WO2012118244A1

WO2012118244A1 - Vacuum drying apparatus of electrode plate for secondary battery and drying method therefor

Info

Publication number: WO2012118244A1
Application number: PCT/KR2011/004018
Authority: WO
Inventors: 김철영
Original assignee: (주)엠오텍
Priority date: 2011-02-28
Filing date: 2011-06-01
Publication date: 2012-09-07
Also published as: KR101077069B1; CN102884656A

Abstract

The present invention relates to a drying apparatus of an electrode plate for a secondary battery, and more specifically, to a drying apparatus of an electrode plate for a secondary battery which includes: a door for inserting and removing an electrode plate; a housing unit(10) wherein a drying chamber(11), which is shielded from the outside by an upper wall unit, a side wall unit, and a lower wall unit, is formed; a heating means(20) formed on the top of the drying chamber(11); a first elevator(30) for lifting the electrode plate (S) laminated on a first loading plate(31) to a predetermined height; a transfer means(50) for transferring the highest electrode plate(S) among electrode plates loaded on the first elevator to a second elevator(40); and a second elevator(40) lowering a second loading plate(41) to a predetermined height while loading the electrode plate(S) supplied from the first elevator(30) to a second loading plate(41) by the transfer means(50).

Description

Vacuum Drying Device and Drying Method of Anode Plate for Secondary Battery

The present invention relates to a secondary battery pole plate drying apparatus and method used in the drying step of the pole plate of the manufacturing process of the pole plate for secondary batteries.

In general, a lot of researches on the production process of a battery and a battery used as a power source of electronic products by the structure of electronic products such as automobiles, portable telephones, video cameras, portable PCs, etc. are lightened or highly functional. Such a battery can be used continuously by charging / discharging.

Generally, nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, lithium secondary batteries, and the like are used as power sources for electronic products. Among them, lithium secondary batteries have been widely used in consideration of their lifespan and capacity.

The lithium secondary battery is classified into a lithium metal battery, a lithium ion battery, and a lithium polymer battery using a high-volume solid electrolyte according to the type of electrolyte. The lithium secondary battery has a structure in which a unit cell or a bi-cell is stacked, wherein the unit cell has a positive plate / separator / negative plate structure, and the bi-cell has a positive plate / separator / negative plate / separator / positive plate structure.

Generally, a lithium ion secondary battery (henceforth a secondary battery) is manufactured largely by a pole plate manufacturing process, an assembly process, and a chemical conversion process. In the electrode plate manufacturing process, a positive electrode plate and a negative electrode plate are manufactured. First, the positive electrode plate is mainly manufactured by coating an active material on both surfaces of an aluminum foil in a predetermined pattern and thickness, and then drying them under high temperature and vacuum. Here, the active material is mainly lithium cobalt oxide (for example, LiCoO 2), which has a form in which a small amount of a conductive agent and a binder are mixed. In addition, the negative electrode plate is mainly produced by coating the active material on both sides of the copper foil in a predetermined pattern and thickness, and then drying at high temperature and vacuum. In this case, the active material is graphite or carbon, in which a small amount of an additive and a binder are mixed.

Recently, development of a lithium ion polymer battery system is being progressed as a power source of a hybrid electric vehicle (HEV) or an electric vehicle. Such lithium ion polymer batteries are known to have a voltage three times higher than that of Ni-MH (nickel-metal hydride) batteries, and have a very high output at room temperature. Therefore, a lithium ion polymer battery, which is a high power and high density battery, is being developed as a battery capable of supplementing automotive packaging and output characteristics. Looking at the configuration of the electrode plate assembly, which is one of the main components of such a lithium ion polymer battery, the electrode plate assembly includes a positive electrode plate and a negative electrode plate. Looking at the configuration of the electrode plate assembly, which is one of the main components of such a lithium ion polymer battery, the electrode plate assembly includes a positive electrode plate and a negative electrode plate, the positive electrode plate, and the negative electrode plate is usually prepared by mixing the active material, the conductive material and the binder by a wet method. do.

The positive and negative electrode plates that generate electrical energy must be excellent in drying conditions when they are manufactured to facilitate the generation of electrical energy, and when the electrode plates contain impurities such as water, oil and gas. The polarity is irregular or poor depending on the content of water, oil, and impurities, so that the rated energy is not generated, and the recharge state is poor due to the water, oil, or impurities, and the battery life is significantly shortened. Because of the closed stage, drying of the electrode plate has become a very important manufacturing process that influences the life of the battery.

