阅读说明：本技术 锰酸锂电池干燥方法及干燥装置 (Lithium manganate battery drying method and drying device ) 是由 陈萍姬 黄欣 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种锰酸锂电池干燥方法,包括：步骤一、将正极浆料涂布于铝箔上；步骤二、干燥前处理：置于温度为40～50℃、压力为0.12～0.13MPa下处理15～20min,然后以2～3kPa/min的速度降压至常压,再升压至0.12～0.13MPa下,温度保持40～50℃处理30～50min；步骤三、真空干燥,辊压、切片；步骤四、将正极极片和负极极片、隔膜、电解液组装为铝壳电池。具有显著提升锰酸锂电池抗低温性能的有益效果。提供一种锰酸锂电池干燥装置,包括：箱体,其上设有进气管、排气管、封闭门；压力检测机构；加热机构；温度检测机构。具有匹配干燥前处理工序,方便电池生产的有益效果。(The invention discloses a lithium manganate battery drying method, which comprises the following steps: coating the positive electrode slurry on an aluminum foil; step two, drying pretreatment: treating for 15-20 min at the temperature of 40-50 ℃ and the pressure of 0.12-0.13 MPa, then reducing the pressure to the normal pressure at the speed of 2-3 kPa/min, increasing the pressure to 0.12-0.13 MPa, and treating for 30-50 min at the temperature of 40-50 ℃; step three, vacuum drying, rolling and slicing; and step four, assembling the positive pole piece, the negative pole piece, the diaphragm and the electrolyte into the aluminum-shell battery. The method has the beneficial effect of remarkably improving the low-temperature resistance of the lithium manganate battery. The lithium manganate battery drying device is provided, including: the box body is provided with an air inlet pipe, an exhaust pipe and a sealing door; a pressure detection mechanism; a heating mechanism; and a temperature detection mechanism. The method has the beneficial effects of matching with the drying pretreatment process and facilitating the production of the battery.)

1. The lithium manganate battery drying method is characterized by comprising the following steps:

step one, coating: coating the lithium manganate anode slurry on an aluminum foil;

step two, drying pretreatment: treating for 15-20 min at the temperature of 40-50 ℃ and the pressure of 0.12-0.13 MPa, then reducing the pressure to the normal pressure at the speed of 2-3 kPa/min, increasing the pressure to 0.12-0.13 MPa, and treating for 30-50 min at the temperature of 40-50 ℃;

step three, drying: vacuum drying at 120-150 ℃ for 18-20 h, rolling and slicing to obtain a positive pole piece;

and step four, assembling the positive pole piece, the negative pole piece, the diaphragm and the electrolyte into the aluminum-shell battery.

2. The method for drying a lithium manganate battery as claimed in claim 1, wherein the method for preparing the lithium manganate positive electrode slurry comprises: mixing lithium manganate, a conductive agent and a binder in N-methyl pyrrolidone according to a mass ratio of 92-93: 3-4: 4, and adjusting the viscosity of the positive electrode slurry to 7250-8250 us/cm.

3. The method of drying a lithium manganate battery as set forth in claim 1, further comprising preparing a negative electrode slurry comprising: and (3) mixing the graphite, the conductive agent, the carbon nanotube and the binder in pure water according to a mass ratio of 93:3:1:3, wherein the viscosity of the negative electrode slurry is 2250-3250 us/cm.

4. The method for drying a lithium manganate battery as claimed in claim 3, wherein the graphite is obtained by mixing graphite particles having particle diameters of 60 to 80 mesh, 100 to 120 mesh and 160 to 180 mesh, respectively, in a mass ratio of 25:30: 45.

5. The method for drying a lithium manganate battery as claimed in claim 1, wherein the conductive agent is SUPER-P.

6. The method of drying a lithium manganate battery as claimed in claim 1, wherein the separator is a polyethylene single layer film.

7. Lithium manganate battery drying device, its characterized in that includes:

the box body is provided with an air inlet pipe, an exhaust pipe and a closed door, the air inlet pipe is communicated with a nitrogen supply part, and valves are arranged on the air inlet pipe and the exhaust pipe;

a pressure detection mechanism for detecting a pressure inside the tank;

the heating mechanism is arranged in the box body;

and the temperature detection mechanism is used for detecting the temperature in the box body.

