Dry-method electrode powder mixing equipment

Abstract

The utility model discloses dry-method electrode powder mixing equipment, which relates to the technical field of lithium ion batteries, and comprises a stirring tank, an electrode powder mixing device and an electrode powder mixing device, the outer heater is positioned on the side wall of the stirring tank; the charging barrel is positioned in the stirring tank; the inner heater is positioned on the outer side of the charging barrel; a solid powdery binder in a charging barrel reaches a melting point in a rapid heating mode through an inner heater, so that solid powder is converted into a molten liquid binder, and then the molten liquid binder is linearly sprayed out from a discharging hole through an extrusion mode of an extrusion device; the prepared battery material powder can be quickly bonded to form a film through a rolling process, the prepared battery pole piece has the characteristics of good uniformity and high cohesiveness, the forming effect of the dry-method battery pole piece is effectively improved, the quality of a dry-method electrode technology finished product is ensured, and the battery pole piece has good application value.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to dry electrode powder mixing equipment. Background Art

[0002] Batteries are playing an increasingly important role in the fields of electric vehicles and electrochemical energy storage. The wet coating method commonly used in traditional secondary lithium-ion batteries requires a large amount of solvents and electricity drying equipment, sites, and production time. In comparison, dry electrode technology has the advantages of low manufacturing cost, low energy consumption, environmental protection, low electrode porosity and high compaction compared to wet electrodes. The specific dry process requires the active material, conductive agent, and binder to be formed into a self-supporting carbon film through mixing, shearing, rolling and other processes, and the dispersion effect of the dry binder will affect the bonding film forming process. That is, once the binder and the raw materials are not mixed evenly, it will directly affect the effect of the dry battery electrode, resulting in unstable quality of the finished product of the dry electrode technology. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the present invention provides a dry electrode powder mixing device.

[0004] According to the dry electrode powder mixing equipment of the embodiment of the present invention, it includes: a stirring tank, the stirring tank has an inner cavity for accommodating solid powder raw materials, and an agitator is provided in the stirring tank; an external heater, located on the side wall of the stirring tank, the external heater can heat the solid powder raw materials in the inner cavity of the stirring tank; a charging barrel, located in the stirring tank, the charging barrel has an inner cavity for accommodating a binder, a discharge hole is provided on the lower side of the charging barrel, and an extrusion device is connected to the upper side of the charging barrel, the extrusion device can extrude the binder in the charging barrel from the discharge hole through the discharge hole into the stirring tank; an internal heater, located outside the charging barrel, the internal heater can heat the inner cavity of the charging barrel.

[0005] According to some embodiments of the present invention, the stirring tank includes a tank body and a sealing cover, the stirring tank includes a tank body and a sealing cover, the agitator is connected to the bottom wall of the tank body, the external heater is connected to the side wall of the tank body, and the loading barrel and the internal heater are connected to the lower side of the sealing cover.

[0006] According to some embodiments of the present invention, a vacuum valve and an air inlet valve are provided on the stirring tank. The vacuum valve can evacuate the inner cavity of the stirring tank, and the air inlet valve can inject protective gas into the inner cavity of the stirring tank.

[0007] According to some embodiments of the present invention, the external heater includes an outer jacket and a heating tube. The outer jacket is located on the outer side wall of the stirring tank, and the heating tube is located inside the outer jacket.

[0008] According to some embodiments of the present invention, the extrusion device includes a high-pressure gas injection valve, which can inject gas into the inner cavity of the charging barrel to increase the pressure by connecting to a high-pressure gas source.

[0009] According to some embodiments of the present invention, the internal heater includes a protective tube and a heating coil, the protective tube has an inner cavity and a barrel through hole, the heating coil is located in the inner cavity of the protective tube, and the loading tube passes through the barrel through hole of the protective tube.

[0010] According to some embodiments of the present invention, a protective coating is provided on the through hole of the cylinder.

[0011] According to some embodiments of the present invention, a lifting device is provided on the internal heater, and the internal heater is connected to the stirring tank via the lifting device.

[0012] According to some embodiments of the present invention, the lifting device includes a rotating screw, the rotating screw is connected to the internal heater via a rotating bearing, and the rotating screw is threadedly connected to the stirring tank via a screw sleeve.

[0013] According to some embodiments of the present invention, a rotating motor is provided on the charging barrel.

