Dry electrode double-sided coating apparatus

Abstract

The present invention relates to a dry electrode double-sided coating apparatus comprising: a current collector supply unit which continuously supplies a wound current collector foil having a predetermined width; a first electrode forming machine which rolls an electrode material powder so as to form a first electrode film to be coated on one side of the current collector foil; a second electrode forming and coating machine which rolls the electrode material powder so as to form a second electrode film to be coated on the other side of the current collector foil, and which compresses the second electrode film that is formed, the current collector foil provided from the current collector supply unit, and the first electrode film transferred from the first electrode forming machine while same simultaneously pass therethrough; a tension control unit which adjusts the tension of the first electrode film transported from the first electrode forming machine to the second electrode forming and coating machine; and a winding unit which winds a laminate laminated while passing through the second electrode forming and coating machine. Thus, through multi-level rolls arranged in the horizontal and vertical directions, dry electrode films having a uniform density and thickness may be continuously formed, and at the same time, may be laminated on the two sides of the current collector foil, and thus a double-sided dry electrode having a precise standard may be manufactured.

Description

Dry electrode double-sided coating device

[0001] The present invention relates to a double-sided electrode coating device for a secondary battery, and more specifically, to a double-sided dry electrode coating device capable of continuously forming a dry electrode film of uniform density and thickness through multi-stage rolls arranged in horizontal and vertical directions and simultaneously laminating the film on both sides of a current collector foil.

[0002] Unlike disposable primary batteries, lithium secondary batteries are rechargeable and reusable. They boast high output and excellent charge-discharge performance. Consequently, they are widely used in a variety of fields, from mobile IT devices like smartphones and laptops to power sources for electric vehicles and storage devices for power generated by wind and solar power.

[0003] Secondary batteries are composed of a positive electrode, a negative electrode, an electrolyte, and a separator. The positive and negative electrodes are manufactured into a secondary battery cell through an electrode process, which involves dispersing or dissolving active materials, conductive materials, and binders in a solvent to create a slurry, coating the slurry onto a current collector, and then drying it. The process then includes an assembly process and an activation process.

[0004] However, wet electrode manufacturing methods using solvents can sometimes produce defects such as pinholes and cracks during the drying process. Pinholes and cracks occur as the contained solvent evaporates. Furthermore, differences in solvent evaporation rates can cause powder floating, which degrades electrode quality.

[0005] To address the aforementioned issues, a dry manufacturing method for manufacturing electrodes without using solvents is known. This dry manufacturing method involves passing electrode powder containing an active material, a binder, and a conductive material through a calender roll. The electrode powder, having passed through the calender roll, is laminated and fixed to a current collector as a dry electrode film of a certain thickness.

[0006] In this regard, Korean Patent Publication No. 10-2022-0052852 (Electrode powder for manufacturing dry electrode for secondary battery, manufacturing method thereof, manufacturing method of dry electrode using same, dry electrode, secondary battery including same, energy storage device, and dry electrode manufacturing device) has been disclosed.

[0007] The disclosed dry electrode manufacturing device is a dry electrode manufacturing device, and comprises: a blender for mixing raw materials for a mixture including an active material, a conductive material, and a binder; a kneader for kneading the mixture to form a mixture lump to fiberize the binder; a crusher for crushing the mixture lump to form an electrode powder; a calender for forming the electrode powder into a mixture film; and a lamination roll for positioning and laminating the mixture film on at least one surface of a current collector.

[0008] However, the above-mentioned conventional dry electrode manufacturing device, although it is described that powder is processed into a film form through calendaring, does not disclose a specific configuration for forming it into a film form.

[0009] The present invention was created to solve the above problems, and the purpose is to provide a dry electrode double-sided coating device that can continuously form a dry electrode film of uniform density and thickness and simultaneously laminate it to both sides of a current collector foil, thereby enabling the manufacture of a dry double-sided electrode having precise specifications.

[0010] As a technical solution for achieving the above object, the dry electrode double-sided coating device of the present invention comprises: a current collector supply unit for continuously supplying a current collector foil of a predetermined width that is wound; a first electrode forming unit having a plurality of rolling rolls that are arranged in a parallel state with some arranged horizontally and the rest arranged vertically, so as to have an overall L-shaped arrangement structure, and that pass electrode material powder through and roll it to form a first electrode film to be coated on one side of the current collector foil; A second electrode forming and coating device is provided, which forms a second electrode film to be coated on the other side of the current collector foil by rolling electrode material powder, and simultaneously passes and presses the formed second electrode film, the current collector foil provided from the current collector supply unit, and the first electrode film delivered from the first electrode forming device, wherein the second electrode forming and coating device comprises a plurality of rolling rolls that are arranged in a parallel state, some horizontally and the rest vertically, and have an overall L-shaped arrangement structure to form the second electrode film, and a pair of coating rolls that are arranged vertically below the lowest rolling roll and pass the current collector and the first and second electrode films; a tension control unit that controls the tension of the first electrode film transferred from the first electrode forming device to the second electrode forming and coating device; and a winding unit that winds up the laminated body that is laminated while passing through the second electrode forming and coating device.

[0011] In addition, the first electrode forming machine is provided with a pair of fixed support plates that provide support and are vertical to the ground and rotatably support the rolling roll, a hopper installed on the upper portion of the rolling roll and discharging electrode powder supplied from the outside toward the rolling roll, and a plurality of roll driving units installed on the fixed support plates and rotating the rolling roll at different speeds.

