Polytetrafluoroethylene dispersion resin condensing and stirring device for dry-method electrode binder

Abstract

The utility model relates to the technical field of high polymer materials, in particular to a polytetrafluoroethylene dispersion resin condensing and stirring device for a dry-method electrode binder, which comprises a condensing barrel, a stirring device, a stirring device, a stirring device and a stirring device, the top of the condensing barrel is provided with a driving mechanism, and the inner wall of the condensing barrel is provided with deflection baffles; the top of the stirring rod extends out of the coagulation barrel and is connected with the driving mechanism, and the bottom extends into the inner cavity of the coagulation barrel; the lower inclined paddle is arranged at the bottom of the stirring rod; the vortex stirring paddle is arranged at the bottom of the stirring rod and is positioned below the lower inclined paddle. The polyfluortetraethylene dispersion resin condensing and stirring device for the dry-method electrode binder, provided by the utility model, can adjust the specific gravity of dispersion resin mother liquor to a lower level so as to produce dispersion resin fine powder with uniform particles, and is good in fiber forming effect, high in fiber forming rate and not easy to break. When being used as a dry-method electrode binder, the active carbon particles exist in a fiber state, so that the contact between the active carbon particles and between the active carbon particles and conductive agent particles is tighter, and the electrode has the advantages of high density, good conductivity, high capacity and the like.

Description

Technical Field

[0001] This utility model relates to the field of polymer materials technology, and in particular to a coagulation and stirring device for polytetrafluoroethylene dispersion resin used in dry electrode binders. Background Technology

[0002] Currently, dry-process batteries using PTFE binders suffer from a series of problems during operation, including the easy shedding of active materials, electrochemical side reactions between electrode material components, difficulty in uniform distribution between binder and electrode materials during processing, and relatively rough equipment for pressing dry self-supporting films.

[0003] In order to be processed into self-supporting films, the dry film must have a certain mechanical tensile strength. If the binder cannot achieve this tensile strength, for example due to very low binder content or defects due to inhomogeneity of the mixture, the risk of film cracking is very high, especially for films smaller than 100 μm. The wider the film and the faster the production, the more unstable the corresponding process steps and dry film quality become.

[0004] In addition, each ton of polytetrafluoroethylene resin (calculated on a dry basis) generates approximately 5 tons of wastewater from coagulation, which most companies discharge directly as industrial wastewater. However, due to limitations in existing polytetrafluoroethylene dispersion resin production processes, the wastewater contains small amounts of resin and added additives (specifically approximately 0.2% PTFE, trace amounts of fluorinated surfactants, and small amounts of other additives). These substances, discharged with the wastewater, not only harm the environment but also result in a certain degree of resource waste.

[0005] To achieve more thorough coagulation, a product with uniform particle size is required. The structure of the coagulation stirring device is referenced in Chinese Utility Model Patent Application No. 202323320558.1, entitled "A Coagulation Stirring Device for PTFE Dispersed Resin Fiber Powder." Existing coagulation stirring devices cannot achieve the ideal level of tightness in contact between carbon micropowder particles and with conductive agent particles, thus impairing the conductivity and capacity retention of the electrode to some extent, making them unsuitable for dry electrode materials in lithium-ion batteries. Furthermore, the coagulation wastewater contains approximately 0.25% resin, resulting in incomplete coagulation, resource waste, and environmental harm. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders that enables more thorough coagulation.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders, comprising:

[0008] The condensation tank is equipped with a drive mechanism at the top and baffles on the inner wall of the condensation tank.

[0009] The stirring rod extends out of the coagulation tank at the top and is connected to the drive mechanism, while its bottom extends into the inner cavity of the coagulation tank.

[0010] The downward-sloping blades are located at the bottom of the stirring rod;

[0011] The vortex agitator is located at the bottom of the agitator rod and below the downward-sloping blades.

[0012] Furthermore, the downward-sloping blade includes a downward-sloping rod, with two or more downward-sloping rods evenly distributed along the circumference on the stirring rod.

[0013] Furthermore, it also includes a spindle-shaped sleeve, which is fitted over two or more lower diagonal bars.

[0014] Furthermore, the vortex agitator includes connecting rods and guide sleeves. Two or more connecting rods are evenly distributed along the circumference of the agitator rod, and each connecting rod is connected to a guide sleeve at its free end. The guide sleeves are provided with through holes in a direction tangent to the circumference of the agitator rod.

[0015] Furthermore, the cross-sectional shape of the inlet end of the through hole is circular, and the cross-sectional shape of the outlet end of the through hole is elliptical.

[0016] Furthermore, the five connecting rods are evenly distributed along the circumference of the stirring rod.