In the drying process of the manufacturing process of the conventional pole plate for secondary batteries described above, if the degree of drying between the pole plates is uneven, and the pole plate is enlarged (for example, A4 size size), such as an electric vehicle battery in one electrode plate There was a problem in that the degree of drying is uneven along the area, the performance of the battery is uneven, leading to quality problems. In addition, when the drying temperature is increased for sufficient drying, the flip may occur due to thermal deformation of the electrode plate, or the binder may be partially dissolved to reduce the adhesive strength between the current collector and the active material.

In particular, in the case of a substrate on which a carbon coating layer is formed, it is difficult to evenly dry the surface from the surface of the coating layer to the inside because carbon has high water absorption and extremely low thermal conductivity. In addition, in the case of the carbon coating layer, the deformation occurs when the temperature inside the drying chamber is 200 ~ 300 ℃ there was a problem that peeling from the current collector.

An object of the present invention is to provide a secondary battery pole plate drying apparatus used in the drying process of the electrode plate for secondary batteries, it is possible to dry uniformly enough not only the surface of the electrode plate coated with the active material (for example, carbon) but also inside the coating layer. The present invention also provides a pole plate drying apparatus for a secondary battery, in which a plurality of pole plates are dried at the same time while the drying variation between the pole plates is small. In addition, even if the electrode plate having a large area of the coated electrode plate is to provide a secondary plate electrode plate drying apparatus that can be uniformly dried in the entire area.

The present invention relates to a vacuum drying apparatus and a drying method of the electrode plate for secondary batteries,

A housing part 10 having a door D for entering and exiting the pole plate and having a drying chamber 11 shielded from the outside by an upper wall part, a side wall part and a bottom wall part;

Heating means 20 formed on an upper portion of the drying chamber 11;

A first elevator 30 for raising the pole plates S stacked on the first mounting plate 31 by a predetermined height;

Moving means (50) for moving the uppermost pole plate (S) from the loaded pole plates of the first elevator (30) to the second elevator (40);

The second elevator loads the pole plates (S) supplied by the moving means 50 from the first elevator 30 to the second mounting plate 41 and lowers the second mounting plate 41 by a predetermined height. It relates to a pole plate drying apparatus for a secondary battery, characterized in that it comprises a.

According to the present invention, the secondary battery can be sufficiently uniformly dried to the inside of the coating layer as well as the top surface of the coating layer of the electrode plate on which the active material (for example, carbon) coating layer is formed. It is to provide a pole plate drying apparatus. In addition, even if the electrode plate having a large area of the coating layer is to provide a secondary battery pole plate drying apparatus that can be uniformly dried in the entire area.

1 is a structural diagram of a pole plate drying apparatus for a secondary battery according to a first embodiment of the present invention.

2 (a, b) is a structural diagram of a pole plate drying apparatus for a secondary battery according to a second embodiment of the present invention.

3 is an explanatory view of a method of drying a pole plate for a secondary battery according to an embodiment of the present invention.

4 is a structural diagram of a pole plate drying apparatus for a secondary battery according to a third embodiment.

5 is a flowchart illustrating a method of drying a pole plate for a secondary battery according to an embodiment of the present invention.

6 is a flowchart illustrating a method of drying a pole plate for a secondary battery according to an embodiment of the present invention.

[Description of the code]

10 housing part 11 drying chamber

20: heating means 30: first elevator

31: first loading plate 33: first lifting screw

34: first driving nut part 35: first pulley

40: second elevator 41: second loading plate

43: second lifting screw 44: second drive nut part

45: second pulley 50: moving means

60: vacuum means 70: cooling means

80: adsorption filter 90: second heating means S: electrode plate

Hereinafter, a pole plate drying apparatus for a secondary battery according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 is a structural diagram of a pole plate drying apparatus for a secondary battery according to a first embodiment of the present invention, Figure 2 (a, b) is a structural diagram of a pole plate drying apparatus for a secondary battery according to a second embodiment of the present invention, Figure 3 Explanatory drawing of a pole plate drying method for a secondary battery according to an embodiment of the. 4 is a structural diagram of a secondary battery pole plate drying apparatus according to a third embodiment, Figure 5 is a flow chart of a secondary battery pole plate drying method according to an embodiment of the present invention, Figure 6 is a secondary battery pole plate according to an embodiment of the present invention Flow chart of drying method.

