Dry powder kneading device and method of forming fiberized dry powder

Abstract

The present disclosure provides a dry powder kneading apparatus and a method of forming a fiberized dry powder. A dry powder kneading device includes: a main body including an internal space into which a mixture containing an active material, a conductive material, and a binder is supplied; and a screw rod in the internal space of the main body, the screw rod being configured to move the mixture in one direction and knead the mixture into the synthesized dry powder, the rotation torque of the screw rod being 1.4 kgfm to 42 kgfm.

Description

Technical Field

[0001] The present disclosure relates to a dry powder kneading apparatus. Background Art

[0002] Generally, a rechargeable battery is a battery that can be repeatedly charged and discharged. Recently, an apparatus for manufacturing a dry electrode of a rechargeable battery without using a solvent is desired. Summary of the invention

[0003] Aspects of the embodiments provide a dry powder kneading device, which includes: a main body, including an internal space, into which a mixture containing an active substance, a conductive substance and a binder is supplied; and a screw, arranged in the internal space of the main body, moving the mixture in one direction and kneading it into a fiberized dry powder, wherein the rotational torque of the screw is 1 to 30 times of 1.4 kgf•m.

[0004] The temperature of the inner space of the main body may be 110° C. or higher.

[0005] The rotational torque of the screw may be 6.1 kgf•m to 34 kgf•m.

[0006] The amount of the active material may be 90 wt % to 99 wt % of the total weight of the mixture, the amount of the conductive material may be 0.5 wt % to 9.5 wt % of the total weight of the mixture, and the amount of the binder may be 0.5 wt % to 10 wt % of the total weight of the mixture.

[0007] The active material may include nickel cobalt aluminum (NCA), the conductive material may include at least one of Ketjen black and carbon nanotubes, and the binder may include polytetrafluoroethylene (PTFE).

[0008] The amount of the active material may be 96 wt % of the total weight of the mixture, the amount of the conductive material may be 1.8 wt % of the total weight of the mixture, and the amount of the binder may be 2.2 wt % of the total weight of the mixture.

[0009] The temperature of the inner space of the main body may be 126°C to 146°C.

[0010] The screw shaft speed may be 60 RPM (revolutions per minute) to 90 RPM.

[0011] The feed rate of the mixture may be 25 kg / hr to 40 kg / hr.

[0012] The dry powder kneading device may further include a feeder supplying the mixture to the main body.

[0013] The dry powder kneading device may further include a motor connected to the screw to rotate the screw.

[0014] The dry powder kneading device may further include a torque meter which is provided between the motor and the screw and measures a rotational torque of the screw.

[0015] The dry powder kneading device may further include a plurality of heaters installed on an outer surface of the main body.

[0016] The screw may include: a conveying element to move the mixture in one direction; a kneading element connected to the conveying element to knead the mixture into a fiberized dry powder; and a neutral element connected to the kneading element to prevent movement of the dry powder in one direction.

[0017] The body may further include an inlet through which the mixture is input, and an outlet adjacent to the neutral element and discharging the dry powder.

[0018] Aspects of an embodiment provide a method for forming a fiberized dry powder, the method comprising: forming a mixture containing an active substance, a conductive substance and a binder; supplying the mixture to an internal space of a main body of a dry powder kneading device; operating a screw within the internal space of the main body with a rotational torque of 1.4 kgf•m to 42 kgf•m, so that the screw moves the mixture through the main body in one direction and kneads the mixture into a fiberized dry powder.

[0019] The amount of the active material may be 90 wt % to 99 wt % of the total weight of the mixture, the amount of the conductive material may be 0.5 wt % to 9.5 wt % of the total weight of the mixture, and the amount of the binder may be 0.5 wt % to 9.5 wt % of the total weight of the mixture.

[0020] The active material may include nickel cobalt aluminum, the conductive material may include at least one of Ketjen black and carbon nanotubes, and the binder may include polytetrafluoroethylene.

[0021] The method may further include heating the interior space of the body to a temperature of 126°C to 146°C.

[0022] Operating the screw may include a shaft that rotates the screw at 60 RPM to 90 RPM. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

[0024] Figure 1 A dry powder kneading device according to an embodiment is shown.

