JP6036324B2 - Storage device manufacturing apparatus and manufacturing method - Google Patents

Description

  The present invention relates to an apparatus and method for manufacturing a power storage device including an electrode having an active material layer coated on the surface of a metal foil.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with secondary batteries such as lithium-ion batteries as power storage devices that store power supplied to the motors that serve as prime movers. This type of secondary battery has a positive electrode and a negative electrode having an active material layer on a metal foil, and has an electrode assembly in which the positive electrode and the negative electrode are insulated with a separator and stacked in layers. .

  The active material layer is formed by applying a slurry containing at least an active material and a binder on a metal foil in a predetermined pattern (application process) and drying it (drying process). Conventionally, in order to increase the binding force between the metal foil and the active material layer, a technique for segregating the binder near the interface between the metal foil and the active material layer has been proposed (Patent Document 1 and Patent Document 2 below). reference)

  While the slurry is being dried in the drying step, depending on the drying conditions, a phenomenon called “skinning” occurs in which drying proceeds locally on the surface of the slurry. Then, the binder is unevenly distributed on the surface side of the slurry and precipitates. Such uneven distribution of the binder on the surface side of the slurry causes a decrease in the adhesion of the active material layer to the metal foil, causing a decrease in power storage performance and a decrease in yield due to dropping of the active material layer in post-processing. Become.

  Therefore, conventionally, in order to prevent the uneven distribution of the binder, a technique is known in which the coating film is slowly dried over a relatively long time in the drying process. Specifically, a drying condition is adopted in which the temperature is changed from a low temperature to a high temperature (or the warm air is changed from a weak wind to a strong wind) with a very gentle gradient from the beginning to the end of the drying process.

JP 2009-4181 A JP 2011-216227 A Japanese Patent No. 4571842

  However, under the conventional drying conditions described above, it is difficult to improve productivity because there is a limit to shortening the drying time. Instead of shortening the drying time, it is possible to increase the length of the metal foil that can be dried at the same time by lengthening the drying line of the drying equipment, but in this case, the equipment investment is increased.

  Such a problem may occur not only in the secondary battery but also in other power storage devices such as an electric double layer capacitor.

  Accordingly, an object of the present invention is to provide a power storage device manufacturing apparatus and a manufacturing method in which the adhesion of the active material layer is improved while shortening the drying time of the slurry to be the active material layer. .

  An apparatus for manufacturing a power storage device according to the present invention is a power storage device manufacturing apparatus for manufacturing a power storage device including an electrode having an active material layer coated on a surface of a metal foil, the active material to be an active material layer, and A drying furnace disposed on a metal foil transport path to which a slurry containing a binder is applied, and a surface on the opposite side of the surface of the metal foil transported in the drying furnace from the surface to which the slurry is applied. First heating means for heating, and gradually lowers the temperature at which the first heating means heats the opposite surface of the metal foil from the upstream side to the downstream side of the transport path.

  In this power storage device manufacturing apparatus, the slurry to be an active material layer conveyed through the drying furnace by the first heating means for heating the opposite surface of the metal foil is not the surface side but the metal foil. Drying proceeds from the side. Therefore, the binder contained in the slurry is unevenly distributed and deposited on the metal foil side, and high adhesion of the active material layer to the metal foil is realized. At this time, when the heating temperature of the first heating means is increased in order to shorten the drying time, the above-described skinning is unlikely to occur, so that the drying time can be easily shortened. In addition, since the heating temperature of the metal foil by the first heating means gradually decreases from the upstream side to the downstream side of the conveyance path, the metal foil side slurry is preferentially and locally dried at the initial stage of drying. Thereafter, the slurry can be totally dried.

  Moreover, it has the 2nd heating means which heats the surface where the slurry was apply | coated among the surfaces of the metal foil conveyed in the drying furnace, and the 2nd heating means heats the surface where the slurry of metal foil was apply | coated. The temperature which performs gradually may be raised from the upstream of a conveyance path to the downstream. In this case, the surface side of the slurry can be more reliably dried at the end of drying.

  Further, in the drying furnace, a metal foil is transported along the transport path, and includes a plurality of rollers that support the metal foil from the opposite surface, and the first heating means heats the roller to provide the metal foil. The aspect which heats the surface on the opposite side may be sufficient. In this case, the opposite surface can be effectively heated by the roller in contact with the opposite surface of the metal foil.