[0017] Furthermore, the baffle plate includes a first curved surface and a second curved surface that are circumferentially connected to the condensation tank.

[0018] Furthermore, three baffles are evenly distributed along the circumference on the inner wall of the condensation tank, and the three baffles are arranged around the vortex agitator.

[0019] Furthermore, the top of the coagulation tank is equipped with a pure water inlet and a mother liquor inlet.

[0020] Furthermore, the drive mechanism includes a motor and a reducer, with the motor, reducer, and stirring rod connected in sequence.

[0021] The beneficial effects of this utility model are as follows: A coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders has a stirring rod whose upper part passes through the top cover of the coagulation tank without separation, and whose lower part extends into the tank body and is suspended in the air, and can rotate relative to it. The stirring rod extending into the tank body is a combination of two layers with different structures. The upper layer is a downward inclined blade, which has axial thrust when rotating, mainly pushing the material downward. The lower layer is a vortex stirring blade, which mainly enhances the radial stirring intensity without damaging the spatial structure of the particles. With the assistance of the baffle structure on the inner wall of the coagulation tank, the fluid blind zone can be reduced, and low-speed full mixing can be achieved. The coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders provided by this utility model can adjust the specific gravity of the dispersion resin mother liquor to a low level, so as to produce uniformly sized dispersion resin fine powder, that is, dispersion resin fine powder with a particle size of 10-100μm, with good fiber-forming effect, high fiber-forming rate, and less prone to fiber breakage. When used as a binder for dry electrodes, it exists in a fibrous state, which allows for closer contact between activated carbon particles and with conductive agent particles, thereby giving the electrode advantages such as high density, good conductivity, and high capacity. Attached Figure Description

[0022] Figure 1 A schematic diagram of a stirring device for coagulating polytetrafluoroethylene dispersion resin as a dry electrode binder.

[0023] Figure 2 A schematic diagram of a stirring device for coagulating polytetrafluoroethylene dispersion resin as a dry electrode binder.

[0024] Figure 3 A schematic diagram of a stirring device for coagulating polytetrafluoroethylene dispersion resin as a dry electrode binder.

[0025] Figure 4 A schematic diagram of a stirring device for coagulating polytetrafluoroethylene dispersion resin as a dry electrode binder.

[0026] Label Explanation:

[0027] 1. Coagulation tank; 11. Drive mechanism; 12. Baffle; 121. First curved surface; 122. Second curved surface; 13. Pure water inlet; 14. Mother liquor inlet; 2. Stirring rod; 3. Inclined impeller; 31. Inclined rod; 32. Spindle-shaped sleeve; 4. Vortex stirring impeller; 41. Connecting rod; 42. Guide sleeve; 421. Through hole. Detailed Implementation

[0028] To explain in detail the technical content, objectives, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0029] Please refer to Figures 1 to 4 As shown, the present invention provides a polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders, comprising:

[0030] The condensation tank 1 is equipped with a drive mechanism 11 at the top and a baffle 12 on the inner wall of the condensation tank 1.

[0031] The stirring rod 2 extends out of the coagulation tank 1 at the top and is connected to the drive mechanism 11, while the bottom extends into the inner cavity of the coagulation tank 1.

[0032] The downward-sloping blade 3 is located at the bottom of the stirring rod 2;

[0033] The vortex agitator 4 is located at the bottom of the agitator rod 2 and below the downward-sloping blade 3.

[0034] As can be seen from the above description, the beneficial effects of this utility model are as follows: A coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders, wherein the upper part of the stirring rod 2 passes through the top cover of the coagulation tank 1 without separation, and the lower part extends into the tank body and is suspended in the air, and can rotate relative to it. The stirring rod 2 extending into the tank body is a combination of two layers with different structures. The upper layer is a downward inclined blade 3, which has axial thrust when rotating, mainly pushing the material downward. The lower layer is a vortex stirring blade 4, which mainly enhances the radial stirring intensity without damaging the particle spatial structure. With the assistance of the baffle 12 structure on the inner wall of the coagulation tank 1, the fluid blind zone can be reduced, and low-speed full mixing can be achieved. The coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders provided by this utility model can adjust the specific gravity of the dispersion resin mother liquor to a low level, so as to achieve the production of uniformly sized dispersion resin fine powder, that is, dispersion resin fine powder with a particle size of 10-100μm, with good fiber-forming effect, high fiber-forming rate, and less prone to fiber breakage. When used as a binder for dry electrodes, it exists in a fibrous state, which allows for closer contact between activated carbon particles and with conductive agent particles, thereby giving the electrode advantages such as high density, good conductivity, and high capacity.