[0025] Figure 2A-2CImages showing respective examples of conveying elements, kneading elements, and idler elements of a screw of a dry powder kneading device according to an embodiment.

[0026] Figure 3 A table showing experimental results for confirming the effect of the dry powder kneading device according to an embodiment. DETAILED DESCRIPTION

[0027] Example embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art.

[0028] In the drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or there may be intervening layers. Additionally, it will be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there may be one or more intervening layers. Like reference numerals refer to like elements throughout.

[0029] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprising” or “including”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0030] In the following, reference will be made to Figure 1 and Figure 2A-2C A dry powder kneading device according to an embodiment is described.

[0031] Figure 1 A dry powder kneading device according to an embodiment is shown. Figure 2A An image showing a conveying element of a screw of a dry powder kneading device according to an embodiment, Figure 2B An image showing a kneading element of a screw of a dry powder kneading device according to an embodiment, Figure 2C An image showing an idle element of a screw of a dry powder kneading device according to an embodiment.

[0032] For example, the dry powder kneading device according to one embodiment may be a device in which a mixture containing an active material, a conductive material, and a binder is kneaded into a fiberized dry powder to manufacture a dry electrode for a rechargeable battery. In another example, the dry powder kneading device according to one embodiment may be a device for supplying a suitable wet electrode material included in a suitable wet electrode manufacturing device. In yet another example, the dry powder fiberized by the dry powder kneading device according to one embodiment may be supplied to a suitable calendering device for manufacturing a self-supporting film.

[0033] Reference Figure 1 The dry powder kneading device according to the embodiment can use the screw 220 to knead the mixture MI containing the active material, the conductive material and the binder into a fiberized dry powder DP, and can supply the fiberized dry powder DP to various suitable dry electrode manufacturing devices.

[0034] For example, the active material may include various suitable electrode active materials (including, for example, nickel cobalt aluminum (NCA)), the conductive material may include various suitable conductive materials (including, for example, at least one of Ketjen black and carbon nanotubes), and the binder may include various suitable fiber binders (including, for example, polytetrafluoroethylene (PTFE)).

[0035] For example, the dry electrode manufacturing device adjacent to the dry powder kneading device may be a device including various suitable calendering rollers for calendering the fiberized dry powder DP to manufacture a self-supporting film.

[0036] The dry powder kneading device according to the embodiment may include a feeder 100 and a kneader 200. The feeder 100 may supply a mixture MI containing an active material, a conductive material, and a binder to a main body 210 of the kneader 200. The feeder 100 may quantitatively supply the mixture MI to the kneader 200 by using various suitable quantitative controllers. The mixture MI supplied from the feeder 100 may be kneaded into a fiberized dry powder DP in the kneader 200 and discharged.

[0037] For example, the feeder 100 may feed the mixture MI to the kneader 200 at a predetermined feed rate. For example, the feeder 100 may feed the mixture MI to the kneader 200 at a feed rate of 25 kg / hr to 40 kg / hr.

[0038] For example, the active material contained in the mixture MI may be 90wt% to 99wt% of the total weight of the mixture MI, the conductive material may be 0.5wt% to 9.5wt% of the total weight of the mixture MI, and the binder may be 0.5wt% to 9.5wt% of the total weight of the mixture MI. For example, the active material contained in the mixture MI may be 96wt% of the total weight of the mixture MI, the conductive material may be 1.8wt% of the total weight of the mixture MI, and the binder may be 2.2wt% of the total weight of the mixture MI.

[0039] The kneading machine 200 may knead the mixture MI supplied from the feeder 100 into a fiberized dry powder DP. The kneading machine 200 may include a body 210 , a screw 220 , a heater 230 , a motor 240 , and a torque meter 250 .

[0040] The body 210 may include an internal space IS, an inlet 211, and an outlet 212. The inlet 211 and the outlet 212 may be in fluid communication with the internal space IS of the body 210.

[0041] The internal space IS may be formed by extending in one direction (e.g., a single direction) from the inside of the body 210, for example, the internal space IS may be a volume space in the inside of the body 210. A mixture MI including an active material, a conductive material, and a binder may be supplied from the feeder 100 into the internal space IS of the body 210 through the inlet 211.