[0014] The dry electrode powder mixing device according to the embodiment of the present invention has at least the following technical effects: the solid powder binder in the charging barrel is rapidly heated to the melting point by the internal heater, so that the solid powder is converted into a molten liquid binder, and then the molten liquid binder is ejected from the discharge hole in a linear shape by the extrusion method of the extrusion device. In this way, the linear molten binder and the solid powder can be quickly and fully mixed in the stirring tank. Under the high-speed shear force of the stirrer and the heating effect of the external heater, the linear binder can be quickly converted into a fiber mesh and mixed evenly with the solid powder. The prepared battery material powder can then be quickly bonded into a film through a rolling process. The prepared battery electrode has the characteristics of good uniformity and high adhesion, effectively improving the forming effect of the dry battery electrode, ensuring the quality of the finished product of the dry electrode technology, and having good application value.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 This is a three-dimensional diagram of the dry electrode powder mixing equipment of the utility model;

[0018] Figure 2 This is a three-dimensional cross-sectional view of the dry electrode powder mixing device of the utility model;

[0019] Figure 3 This is a three-dimensional cross-sectional view of the charging barrel and the internal heater in the utility model;

[0020] Figure 4 It is a working schematic diagram of the utility model.

[0021] Reference numerals:

[0022] Mixing tank 100, tank body 110, observation and feeding port 111, hole end cover 112, sealing cover 120, vacuum valve 121, air inlet valve 122, agitator 130, fixed base 140, fixed vertical pole 141; external heater 200, outer jacket 210, heating tube 220; charging barrel 300, discharge hole 310, extrusion device 320, high-pressure gas injection valve 321, rotating motor 330; internal heater 400, protective barrel 410, barrel through hole 411, heating coil 420; lifting device 500, rotating screw 510, rotating bearing 520, screw sleeve 530. DETAILED DESCRIPTION

[0023] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0024] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0025] In the description of this utility model, "a plurality" means more than two, and "greater than," "less than," "exceed," etc. are understood to exclude the number itself. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number or order of the technical features indicated.

[0026] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0027] Reference below Figure 1 and Figure 2 The dry electrode powder mixing device according to the embodiment of the present invention is described.

[0028] like Figure 1 and Figure 2 As shown, the dry electrode powder mixing device according to an embodiment of the present invention includes a stirring tank 100 , an external heater 200 , a charging cylinder 300 and an internal heater 400 .

[0029] The stirring tank 100 has an inner cavity that can accommodate solid powder raw materials, and an agitator 130 is provided in the stirring tank 100; the external heater 200 is located on the side wall of the stirring tank 100, and the external heater 200 can heat the solid powder raw materials in the inner cavity of the stirring tank 100; the charging barrel 300 is located in the stirring tank 100, and the charging barrel 300 has an inner cavity that can accommodate a binder, and a discharge hole 310 is provided on the lower side of the charging barrel 300, and an extrusion device 320 is connected to the upper side of the charging barrel 300, and the extrusion device 320 can extrude the binder in the charging barrel 300 from the discharge hole 310 through the discharge hole 310 into the stirring tank 100; the internal heater 400 is located outside the charging barrel 300, and the internal heater 400 can heat the inner cavity of the charging barrel 300.

[0030] For example, Figure 1 and Figure 2 As shown, the mixing tank 100 has an inner cavity, which can hold solid powder raw materials. The mixing tank 100 is provided with an agitator 130 for stirring. An external heater 200 is located on the side wall of the mixing tank 100 and can heat the inner cavity of the mixing tank 100 to heat the solid powder raw materials inside.

[0031] Reference Figure 2 、 Figure 3 The charging barrel 300 is located within the mixing tank 100 and has an inner cavity in which the adhesive can be loaded. A discharge hole 310 is provided on the lower side of the charging barrel 300. The charging barrel 300 is connected to an extrusion device 320 for extruding the adhesive in the charging barrel 300 through the discharge hole 310. An internal heater 400 is located outside the charging barrel 300 and is capable of heating the inner cavity of the charging barrel 300 to heat the adhesive in the charging barrel 300.

[0032] In actual work, refer to Figure 4 , the mixing tank 100 is loaded with solid powder raw materials, and the loading barrel 300 is loaded with internal solid powder binder. Then, the internal heater 400 rapidly heats the solid powder binder in the loading barrel 300 to its melting point, converting the solid powder into a molten liquid binder. The molten liquid binder is then extruded from the discharge hole 310 in a linear form. In this way, the linear molten binder and the solid powder can be quickly and thoroughly mixed in the mixing tank 100. Under the high-speed shear force of the stirrer 130 and the heating action of the external heater 200, the linear binder can be quickly converted into a fibrous network and mixed evenly with the solid powder to prepare battery material powder.