[0012] In addition, among the rolling rolls constituting the first electrode forming machine, there are three or more rolling rolls arranged in a horizontal direction.

[0013] In addition, among the rolling rolls applied to the second electrode forming and coating machine, there are three or more rolling rolls arranged in a horizontal direction.

[0014] In addition, each of the above fixed support plates takes the form of a plate having a certain thickness and is perpendicular to the ground, and has an L-shaped mounting space portion formed by a passage extending horizontally through the thickness direction, a horizontal extension space extending horizontally, and a vertical extension space extending vertically and connected to an end of the horizontal extension space, and a roll support block that supports both ends of the rolling roll so as to be able to rotate about an axis is installed in the mounting space portion.

[0015] In addition, a gap adjustment unit is further included to adjust the gap between adjacent rolling rolls by adjusting the gap between the roll support blocks.

[0016] In addition, among the opposing surfaces of the neighboring roll support blocks in the above-mentioned mounting space, a pressure inclined surface inclined at a certain angle is formed on one or both opposing surfaces, and the gap adjustment unit is provided with a taper block that is interposed between the neighboring roll support blocks and contacts the roll support blocks, and a block driving unit that moves the taper block linearly so that the taper block presses the pressure inclined surface, thereby adjusting the gap of the roll support blocks.

[0017] In addition, the taper block has a female screw hole formed therein, and the block driving unit includes a screw rod that is supported rotatably on a fixed support plate and screw-connected to the female screw hole of the taper block, and a rod rotating unit that rotates the screw rod axially.

[0018] In addition, a spacing indicator is installed between adjacent roll support blocks within the above-mentioned mounting space to indicate the spacing between the roll support blocks.

[0019] In addition, a heating means for heating the above rolling roll is further included.

[0020] In addition, the second electrode forming and coating machine includes a pair of fixed support plates that provide support and are vertical to the ground and support the rolling roll and the coating roll in parallel, a hopper located on the upper portion of the rolling roll and that receives electrode powder provided from the outside and discharges it toward the rolling roll, and a roll driving unit that rotates the rolling roll and the coating roll.

[0021] In addition, each of the above fixed support plates takes the form of a plate having a certain thickness, and has an L-shaped mounting space portion consisting of a horizontal extension space of a certain width extending horizontally as a passage extending in the thickness direction, and a vertical extension space of a certain width extending vertically and connected to an end of the horizontal extension space, and a roll support block that supports both ends of the rolling roll and coating roll is accommodated in the mounting space portion so that the position thereof can be adjusted.

[0022] In addition, a gap adjustment unit is further included to adjust the gap between the adjacent rolling rolls, the gap between a pair of coating rolls, and the gap between the coating roll and the rolling roll by adjusting the gap between the roll support blocks.

[0023] In addition, a pressure inclined surface inclined with respect to a vertical plane or a horizontal plane is formed on one or both sides of the opposing surfaces of the neighboring roll support blocks within the above-mentioned mounting space, and the gap adjustment unit comprises: a taper block interposed between the neighboring roll support blocks and contacting the roll support blocks; and a block driving unit that moves the taper block linearly so that the taper block presses the pressure inclined surface, thereby adjusting the gap between the roll support blocks.

[0024] In addition, the taper block has a female screw hole formed therein, and the block driving unit has a screw rod that is supported rotatably on a fixed support plate and screw-connected to the female screw hole of the taper block, and a rod rotating unit that rotates the screw rod axially.

[0025] Additionally, a spacing indicator is installed between adjacent roll support blocks within the above-mentioned mounting space to indicate the spacing between the roll support blocks.

[0026] In addition, a heating means for heating the rolling roll and coating roll is further provided.

[0027] In addition, the rotation speed of the plurality of rolling rolls gradually increases from the uppermost rolling roll to the lowermost rolling roll, and the rotation speed of the coating roll is faster than the rotation speed of the lowermost rolling roll.

[0028] Additionally, the speeds of the pair of coating rolls are the same.

[0029] In addition, the tension control unit comprises: a dancer roll that comes into contact with the first electrode film and rises and falls according to changes in tension of the first electrode film; a sensor that detects changes in the position of the dancer roll; a controller that receives detection information from the sensor and outputs a control signal; and an actuator that operates by the controller to raise and lower the dancer roll so that the tension of the first electrode film is maintained constant.

[0030] In addition, the current collector supply unit comprises: a support structure providing support; a reel shaft supporting a current collector foil that is horizontally supported and wound on the support structure; and an unwinder that rotates the reel shaft, and the unwinder determines the rotation speed of the reel shaft based on a change in torque transmitted to the reel shaft according to a change in tension of the current collector foil.

[0031] In addition, the winding unit includes a winding shaft that is horizontally supported on a fixed support plate and winds the laminate, and a winder that rotates the winding shaft, and the winder determines the rotation speed of the winding shaft based on a change in torque transmitted to the winding shaft according to a change in tension of the laminate.

[0032] The dry electrode double-sided coating device of the present invention, which is constructed as described above, can continuously form a dry electrode film of uniform density and thickness through multi-stage rolls arranged in horizontal and vertical directions, and simultaneously laminate it to both sides of a current collector foil, thereby enabling the manufacture of a dry double-sided electrode having precise specifications.

[0033] FIG. 1 is a drawing showing the overall configuration of a dry electrode double-sided coating device according to one embodiment of the present invention.