[0042] For example, the temperature of the internal space IS of the main body 210 may be 110° C. or higher, for example, the temperature of the internal space IS of the main body 210 may be 126° C. to 146° C. For example. The temperature of the internal space IS of the main body 210 may be controlled by the heater 230, for example, the heater 230 may include at least one sensor and a controller to adjust the temperature in the internal space IS. In another example, the temperature of the internal space IS of the main body 210 may be controlled by various suitable heating members.

[0043] The inlet 211 is a portion into which the mixture MI is input from the feeder 100. The mixture MI may be supplied from the feeder 100 to the internal space IS through the inlet 211. The inlet 211 may be adjacent to a conveying element 221 (e.g., a conveyor) of the screw 220. The mixture MI supplied to the internal space IS through the inlet 211 may be moved to a kneading element 222 (e.g., a fiberizer) of the screw 220 through the conveying element 221 of the screw 220.

[0044] The outlet 212 may be spaced apart from the inlet 211, with the internal space IS interposed therebetween, for example, the outlet 212 and the inlet 211 may be at opposite ends of the internal space IS along the longitudinal direction of the screw 220 and at opposite ends of the screw 220. The outlet 212 is a portion of the internal space IS from which the dry powder DP fiberized from the mixture MI is discharged through the screw 220. The outlet 212 may be adjacent to an idle element 223 (e.g., a stopper) of the screw 220. The dry powder DP that is prevented from moving in one direction in the internal space IS by the idle element 223 of the screw 220 may be discharged to the outside through the outlet 212.

[0045] The screw 220 may be disposed in the internal space 15 of the body 210. The screw 220 may be rotated by the motor 240 to move the mixture MI supplied to the internal space IS in one direction in the internal space IS and knead the mixture MI into a fiberized dry powder DP.

[0046] The screw 220 may include a conveying element 221, a kneading element 222, and an idle element 223. For example, Figure 1 As shown, the kneading element 222 can be between the idler element 223 and the conveying element 221 along the long axis of the screw 220 (e.g., along the longitudinal direction of the screw 220). Figure 1 As shown, the conveying element 221, the kneading element 222 and the idler element 223 can be aligned along the same main axis extending in the longitudinal direction of the screw 220. For example, Figure 1 As shown, the conveying element 221 , the kneading element 222 , and the idler element 223 may be attached to and aligned along the axis 220 a (eg, the same axis) of the screw 220 .

[0047] Reference Figure 1 and Figure 2A , the conveying element 221 moves the mixture MI in one direction. The conveying element 221 moves the mixture MI to the kneading element 222. For example, Figure 2A As shown, the conveying element 221 may include a plurality of threads extending continuously around the body of the screw 220. For example, referring to Figure 2A The threads may be defined by a helical ridge that is continuously wound multiple times around the body of the screw 220 so that the mixture MI can move along the threads, such as in the spaces between portions of the helical ridges. In another example, the conveying element 221 may include any suitable conveying screw shape capable of moving the mixture MI in one direction.

[0048] Reference Figure 1 and Figure 2B The kneading element 222 may be disposed between the conveying element 221 and the neutral element 223. The kneading element 222 may be connected to the conveying element 221 to knead the mixture MI moved from the conveying element 221 to the kneading element 222 into a fiberized dry powder DP and move the dry powder DP to the neutral element 223. For example, Figure 2B As shown, the kneading element 222 may include crushing elements facing each other and movable toward each other, such as two rows of hammers or teeth facing each other and movable toward each other to contact each other, so that the mixture MI moved from the conveying element 221 to the kneading element 222 can move through the crushing elements of the kneading element 222 (e.g., through the teeth of the kneading element 222) to be fiberized into a fiberized dry powder DP. In another example, the kneading element 222 may include any suitable kneading screw shape capable of kneading the mixture MI into a fiberized dry powder DP.