  Further, in the drying furnace, a belt for transporting the metal foil along the transport path and supporting the metal foil from the opposite surface is provided, and the first heating means is opposite to the metal foil by heating the belt. The aspect which heats the surface of a side may be sufficient. In this case, the opposite surface can be effectively heated by the belt in contact with the opposite surface of the metal foil.

  The aspect which is a some spraying means which sprays warm air on the surface on the opposite side of metal foil, and a 1st heating means may be sufficient. In this case, the surface on the opposite side can be remotely heated without providing a member in contact with the surface on the opposite side of the metal foil.

  A method for manufacturing a power storage device according to the present invention is a method for manufacturing a power storage device including an electrode in which an active material layer is coated on a surface of a metal foil, and includes an active material to be an active material layer and a binder. A coating step for applying the slurry to the metal foil, and a drying step for drying the slurry by heating the surface of the metal foil opposite to the surface on which the slurry is applied. The temperature at which the opposite surface of the metal foil is heated is gradually lowered from the initial stage to the final stage.

  In this power storage device manufacturing method, during the drying process, the slurry applied to the surface of the metal foil proceeds from the metal foil side, not the surface side. Therefore, the binder contained in the slurry is unevenly distributed and deposited on the metal foil side, and high adhesion of the active material layer to the metal foil is realized. At this time, when the heating temperature in the drying process is increased in order to shorten the drying time, the above-described skinning is unlikely to occur, so that the drying time can be easily shortened. In addition, since the heating temperature gradually decreases from the initial stage to the final stage in the drying process, the metal foil side slurry is preferentially and locally dried in the initial stage of drying, and then the slurry is entirely dried. Can do.

  Moreover, the aspect which heats also the surface to which the slurry was apply | coated among the surfaces of metal foil in the drying process, and the temperature which heats the surface to which the slurry was apply | coated may be gradually raised from the initial stage to the end. In this case, the surface side of the slurry can be more reliably dried at the end of drying.

  Note that the power storage device may be a secondary battery.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing apparatus and manufacturing method of an electrical storage apparatus with which the adhesiveness of the active material layer was improved, aiming at shortening of the drying time of the slurry which should become an active material layer are provided.

FIG. 1 is a perspective view illustrating an appearance of a secondary battery according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing components of the electrode assembly of the secondary battery shown in FIG. FIG. 3 is a view schematically showing the secondary battery manufacturing apparatus shown in FIG. FIG. 4 is a graph showing a heating state of the drying furnace shown in FIG. FIG. 5 is a diagram showing a state of segregation of the binder contained in the slurry. FIG. 6 is a view showing a manufacturing apparatus of a different mode. FIG. 7 is a view showing a manufacturing apparatus of a different mode.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected about the same or equivalent element, and the description is abbreviate | omitted when description overlaps.

  As shown in FIG. 1, in a secondary battery 10 as a power storage device, an electrode assembly 12 is accommodated in a case 11. The case 11 includes a rectangular parallelepiped main body member 13 and a rectangular flat plate-shaped lid member 14 that closes an opening of the main body member 13. Both the main body member 13 and the lid member 14 constituting the case 11 are made of metal (for example, stainless steel or aluminum). Further, the secondary battery 10 of the present embodiment is a prismatic battery whose appearance is square. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  The electrode assembly 12 includes a positive electrode terminal 15 and a negative electrode terminal 16 that are electrically connected to the electrode assembly 12. The positive electrode terminal 15 and the negative electrode terminal 16 are each attached with a ring-shaped insulating ring 17 a for insulating from the case 11.

  As shown in FIG. 2, the electrode assembly 12 insulates the positive electrode 18 as a sheet-like first electrode, the negative electrode 19 as a sheet-like second electrode, and the positive electrode 18 and the negative electrode 19 from each other. A sheet-like separator 20. The electrode assembly 12 is a laminate in which the separators 20 are disposed between the positive electrode 18 and the negative electrode 19 in a layered manner. The electrode assembly 12 is configured by alternately stacking a plurality of positive electrodes 18 and a plurality of negative electrodes 19. That is, the electrode assembly 12 is provided with a plurality of sets each including the positive electrode 18, the negative electrode 19, and the separator 20.