[0034] Figure 2 is a drawing for explaining the structure and operating principle of the tension control unit of Figure 1.

[0035] Figures 3 and 4 are perspective views of a dry electrode double-sided coating device according to one embodiment of the present invention.

[0036] Figure 5 is a partially exploded perspective view of the coating device illustrated in Figure 3.

[0037] FIG. 6 is a drawing for explaining a gap adjustment method of each roll in a coating device according to one embodiment of the present invention.

[0038] Figure 7 is a perspective view separately illustrating the taper block illustrated in Figure 6.

[0039] Fig. 8 is an enlarged drawing showing the mounting structure of the dial gauge of Fig. 3.

[0040] FIG. 9 is a drawing for explaining the heating method of each roll in a coating device according to one embodiment of the present invention.

[0041] Hereinafter, one embodiment according to the present invention will be described in more detail with reference to the attached drawings.

[0042] FIG. 1 is a drawing showing the overall configuration of a dry electrode double-sided coating device (10) according to an embodiment of the present invention, FIG. 2 is a drawing for explaining the structure and operating principle of the tension control unit of FIG. 1, and FIGS. 3 and 4 are perspective views of a dry electrode double-sided coating device according to an embodiment of the present invention. In addition, FIG. 5 is a partially exploded perspective view of the coating device. In addition, FIG. 6 is a drawing for explaining a gap adjustment method of each roll in a coating device according to an embodiment of the present invention, FIG. 7 is a perspective view separately showing the taper block illustrated in FIG. 6, and FIG. 8 is an enlarged drawing showing the mounting structure of the dial gauge of FIG. 3. In addition, FIG. 9 is a drawing for explaining a heating method of each roll in a coating device according to an embodiment of the present invention.

[0043] As shown, the dry electrode double-sided coating device (10) according to the present embodiment includes a current collector supply unit (40), a first electrode forming machine (20), a tension control unit (37), a second electrode forming and coating machine (60), and a winding unit (70).

[0044] A double-sided coating device (10) is equipment for continuously producing a laminate (80) in which a positive electrode material or a negative electrode material is coated on both sides of a current collector foil (45). The laminate (80) is used in the production of a secondary battery through a subsequent process. The laminate (80) has a laminated structure composed of a current collector foil (45), a first electrode film (38), and a second electrode film (67). The first electrode film (38) and the second electrode film (67) are positioned on opposite sides with the current collector foil (45) interposed therebetween.

[0045] If the first electrode film (38) is a positive electrode material, the second electrode film (67) is also a positive electrode material, and if the second electrode film (38) is a negative electrode material, the second electrode film (67) is also a negative electrode material, with the same active material positioned with the current collector foil (45) in between.

[0046] The current collector supply unit (40) continuously supplies a current collector foil (45) of a predetermined width that is wound. In the case of the positive electrode, aluminum foil with a thickness of 6 to 14 ㎛ is used as the current collector material, and in the case of the negative electrode, copper foil with a thickness of 6 to 10 ㎛ is used.

[0047] The current collector foil (45) supplied from the current collector supply unit (40) passes between the coating rolls (63e, 63f) described later and is combined with the first electrode film (38) and the second electrode film (67).

[0048] The current collector supply unit (40) is placed between the first electrode forming machine (20) and the second electrode forming and coating machine (60), and has a support structure (41), a reel shaft (43d), and an unwinder (43).

[0049] The support structure (41) is positioned close to the fixed support plate (21) described later and supports the current collector foil (45). The support structure (41) is provided with a plurality of guide rolls (41a). The guide rolls (41a) guide the movement of the current collector foil (45).

[0050] The reel shaft (43d) supports a horizontally extended and wound current collector foil (45), as shown in Fig. 5. The reel shaft (43d) can be rotated about its axis by the unwinder (43).

[0051] The unwinder (43) has a torque output unit (43a), a belt (43b), and a driven pulley (43c). The unwinder (43) rotates the reel shaft (43d) so that the current collector foil (45) can be released.

[0052] The torque output unit (43a) is mounted on the support structure (41) and outputs rotational force. In addition, the driven pulley (43c) is a member fixed to the end of the reel shaft (43d) (the end of the reel shaft (43d) is connected to the driven pulley (43c) while passing horizontally through the support structure (41).) and is connected to the torque output unit (43a) via a belt (43b). For this purpose, the torque output unit (43a) is provided with a drive pulley (not visible) on which the belt (43b) is filled. When the torque output unit (43a) is driven to rotate the reel shaft (43d), the current collector foil (45) is unwound at a constant speed.

[0053] In particular, the control of the rotation speed of the reel shaft (43d) is determined based on the tension of the collector foil (45) transmitted to the reel shaft (43d). That is, when the tension of the collector foil (45) during transport becomes greater than the set tension, the rotation speed of the reel shaft increases, and conversely, when the tension of the collector foil becomes less than the set tension, the rotation speed of the horizontal shaft decreases. The control of the transport speed of the collector foil (45) is based on the change in the torque transmitted to the reel shaft (43d).

[0054] Meanwhile, the first electrode forming machine (20) rolls the electrode material powder (90) to form a first electrode film (38) to be coated on one side (bottom surface in the drawing) of the current collector foil.

[0055] The first electrode forming machine (20) includes a fixed support plate (21), a hopper (22), a plurality of rolling rolls (23a to 23f), and a roll driving unit (33).