[0049] Reference Figure 1 and Figure 2C, the neutral element 223 may be connected to the kneading element 222. The neutral element 223 may prevent the fiberized dry powder DP moving from the kneading element 222 from moving in one direction in the internal space IS. The dry powder DP prevented from moving in one direction by the neutral element 223 may be discharged to the outside through the outlet 212 of the main body 210. For example, Figure 2C As shown, the idle element 223 may include a plurality of protrusions arranged to be spaced apart from each other along the longitudinal direction of the screw 220 and along the circumferential direction of the body of the screw 220, for example, the protrusions may be offset from each other along the longitudinal direction and the circumferential direction of the body of the screw 220, so that the protrusions may prevent the movement of the material (e.g., the fiberized dry powder DP) along the longitudinal direction of the screw 220. In another example, the idle element 223 may include any suitable idle screw shape that may prevent the movement of the dry powder DP from the kneading element 222 along the screw 220 through the idle element 223 in the internal space IS.

[0050] For example, the rotation torque of the screw 220 may be 1 to 30 times of 1.4 kgf·m (i.e., 1.4 kgf·m to 42 kgf·m), such as 6.1 kgf·m to 34 kgf·m. For example, the shaft speed of the screw 220 may be 60 RPM to 90 RPM. The shaft speed of the screw 220 may be controlled using the motor 240 or various suitable gear components.

[0051] The heater 230 may be mounted on the outer surface of the body 210. The heater 230 may include a heating member. The internal space IS of the body 210 may be heated by the heater 230 so that the temperature of the internal space IS may have a predetermined set temperature. For example, the heater 230 may continuously surround the entire outer surface of the body 210. In another example, the heater 230 may include a plurality of heating members spaced apart from each other on the entire outer surface of the body 210. For example, the heater 230 may be mounted on at least one of the inner surface and the outer surface of the body 210.

[0052] The motor 240 may be connected to the screw 220 to rotate the screw 220. The rotation shaft of the motor 240 may be directly connected to the shaft 220a of the screw 220, or connected to the shaft 220a of the screw 220 through various gear members. For example, the motor 240 may rotate the screw 220 so that the screw 220 rotates at a predetermined rotation torque. In another example, the rotation torque of the screw 220 may be set by any suitable rotation torque control member.

[0053] The torque meter 250 may be disposed between the motor 240 and the screw 220. The torque meter 250 may measure the rotational torque of the screw 220 and the rotational torque of the motor 240. The torque meter 250 may include a suitable rotational torque measuring member (e.g., at least one sensor and a controller) to adjust a gear that sets the rotational torque of the screw 220.

[0054] The dry powder kneading device according to the present embodiment may include a configuration in which the rotational torque of the screw 220 is 1 to 30 times of 1.4 kgf·m and the temperature of the internal space IS of the body 210 is 110° C. or higher. Therefore, damage to the screw 220 for kneading the mixture MI containing an active material, a conductive material, and a binder into a fiberized dry powder DP can be suppressed and the mixture MI can be easily kneaded into a fiberized dry powder DP to manufacture a dry electrode including a self-supporting film with improved tensile strength.

[0055] The dry powder kneading device according to the embodiment may include a configuration in which the rotation torque of the screw 220 is 6.1 kgf·m to 34 kgf·m and the temperature of the internal space IS of the body 210 is 126° C. to 146° C. Therefore, damage to the screw 220 for kneading the mixture MI including the active material, the conductive material, and the binder into the fiberized dry powder DP can be suppressed and the mixture MI can be easily kneaded into the fiberized dry powder DP to manufacture a dry electrode including a self-supporting film with improved tensile strength.

[0056] The following experimental examples and comparative examples are provided to highlight the features of one or more embodiments, but it will be understood that the experimental examples and comparative examples will not be interpreted as limiting the scope of the embodiments, and the comparative examples will not be interpreted as being outside the scope of the embodiments. In addition, it will be understood that the embodiments are not limited to the specific details described in the experimental examples and comparative examples.

[0057] Will refer to Figure 3 Describe the results of experimental examples and comparative examples. Figure 3 A table showing experimental results for confirming the effects of the dry powder kneading device according to the embodiment.

[0058] Reference Figure 3 , Experimental Example 1 (EX1), Experimental Example 2 (EX2), Experimental Example 3 (EX3), Comparative Example 1 (CO1), Comparative Example 2 (CO2), and Comparative Example 3 (CO3) were performed using the dry powder kneading apparatus according to the embodiment.