8. The lithium manganate battery drying device of claim 7, further comprising a plurality of partitions, said partitions being horizontally disposed in said case at intervals.

9. The lithium manganate battery drying device of claim 7, further comprising an air extracting mechanism, which comprises an air extracting pipe disposed on said box and an air extracting pump communicated with said air extracting pipe, wherein said air extracting pipe is provided with an air extracting pump.

Technical Field

The invention relates to the technical field of lithium manganate battery preparation. More specifically, the invention relates to a lithium manganate battery drying method and a lithium manganate battery drying device.

Background

The lithium manganate battery has the advantages of long service life, long storage time, low self-discharge rate and stable discharge at normal temperature, but the lithium manganate battery is inevitably required to adapt to different application environments when being suitable for practical application, has the advantages at normal temperature, and has excellent performance and enough safety under the low-temperature condition. Therefore, how to improve the temperature resistance of the lithium manganate battery is worthy of research.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.

The invention also aims to provide a lithium manganate battery drying method which can obviously improve the low-temperature resistance of the lithium manganate battery.

The utility model provides a lithium manganate battery drying device can match the dry pretreatment process of this application, convenient and fast's production battery.

To achieve these objects and other advantages in accordance with the present invention, there is provided a lithium manganate battery drying method comprising the steps of:

step one, coating: coating the lithium manganate anode slurry on an aluminum foil;

step two, drying pretreatment: treating for 15-20 min at the temperature of 40-50 ℃ and the pressure of 0.12-0.13 MPa, then reducing the pressure to the normal pressure at the speed of 2-3 kPa/min, increasing the pressure to 0.12-0.13 MPa, and treating for 30-50 min at the temperature of 40-50 ℃;

step three, drying: vacuum drying at 120-150 ℃ for 18-20 h, rolling and slicing to obtain a positive pole piece;

and step four, assembling the positive pole piece, the negative pole piece, the diaphragm and the electrolyte into the aluminum-shell battery.

Preferably, the preparation method of the lithium manganate positive electrode slurry comprises the following steps: mixing lithium manganate, a conductive agent and a binder in N-methyl pyrrolidone according to a mass ratio of 92-93: 3-4: 4, and adjusting the viscosity of the positive electrode slurry to 7250-8250 us/cm.

Preferably, the method further comprises preparing a negative electrode slurry comprising: and (3) mixing the graphite, the conductive agent, the carbon nanotube and the binder in pure water according to a mass ratio of 93:3:1:3, wherein the viscosity of the negative electrode slurry is 2250-3250 us/cm.

Preferably, the graphite is obtained by mixing 60-80 meshes, 100-120 meshes and 160-180 meshes of graphite according to a mass ratio of 25:30: 45.

Preferably, the conductive agent is SUPER-P.

Preferably, the separator is a polyethylene monolayer film.

The lithium manganate battery drying device is provided, including:

the box body is provided with an air inlet pipe, an exhaust pipe and a closed door, the air inlet pipe is communicated with a nitrogen supply part, and valves are arranged on the air inlet pipe and the exhaust pipe;

a pressure detection mechanism for detecting a pressure inside the tank;

the heating mechanism is arranged in the box body;

and the temperature detection mechanism is used for detecting the temperature in the box body.

Preferably, the box body further comprises a plurality of interlayer which are horizontally arranged in the box body at intervals.

Preferably, the air extractor further comprises an air extracting mechanism, wherein the air extracting mechanism comprises an air extracting pipe arranged on the box body and an air extracting pump communicated with the air extracting pipe, and the air extracting pipe is provided with the air extracting pump.

The invention at least comprises the following beneficial effects:

first, repeated pressurization and temperature control treatment of drying pretreatment can make each particle of positive slurry arrange more finely, and because of adopting nitrogen pressurization's mode, make each particle do all can evenly when the pressurized pressure, promoted the homogeneity of particle distribution, thereby, after the drying, when ambient temperature changes, each particle form and the arrangement of positive slurry are because when the temperature changes, are the change of uniform adaptability, and the whole influence reduces, thereby reduces the problem defect of discharge capacity change because the temperature changes and causes.