[0056] The fixed support plates (21) are plate-shaped members that provide support, are vertical to the ground, and are spaced apart from each other. The fixed support plates (21) are made of steel and have a thickness of 70 mm or more. The fixed support plates (21) are paired in pairs, and a rolling roll is accommodated between them. The dimensions and shapes of the fixed support plates (21) on both sides are identical.

[0057] In addition, each fixed support plate (21) is provided with a mounting space (21c). The mounting space (21c) is an 'ㄱ' shaped passage (hole) that penetrates in the thickness direction of the fixed support plate (21). As illustrated in Fig. 5, the mounting space (21c) has a horizontal extension space (21a) that extends horizontally and a vertical extension space (21b) that is connected to the end of the horizontal extension space (13a) and extends vertically. The horizontal extension space (21a) and the vertical extension space (21b) each have a constant width and are bent at a right angle.

[0058] In addition, three vertical passages (21f) are provided on the upper part of the horizontal extension space (21a). The vertical passages (21f) are holes into which male screw rods (27a) are mounted. The male screw rods (27a) can rotate about an axis while being accommodated in the vertical passages (21f). In addition, four horizontal passages (21e) are formed on the side of the vertical extension space (21b). The horizontal passages (21e) are holes through which male screw rods (27a) pass. The male screw rods (27a) can rotate about an axis while being accommodated in the horizontal passages (21e).

[0059] In addition, a plurality of roll support blocks (24) are installed in the mounting space (21c) to support both ends of the first rolling roll (23a) to the sixth rolling roll (23f) so as to be able to rotate about an axis. The roll support blocks (24) are square plates having the same thickness as the fixed support plate (21) and are symmetrical with the first rolling roll (23a) to the sixth rolling roll (23f) interposed therebetween. The roll support blocks (24) are positionally adjustable by contacting the inner surface of the mounting space (21c).

[0060] In this embodiment, a total of six roll support blocks (24) are applied. Among the plurality of roll support blocks (24), the roll support block (24) located at the corner where the horizontal extension space (21a) and the vertical extension space (21b) meet is fixed and does not move, and serves as a reference point for the remaining roll support blocks (24). The internal angle of the lower left corner of the roll support block (24) fixed at the corner forms a right angle.

[0061] The remaining two roll support blocks (24) accommodated in the horizontal extension space (21a) can be positionally adjusted in the horizontal direction. In addition, the three roll support blocks (24) installed in the vertical extension space (21b) can be spaced vertically below the roll support blocks (24) fixed to the corners.

[0062] In addition, a separation prevention plate (25) is fixed to the edge of each roll support block (24). The separation prevention plate (25) prevents the roll support block (24) from falling out of the fixed support plate (21).

[0063] In addition, as illustrated in Fig. 6, an end block (29) is fixed to the left end of the horizontal extension space (21a) and the lower floor of the vertical extension space (21b), respectively. The end block (29) is a member that interfaces with the tapered block (28) described later. A support slope (29a) is formed on the end block (23) provided in the horizontal extension space (13a).

[0064] In particular, a pressure inclined surface (24a) inclined at a certain angle is formed on one or both sides of the adjacent roll support blocks (24) (excluding the roll support blocks (24) fixed to the corners mentioned above) within the mounting space (21c). The opposed surface means a surface facing each other between the adjacent roll support blocks (24).

[0065] Referring to Fig. 6, the roll support block (24) located directly below the roll support block fixed to the corner has a pressure inclined surface (24a) on both the upper and lower surfaces. In contrast, the remaining roll support blocks (24) have a pressure inclined surface (24a) on one side facing surface and a guide plane (24b) on the opposite side facing surface.

[0066] The pressure inclined surface (24a) is an inclined plane inclined at a certain angle with respect to a vertical plane or a horizontal plane. That is, in the case of the roll support block (24) accommodated in the horizontal extension space (21a), the pressure inclined surface (24a) is inclined at a certain angle with respect to an imaginary vertical plane, and the guide plane (24b) is parallel to the vertical line. In addition, the pressure inclined surface (24a) of the roll support block (24) installed in the horizontal extension space (21b) is inclined at a certain angle with respect to an imaginary horizontal plane, and the guide plane (24b) is horizontal.

[0067] Meanwhile, the first rolling roll (23a) to the sixth rolling roll (23f) are members whose ends are axially supported on a roll support block (24). The first rolling roll to the sixth rolling roll are arranged parallel to each other between the fixed support plates (21), some are arranged horizontally, and the rest are arranged vertically. In other words, they have an 'ㄱ'-shaped arrangement pattern. The rolling rolls pass the electrode powder (90) supplied from the hopper (22) through them and roll them to form them into a film shape.

[0068] In this embodiment, among the six rolling rolls, three are arranged horizontally. The remaining rolling rolls are arranged vertically. By arranging some of the rolling rolls horizontally, the electrode powder receiving structure can be simplified. To receive the electrode powder, a hopper simply needs to be installed on top of the rolling rolls. Furthermore, by arranging some of the rolling rolls vertically, the overall size of the equipment is reduced, resulting in a compact configuration and improved maintainability.

[0069] The advantage of arranging the rolling rolls in an 'ㄱ' shape is also present in the second electrode forming and coating machine.