As shown in FIG. 1, FIG. 2, the electrode plate drying apparatus for a secondary battery according to an embodiment of the present invention includes a housing part 10, a heating means 20, a first elevator 30, and a second elevator 40. And it comprises a moving means 50 and the vacuum means 60, and may further comprise a cooling means (70).

The housing part 10 is provided with a door D for entering and exiting the pole plate, and a drying chamber 11 shielded from the outside by an upper wall part, a side wall part, and a bottom wall part is formed. The housing part 10 may be formed of a plastic or metal material having a conventional door. The heating means 20 is formed above the drying chamber 11. In the present invention, the heating means 20 is preferably a far infrared lamp.

The moving means 50 moves the uppermost pole plate S from the loaded pole plates of the first elevator 30 to the second elevator 40. In the present invention, the moving means 50 is provided at a position higher than the maximum lift height of the first mounting plate 31 attached to the first elevator 30 so that the uppermost pole plate S is adjacent to the adjacent second elevator 40. What is necessary is just a structure which can be moved. Moving means known prior to the filing date of the present invention, which can move a thin, rigid or flexible thin plate in a short distance, are considered to be included in the scope of the present invention.

For example, the moving means 50 may be a conventional vacuum suction device having a vacuum means, a control unit for controlling the vacuum means, and a vacuum suction unit 53 connected to the vacuum means. The reciprocating block 52 provided with the vacuum suction unit 53 moves along the horizontal rail 51. In addition, the moving means 50 is connected to the piston forward and backward by the pneumatic cylinder, the touch bar (not shown) is connected, the control unit controls the forward and backward movement of the piston and the touch bar (not shown) of the elevator adjacent to the top plate It may be a form of pushing towards trial.

1 and 2, the first elevator 30 raises the pole plates S stacked on the first mounting plate 31 by a predetermined height. The second elevator 40 loads the pole plates S supplied by the moving means 50 to the second mounting plate 41 and lowers the second mounting plate 41 by a predetermined height. Thus, the 1st elevator 30 is equipped with the 1st loading board 31 which moves up and down.

In the present invention, the

elevators

30 and 40 include a loading plate, a guide along which the loading plate moves, a driving unit providing power for raising and lowering the loading plate, and a control unit controlling the driving unit. The lifting device structure known before the filing date of the present invention and capable of raising and lowering the loading plate by small collection height is considered to be included in the scope of the elevator of the present invention. The controller (not shown) controls the driving unit (not shown) at the storage time to raise and lower the stacking

plates

31 and 41 by the smallest height.

In detail with respect to the

elevators

30 and 40, for example, as shown in Fig. 2, the moving means includes a cylinder, a piston which is lifted inside the cylinder and provided with a magnet, and a magnetic force of the magnet of the piston. It may be a control plate for controlling the pneumatic pressure before and after the piston and the cylinder of the cylinder plate integrally lifting up and down together with the magnet (M). In addition, the moving means may be a servo motor and a screw column that is rotated by the servo motor, a nut part which is extrapolated and lifted by the screw column, a loading plate integrated with the nut part, and a controller for controlling the servo motor.

In the present invention, the vacuum means 60 sucks the air in the drying chamber 11 to make a vacuum of 10 ^-15 ~ 100 Torr. The vacuum means 60 may be a conventional vacuum pump. It is a concept including the conventional well-known means which can drop the inside of the drying chamber 11 below atmospheric pressure. In the embodiment of the present invention, the vacuum means 60 sucks air in the drying chamber 11 through the connecting pipe (H), the connecting pipe (H) is the intermediate path between the drying chamber 11 and the vacuum means (50) It may be via the cooling means 70 located in.

4 is a structural diagram of a pole plate drying apparatus for a secondary battery according to a third embodiment. As shown in FIG. 4, the connection pipe H may further pass through the adsorption device 80 positioned in the intermediate path between the drying chamber 11 and the vacuum means 50. The adsorption filter 80 may collect adhesives, solvents, solvents, moisture, electrolytes, solvents, and other chemicals used to attach the active material to prevent failure of the vacuum means and to remove harmful substances. The bearing B of FIG. 4 seals between a stationary object and a rotating object and includes known means such as oil bearings, fluid seals, and the like.