Secondly, during heavy current discharge, the lithium manganate power battery has polarization phenomenon. When large current is discharged, the speed of positive electrode electrons flowing into the electrode is high, so that the accumulation of electrons is caused, but the speed of negative electrode lithium ions flowing out is not increased, so that the accumulation of lithium ions is caused, the negative electrode potential moves in a negative direction, the original balance state is broken, and the polarization of the battery is caused. After the carbon nano tube is added into the negative electrode slurry, the space structure of the carbon nano tube is smooth, and the flowing of negative electrode lithium ions is facilitated, so that the accumulation of the lithium ions is reduced, the polarization degree of the battery is reduced, and finally the discharge capacity of large-current discharge can be improved.

Thirdly, the particle size of the graphite can influence the cycle discharge quality of the lithium manganate power battery. The combination of the graphite with the particle size of 80-100 meshes and 120-180 meshes has adverse effect on the retention rate of the battery cyclic discharge, and the combination of 60-80 meshes, 100-120 meshes and 160-180 meshes has remarkable improvement on the retention rate of the battery cyclic discharge.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

Fig. 1 is a schematic front structural view of the drying device according to one embodiment of the present invention;

fig. 2 is a schematic back structure diagram of the drying device according to one embodiment of the present invention.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials, if not otherwise specified, are commercially available; in the description of the present invention, the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings only for the convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

< example 1>

The lithium manganate battery drying method comprises the following steps:

step one, coating: coating the lithium manganate anode slurry on an aluminum foil, wherein the wet coating thickness is 200 mu m, and the aluminum foil thickness is 15 mu m;

coating the negative electrode slurry on a copper foil, wherein the wet coating thickness is 200 mu m, and the copper foil thickness is 15 mu m;

step two, drying pretreatment: treating the aluminum foil coated with the positive electrode slurry at 40 ℃ and 0.12MPa for 15min, reducing the pressure to normal pressure at the speed of 2kPa/min, increasing the pressure to 0.12MPa, and keeping the temperature at 40 ℃ for 30 min;

step three, drying: placing the aluminum foil with the positive electrode slurry after the drying pretreatment at 120 ℃ for vacuum drying for 18h, and rolling until the compaction density of the positive electrode plate is 2.3g/cm³Slicing to obtain a positive pole piece;

the copper foil coated with the negative electrode slurry is placed at the temperature of 90 ℃ for vacuum drying for 18h, and is rolled until the compaction density of the negative electrode plate is 1.3g/cm³Slicing to obtain a negative pole piece;

and step four, assembling the sliced positive pole piece, negative pole piece, diaphragm and electrolyte into the aluminum-shell battery.

The preparation method of the lithium manganate anode slurry comprises the following steps: uniformly mixing lithium manganate, a conductive agent and a binder in N-methyl pyrrolidone according to the mass ratio of 92:4:4, wherein the viscosity of the positive electrode slurry is 7250 us/cm;

the preparation method of the cathode slurry comprises the following steps: the graphite, the conductive agent and the binder are uniformly mixed in pure water according to the mass ratio of 91:5:4, the viscosity of the negative electrode slurry is 2250us/cm, and the particle size of the graphite is below 60 meshes.

The conductive agent adopts SUPER-P, the diaphragm adopts a polyethylene single-layer film, and the electrolyte is LiPF₆EC (1mol/L) + EMC + DEC, and the volume ratio is 1:1:1, and the dosage is 30 g;

the formation system is as follows:

the 1000mA is charged to 55% of the charge capacity with constant current, then the 1000mA is discharged to 3.2V with constant current, then the 1000mA is charged with constant current to 70% of the charge capacity, and then the 1000mA is discharged to 4V with constant current.

< example 2>

The lithium manganate battery drying method comprises the following steps:

step one, coating: coating the lithium manganate anode slurry on an aluminum foil, wherein the wet coating thickness is 200 mu m, and the aluminum foil thickness is 15 mu m;

coating the negative electrode slurry on a copper foil, wherein the wet coating thickness is 200 mu m, and the copper foil thickness is 15 mu m;

step two, drying pretreatment: treating the aluminum foil coated with the positive electrode slurry at 50 ℃ and 0.13MPa for 20min, reducing the pressure to normal pressure at the speed of 3kPa/min, increasing the pressure to 0.13MPa, and keeping the temperature at 50 ℃ for 50 min;

step three, drying: placing the aluminum foil with the positive electrode slurry after the drying pretreatment at 150 ℃ for vacuum drying for 20h, and rolling until the compaction density of the positive electrode plate is 2.3g/cm³Slicing to obtain a positive pole piece;

the copper foil coated with the negative electrode slurry is placed at the temperature of 90 ℃ for vacuum drying for 18h, and is rolled until the compaction density of the negative electrode plate is 1.3g/cm³Slicing to obtain a negative pole piece;

and step four, assembling the sliced positive pole piece, negative pole piece, diaphragm and electrolyte into the aluminum-shell battery.