  As shown in FIG. 2, the positive electrode 18 includes a positive metal foil 21 and a positive electrode active material layer 22. Further, a positive electrode tab 23 made of a positive electrode metal foil 21 protrudes from the edge 18 a of the positive electrode 18. The positive electrode active material layer 22 is not formed on the positive electrode tab 23. The positive electrode tab 23 is a terminal connection portion that is electrically connected to the positive electrode terminal 15. The positive electrode tab 23 is formed in the same position and in the same shape in each positive electrode 18 constituting the electrode assembly 12.

  As shown in FIG. 2, the negative electrode 19 has a negative metal foil 25 and a negative electrode active material layer 26. Further, a negative electrode tab 27 made of a negative electrode metal foil 25 protrudes from the edge 19 a of the negative electrode 19. The negative electrode active material layer 26 is not formed on the negative electrode tab 27. The negative electrode tab 27 is a terminal connection part that is electrically connected to the negative electrode terminal 16. The negative electrode tab 27 is formed in the same shape at the same position in each negative electrode 19 constituting the electrode assembly 12. The negative electrode tab 27 is formed at a position where it does not overlap the positive electrode tab 23 when the positive electrode 18 and the negative electrode 19 are overlapped.

  A conductive material such as aluminum, copper, nickel, iron, and stainless steel can be used for the metal foil. For example, an aluminum foil can be used for the positive electrode metal foil 21, while a copper foil can be used for the negative electrode metal foil 25.

  The positive electrode active material layer 22 is a mixture of a positive electrode active material, a conductive additive, and a binder (binder), and a positive electrode slurry S1 as an electrode material kneaded by adding a solvent is applied to the positive electrode metal foil 21 and dried. It is formed by letting. Similarly, the negative electrode active material layer 26 is obtained by applying a negative electrode slurry S2 as an electrode material obtained by mixing a negative electrode active material, a conductive additive, and a binder, adding a solvent, and kneading the mixture to the negative electrode metal foil 25 and drying it. Formed with. The positive electrode slurry S1 and the negative electrode slurry S2 are slurry-like or paste-like materials prepared to have a predetermined viscosity.

  As the positive electrode active material, lithium transition metal oxides such as lithium manganate, lithium cobaltate, and lithium nickelate can be used. As the negative electrode active material, carbon or a lithium transition metal oxide can be used. As carbon, hard carbon, carbon black, or the like can be used. As the conductive auxiliary agent, acetylene black or the like can be used. As the binder, PVdF (polyvinylidene fluoride) or the like can be used. As the solvent, NMP (normal methyl pyrrolidone) or the like can be used.

  The positive electrode 18 and the negative electrode 19 are different in the material of the metal foil and the composition of the active material layer, but the configuration is the same. Therefore, in the following description, the positive electrode 18 and the negative electrode 19 are collectively referred to as “electrode”. 30 ”, the positive electrode metal foil 21 and the negative electrode metal foil 25 are collectively described as“ metal foil 31 ”, and the positive electrode active material layer 22 and the negative electrode active material layer 26 are collectively described as“ active material layer 32 ”.

  FIG. 3 schematically shows a coating / drying device (power storage device manufacturing device) 35 for manufacturing the electrode 30 by applying a slurry to the metal foil 31 and drying it.

  The coating drying device 35 includes a supply mechanism 36 for supplying the metal foil 31, a coating mechanism 37 for applying the slurry to the metal foil 31, a drying mechanism 38 for drying the slurry after coating, and a metal after drying. A winding mechanism 39 for winding the foil 31. The supply mechanism 36 includes a supply roll 36 a around which a long strip-shaped metal foil 31 is wound. The supply roll 36a is rotatably supported by a support mechanism. The coating mechanism 37 includes a slit die 37a that applies slurry to the first surface 31a of the metal foil 31 fed from the supply roll 36a. An application process for applying the slurry to the metal foil 31 is performed by the coating mechanism 37.

  The drying mechanism 38 includes a dryer (drying furnace) 38 a that dries the slurry coated on the metal foil 31.

  In addition, the drying mechanism 38 transports the metal foil 31 along the transport path in the dryer 38a, and the metal foil 31 from the second surface 31b that is the surface opposite to the first surface 31a of the metal foil 31. Are provided with a plurality of rollers 381. Each roller 381 is made of a material (for example, metal) having a high thermal conductivity.