[0035] In an optional embodiment, the downward-sloping blade 3 includes a downward-sloping rod 31, and two or more downward-sloping rods 31 are evenly distributed along the circumferential direction on the stirring rod 2.

[0036] As can be seen from the above description, the material is pushed downward by the axial thrust generated by two or more downward inclined rods 31 during rotation.

[0037] In an optional embodiment, a spindle-shaped sleeve 32 is also included, which is sleeved on the outside of two or more lower inclined rods 31.

[0038] As can be seen from the above description, after the material is pushed downward by the spindle-shaped sleeve 32, it flows through the middle constriction of the spindle-shaped sleeve 32, which can enhance the turbulence of the fluid, accelerate particle mixing and collision, speed up coagulation, and reduce the coagulation time of the material.

[0039] In an optional embodiment, the vortex stirring paddle 4 includes a connecting rod 41 and a flow guide sleeve 42. Two or more connecting rods 41 are evenly distributed along the circumferential direction on the stirring rod 2. Each connecting rod 41 is connected to a flow guide sleeve 42 at its free end. The flow guide sleeve 42 is provided with a through hole 421 in a direction tangent to the circumferential direction surrounding the stirring rod 2.

[0040] As described above, each connecting rod 41 is equipped with a flow guide sleeve 42 at its tail. The flow guide sleeve 42 can generate vortices and force the formation of radial fluid.

[0041] In an optional embodiment, the cross-sectional shape of the water inlet end of the through hole 421 is circular, and the cross-sectional shape of the water outlet end of the through hole 421 is elliptical.

[0042] As described above, the material flows in through the circular opening and out through the elliptical opening, forming a vortex and generating a forced radial flow. This achieves turbulence at low speeds, minimizing damage to the spatial structure of the particles. Because the radial flow from the elliptical opening differs in velocity and direction from other materials, it enhances the fluid's turbulence, increases the probability of PTFE particles colliding, and promotes more thorough coagulation.

[0043] In an optional embodiment, five connecting rods 41 are evenly distributed along the circumferential direction on the stirring rod 2.

[0044] In an optional embodiment, the baffle 12 includes a first curved surface 121 and a second curved surface 122 that are circumferentially connected along the condensation tank 1.

[0045] As described above, the fluid flows through the lower stirring blade region to form a radial flow. The fluid reaches the baffle 12 on the inner wall of the condensation tank 1 and is divided into three streams after passing through the first curved surface 121 and the second curved surface 122. One stream flows upward along the inner wall of the tank back to the upper stirring blade disturbance region to participate in the axial flow. Another part flows downward along the inner wall to the bottom of the condensation tank 1 and returns upward after a secondary collision. When it reaches the lower stirring blade disturbance region, it continues to participate in the radial flow under its influence. A third part forms a local annular laminar flow after passing through the baffle plate outside the lower stirring disturbance region. Thus, the axial flow of the upper stirring blade and the radial flow of the lower stirring blade form a circulating flow field. The fluid will roll up along the inner wall of the tank and then repeat the above actions.

[0046] In an optional embodiment, three baffles 12 are evenly distributed along the circumferential direction on the inner wall of the condensation tank 1, and the three baffles 12 are arranged around the vortex stirring paddle 4.

[0047] As can be seen from the above description, the cross-circulation flow field achieved by the three baffles 12 greatly promotes the collision between resins, and also enables the coagulant to be quickly and evenly dispersed in the solution. The resulting resin particles are more uniform and the coagulation is more thorough, and the resin residue in the wastewater can reach less than 0.03%.

[0048] In an optional embodiment, the top of the coagulation tank 1 is provided with a pure water inlet 13 and a mother liquor inlet 14.

[0049] In an optional embodiment, the drive mechanism 11 includes a motor and a reducer, and the motor, reducer and stirring rod 2 are connected in sequence.

[0050] As can be seen from the above description, the motor and reducer are fixed to the top cover of the condensation tank 1 by a fixing bracket for outputting power.

[0051] Please refer to Figures 1 to 4 As shown, Embodiment 1 of this utility model is: a coagulation and stirring device for polytetrafluoroethylene dispersion resin in dry electrode binders, comprising:

[0052] The condensation tank 1 is equipped with a drive mechanism 11 at the top and a baffle 12 on the inner wall of the condensation tank 1.

[0053] The stirring rod 2 extends out of the coagulation tank 1 at the top and is connected to the drive mechanism 11, while the bottom extends into the inner cavity of the coagulation tank 1.

[0054] The downward-sloping blade 3 is set at the bottom of the stirring rod 2, and the downward-sloping blade 3 is inclined upward at a certain angle from the connection part with the stirring rod 2 to the free end;

[0055] The vortex agitator 4 is located at the bottom of the agitator rod 2 and below the downward-sloping blade 3.