4 is a pole plate drying apparatus for a secondary battery according to a third embodiment, the first heating means 20 is a movement path (Loot) and the first, second elevator 30, the pole plate is moved by the moving means 50 , 40) is positioned higher than the uppermost electrode plate and irradiated toward the upper surface of the electrode plate. It is preferable that the second heating means 90 is further provided at a position lower than the movement route (Loot) through which the pole plate moves by the moving means 50.

As shown in Figure 4, in the pole plate drying apparatus for a secondary battery according to an embodiment of the present invention, the second heating means 90 is provided between the first elevator 30 and the second elevator 40, The moving means 50 is a predetermined time in the upper portion of the second heating means 90 in the movement path, so that the second heating means 90 can heat the lower surface of the pole plate being moved to another elevator for a predetermined time. It is preferable to stop for a while while holding the pole plate or to mount it on a holder positioned above the second heating means 90 for a predetermined time.

As shown in FIG. 4, in the pole plate drying apparatus for a secondary battery according to an embodiment of the present invention, when the first elevator 30 rises, the second elevator 40 descends, and vice versa. When the 30 is lowered, the second elevator 40 is raised, and the lifting operation of the first elevator 30 and the second elevator 40 is preferably performed simultaneously by the same height.

As shown in FIG. 4, in the pole plate drying apparatus for the secondary battery according to the exemplary embodiment of the present invention, the first elevator 30 has a screw thread formed on an outer circumferential surface thereof and supports the first mounting plate 31. And a first driving nut part 34 for elevating the first elevating screw 33 while being extrapolated to the first elevating screw 33 and elevating the first elevating screw 33. It is preferably configured to include a first pulley 35 which rotates integrally with the nut part 34.

As shown in FIG. 4, in the pole plate drying apparatus for a secondary battery according to an embodiment of the present invention, the second elevator 40 has a screw thread formed on an outer circumferential surface thereof and supports the first mounting plate 31. And a second drive nut portion 44 for elevating and lifting the second elevating screw 43 while being extrapolated to the second elevating screw 43 to rotate in and out of the second elevating screw 43. It is preferable to comprise the 2nd pulley 45 which rotates integrally with the nut part 44. FIG.

As shown in FIG. 4, in the pole plate drying apparatus for a secondary battery according to an embodiment of the present invention, the first pulley 35 and the second pulley 45 are the same by the motor 49 and the belt V. FIG. Direction, the first lifting screw 33 and the second lifting screw 43 is preferably a screw thread is formed opposite to rotate in the opposite direction to each other.

As shown in FIG. 5, the vacuum drying method of the electrode plate for the secondary battery according to the exemplary embodiment of the present invention includes a housing part 10 having a heating means 20 on the drying chamber 11 and a first loading plate. The 1st elevator 30 provided with the 31, the 2nd elevator 40 provided with the 2nd loading board 41, and the pole plate of the 1st loading board 31 are moved to the 2nd elevator 40. As shown in FIG. Providing a pole plate drying apparatus for a secondary battery comprising a moving means to make (S10); Stacking a plurality of electrode plates on the first elevator (30) (S20); It comprises a; making the drying chamber 11 in a vacuum state of 10 ^-15 ~ 100 Torr, and heating the interior of the drying chamber 11 by the heating means 20 (S30).

As shown in FIG. 5, in the vacuum drying method of the electrode plate for the secondary battery according to the exemplary embodiment of the present invention, the moving means 50 further moves the uppermost electrode plate of the first mounting plate 31 to the second elevator 40. Moving to the second stacking plate 41 (S40); The first elevator 30 raises the first mounting plate 31 by the predetermined height H1, and the second elevator 40 lowers the second mounting plate 41 by the predetermined height H1 (S50). )Wow; Drying the electrode plate for a predetermined time (T1) (S60); And repeating step S40, step S50, and step S60 until all of the pole plates of the first mounting plate 31 move to the second mounting plate 41 (S70).