  Further, the drying mechanism 38 further includes roller heating means (first heating means) 382 attached to each roller 381. The roller heating means 382 heats each of the plurality of rollers 381, and heats the rollers 381 by a built-in heater, electromagnetic induction heating, and circulation of a heat medium. The roller heating means 382 heats the roller 381 to heat the second surface 31b of the metal foil 31 and dry the slurry from the metal foil 31 side. Each roller 381 is provided with a control unit that can set heating conditions (heating temperature, heating time, etc.).

  In addition, the drying mechanism 38 includes a plurality of upper air nozzles (second heating means) 383 arranged along the conveyance path above the metal foil 31 in the dryer 38a. Each upper air nozzle 383 blows hot air having a temperature higher than room temperature as air to the first surface 31a of the metal foil 31 to be conveyed. Therefore, the upper air nozzle 383 heats the first surface 31a of the metal foil 31 to dry the slurry from the surface side. A control unit (not shown) that can set an air temperature condition (air temperature, blowing time, etc.) is attached to each upper air nozzle 383.

  A drying process for drying the slurry applied to the metal foil 31 is performed by the drying mechanism 38 having the above configuration.

  The winding mechanism 39 includes a winding roll 39a that can be rotated by a motor drive. The take-up roll 39a rotates at a constant rotation speed and takes up the metal foil 31 sent out from the supply roll 36a. For this reason, the metal foil 31 is conveyed from the supply roll 36a toward the winding roll 39a at a constant conveyance speed. In the coating / drying device 35, a supply mechanism 36, a coating mechanism 37, a drying mechanism 38, and a winding mechanism 39 are disposed in order from the upstream side to the downstream side of the conveyance path of the metal foil 31. As a result, the metal foil 31 delivered from the supply roll 36a is coated with the slurry by the coating mechanism 37 (application process), dried by the drying mechanism 38 (drying process), and then wound around the winding roll 39a. Taken. In the coating and drying apparatus 35, a plurality of support rolls 40 that support the metal foil 31 to be conveyed are disposed between the supply mechanism 36 and the winding mechanism 39.

  By the way, it is known that the active material layer 32 formed on the metal foil 31 through coating and drying of the slurry may cause segregation of the conductive additive and the binder in the active material layer 32 when the slurry is rapidly dried. ing. This segregation can be caused by facilitating the transfer of the conductive additive and the binder along with the evaporation of the solvent added to the slurry, thereby facilitating the transfer of the conductive additive and the binder in the vapor discharge direction. When the segregation of the binder occurs on the surface side of the slurry applied to the metal foil 31, the binding force between the metal foil 31 and the active material layer 32 is reduced. Moreover, when the segregation of the conductive auxiliary agent occurs on the surface side of the slurry applied to the metal foil 31, the resistance of the electrode increases, leading to a decrease in the output of the electrode.

  For this reason, in this embodiment, the temperature of the roller 381 and the upper air nozzle 383 is controlled during the slurry drying process performed in the dryer 38a. Specifically, as shown in FIG. 4, the temperature T1 of the roller 381 has a temperature gradient that gradually decreases from the upstream side to the downstream side of the transport path, and the temperature T2 of the upper air nozzle 383 is upstream of the transport path. The temperature gradient gradually increases from the side to the downstream side.

  The temperature gradient of the roller 381 indicated by reference numeral T1 in FIG. 4 is set, for example, by setting the temperature of the roller 381 located on the most upstream side to a high temperature (for example, heating the roller to 200 ° C.) The temperature of the roller 381 is lowered stepwise, and the temperature of the roller 381 located on the most downstream side is set to the lowest temperature (no heating, actual temperature 90 ° C.).

  The temperature gradient of the upper air nozzle 383 indicated by reference numeral T2 in FIG. 4 is set, for example, by setting the spraying temperature of the uppermost air nozzle 383 located on the most upstream side to a low temperature (for example, 80 ° C.), and the upper air nozzle located further downstream. This can be realized by raising the spraying temperature of 383 stepwise and setting the temperature of the upper air nozzle 383 located on the most downstream side to the highest temperature (for example, 100 ° C.).

  In the drying step described above, at the initial stage of drying, the roller 381 that heats the second surface 31b of the metal foil 31 heats and dries the slurries S1 and S2 at a higher temperature than the upper air nozzle 383. Therefore, the drying of the slurries S1 and S2 proceeds not from the surface side but from the metal foil side. As a result, in the active material layer 32 that has undergone the drying process, as shown in FIG. 5, the segregation of the conductive assistant and the binder toward the metal foil side with the metal foil 31 is promoted, whereby the surface of the active material layer 32. The occupied volume ratio of the conductive assistant and the binder increases as it goes from the side to the metal foil side (interface side). Therefore, high adhesion of the active material layer 32 to the metal foil 31 is realized. In FIG. 5, the size of the occupied volume ratio is represented by the density of dots illustrated in the active material layer 32.