[0070] The gap between the fifth rolling roll (23e) and the sixth rolling roll (23f) is narrower than the gap between the fourth rolling roll (23d) and the fifth rolling roll (23e). In addition, the gap between the fourth and fifth rolling rolls (23d, 23e) is narrower than the gap between the third and fourth rolling rolls (23c, 23d). Similarly, the gap between the third and fourth rolling rolls is narrower than the gap between the second and third rolling rolls, and the gap between the second and third rolling rolls is narrower than the gap between the first and second rolling rolls.

[0071] And, the rotation speed of the first rolling roll (23a) from the fifth rolling roll (23e) gradually decreases, and the rotation speeds of the fifth rolling roll (23e) and the sixth rolling roll (23f) are the same. The rotation speeds of the fifth and sixth rolling rolls (23e, 24f) depend on the rotation speed of the coating rolls (63e, 63f) described later. When the rotation speed of the coating rolls (63e, 63f) increases, the rotation speed also increases, and when it decreases, the rotation speed also decreases.

[0072] The first rolling roll (23a) to the sixth rolling roll (23f) are individually rotated by the roll driving unit (33). As illustrated in Fig. 4, the roll driving unit (33) is located on the outside of the one-side fixed support plate (21) and is independently driven to output rotational force. By the roll driving unit (33), the first rolling roll (23a) to the sixth rolling roll (15d) can be rotated at different speeds.

[0073] In addition, the first to sixth rolling rolls are heated by a heating means. In the present embodiment, a heater rod (26 in Fig. 9) is used as the heating means. The heater rod (26) is a heating member built into each rolling roll, and generates heat by externally supplied power to heat the rolling roll to a temperature of 200°C or lower. The rolling roll can maintain a temperature range from room temperature to 200°C by the heater rod.

[0074] In addition, the hopper (22) is installed on the upper part of the rolling roll, receives the electrode powder (90) provided from the outside, and discharges it downward. The electrode powder (90) discharged from the hopper (22) enters between the first rolling roll (23a) and the second rolling roll (23b) and begins to be rolled. The electrode powder (90) passes between the first and second rolling rolls (23a, 23b), between the second and third rolling rolls, between the third and fourth rolling rolls, between the fourth and fifth rolling rolls, and between the fifth and sixth rolling rolls, becomes thinner and is formed into a film shape, and then departs toward the second electrode forming and coating machine (60).

[0075] Meanwhile, a gap adjustment unit is further included to adjust the gap of the above rolling rolls. The gap adjustment unit adjusts the gap between adjacent rolling rolls (supported by the roll support blocks) by adjusting the gap between the roll support blocks (24).

[0076] The gap adjustment unit is equipped with a taper block (28) and a block driving unit. The taper block (28) is interposed between the roll support block (24) and the end block (29) and is a member that contacts the roll support block and the end block.

[0077] The taper block (28) has a shape roughly hexahedral and has a shape illustrated in Fig. 7. As illustrated, the taper block (28) has a pressure surface (28b) on the upper surface and a support surface (28c) on the lower surface. The pressure surface (28b) contacts the pressure inclined surface (24a) described above, and the support surface (28c) contacts the guide plane (24b). The taper block (28) also contacts the end block (29) as illustrated in Fig. 6. In addition, a female thread (28a) is formed inside the taper block (28). The female thread (28a) is a passage formed with a female thread and is screw-connected to a male thread rod (27a).

[0078] The block driving unit (27) causes the taper block (28) to move linearly, so that the taper block (28) presses the pressure slope (24a) to adjust the gap of the roll support block (24). The block driving unit includes a male screw rod (27a) and a handle (27b) as a rod rotation unit.

[0079] The male screw rod (27a) is a straight member that is rotatably supported on the fixed support plate (21) and screw-connected to the female screw hole (28a) of the taper block (28). In addition, the handle (27b) is manually operated by the operator. In some cases, the block driving unit (27) can be configured as an electric type. For example, an electric type implementation is possible by applying a servo motor instead of the handle (27b). Ultimately, the gap of the roll support block (24) is adjusted by rotating the handle (27b).

[0080] The spacing between the roll support blocks (24) can be determined through the spacing indicator. The spacing indicator is installed between adjacent roll support blocks and indicates the spacing between the roll support blocks. In this embodiment, the spacing indicator is a dial gauge (31).

[0081] As shown in Fig. 8, in order to apply the dial gauge (31), a first measuring block (32a) is mounted on one side of the roll support block (24) (among the neighboring roll support blocks), and a second measuring block (32b) is mounted on the other side of the roll support block (24). The main body (31a) of the dial gauge (31) is fixed to the second measuring block (32b), and the sensor button (31c) is in elastic contact with the first measuring block (32a). When the gap of the roll support blocks (24) changes, the sensor button (31c) moves, and the gap value after the change is displayed on the scale on the front of the main body (31a). The operator adjusts the gap of the roll support blocks while looking at the dial gauge (31).

[0082] Meanwhile, the tension control unit (37) controls the tension of the first electrode film (38) being transferred from the first electrode forming machine (20) to the second electrode forming and coating machine (60). The tension control unit (37) includes a dancer roll (37g), a dancer arm (37f), a sensor (37a), a controller (37c), and an actuator (37e).

[0083] The dancer roll (37g) is a roll that is installed at one end of the dancer arm (37f) to enable rolling motion and supports the first electrode film (38) on its upper portion. The dancer roll (37g) is in contact with the first electrode film and moves up and down according to changes in the tension of the first electrode film. The first electrode film (38), which is supported by a plurality of guide rolls (35) and transported, passes through the upper portion of the dancer roll (37g).