[0033] The battery material powder can be quickly bonded into a film through a rolling process. The prepared battery pole pieces have good uniformity and high adhesion, which effectively improves the forming effect of dry-process battery pole pieces, ensures the quality of dry-process electrode technology products, and has good application value.

[0034] In some embodiments of the present invention, referring to Figure 1 、 Figure 2 The mixing tank 100 includes a tank body 110 and a sealing cover 120. The sealing cover 120 covers the tank body 110 to form a sealed space within the mixing tank 100. The agitator 130 is connected to the bottom wall of the tank body 110, the external heater 200 is connected to the side wall of the tank body 110, and the charging barrel 300 and the internal heater 400 are connected to the lower side of the sealing cover 120.

[0035] In some embodiments of the present invention, the mixing tank 100 is provided with a vacuum valve 121 and an air inlet valve 122. The vacuum valve 121 can evacuate the interior of the mixing tank 100, and the air inlet valve 122 can inject a protective gas into the interior of the mixing tank 100. The vacuum valve 121 is used to evacuate the interior of the mixing tank 100, and the air inlet valve 122 is used to introduce a protective gas into the mixing tank 100, thereby ensuring that the reaction in the mixing tank 100 is sufficiently reliable.

[0036] In a further embodiment of the present invention, a multi-layer filter screen is provided on the valve opening of the vacuum valve 121 to prevent dust from being sucked into the mixing tank 100 .

[0037] In some embodiments of the present invention, the external heater 200 includes an outer jacket 210 and a heating tube 220. The outer jacket 210 is located on the outer wall of the mixing tank 100, and the heating tube 220 is located within the outer jacket 210. The heating tube 220 is responsible for heating. In addition to protecting the heating tube 220 and reducing unnecessary heat loss from the heating tube 220, the outer jacket 210 can also be filled with cooling water for cooling.

[0038] In some embodiments of the present invention, the extrusion device 320 includes an injection piston cylinder, that is, the charging cylinder 300 adopts a syringe-type design. The extrusion device 320 extrude the adhesive from the discharge hole 310 through the injection piston cylinder.

[0039] In some embodiments of the present invention, referring to Figure 3 The extrusion device includes a high-pressure gas injection valve 321, which can inject gas into the inner cavity of the charging barrel 300 to increase the pressure by connecting to a high-pressure gas source. The high-pressure gas injection valve 321 is connected to an external high-pressure gas source to generate high pressure inside the charging barrel 300, forcing the adhesive out of the discharge hole 310.

[0040] In some embodiments of the present invention, the internal heater 400 includes a protective tube 410 and a heating coil 420. The protective tube 410 has an inner cavity and a through hole 411. The heating coil 420 is located within the inner cavity of the protective tube 410, and the charging tube 300 passes through the through hole 411 of the protective tube 410. The heating coil 420 is responsible for heating. The protective tube 410 protects the heating coil 420, reduces unnecessary heat loss from the heating coil 420, and ensures that the heating function within the mixing tank 100 is not affected by the internal heater 400.

[0041] In some embodiments of the present invention, a protective coating is provided on the barrel through hole 411 to reduce friction and thereby protect the inner wall of the barrel through hole 411 and the discharge hole 310 .

[0042] In some specific embodiments of the present invention, the protective coating is a SiC coating with a thickness of 10 microns.

[0043] In some embodiments of the present invention, the internal heater 400 is provided with a lifting device 500. The internal heater 400 is connected to the mixing tank 100 via the lifting device 500, and the lifting and lowering movement of the internal heater 400 is controlled by the lifting device 500. When the adhesive in the charging barrel 300 needs to be heated, the internal heater 400 is lowered to a position below the hot charging barrel 300 to heat the adhesive in a targeted manner. When the adhesive in the charging barrel 300 needs to be extruded, the internal heater 400 is raised to avoid blocking the discharge hole 310 of the hot charging barrel 300, allowing the adhesive to be extruded smoothly.

[0044] In a further embodiment of the present invention, the lifting device 500 includes a rotating screw 510. The rotating screw 510 is connected to the internal heater 400 via a rotating bearing 520. The rotating screw 510 is threadedly connected to the mixing tank 100 via a screw sleeve 530. When the rotating screw 510 rotates, the rotating screw 510 and the screw sleeve 530 engage with each other, thereby driving the internal heater 400 to move upward and downward.

[0045] In some embodiments of the present invention, a rotating motor 330 is provided on the charging barrel 300 for controlling the rotation of the charging barrel 300 to cooperate with the binder extrusion process and ensure that the binder and the solid powder raw material are evenly mixed.