The preparation method of the lithium manganate anode slurry comprises the following steps: uniformly mixing lithium manganate, a conductive agent and a binder in N-methyl pyrrolidone according to the mass ratio of 93:3:4, wherein the viscosity of the positive electrode slurry is 8250 us/cm;

the preparation method of the cathode slurry comprises the following steps: and uniformly mixing graphite, a conductive agent and a binder in pure water according to a mass ratio of 94:2:4, wherein the viscosity of the negative electrode slurry is 3250us/cm, and the particle size of the graphite is below 60 meshes.

The conductive agent adopts SUPER-P, the diaphragm adopts a polyethylene single-layer film, and the electrolyte is LiPF₆/EC(1mol/L)

+ EMC + DEC in a volume ratio of 1:1:1, in an amount of 30 g;

the formation system is as follows:

the 1000mA is charged to 55% of the charge capacity with constant current, then the 1000mA is discharged to 3.2V with constant current, then the 1000mA is charged with constant current to 70% of the charge capacity, and then the 1000mA is discharged to 4V with constant current.

< example 3>

The lithium manganate battery drying method comprises the following steps:

step one, coating: coating the lithium manganate anode slurry on an aluminum foil, wherein the wet coating thickness is 200 mu m, and the aluminum foil thickness is 15 mu m;

coating the negative electrode slurry on a copper foil, wherein the wet coating thickness is 200 mu m, and the copper foil thickness is 15 mu m;

step two, drying pretreatment: treating the aluminum foil coated with the positive electrode slurry at 45 ℃ under 0.12MPa for 18min, reducing the pressure to normal pressure at the speed of 2kPa/min, increasing the pressure to 0.12MPa, and maintaining the temperature at 45 ℃ for 40 min;

step three, drying: placing the aluminum foil with the positive electrode slurry after the drying pretreatment at 140 ℃ for vacuum drying for 18h, and rolling until the compaction density of the positive electrode plate is 2.3g/cm³Slicing to obtain a positive pole piece;

the copper foil coated with the negative electrode slurry is placed at the temperature of 90 ℃ for vacuum drying for 18h, and is rolled until the compaction density of the negative electrode plate is 1.3g/cm³Slicing to obtain a negative pole piece;

and step four, assembling the sliced positive pole piece, negative pole piece, diaphragm and electrolyte into the aluminum-shell battery.

The preparation method of the lithium manganate anode slurry comprises the following steps: uniformly mixing lithium manganate, a conductive agent and a binder in N-methyl pyrrolidone according to the mass ratio of 93:3:4, wherein the viscosity of the positive electrode slurry is 8000 us/cm;

the preparation method of the cathode slurry comprises the following steps: and uniformly mixing graphite, a conductive agent and a binder in pure water according to a mass ratio of 93:3:4, wherein the viscosity of the negative electrode slurry is 3000us/cm, and the particle size of the graphite is below 60 meshes.

The conductive agent adopts SUPER-P, the diaphragm adopts a polyethylene single-layer film, and the electrolyte is LiPF₆EC (1mol/L) + EMC + DEC, and the volume ratio is 1:1:1, and the dosage is 30 g;

the formation system is as follows:

the 1000mA is charged to 55% of the charge capacity with constant current, then the 1000mA is discharged to 3.2V with constant current, then the 1000mA is charged with constant current to 70% of the charge capacity, and then the 1000mA is discharged to 4V with constant current.

< example 4>

The lithium manganate battery drying method is the same as in example 3, wherein the difference is that a carbon nanotube is added to the negative electrode slurry, that is, the preparation method of the negative electrode slurry is as follows: and uniformly mixing graphite, a conductive agent, a carbon nano tube and a binder in pure water according to a mass ratio of 93:3:1:3, wherein the viscosity of the negative electrode slurry is 3000 us/cm.

The graphite is obtained by mixing 60-80 meshes, 100-120 meshes and 160-180 meshes according to the mass ratio of 25:30: 45.