[0084] The above dancer arm (37f) is a rod-shaped member extending in the longitudinal direction and is mounted to a fixed support plate (21) via a support pin (37d). The dancer arm (37f) can rotate about the support pin (37d) as the center of rotation.

[0085] The actuator (37e) is positioned on the opposite side of the dancer roller (37g) with the support pin (37d) in the center. The piston rod of the actuator (37e) is linked to the dancer arm (37f) to rotate the dancer arm. The dancer roller (37g) can be moved up and down by the actuator (37e). An air cylinder can be used as the actuator (37e).

[0086] In addition, the sensor (37a) detects a change in the position of the dancer roll (37g). For example, if the tension of the first electrode film (38) during transport increases, the dancer roll (37g) descends, and this descending is detected. The controller (37c) is connected to the sensor (37a), receives the detection information of the sensor (37a), and outputs a control signal. The control signal of the controller (37c) is transmitted to the actuator (37e).

[0087] The actuator (37e) is operated by the controller (37c) to move the dancer roll by adjusting the angle of the dancer arm (37f). The reason for moving the dancer roll (37g) is to maintain the tension of the first electrode film (38) constant. This control method is a typical PID control (proportional integral derivative control) method.

[0088] The first electrode film (38) that has passed through the tension control unit (37) enters between the coating rolls (63e, 63f) of the second electrode forming and coating machine (60) via the guide roll (41a) of the current collector supply unit (40).

[0089] The second electrode forming and coating machine (60) performs two operations: forming a second electrode film (67) to be coated on the other side (upper side in the drawing) of the current collector foil (45) by rolling the electrode material powder (90), and simultaneously passing and pressing the formed second electrode film (67), the current collector foil (45), and the first electrode film (38). In other words, it performs forming and coating of the second electrode.

[0090] The second electrode forming and coating machine (60) has almost the same configuration as the first electrode forming machine (20) described above.

[0091] Hereinafter, the same drawing symbols as the above-mentioned drawing symbols indicate the same components with the same functions, and for convenience, a repeated description thereof is omitted.

[0092] As shown, the second electrode forming and coating machine (60) is equipped with a pair of fixed support plates (21), a hopper (22), a plurality of rolling rolls (63a to 63d), a pair of coating rolls (63e, 63f), and a roll driving unit (33).

[0093] The fixed support plates (21) are formed in pairs of two, are perpendicular to the ground, and are spaced apart from each other. In addition, an L-shaped mounting space (21c) is provided on each fixed support plate (21), and a number of roll support blocks (24), taper blocks (28), and end blocks (29) are installed within the mounting space (21c).

[0094] A gap adjustment unit is also applied to the second electrode forming and coating machine (60). The gap adjustment unit has a taper block (28) that is interposed between adjacent roll support blocks (24) and contacts the roll support blocks, and a block driving unit (27) that moves the taper block linearly so that the taper block presses the pressure slope, thereby adjusting the gap between the roll support blocks.

[0095] The above rolling rolls are composed of the first rolling roll (63a) to the fourth rolling roll (63d). The first, second, third, and fourth rolling rolls (63a, 63b, 63c, 63d) are individually rotated by the roll driving unit (33). Each rolling roll is supported on a roll support block (24) so ​​as to be able to rotate about its axis and is parallel to one another.

[0096] In addition, the first, second, and third rolling rolls (63a, 63b, and 63c) are arranged horizontally, and the third rolling roll (63c) and the fourth rolling roll (63) are arranged vertically. The third rolling roll (63c) is located at a corner of the mounting space (21c) and only rotates about its axis and does not move up, down, left, or right. The first, second, third, and fourth rolling rolls roll the electrode material powder supplied from the hopper (22) to form a second electrode film.

[0097] After passing between the first, second, third, and fourth rolling rolls, the second electrode film (67) that is formed by passing between the fourth rolling roll and the upper coating roll passes between the coating rolls (63e, 63f) together with the current collector foil (45) and the first electrode film (38). The first electrode film (38), the current collector foil (45), and the second electrode film (67) pass through the coating rolls (63e, 63f) and are combined to form a laminate (80). The laminate (80) is moved to the winding unit (70) and wound.

[0098] The above coating rolls (63e, 63f) are arranged in pairs and vertically below the fourth rolling roll (63d). The coating rolls (63e, 63f) are also driven by the roll drive unit (33). The rotation speed of the coating rolls (63e, 63f) is faster than the rotation speed of the fourth rolling roll. In addition, the rotation speeds of the coating rolls are the same, and only the rotation directions are opposite.

[0099] By the roll drive unit (33), the first rolling roll (63a) to the fourth rolling roll (63d) and the coating rolls (63e, 63f) rotate at different rotation speeds.

[0100] For example, the second rolling roll (63b) rotates 50% faster than the rotation speed of the first rolling roll (63a), the third rolling roll (63c) rotates 50% faster than the second rolling roll (63b), and the fourth rolling roll (63d) rotates 50% faster than the third rolling roll (63c). In addition, the upper coating roll (63e) rotates 50% faster than the fourth rolling roll (63d). However, as described above, the speed of the lower coating roll (63f) is the same as the speed of the upper coating roll. In addition, the speed of the coating roll (63e) is the same as the rotation speed of the fifth and sixth rolling rolls (23e, 23f) of the first electrode forming machine (20).

