and provide an integrated device for pre-pressing and molding aqueous sodium ion battery electrodes, which can demulsify the PTFE emulsion to exert the excellent ductility of polytetrafluoroethylene, mix with powder to form a fibrous network, and pre-form irregular and unformed materials.

[0005] The technical solution to achieve the above-mentioned purpose is: an integrated device for pre-pressing aqueous sodium-ion battery electrodes, comprising a press head and a material tray located below the press head, wherein the lower surface of the press head and the upper surface of the material tray are both non-flat surfaces; the non-flat surface contains 10 to 50 extension spaces.

[0006] In the above-mentioned integrated device for pre-pressing electrodes for aqueous sodium-ion batteries, the depth of each extended space is 2 to 5 mm and the width is 1 to 5 cm.

[0007] In the above-mentioned integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries, the extension space allows the material to undergo shear stretching.

[0008] In the above-mentioned integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries, the extension space of the press head and the extension space of the material tray are arranged opposite to each other in the upper and lower directions.

[0009] In the above-mentioned integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries, the extension space of the press head and the extension space of the material tray are not arranged in an up-and-down relative manner.

[0010] In the above-mentioned integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries, the dimensions of each extension space are the same.

[0011] In the above-mentioned integrated device for pre-pressing and forming electrodes for aqueous sodium-ion batteries, the size of each extension space is different.

[0012] In the above-mentioned integrated device for pre-pressing and molding aqueous sodium ion battery electrodes, the calendering speed of the press head is 0.1-10 mm / s, and the pressure is controlled at 140-170N.

[0013] The utility model discloses an integrated device for pre-pressing and molding aqueous sodium ion battery electrodes, which can demulsify PTFE emulsion to exert the excellent ductility of polytetrafluoroethylene, mix with powder to form a fibrous network, and pre-mold irregular and unshaped materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an integrated device for pre-pressing and forming electrodes for aqueous sodium ion batteries according to Example 1;

[0015] Figure 2 It is a structural schematic diagram of a spherical die head;

[0016] Figure 3 It is a schematic diagram of the structure of an oblique triangular grinding tool head. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solution of the utility model, the specific implementation method thereof is described in detail below in conjunction with the accompanying drawings:

[0018] Example 1

[0019] See also Figure 1 and Figure 2Embodiment 1 of the utility model is an integrated device for pre-pressing and molding aqueous sodium-ion battery electrodes, comprising a press head 1 and a material tray 4 located below the press head 1, wherein the lower surface of the press head 1 and the upper surface of the material tray 4 are both non-flat surfaces 2; specifically, the non-flat surfaces of the press head 1 and the material tray 4 both adopt a spherical die head 5. Since there are several or dozens of spherical gaps in the die head, there are dozens of small extension spaces in the extrusion process of the material 3, which is similar to kneading calendering. At the same time, the calendering speed and pressure are controlled, and the material is very easy to be molded without solution extrusion.

[0020] This principle is that during the production process, it is difficult to flatten the material with the palm of the hand, and the solution inside the material will be squeezed out. However, when the material is rolled with a fist, it is easy to press the material into shape. Analysis shows that the gap between the fists can allow the material to have a small amount of expansion space, while the palm without gaps can only allow the material to be strongly squeezed and the edge of the material will have a small amount of expansion. Therefore, analysis shows that a certain amount of expansion space should be left for the material during the compression and molding process, so that the material is easy to mold and the solution inside the material will not be squeezed out. Therefore, in this embodiment, a spherical mold head 11 is specially designed to imitate the gap between the fists. The expansion space formed by it can apply shear force to the material, and ensure the retention of the internal solution while applying shear force, without affecting the material properties, accelerating demulsification, giving full play to the excellent ductility of polytetrafluoroethylene, and mixing with the powder to form a fibrous network, so that the irregular and unformed material 3 can be preformed.

[0021] Example 2

[0022] See also Figure 3 , Embodiment 2 of the present utility model, an integrated device for pre-pressing and forming electrodes for aqueous sodium ion batteries, is different from Embodiment 1 in that the non-flat surfaces of the press head 1 and the material tray 4 adopt an oblique triangular-shaped mold head 6, similar to a washboard structure. Because there are several or dozens of triangular gaps in the mold head, there are dozens of triangular extension spaces in the material extrusion process, similar to washboard-style calendering. It was found during the pressing process that the material extrusion process still has a good extension space, but the pressing speed is not easy to be too fast, because the extension of the material requires release time, otherwise the speed is too fast and the material will be directly broken due to shear force. When the pressing mold speed is controlled at 0.1-0.3mm / s, the material can still be formed and tightened, and no solution is extruded.

[0023] Example 3

[0024] See also Figure 2 and Figure 3Embodiment 3 of the present utility model is an integrated device for pre-pressing and forming aqueous sodium ion battery electrodes. The difference from Embodiment 1 and Embodiment 2 is that the non-flat surface of the press head 1 adopts a spherical mold head 5, and the non-flat surface of the material tray 4 adopts an oblique triangular mold head 6. The press head 1 and the spherical mold head 5 are arranged one above and one below. When pressing down at high speed, the upper part is better formed and the lower part has a cut-off shape. When the pressing speed of the mold head is reduced, the cut-off shape gradually disappears. When the speed is controlled at a pressing speed of 0.1-0.3 mm / s and the pressure is 140-170 N, the material is better formed and no solution is extruded.

[0025] In the integrated device for pre-pressing and forming aqueous sodium ion battery electrodes of the utility model, each extension space has a depth of 2 to 5 mm and a width of 1 to 5 cm. The extension space allows the material to be sheared and stretched. The extension space of the press head and the extension space of the material tray can be arranged relative to each other up and down, or they can be arranged non-relatively up and down. The size of each extension space can be the same or different.

[0026] In summary, the integrated device for pre-pressing and molding aqueous sodium-ion battery electrodes of the utility model can demulsify the PTFE emulsion to exert the excellent ductility of polytetrafluoroethylene, mix with the powder to form a fibrous network, and pre-form irregular and unformed materials.

[0027] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. An integrated device for pre-pressing and forming aqueous sodium ion battery electrodes, characterized in that: It includes a press head and a material tray located below the press head, wherein the lower surface of the press head and the upper surface of the material tray are both uneven surfaces; the uneven surface contains 10 to 50 extension spaces.

2. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: The depth of each extended space is 2 to 5 mm and the width is 1 to 5 cm.

3. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: The expansion space allows the material to undergo shear stretching.

4. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: The extension space of the press head and the extension space of the material tray are arranged opposite to each other up and down.

5. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: The extension space of the press head and the extension space of the material tray are not arranged in an up-and-down relative manner.

6. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: Each extension space has the same dimensions.

7. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: Each extension has a different size.

8. The integrated device for pre-pressing and forming aqueous sodium ion battery electrodes according to claim 1, characterized in that: The calendering speed of the press head is 0.1-10 mm / s, and the pressure is controlled at 140-170 N.

Images