[0046] In some embodiments of the present invention, the mixing tank 100 is provided with an observation port 111 having a through hole communicating with the inner cavity of the mixing tank 100 and a hole end cap 112. After opening the hole end cap 112, a small amount of powder sample can be taken out of the mixing tank 100 through the observation port 111 for testing to ensure uniform mixing of the binder and the solid powder raw material.

[0047] In some embodiments of the present invention, the mixing device further comprises a fixed base 140, on which a fixed upright 141 is provided. The mixing tank 100 can be placed on the fixed base 140 and fixed by the fixed upright 141 to ensure safe and reliable mixing operation.

[0048] Other structures and operations of the mixing device according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0049] Reference below Figure 1 and Figure 2 The dry electrode powder mixing device according to the embodiment of the present invention is described in detail with a specific embodiment. It is worth noting that the following description is only for illustrative purposes and is not intended to limit the present invention.

[0050] like Figure 1 and Figure 2 As shown, the dry electrode powder mixing equipment of the embodiment of the present invention includes a stirring tank 100 , an external heater 200 , a charging cylinder 300 and an internal heater 400 .

[0051] The mixing tank 100 is a vertical structure, secured by a fixed base 140 and a fixed upright 141. The mixing tank 100 comprises a tank body 110 and a sealing cover 120. An agitator 130 is housed within the mixing tank 100. The tank body 110 is provided with an observation port 111 and an end cap 112. The sealing cover 120 is equipped with a vacuum valve 121 and an air inlet valve 122.

[0052] The external heater 200 includes an outer jacket 210 and a heating tube 220 .

[0053] A discharge hole 310 is provided at the lower side of the charging barrel 300 , and a high-pressure gas injection valve 321 and a rotating motor 330 are provided at the upper side of the charging barrel 300 .

[0054] The internal heater 400 includes a protective tube 410 and a heating coil 420 .

[0055] The lifting device 500 includes a rotating screw 510 , a rotating bearing 520 , and a screw sleeve 530 .

[0056] In actual operation, the charging barrel 300 is installed on the sealing cover 120 from bottom to top through the protective barrel 410, and the protective barrel 410 is lowered by the lifting device 500 to slightly exceed the bottom of the charging barrel 300 to heat the inside of the charging barrel 300.

[0057] The solid powder raw material loaded into the stirring tank 100 is negative electrode artificial graphite with a D50 of 13.8 μm, and the solid powder binder loaded into the charging cylinder 300 is modified polytetrafluoroethylene (PTFE) binder powder with a molecular weight of 500,000.

[0058] Place the negative electrode artificial graphite in a stirred tank 100 with an inner diameter of 70 cm. Add modified polytetrafluoroethylene (PTFE) binder powder to the bottom of the charging barrel 300 at a mass ratio of 2% to the artificial graphite. Turn on the agitator 130 to 1500 rpm. Pass 99.9% nitrogen through the inlet valve 122 for 10 minutes, then close the inlet valve 122. Open the vacuum valve 121 and evacuate the chamber for 5 minutes. Open the inlet valve 122 again and pass 99.9% nitrogen to 1 atmosphere, then close the inlet valve 122. After injecting 99.9% nitrogen to 10 atmospheres through the high-pressure gas injection valve 321, keep the high-pressure gas injection valve 321 closed.

[0059] Then, turn on heating tube 220 and raise the temperature to 80°C. Stir continuously at a constant temperature of 80°C for 50 minutes until the powder temperature inside stirring tank 100 is uniform. Turn on heating coil 420 and raise the temperature to 340°C to melt the modified polytetrafluoroethylene (PTFE) binder powder into a liquid state in a short period of time.

[0060] The protective cylinder 410 is then raised by rotating the screw 510 to a position above the upper end of the discharge hole 310 of the charging barrel 300. The high-pressure gas injection valve 321 is opened, and the rotary motor 330 is turned on to rotate the charging barrel 300 at a high speed of 1000 rpm. Under the action of high-pressure nitrogen, the molten liquid modified polytetrafluoroethylene (PTFE) binder is sprayed through the discharge hole 310 with a diameter of 0.3 mm into filaments and mixed thoroughly with the rapidly stirred artificial graphite powder.