  As shown in FIG. 5, for example, the active material layer 32 is equally divided into three in the thickness direction, and regions a1, a2, and a3 are defined from the surface side of the active material layer 32 toward the metal foil side. The occupied volume ratio when the regions a1 to a3 are defined in this way is larger than the region a1 closest to the surface side of the active material layer 32 in the region a3 closest to the metal foil side of the active material layer 32. Will be bigger. In addition, it is preferable that the occupied volume ratio of the area a3 is larger than 1 time and within the range of about 10 times the occupied volume ratio of the area a1.

  In the active material layer 32, the occupied volume ratio of the regions a1 to a3 is larger in the region a2 than in the region a1, and larger in the region a3 than in the region a2. That is, in the active material layer 32, the occupied volume ratio of the conductive assistant and the binder increases from the surface side toward the metal foil side. In other words, in the active material layer 32, the occupied volume ratio of the conductive auxiliary agent and the binder decreases from the metal foil side toward the surface side.

  In addition, in the drying process described above, the temperature T1 of the roller 381 and the temperature T2 of the upper air nozzle 383 are reversed from the middle stage of drying, and the temperature T2 of the upper air nozzle 383 is higher at the end of drying. In the latter half of the drying process, the drying of the slurry on the metal foil side is almost completed, and the high adhesion of the active material layer 32 to the metal foil 31 is already ensured, so that the slurry can be dried from the surface side. . That is, by drying at a relatively high temperature by the upper air nozzle 383 at the end of drying, the surface side of the slurry is more reliably dried, and the entire slurry is surely dried.

  In the manufacturing apparatus and manufacturing method of the secondary battery 10 described above, the slurry to be the active material layer 32 conveyed through the dryer 38 a is the roller heating means 382 that heats the second surface 31 b of the metal foil 31. However, by heating the metal foil 31 via the roller 381, the drying proceeds from the metal foil 31 side, not the surface side. Therefore, the binder contained in the slurry is unevenly distributed and precipitated on the metal foil 31 side, and high adhesion of the active material layer 32 to the metal foil 31 can be realized.

  At this time, when the temperature for heating the roller 381 of the roller heating means 382 is increased in order to shorten the drying time, since the drying proceeds from the metal foil 31 side, skinning is unlikely to occur, and the drying time is easily shortened. be able to.

  In addition, since the heating temperature of the metal foil 31 by the roller heating means 382 gradually decreases from the upstream side to the downstream side of the conveyance path, the temperature difference between the roller heating temperature and the temperature around the metal foil gradually decreases. . Therefore, the slurry on the metal foil 31 side is preferentially and locally dried at the initial stage of drying, and thereafter, the slurry is entirely dried from the entire circumference.

  The first heating means for heating the second surface 31b of the metal foil 31 is not limited to the roller heating means 382 but may be as shown in FIG. 6 or FIG.

  In FIG. 6, a belt heating unit 384 is provided as a first heating unit for heating the second surface 31b of the metal foil 31, and the belt heating unit 384 causes the metal foil 31 to be moved in the same manner as the roller 381 described above. The metal foil 31 is heated on the second surface 31b via a belt 385 supported from the second surface 31b side. The belt 385 is an endless belt, and is provided so as to be suspended between a pair of rollers 386 disposed on the upstream side and the downstream side of the conveyance path in the dryer 38a.

  The belt heating means 384 has a control unit that heats the temperature of the belt 385, and the temperature of the belt 385 can be set as shown in the temperature gradient T1 shown in the graph of FIG. 4 by this control unit.

  Therefore, even in the mode shown in FIG. 6, the same operational effects as the roller heating unit 382 of the above-described embodiment can be obtained.

  In FIG. 7, as the first heating means for heating the second surface 31b of the metal foil 31, a plurality of lower air nozzles 387 arranged along the conveyance path are provided below the metal foil 31 in the dryer 38a. I have.