[0059] Experimental Example 1

[0060] A mixture containing 96 wt% of an active material containing NCA (nickel cobalt aluminum), 1.8 wt% of a conductive material containing Ketjen black, and 2.2 wt% of a binder containing PTFE (polytetrafluoroethylene) was fed into the inner space of the kneader at a feed rate of 25 kg / hr. The shaft speed of the screw of the kneader kneading the mixture into a fiberized dry powder was 60 RPM, the rotation torque of the screw was 7.8 kgf•m, and the temperature of the inner space of the kneader was 139°C. As a result of the experiment in Experimental Example 1 (EX1), fiberization kneading from the mixture to a dry powder was easily performed (OK), as confirmed in the optical image and the SEM image.

[0061] Experimental Example 2

[0062] A mixture containing 96 wt% of an active material containing NCA (nickel cobalt aluminum), 1.8 wt% of a conductive material containing Ketjen black, and 2.2 wt% of a binder containing PTFE (polytetrafluoroethylene) was fed into the inner space of the kneader at a feed rate of 40 kg / hr. The shaft speed of the screw of the kneader kneading the mixture into a fiberized dry powder was 90 RPM, the rotation torque of the screw was 6.1 kgf•m, and the temperature of the inner space of the kneader was 126°C. As a result of the experiment in Experimental Example 2 (EX2), fiberization kneading from the mixture to a dry powder was easily performed (OK), as confirmed by the optical image and the SEM image.

[0063] Experimental Example 3

[0064] A mixture containing 96 wt% of an active material containing NCA (nickel cobalt aluminum), 1.8 wt% of a conductive material containing Ketjen black, and 2.2 wt% of a binder containing PTFE (polytetrafluoroethylene) was fed into the inner space of the kneader at a feed rate of 25 kg / hr. The shaft speed of the screw of the kneader kneading the mixture into a fiberized dry powder was 60 RPM, the rotation torque of the screw was 34 kgf•m, and the temperature of the inner space of the kneader was 146°C. As a result of the experiment in Experimental Example 3 (EX3), fiberization kneading from the mixture to a dry powder was easily performed (OK), as confirmed by the optical image and the SEM image.

[0065] Comparative Example 1

[0066] A mixture containing 96 wt% of an active material containing NCA (nickel cobalt aluminum), 1.8 wt% of a conductive material containing Ketjen black, and 2.2 wt% of a binder containing PTFE (polytetrafluoroethylene) was fed into the inner space of a kneader at a feed rate of 10 kg / hr. The shaft speed of the screw of the kneader kneading the mixture into a fiberized dry powder was 60 RPM, the rotation torque of the screw was 1.6 kgf•m, and the temperature of the inner space of the kneader was 93°C. As a result of the experiment in Comparative Example 1 (CO1), as confirmed by the optical image and the SEM image, fiberization kneading from the mixture to the dry powder was not performed (NG) due to the low temperature of the inner space of the kneader.

[0067] Comparative Example 2

[0068] A mixture containing 96 wt% of an active material containing NCA (nickel cobalt aluminum), 1.8 wt% of a conductive material containing Ketjen black, and 2.2 wt% of a binder containing PTFE (polytetrafluoroethylene) was fed into the inner space of a kneader at a feed rate of 25 kg / hr. The shaft speed of the screw of the kneader that kneaded the mixture into a fiberized dry powder was 60 RPM, the rotational torque of the screw was 44 kgf•m, and the temperature of the inner space of the kneader was 148°C. As a result of the experiment in Comparative Example 2 (CO2), due to an excessive rotational torque allowed in the screw of the kneader, the screw was stopped by various known protective members (such as shaft interlocks) and fiberization kneading from the mixture to the dry powder was not performed (NG).

[0069] Comparative Example 3

[0070] A mixture containing 96 wt% of an active material (containing NCA (nickel cobalt aluminum)), 1.8 wt% of a conductive material (containing Ketjen black), and 2.2 wt% of a binder (containing PTFE (polytetrafluoroethylene)) was fed into the inner space of a kneader at a feed rate of 25 kg / hr. The shaft speed of the screw of the kneader that kneaded the mixture into a fiberized dry powder was 60 RPM, the rotational torque of the screw was 50 kgf•m, and the temperature of the inner space of the kneader was 148°C. As a result of the experiment in Comparative Example 3 (CO3), due to excessive rotational torque allowed in the screw of the kneader, the screw broke, and fiberization kneading from the mixture to the dry powder was not performed (NG). Comparative Example 3 (CO3) was performed by disengaging a protective member such as a shaft interlock.