As shown in FIG. 6, in the vacuum drying method of the electrode plate for the secondary battery according to the exemplary embodiment of the present invention, when the first stacking plate 31 lifts the bottom, the moving unit 50 returns to the second stacking plate 41. Moving the uppermost pole plate of the first loading plate 31 of the first elevator 30 (S140); The first elevator 30 lowers the first mounting plate 31 by the predetermined height H1, and the second elevator 40 raises the second mounting plate 41 by the predetermined height H1 (S150). )Wow; Drying the electrode plate for a predetermined time (T1) (S160); The step (S170) of repeating the step (S140) and step (S150) and step (S160) until all of the pole plates of the second mounting plate 41 is moved to the first mounting plate 31; It is preferable.

As shown in FIG. 5, in the vacuum drying method of the secondary battery pole plate according to the embodiment of the present invention, the moving means 50 moves the uppermost pole plate of the first mounting plate 31 to the second elevator 40. In the middle of the step (S40) of moving to the second loading plate 41, the moving means 50 is positioned between the first elevator 30 and the second elevator 40 for a predetermined time, The second heating means 90 provided between the first elevator 30 and the second elevator 40 is a step (S45) for heating the pole plate in the lower portion of the pole plate;

In the present invention, the predetermined height will be the height occupied by one pole plate and can be generally thick. It is natural that the predetermined time T1 can be appropriately selected by the designer according to the temperature of the heater, the irradiation amount, the size of the drying chamber, the quantity of drying of the electrode plate, the width of the electrode plate, and the degree of drying required.

When drying by the above-described method using the apparatus of the present invention, the electrode plate is subjected to the same temperature conditions and irradiation conditions in a constant time flow to achieve a uniform drying compared to the electrode plate and the electrode plate, and even to a very high temperature in one electrode plate Prototype test results showed that it was possible to achieve a uniform and sufficient drying effect deep into the coating layer for an appropriate drying time without raising.

Although the invention has been described in connection with the above-mentioned preferred embodiments, the scope of the invention is not limited to these embodiments, the scope of the invention is defined by the claims below and equivalent to the scope of the invention It will include various modifications and variations to which it belongs.

The reference numerals set forth in the claims below are merely to aid the understanding of the present invention, not to affect the interpretation of the scope of the claims, and the scope of the claims should not be construed narrowly.

The present invention includes a housing part (10) having a door (D) for entering and exiting the pole plate and having a drying chamber (11) shielded from the outside by an upper wall portion, a side wall portion and a bottom wall portion;

First heating means 20 formed on an upper portion of the drying chamber 11 to heat the electrode plate S;

A second loading of the pole plates S supplied by the moving means 50 from the first elevator 30 to the second loading plate 41, and lowering the second loading plate 41 by a predetermined height; An elevator 40; relates to a pole plate drying apparatus for a secondary battery, characterized in that it comprises a.

Claims

A housing part 10 having a door D for entering and exiting the pole plate and having a drying chamber 11 shielded from the outside by an upper wall part, a side wall part and a bottom wall part;

First heating means 20 formed on an upper portion of the drying chamber 11 to heat the electrode plate S;

A first elevator 30 for raising the pole plates S stacked on the first mounting plate 31 by a predetermined height;

Moving means (50) for moving the uppermost pole plate (S) from the loaded pole plates of the first elevator (30) to the second elevator (40);

A second loading of the pole plates S supplied by the moving means 50 from the first elevator 30 to the second loading plate 41, and lowering the second loading plate 41 by a predetermined height; Elevator (40); pole plate drying apparatus for a secondary battery, characterized in that comprises a.
The method of claim 1,

And a vacuum means (60) for sucking air in the drying chamber (11) to a vacuum state of 10 -15 to 100 Torr.
The method of claim 2,

The vacuum means 60 sucks the air in the drying chamber 11 through the connecting pipe (H),

The connecting pipe (H) is a pole plate drying apparatus for a secondary battery, characterized in that via the cooling means (70) located in the intermediate path between the drying chamber (11) and the vacuum means (50).
The method of claim 1,

The heating means 20 is a pole plate drying apparatus for a secondary battery, characterized in that the far infrared lamp.
The method of claim 3,

The connecting pipe (H) is a pole plate drying apparatus for a secondary battery, characterized in that further via the adsorption filter (80) located in the intermediate path between the drying chamber (11) and the vacuum means (50).
The method of claim 1,

The first heating means 20 is located higher than the movement path (Loot) in which the pole plate is moved by the moving means 50 and the uppermost pole plates of the first and second elevators 30 and 40 and irradiated toward the upper surface of the pole plate. and,