  Each lower air nozzle 387 blows hot air having a temperature higher than room temperature as air to the second surface 31b of the metal foil 31 to be conveyed, like the upper air nozzle 383 described above. Therefore, the lower air nozzle 387 heats the second surface 31b of the metal foil 31 to dry the slurry from the metal foil 31 side. A control unit (not shown) that can set an air temperature condition (air temperature, blowing time, etc.) is attached to each lower air nozzle 387. By this controller, the temperature of the lower air nozzle 387 can be set according to the temperature gradient T1 shown in the graph of FIG.

  Therefore, even in the mode shown in FIG. 7, the same operational effects as the roller heating unit 382 of the above-described embodiment can be obtained.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, the power storage device is not limited to a secondary battery such as a lithium ion secondary battery, but may be another power storage device (for example, an electric double layer capacitor or a lithium ion capacitor).

  In the above-described embodiment, the roller heating unit has shown an aspect in which all of the plurality of rollers are heated. However, an aspect in which only some of the plurality of rollers are heated may be used.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 31 ... Metal foil, 32 ... Active material layer, 38a ... Dryer, 381 ... Roller, 382 ... Roller heating means, 383 ... Upper air nozzle, 384 ... Belt heating means, 385 ... Belt, 387 ... Bottom Side air nozzle, S1, S2 ... slurry.

Claims (10)

A power storage device manufacturing apparatus for manufacturing a power storage device including an electrode having an active material layer coated on a surface of a metal foil,
A drying furnace arranged on a metal foil transport path coated with a slurry containing an active material and a binder to be an active material layer;
A first heating means for heating the surface of the metal foil conveyed in the drying furnace on the opposite side of the surface to which the slurry is applied;
The set temperature of the first heating means for heating the opposite surface of the front Symbol metal foil, gradually decreasing from the upstream side to the downstream side of the conveying path, apparatus for manufacturing a power storage device. A second heating means for heating the surface of the metal foil transported in the drying furnace to which the slurry is applied;
The set temperature of the second heating means said slurry before Symbol metal foil heats the coated surface, increasing gradually from the upstream side to the downstream side of the conveying path, apparatus for manufacturing a power storage device according to claim 1 . On the transport path in the drying furnace, the set temperature of the first heating means and the set temperature of the second heating means are reversed, and the upstream side of the transport path is the second heating means. The set temperature of the first heating unit is higher than the set temperature, and the set temperature of the second heating unit is higher than the set temperature of the first heating unit on the downstream side of the conveyance path. 3. A power storage device manufacturing apparatus according to 2. In the drying furnace, comprising a plurality of rollers for conveying the metal foil along the conveyance path and supporting the metal foil from the opposite surface,
The said 1st heating means is a manufacturing apparatus of the electrical storage apparatus as described in any one of Claims 1-3 which heats the said opposite surface of the said metal foil by heating the said roller. In the drying furnace, comprising a belt that conveys the metal foil along the conveyance path and supports the metal foil from the opposite surface,
The said 1st heating means is a manufacturing apparatus of the electrical storage apparatus as described in any one of Claims 1-3 which heats the said other surface of the said metal foil by heating the said belt. The power storage device manufacturing apparatus according to any one of claims 1 to 3, wherein the first heating means is a plurality of blowing means that heats the metal foil by blowing hot air onto the opposite surface. . The power storage device manufacturing apparatus according to any one of claims 1 to 6 , wherein the power storage device is a secondary battery. A method for manufacturing a power storage device comprising an electrode having an active material layer coated on the surface of a metal foil,
An application step of applying a slurry containing an active material to be an active material layer and a binder to a metal foil;
A drying step of drying the slurry by heating the surface of the metal foil opposite to the surface coated with the slurry by a first heating means ;
A method for manufacturing a power storage device, wherein a set temperature of the first heating means for heating the opposite surface of the metal foil is gradually lowered from the initial stage to the final stage during the drying step. Wherein during the drying step, the surface on which the slurry has been applied among the surface of the metal foil is heated by the second heating means, the set temperature of the second heating means for heating the slurry has been applied surface The method of manufacturing a power storage device according to claim 8 , wherein the power is gradually increased from an initial stage to an end stage. Between the initial stage and the final stage of drying in the drying step, the level of the set temperature of the first heating unit and the set temperature of the second heating unit are reversed, and in the initial stage of drying, the temperature of the second heating unit is reversed. The set temperature of the first heating unit is higher than the set temperature, and at the end of drying, the set temperature of the second heating unit is higher than the set temperature of the first heating unit. Manufacturing method of power storage device.

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