[0101] Ultimately, the rotation speed of the multiple rolling rolls gradually increases from the uppermost rolling roll to the lowermost rolling roll, and the rotation speed of a pair of coating rolls is faster than the rotation speed of the lowermost rolling roll.

[0102] Meanwhile, the winding unit (70) winds the laminated body (80) that passes through the second electrode forming and coating machine (60).

[0103] The winding unit (70) includes a winding shaft (71d) and a winder (71).

[0104] The winding shaft (71d) is supported horizontally on a fixed support plate (21) and receives rotational force from the winder (71) to rotate around its axis and wind the laminate (80). In addition, the winder (71) determines the rotational speed of the winding shaft based on a change in torque transmitted to the winding shaft (71d) according to a change in tension of the laminate (80).

[0105] In addition, the winder (71) includes a torque output unit (71a), a belt (71b), and a driven pulley (71c). The torque output unit (71a) outputs rotational force while being fixed to the outer side of the fixed support plate (21). In addition, the driven pulley (71c) is fixed to the end of the winding shaft (71d) and is connected to the torque output unit (71a) via a belt (71b). The torque output unit (71a) is provided with a drive pulley (not shown) on which the belt (71b) is filled. When the torque output unit (71a) is driven to rotate the winding shaft (71d), the laminate (80) is wound.

[0106] As with the current collector supply unit (40), the rotation speed of the take-up shaft (71d) is determined by the tension of the laminate (80) transmitted to the take-up shaft (71d). That is, when the tension of the laminate (80) during transport becomes greater than the set tension, the rotation speed of the take-up shaft (71d) increases, and when the tension becomes less than the set tension, the rotation speed of the take-up shaft (71d) decreases.

[0107] The operation of the dry electrode double-sided coating device (10) of this embodiment configured as described above is as follows.

[0108] First, electrode powder (90) is supplied to the hopper (22), and then the first electrode forming machine (20) and the second electrode forming and coating machine (60) are driven. At the same time, the current collector supply unit (40) is also driven to supply the current collector foil (45).

[0109] Accordingly, the electrode material powder supplied to the hopper (22) of the first electrode forming machine (20) is processed into a very thin layer while passing through the first rolling roll (23a) to the sixth rolling roll (23f). The first electrode film (38) exiting the first electrode forming machine passes through the tension control unit (37) and the collector supply unit (40) and enters between the coating rolls (63e, 63f).

[0110] While this process is in progress, a second electrode film (67) is produced in the second electrode forming and coating machine (60), and the produced second electrode film (67) is guided between the coating rolls (63e, 63f). At the same time, the current collector foil (45) also enters between the coating rolls.

[0111] Finally, a second electrode film (67) is laminated on the upper surface of the current collector foil (45), and a first electrode film (38) is laminated on the lower surface. The laminate composed of the current collector foil and the first and second electrode films is compressed while passing through a coating roll (63e, 63f), and then wound on a winding unit (70).

[0112] Above, the present invention has been described in detail through specific examples, but the present invention is not limited to the above examples, and various modifications are possible by a person of ordinary skill within the scope of the technical idea of ​​the present invention.

[0113] It is industrially applicable because it allows for the continuous formation of a dry electrode film of uniform density and thickness through multi-stage rolls arranged in horizontal and vertical directions, and simultaneous lamination on both sides of a current collector foil.

Claims

1. A current collector supply unit that continuously supplies a current collector foil of a certain width that is wound; A first electrode forming machine having a plurality of rolling rolls arranged in a mutually parallel state, some arranged horizontally and others arranged vertically, having an overall L-shaped arrangement structure, and forming a first electrode film to be coated on one side of the current collector foil by passing and rolling electrode material powder therethrough; A second electrode forming and coating machine having a plurality of rolling rolls that form the second electrode film by rolling electrode powder to coat the other side of the current collector foil, and simultaneously passing and pressing the formed second electrode film, the current collector foil provided from the current collector supply unit, and the first electrode film delivered from the first electrode forming machine, and having an overall L-shaped arrangement structure with some of the rolling rolls arranged horizontally and the rest arranged vertically in a state parallel to each other to form the second electrode film, and a pair of coating rolls arranged vertically below the lowest rolling roll and passing the current collector and the first and second electrode films; A tension control unit for controlling the tension of a first electrode film transferred from a first electrode forming machine to a second electrode forming and coating machine; A winding unit that winds the laminated body while passing through the second electrode forming and coating machine is included. Dry electrode double-sided coating device.

2. In paragraph 1, In the first electrode forming machine; A pair of fixed support plates that provide support and are perpendicular to the ground and rotatably support the rolling rolls, A hopper installed on the upper part of the rolling roll and discharging electrode powder supplied from the outside toward the rolling roll side, It is installed on a fixed support plate and has a plurality of roll driving units that rotate the rolling rolls at different speeds. Dry electrode double-sided coating device.

3. In paragraph 1, Among the rolling rolls constituting the first electrode forming machine, there are three or more rolling rolls arranged in a horizontal direction. Dry electrode double-sided coating device.

4. In paragraph 1, Among the rolling rolls applied to the second electrode forming and coating machine, there are three or more rolling rolls arranged in a horizontal direction. Dry electrode double-sided coating device.