[0056] The downward-sloping impeller 3 includes three downward-sloping rods 31, which are evenly distributed circumferentially on the stirring rod 2. It also includes a spindle-shaped sleeve 32, which is fitted over two or more downward-sloping rods 31. The vortex agitator 4 includes connecting rods 41 and guide sleeves 42. Two or more connecting rods 41 are evenly distributed circumferentially on the stirring rod 2. Each connecting rod 41 has a guide sleeve 42 connected to its free end. The guide sleeve 42 has a through hole 421 in a direction tangential to the circumference of the stirring rod 2. The arc-shaped sleeve is connected to the stirring head by a cylindrical stainless steel column and fixed to the stirring shaft by the stirring head. The inlet end of the through hole 421 has a circular cross-section, and the outlet end has an elliptical cross-section. Five connecting rods 41 are evenly distributed circumferentially on the stirring rod 2. The baffle 12 includes a first curved surface 121 and a second curved surface 122 that are circumferentially connected to each other on the condensation tank 1. Three baffles 12 are evenly distributed circumferentially on the inner wall of the condensation tank 1, and are arranged around the vortex stirring paddle 4. The top of the condensation tank 1 is provided with a pure water inlet 13 and a mother liquor inlet 14. The drive mechanism 11 includes a motor and a reducer, and the motor, reducer, and stirring rod 2 are connected in sequence.

[0057] In summary, the polytetrafluoroethylene (PTFE) dispersion resin coagulation and stirring device for dry electrode binders of this invention features a stirring rod whose upper part passes through the top cover of the coagulation tank without separation, and whose lower part extends into the tank body and is suspended in the air, allowing for relative rotation. The stirring rod extending into the tank consists of a combination of upper and lower layers with different structures. The upper layer is a downward-sloping impeller, which provides axial thrust during rotation, primarily pushing the material downwards. The lower layer is a vortex stirring impeller, which mainly enhances radial stirring intensity without damaging the spatial structure of the particles. The device is further aided by a baffle structure on the inner wall of the coagulation tank, which reduces the fluid blind zone and achieves low-speed, fully mixed flow. The polytetrafluoroethylene (PTFE) dispersion resin coagulation and stirring device for dry electrode binders provided by this invention can adjust the specific gravity of the dispersion resin mother liquor to a low level, thereby producing uniformly sized fine dispersion resin powder, i.e., dispersion resin powder with a particle size of 10–100 μm, exhibiting good fiber-forming effect, high fiber-forming rate, and reduced filament breakage. When used as a binder for dry electrodes, it exists in a fibrous state, which allows for closer contact between activated carbon particles and with conductive agent particles, thereby giving the electrode advantages such as high density, good conductivity, and high capacity.

[0058] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A device for coagulating and stirring polytetrafluoroethylene dispersion resin for dry electrode binders, characterized in that, include: The condensation tank is equipped with a drive mechanism at the top and baffles on the inner wall of the condensation tank. The stirring rod extends out of the coagulation tank at the top and is connected to the drive mechanism, while its bottom extends into the inner cavity of the coagulation tank. The downward-sloping blades are located at the bottom of the stirring rod; The vortex agitator is located at the bottom of the agitator rod and below the downward-sloping blades.

2. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 1, characterized in that, The downward-sloping blade includes a downward-sloping rod, and two or more downward-sloping rods are evenly distributed along the circumference on the stirring rod.

3. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 2, characterized in that, It also includes a spindle-shaped sleeve, which is fitted over two or more lower diagonal bars.

4. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 1, characterized in that, The vortex agitator includes connecting rods and guide sleeves. Two or more connecting rods are evenly distributed along the circumference of the agitator. Each connecting rod is connected to a guide sleeve at its free end. The guide sleeve has a through hole in a direction tangent to the circumference of the agitator.

5. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 4, characterized in that, The inlet end of the through hole has a circular cross-sectional shape, while the outlet end has an elliptical cross-sectional shape.

6. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 4, characterized in that, Five connecting rods are evenly distributed along the circumference of the stirring rod.

7. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 1, characterized in that, The baffle includes a first curved surface and a second curved surface that are connected circumferentially along the condensation tank.

8. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 7, characterized in that, Three baffles are evenly distributed along the circumference on the inner wall of the condensation tank, and the three baffles are arranged around the vortex agitator.

9. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 1, characterized in that, The top of the coagulation tank is equipped with a pure water inlet and a mother liquor inlet.

10. The polytetrafluoroethylene dispersion resin coagulation and stirring device for dry electrode binders according to claim 1, characterized in that, The drive mechanism includes a motor and a reducer, and the motor, reducer and stirring rod are connected in sequence.

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