[0071] Experimental Results

[0072] According to the experimental results of the above-mentioned Experimental Example 1 (EX1), Experimental Example 2 (EX2), Experimental Example 3 (EX3), Comparative Example 1 (CO1), Comparative Example 2 (CO2) and Comparative Example 3 (CO3), in order to achieve the task and effect of manufacturing a dry electrode (which suppresses damage to a screw that kneads a mixture containing an active substance, a conductive substance and a binder into a fiberized dry powder, and at the same time includes a self-supporting film with improved tensile strength by easily kneading the mixture into a fiberized dry powder), it is confirmed that the configuration in which the rotational torque of the screw of the kneading machine of the dry powder kneading device according to the embodiment is limited to a value of 6.1 kgf•m to 34 kgf•m is of key significance for confirming the upper and lower limits as thresholds.

[0073] In addition, according to the experimental results of the above-mentioned Experimental Example 1 (EX1), Experimental Example 2 (EX2), Experimental Example 3 (EX3), Comparative Example 1 (CO1), Comparative Example 2 (CO2) and Comparative Example 3 (CO3), in order to achieve the task and effect of manufacturing a dry electrode (which suppresses damage to a screw that kneads a mixture containing an active material, a conductive material and a binder into a fiberized dry powder, and at the same time includes a self-supporting film with improved tensile strength by easily kneading the mixture into a fiberized dry powder), it is confirmed that the configuration in which the rotational torque of the screw of the kneading machine of the dry powder kneading device according to the embodiment is limited to a value of 6.1 kgf•m to 34 kgf•m and the temperature of the internal space of the main body of the kneading machine thereof is limited to a value of 126°C to 146°C is of key significance for confirming that the upper and lower limits are threshold values.

[0074] In addition, according to the experimental results of the above-mentioned Experimental Example 1 (EX1), Experimental Example 2 (EX2), Experimental Example 3 (EX3), Comparative Example 1 (CO1), Comparative Example 2 (CO2) and Comparative Example 3 (CO3), in order to achieve the task and effect of manufacturing a dry electrode (the dry electrode suppresses damage to a screw that kneads a mixture containing an active material, a conductive material and a binder into a fiberized dry powder, and at the same time includes a self-supporting film with improved tensile strength by easily kneading the mixture into a fiberized dry powder), it is confirmed that the rotational torque of the screw of the kneading machine of the dry powder kneading device according to one embodiment is 6.1kgf•m to 34kgf•m (a mixture containing 96wt% of an active material (which contains NCA (nickel cobalt aluminum)), 1.8wt% of a conductive material (which contains Ketjen black) and 2.2wt% of a binder (which contains PTFE (polytetrafluoroethylene)) and the temperature of the internal space of the main body of the kneading machine is 126°C to 146°C. The configuration in which the values ​​are limited is critical for confirming that the upper and lower limits are threshold values.

[0075] By summarizing and reviewing, a dry electrode can be manufactured by kneading a mixture comprising an active material, a conductive material, and a binder into a fiberized dry powder using a dry powder kneading device, manufacturing the fiberized dry powder into a self-supporting film using a calendering roller, and laminating the self-supporting film to a current collector. A conventional dry powder kneading device may include a screw for kneading a mixture comprising an active material, a conductive material, and a binder into a fiberized dry powder.

[0076] Conventional dry powder kneading devices knead by increasing the rotational torque of the screw because the dry powder fiberized from the mixture by the screw has low fluidity and high cohesiveness. However, as the rotational torque increases, the screw may be damaged or may stop.

[0077] In contrast, an exemplary embodiment provides a dry powder kneading device for manufacturing a dry electrode, which can suppress damage to a screw that kneads a mixture containing an active material, a conductive material, and a binder into a fiberized dry powder, and can include a self-supporting film with improved tensile strength by easily kneading the mixture into a fiberized dry powder.