5. In paragraph 2, Each of the above fixed support plates, It takes the form of a plate that is perpendicular to the ground and has a certain thickness, and has a L-shaped mounting space that is formed by a passage that penetrates in the direction of the thickness, a horizontal extension space that extends horizontally, and a vertical extension space that is connected to the end of the horizontal extension space and extends vertically. In the mounting space, a roll support block is installed to support both ends of the rolling roll so that they can rotate. Dry electrode double-sided coating device.

6. In paragraph 5, A gap adjustment unit is further included to adjust the gap between adjacent rolling rolls by adjusting the gap between the above roll support blocks. Dry electrode double-sided coating device.

7. In paragraph 6, Among the opposing surfaces of the adjacent roll support blocks within the above-mentioned mounting space, a pressure slope inclined at a certain angle is formed on one or both opposing surfaces, The above gap adjustment unit; A tapered block that is interposed between adjacent roll support blocks and is interviewed by the roll support blocks, A block driving unit is provided that moves the taper block in a linear manner, thereby allowing the taper block to pressurize the pressure slope and adjust the gap between the roll support blocks. Dry electrode double-sided coating device.

8. In paragraph 7, The above taper block has a female screw hole formed, In the above block driving part, A screw rod that is supported rotatably on a fixed support plate and is screwed into the female screw hole of the taper block, Includes a rod rotating part that rotates the screw rod. Dry electrode double-sided coating device.

9. In paragraph 6, Between adjacent roll support blocks within the above mounting space, Equipped with a spacing indicator that indicates the spacing of the roll support blocks, Dry electrode double-sided coating device.

10. In paragraph 2, Further comprising a heating means for heating the above rolling roll, Dry electrode double-sided coating device.

11. In paragraph 1, The above second electrode forming and coating machine; A pair of fixed support plates that provide support and are vertical to the ground and support the rolling roll and coating roll in parallel, A hopper located on the upper part of the rolling roll, which receives electrode powder supplied from the outside and discharges it toward the rolling roll side, Including a roll driving unit that rotates the above rolling roll and coating roll, Dry electrode double-sided coating device.

12. In paragraph 11, Each of the above fixed support plates, It takes the form of a plate with a certain thickness, and has a L-shaped mounting space portion consisting of a horizontal extension space of a certain width extended horizontally as a passage extending in the direction of the thickness, and a vertical extension space of a certain width extended vertically and connected to the end of the horizontal extension space. In the mounting space, a roll support block that supports both ends of the rolling roll and coating roll is accommodated so that the position thereof can be adjusted. Dry electrode double-sided coating device.

13. In paragraph 12, A gap adjustment unit is further included to adjust the gap between adjacent rolling rolls, the gap between a pair of coating rolls, and the gap between the coating roll and the rolling roll by adjusting the gap between the above roll support blocks. Dry electrode double-sided coating device.

14. In paragraph 13, A pressure inclined surface inclined with respect to a vertical or horizontal plane is formed on one or both sides of the opposing surfaces of the adjacent roll support blocks within the above-mentioned mounting space, The above gap adjustment unit; A tapered block that is interposed between adjacent roll support blocks and is interviewed by the roll support blocks, A block driving unit is provided that moves the taper block in a linear manner, thereby allowing the taper block to pressurize the pressure slope and adjust the gap between the roll support blocks. Dry electrode double-sided coating device.

15. In paragraph 14, The above taper block has a female screw hole formed, The above block driving part is, A screw rod that is supported rotatably on a fixed support plate and is screwed into the female screw hole of the taper block, Having a rod rotation part that rotates the screw rod, Dry electrode double-sided coating device.

16. In paragraph 15, Between the adjacent roll support blocks within the above mounting space, Equipped with a spacing indicator that indicates the spacing of the roll support blocks, Dry electrode double-sided coating device.

17. In paragraph 11, Further provided is a heating means for heating the above rolling roll and coating roll. Dry electrode double-sided coating device.

18. In paragraph 11, The rotation speed of the above plurality of rolling rolls is The rotation speed of the coating roll gradually increases from the uppermost rolling roll to the lowermost rolling roll, and the rotation speed of the coating roll is faster than the rotation speed of the lowermost rolling roll. Dry electrode double-sided coating device.

19. In paragraph 18, The speeds of the above pair of coating rolls are the same. Dry electrode double-sided coating device.

20. In paragraph 1, The above tension control unit; A dancer roll that rises and falls according to the change in tension of the first electrode film when in contact with the first electrode film, A sensor that detects changes in the position of the dancer roll, A controller that receives detection information from a sensor and outputs a control signal, Equipped with an actuator that is operated by a controller to raise and lower the dancer roll so that the tension of the first electrode film is maintained constant. Dry electrode double-sided coating device.

21. In paragraph 1, The above-mentioned power supply unit; It comprises a support structure that provides support, a reel shaft that supports a current collector foil that is horizontally supported and wound on the support structure, and an unwinder that rotates the reel shaft. The unwinder is; The rotation speed of the reel shaft is determined based on the change in torque transmitted to the reel shaft according to the change in tension of the current collector foil. Dry electrode double-sided coating device.

22. In paragraph 21, The above winding part; It is supported horizontally on a fixed support plate and includes a winding shaft for winding the laminate, and a winder for rotating the winding shaft. The winder; The rotation speed of the winding shaft is determined based on the change in torque transmitted to the winding shaft according to the change in tension of the laminate. Dry electrode double-sided coating device.

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