[0061] Under the high shear force of agitator 130, agitator 130 stirred at a constant temperature of 80°C for 5 hours. After 25°C cooling water was introduced into outer jacket 210, stirring continued for 1 hour. After opening inlet valve 122 and introducing 99.9% nitrogen, a small amount of powder sample was removed from observation port 111 to test whether the modified polytetrafluoroethylene (PTFE) binder was uniformly dispersed into a mesh of fibers with a diameter of approximately 70 nm and the artificial graphite powder was uniformly mixed. The negative electrode material dry powder obtained in the above preparation process was then rolled onto 7 μm copper foil to produce a negative electrode sheet.

[0062] According to the dry electrode powder mixing device of the embodiment of the present invention, by such a configuration, at least the following effects can be achieved: the solid powder binder in the charging barrel 300 is rapidly heated to a melting point by the internal heater 400, so that the solid powder is converted into a molten liquid binder, and then the molten liquid binder is ejected from the discharge hole 310 in a linear manner by extrusion of the extruder. In this way, the linear molten binder and the solid powder can be quickly and fully mixed in the stirring tank 100. Under the high-speed shear force of the stirrer 130 and the heating effect of the external heater 200, the linear binder can be quickly converted into a fiber mesh and mixed evenly with the solid powder. The prepared battery material powder can then be quickly bonded into a film through a rolling process. The prepared battery electrode has the characteristics of good uniformity and high adhesion, which effectively improves the forming effect of the dry battery electrode, ensures the quality of the finished product of the dry electrode technology, and has good application value.

[0063] Throughout this specification, references to the terms "some embodiments" or "it is contemplated that" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0064] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A dry electrode powder mixing device, characterized in that: include: A stirring tank (100), the stirring tank (100) having an inner cavity capable of accommodating solid powder raw materials, and a stirrer (130) provided in the stirring tank (100); an external heater (200) located on a side wall of the stirring tank (100), the external heater (200) being capable of heating the solid powder raw material in the inner cavity of the stirring tank (100); A charging barrel (300) is located in the stirring tank (100), the charging barrel (300) has an inner cavity capable of accommodating an adhesive, a discharge hole (310) is provided on the lower side of the charging barrel (300), and an extrusion device (320) is connected to the upper side of the charging barrel (300), and the extrusion device can extrude the adhesive in the charging barrel (300) from the discharge hole (310) through the discharge hole (310) into the stirring tank (100); An internal heater (400) is located outside the charging barrel (300), and the internal heater (400) is capable of heating the inner cavity of the charging barrel (300).

2. The dry electrode powder mixing device according to claim 1, characterized in that: The stirring tank (100) includes a tank body (110) and a sealing cover (120), the stirrer (130) is connected to the bottom wall of the tank body (110), the external heater (200) is connected to the side wall of the tank body (110), and the charging barrel (300) and the internal heater (400) are connected to the lower side of the sealing cover (120).

3. The dry electrode powder mixing device according to claim 1 or 2, characterized in that: The stirring tank (100) is provided with a vacuum valve (121) and an air inlet valve (122). The vacuum valve (121) can evacuate the inner cavity of the stirring tank (100), and the air inlet valve (122) can inject protective gas into the inner cavity of the stirring tank (100).

4. The dry electrode powder mixing device according to claim 1, characterized in that: The external heater (200) comprises an outer jacket (210) and a heating tube (220), wherein the outer jacket (210) is located on the outer side wall of the stirring tank (100), and the heating tube (220) is located inside the outer jacket (210).

5. The dry electrode powder mixing device according to claim 1, characterized in that: The extrusion device comprises a high-pressure gas injection valve (321), which is capable of injecting gas into the inner cavity of the charging barrel (300) to increase the pressure by connecting to a high-pressure gas source.

6. The dry electrode powder mixing device according to claim 1, characterized in that: The internal heater (400) includes a protective tube (410) and a heating coil (420). The protective tube (410) has an inner cavity and a barrel through hole (411). The heating coil (420) is located in the inner cavity of the protective tube (410). The loading tube (300) passes through the barrel through hole (411) of the protective tube (410).

7. The dry electrode powder mixing device according to claim 6, characterized in that: A protective coating is provided on the cylindrical through hole (411).

8. The dry electrode powder mixing device according to claim 1, characterized in that: A lifting device (500) is provided on the internal heater (400), and the internal heater (400) is connected to the stirring tank (100) via the lifting device (500).

9. The dry electrode powder mixing device according to claim 8, characterized in that: The lifting device (500) includes a rotating screw (510), the rotating screw (510) is connected to the internal heater (400) via a rotating bearing (520), and the rotating screw (510) is threadedly connected to the stirring tank (100) via a screw sleeve (530).

10. The dry electrode powder mixing device according to claim 1, characterized in that: The charging barrel (300) is provided with a rotating motor (330).

Images