[0078] Example embodiments have been disclosed herein, and although specific terms are employed, these specific terms are used and interpreted only in a general and descriptive sense, and not for purposes of limitation. In some cases, as will be apparent to one of ordinary skill in the art at the time of filing this application, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A dry powder kneading device comprising: a body including an interior space into which a mixture comprising an active material, a conductive material, and a binder can be supplied; as well as A screw is provided in the inner space of the body, the screw being configured to move the mixture in one direction and knead the mixture into a fiberized dry powder, the rotation torque of the screw being 1.4 kgf·m to 42 kgf·m. 2 . The dry powder kneading device according to claim 1 , wherein the temperature of the inner space of the main body can be heated to 110° C. or higher. 3 . The dry powder kneading device according to claim 1 , wherein the rotational torque of the screw is 6.1 kgf·m to 34 kgf·m.

4. The dry powder kneading device according to claim 3, wherein: The amount of the active substance is 90 wt % to 99 wt % of the total weight of the mixture. The amount of the conductive material is 0.5 wt % to 9.5 wt % of the total weight of the mixture, and The amount of the binder is 0.5 wt % to 9.5 wt % based on the total weight of the mixture.

5. The dry powder kneading device according to claim 4, wherein: The active material includes nickel, cobalt, and aluminum. The conductive material includes at least one of Ketjen black and carbon nanotubes, and The binder includes polytetrafluoroethylene.

6. The dry powder kneading device according to claim 5, wherein: The amount of the active substance is 96wt% of the total weight of the mixture, The amount of the conductive material is 1.8 wt % of the total weight of the mixture, and The amount of the binder is 2.2 wt % of the total weight of the mixture.

7. The dry powder kneading device according to claim 3, wherein the temperature of the inner space of the main body is 126°C to 146°C.

8. The dry powder kneading device according to claim 3, wherein the shaft speed of the screw is 60 RPM to 90 RPM. 9 . The dry powder kneading device according to claim 1 , further comprising a feeder configured to supply the mixture to the main body. 10 . The dry powder kneading apparatus according to claim 9 , wherein the feeder is configured to have a feed rate of 25 kg / hr to 40 kg / hr. 11 . The dry powder kneading device according to claim 1 , further comprising a motor connected to the screw, the motor being configured to rotate the screw. 12 . The dry powder kneading device according to claim 11 , further comprising a torque meter between the motor and the screw, the torque meter being configured to measure a rotational torque of the screw.

13. The dry powder kneading device according to claim 1, further comprising a plurality of heaters on an outer surface of the body.

14. The dry powder kneading device according to claim 1, wherein the screw comprises: a conveying element configured to move the mixture in the one direction; a kneading element connected to the conveying element, the kneading element being configured to knead the mixture into the fiberized dry powder; as well as A neutral element is connected to the kneading element, and the neutral element is configured to block the movement of the dry powder in the one direction.

15. The dry powder kneading device according to claim 14, wherein the main body further comprises an inlet and an outlet, the mixture is input through the inlet, and the outlet is adjacent to the idler element and configured to discharge the dry powder.

16. A method of forming a fiberized dry powder, the method comprising: forming a mixture comprising an active material, a conductive material, and a binder; supplying the mixture into the inner space of a body of a dry powder kneading device; as well as The screw within the inner space of the body is operated at a rotational torque of 1.4 to 42 kgf·m, so that the screw moves the mixture through the body in one direction and kneads the mixture into a fiberized dry powder.

17. The method of claim 16, wherein: The amount of the active substance is 90 wt % to 99 wt % of the total weight of the mixture. The amount of the conductive material is 0.5 wt % to 9.5 wt % of the total weight of the mixture, and The amount of the binder is 0.5 wt % to 9.5 wt % based on the total weight of the mixture.

18. The method of claim 17, wherein: The active material includes nickel, cobalt, and aluminum. The conductive material includes at least one of Ketjen black and carbon nanotubes, and The binder includes polytetrafluoroethylene.

19. The method of claim 18, further comprising heating the interior space of the body to a temperature of 126°C to 146°C.

20. The method of claim 18, wherein operating the screw comprises rotating a shaft of the screw at 60 RPM to 90 RPM.

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