< example 5>

The lithium manganate battery drying method is the same as in example 3, except that graphite is obtained by mixing 60-80 mesh, 100-120 mesh and 160-180 mesh in a mass ratio of 25:30: 45.

< comparative example 1>

The lithium manganate battery drying method is the same as example 3, except that the drying pretreatment of the second step is not performed, that is, the aluminum foil coated with the positive electrode slurry is directly dried, placed at 140 ℃ for vacuum drying for 18 hours, rolled until the compaction density of the positive electrode piece is 2.3g/cm³And slicing to obtain the positive pole piece.

< comparative example 2>

The lithium manganate battery drying method is the same as example 3, wherein the difference is that the particle size of the graphite is 60-180 meshes.

< comparative example 3>

The lithium manganate battery drying method is the same as example 3, except that graphite is obtained by mixing particles of 80-100 meshes and 120-180 meshes in a mass ratio of 40: 60.

< detection of Battery Performance >

1. Influence of temperature on discharge Capacity

The lithium manganate batteries prepared in examples 1 to 5 and comparative example 1 were placed at-10 ℃, 0 ℃ and 20 ℃ respectively, and their discharge capacities were measured at 0.5C, with the results shown in table 1:

TABLE 1 Effect of temperature on discharge Capacity

As can be seen from Table 1, the low temperature has a significant influence on the discharge capacity of the lithium manganate battery, and as can be seen from the data of example 3 (after the anode slurry is coated on the aluminum foil, the pre-drying treatment is performed) and comparative example 1 (after the anode slurry is coated on the aluminum foil, the drying treatment is not performed, but the drying treatment is directly performed), the pre-drying treatment (the aluminum foil coated with the anode slurry is treated at a temperature of 40-50 ℃ and a pressure of 0.12-0.13 MPa for 15-20 min, then the pressure is reduced to the normal pressure at a speed of 2-3 kPa/min, then the pressure is increased to 0.12-0.13 MPa, the temperature is maintained at 40-50 ℃ for 30-50 min), not only can the absolute discharge capacity be improved, but also the influence of the low temperature is significantly reduced, the discharge capacity of the battery prepared in example 3 is only reduced by 0.9% compared with 20 ℃ at 0 ℃, namely, the retention rate is 99.1%, and at-10 ℃, the discharge capacity of the lithium manganate battery is reduced by 3.4% only when the lithium manganate battery is at 20 ℃, namely, the retention rate reaches 96.6%, while the battery prepared in comparative example 1 has the discharge capacity reduced by 1.9% when the lithium manganate battery is at 0 ℃, namely, the retention rate reaches 98.1%, and has the discharge capacity reduced by 5.3% only when the lithium manganate battery is at-10 ℃, namely, the retention rate reaches 94.7%, namely, the low-temperature resistance of the lithium manganate battery can be obviously improved after the lithium manganate battery is subjected to drying pretreatment.

The analysis reason may be that repeated pressurization and temperature control treatment before drying can make the arrangement of each particle of the anode slurry finer, and the nitrogen pressurization mode is adopted, so that the force of each particle is uniform when the particles are pressed and compacted, and the uniformity of particle distribution is improved, so that after drying and when the external temperature changes, the shape and arrangement of each particle of the anode slurry are changed uniformly and adaptively due to the temperature change, the overall influence is reduced, and the defect of discharge capacity change caused by the temperature change is reduced.

2. Rate capability

The rate performance of the lithium manganate batteries prepared in examples 1 to 5 were tested by 0.5C, 2C, 5C discharge, respectively, and the results are shown in table 2:

TABLE 2 multiplying power test results of lithium manganate batteries

As can be seen from the data in table 2, the retention rates of the batteries prepared in examples 1 to 5 at 2C discharge capacity ratio of 0.5C were all 95.8% or more, while the discharge capacity decreased significantly at 5C discharge.

As can be seen from comparison between example 3 (in which the negative electrode slurry does not contain carbon nanotubes) and example 4 (in which the negative electrode slurry contains carbon nanotubes), the retention rate of example 3 is 88.1% when 5C is discharged, while the retention rate of example 4 is 91.4%, and the amount of decrease in the battery discharge capacity of example 4 is significantly reduced, which indicates that the discharge capacity during large-current discharge can be significantly increased by adding carbon nanotubes to the negative electrode slurry.