The pole plate drying apparatus for a secondary battery, characterized in that the second heating means 90 is provided at a position lower than the movement path (Loot) that the pole plate is moved by the moving means (50).
The method of claim 6,

The second heating means 90 is provided between the first elevator 30 and the second elevator 40,

The moving means 50 is predetermined at an upper portion of the second heating means 90 in the moving path so that the second heating means 90 can heat the lower surface of the electrode plate being moved to another elevator in a stationary state for a predetermined time. The pole plate drying apparatus for a secondary battery, characterized in that stopped in the state holding the pole plate for a period of time or mounted on a cradle located above the second heating means (90) for a predetermined time.
The method of claim 1,

When the first elevator 30 rises, the second elevator 40 descends,

On the contrary, when the first elevator 30 descends, the second elevator 40 rises, and the lifting operation of the first elevator 30 and the second elevator 40 is simultaneously performed by the same height. Pole plate drying device for secondary batteries.
The method of claim 6,

The first elevator 30,

A first lifting screw 33 which is formed on an outer circumferential surface and which is lifted while supporting the first mounting plate 31;

A first driving nut part 34 which extrapolates and rotates the first lifting screw 33 while being extrapolated to the first lifting screw 33;

A first pulley (35) which rotates integrally with the first drive nut portion (34);

The second elevator 40,

A second elevating screw 43 which is formed on an outer circumferential surface thereof and which is lifted while supporting the first mounting plate 31;

A second driving nut part 44 which extrapolates and rotates the second lifting screw 43 while being extrapolated to the second lifting screw 43;

And a second pulley (45) integrally rotating with the second driving nut part (44).
The method of claim 7, wherein

The first pulley 35 and the second pulley 45 are rotated in the same direction by the motor 49 and the belt (V),

The first elevating screw (33) and the second elevating screw (43) is a pole plate drying apparatus for a secondary battery, characterized in that the threads are formed opposite to rotate in opposite directions.
The housing part 10 provided with the heating means 20 in the upper part of the drying chamber 11, the 1st elevator 30 provided with the 1st loading board 31, and the 2nd loading board 41 are provided. Providing an electrode plate drying apparatus for a secondary battery including an elevator 40 and a moving means 50 for moving the pole plate of the first loading plate 31 to the second elevator 40 (S10);

Stacking a plurality of electrode plates on the first elevator (30) (S20);

Making the drying chamber 11 in a vacuum state of 10 −15 to 100 Torr and heating the interior of the drying chamber 11 by the heating means 20 (S30);

Moving means 50 moves the uppermost pole plate of the first loading plate 31 to the second loading plate 41 of the second elevator 40 (S40);

The first elevator 30 raises the first mounting plate 31 by the predetermined height H1, and the second elevator 40 lowers the second mounting plate 41 by the predetermined height H1 (S50). )Wow;

Drying the electrode plate for a predetermined time (T1) (S60);

And a step (S70) of repeating step S40, step S50, and step S60 until all of the pole plates of the first mounting plate 31 move to the second mounting plate 41. A pole plate drying method for a secondary battery characterized in that.
The method of claim 11,

When the first loading plate 31 lifts the floor, the moving means 50 moves the uppermost pole plate of the second loading plate 41 to the first loading plate 31 of the first elevator 30 (S140). )Wow;

The first elevator 30 lowers the first mounting plate 31 by the predetermined height H1, and the second elevator 40 raises the second mounting plate 41 by the predetermined height H1 (S150). )Wow;

Drying the electrode plate for a predetermined time (T1) (S160);

The step (S170) of repeating the step (S140) and step (S150) and step (S160) until all of the pole plates of the second mounting plate 41 is moved to the first mounting plate 31; A pole plate drying method for a secondary battery, characterized in that.
The method of claim 11,

In the middle of the step (S40) of the moving means 50 to move the uppermost pole plate of the first loading plate 31 to the second loading plate 41 of the second elevator 40,

The moving means 50 locates the pole plate between the first elevator 30 and the second elevator 40 for a predetermined time, and the second heating provided between the first elevator 30 and the second elevator 40. Means (90) for heating the pole plate in the lower portion of the pole plate (S45); characterized in that it further comprises a pole plate drying method for a secondary battery.