The analysis reason is as follows: when the large current is discharged, the lithium manganate power battery has polarization phenomenon. When large current is discharged, the speed of positive electrode electrons flowing into the electrode is high, so that the accumulation of electrons is caused, but the speed of negative electrode lithium ions flowing out is not increased, so that the accumulation of lithium ions is caused, the negative electrode potential moves in a negative direction, the original balance state is broken, and the polarization of the battery is caused. After the carbon nano tube is added into the negative electrode slurry, the space structure of the carbon nano tube is smooth, and the flowing of negative electrode lithium ions is facilitated, so that the accumulation of the lithium ions is reduced, the polarization degree of the battery is reduced, and finally the discharge capacity of large-current discharge can be improved.

3. Battery cycling capacity test

The 1C current multiplying power tests the capacity and cycle performance of the lithium manganate batteries prepared in examples 1-5 and comparative examples 2 and 3, respectively, and the results are shown in the following table:

TABLE 3 influence of graphite particle size combination on the capacity and cycling performance of lithium manganate batteries

Group of	Capacity retention ratio 100 times%	Capacity retention ratio 200 times%	Capacity retention ratio at 300 times%
				Example 1	97.8	94.0	91.2
Example 2	97.0	93.2	91.0
				Example 3	97.6	93.8	91.5
Example 4	97.4	93.9	91.4
				Example 5	98.1	94.6	92.7
Comparative example 2	97.2	93.3	91.0
				Comparative example 3	96.9	92.7	90.6

After the lithium manganate power batteries prepared in the embodiments 1-5 and the comparative examples 1 and 2 are cycled for 300 times, the capacity retention rate is more than 90%, the attenuation rate is lower than 10%, and the lithium manganate power batteries accord with GB/T18287-2000 national standards;

as can be seen from the comparison of the data in Table 3 for example 3 (the particle size of graphite is below 60 mesh) and example 5 (the particle size of graphite is 60-80 mesh, 100-120 mesh and 160-180 mesh respectively), the particle size of graphite affects the cycle discharge quality of lithium manganate-based power batteries.

As can be seen from comparison of the data in example 5 and comparative examples 2 and 3, the combination of graphite particles with particle sizes in the ranges of 80-100 meshes and 120-180 meshes has an adverse effect on the retention rate of the battery cycle discharge, while the combination of graphite particles with particle sizes in the ranges of 60-80 meshes, 100-120 meshes and 160-180 meshes has a significant improvement on the retention rate of the battery cycle discharge.

As shown in FIGS. 1-2, the lithium manganate battery drying device comprises:

the box body 1 is provided with an air inlet pipe 5, an air outlet pipe 4 and a closed door 2, the air inlet pipe 5 is used for being communicated with a nitrogen supply part, and valves are arranged on the air inlet pipe 5 and the air outlet pipe 4;

a pressure detection mechanism for detecting a pressure inside the case 1;

a heating mechanism provided in the case 1;

and a temperature detection mechanism for detecting the temperature in the case 1.

In the above technical scheme, the aluminum foil coated with the positive electrode slurry is horizontally placed in the preheated box body 1, the air inlet pipe 5 and the exhaust pipe 4 are opened, when the air is discharged to a certain value, the exhaust pipe 4 is closed, the pressure in the box body 1 rises, when the preset pressure value is reached, the inflation is stopped, and the drying pretreatment is carried out according to the preset process. Therefore, can match the dry pretreatment process of this application, convenient and fast's production battery.

In another technical scheme, the box body further comprises a plurality of partition layers 3, and the partition layers 3 are horizontally arranged in the box body 1 at intervals. The space utilization rate of the box body 1 can be increased by arranging the plurality of layers.

In another technical scheme, the air extracting device further comprises an air extracting mechanism, the air extracting mechanism comprises an air extracting pipe 6 arranged on the box body 1 and an air extracting pump communicated with the air extracting pipe 6, and the air extracting pipe 6 is provided with the air extracting pump. The process of vacuum drying can be directly finished in the box body 1, so that the operation flow is saved, the time is saved, and the production efficiency is improved. After the drying pretreatment process is finished, the air inlet pipe 5 can be closed, and the exhaust pipe 6 and the heating mechanism are opened to realize vacuum drying.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.