CN115615194A

CN115615194A - Precursor sintering device for preparing positive electrode of sodium-ion battery

Info

Publication number: CN115615194A
Application number: CN202211234059.8A
Authority: CN
Inventors: 梁风; 向孙祖; 张涛; 沈可
Original assignee: Jiangsu Fengchi Carbon Based New Materials Research Institute Co ltd
Current assignee: Jiangsu Fengchi Carbon Based New Materials Research Institute Co ltd
Priority date: 2022-10-10
Filing date: 2022-10-10
Publication date: 2023-01-17

Abstract

The invention relates to the field of sintering equipment, and particularly discloses a precursor sintering device for preparing a sodium-ion battery anode. The technical scheme comprises the following steps: a sealed sintering space is formed inside the sintering furnace; the inside of fritting furnace rotates and is provided with the axis of rotation, and the axis of rotation is hollow structure, and the top of axis of rotation stretches out the fritting furnace and the intercommunication is provided with condensing agent valve interface. The screw rod sleeve is nested on the rotating shaft in a matched mode, the screw rod sleeve is fixedly provided with the helical blade, the friction force between the rotating shaft and the screw rod sleeve is smaller than the sum of the gravity of the screw rod sleeve and the gravity of the helical blade, and the heating unit and the cavity are arranged inside the helical blade. And the rotation driving structure is fixedly arranged on the furnace body of the sintering furnace. And the temperature sensor is arranged inside the sintering furnace. The second electromagnet is fixedly connected to the furnace cover. And the controller is used for controlling the heating unit to heat. The invention can automatically adjust feeding and scraping blades, and can better heat and cool the precursor.

Description

Precursor sintering device for preparing positive electrode of sodium-ion battery

Technical Field

The invention relates to the field of sintering equipment, in particular to a precursor sintering device for preparing a sodium-ion battery anode.

Background

The concept of sodium ion batteries began in the 80's of the 20 th century almost simultaneously with lithium ion batteries. The working principle of the sodium ion battery is similar to that of lithium ion, and Na is generated during charging ⁺ The electrolyte is removed from the anode material, and is embedded into the cathode material through the electrolyte, and meanwhile, electrons are transferred to the cathode through an external circuit to keep charge balance; the opposite is true for discharge.

In principle, the charging time of a sodium ion battery can be shortened to 1/5 of that of a lithium ion battery. The most important characteristic of the sodium ion battery is that Na + is used to replace expensive Li +, and in order to adapt to the sodium ion battery, the anode material, the cathode material, the electrolyte and the like are changed correspondingly. Compared with lithium, the sodium ion battery has the advantages that the resource is rich, the method for obtaining sodium by sodium resource accounts for about 2.64% of the storage amount of crust element is also very simple, and therefore, compared with the lithium ion battery, the sodium ion battery has more advantages in cost.

Although the energy density of the sodium ion battery is lower than that of the lithium ion battery, the sodium ion battery still has a very wide application prospect in the aspect of the high price rise of lithium carbonate at present: and the method has wide application prospect in the fields with low energy density requirement, such as power grid energy storage, peak shaving, wind power generation energy storage and the like. In the future, the sodium ion battery will gradually replace a lead-acid battery, is widely applied to various low-speed electric vehicles, and is complementary with a lithium ion battery.

The sintering furnace at the present stage can meet the basic use requirements when in use, but still has defects and shortcomings in some aspects when in actual use: the precursor is easy to agglomerate and is easy to be heated unevenly during heating.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a precursor sintering device for preparing a positive electrode of a sodium ion battery, including:

a sintering furnace, wherein a sealed sintering space is formed inside the sintering furnace; a rotating shaft is rotatably arranged in the sintering furnace, the rotating shaft is of a hollow structure, the top of the rotating shaft extends out of the sintering furnace and is communicated with a condensing agent valve interface, and the condensing agent valve interface is used for being communicated with a nitrogen cylinder and controlling the flow; the screw rod sleeve is nested on the rotating shaft in a matched mode, the screw rod sleeve is fixedly provided with a helical blade, the friction force between the rotating shaft and the screw rod sleeve is smaller than the sum of the gravity of the screw rod sleeve and the gravity of the helical blade, a heating unit and a cavity are arranged inside the helical blade, and the cavity inside the helical blade is communicated with the rotating shaft in a sliding mode; the bottom of the sintering furnace is provided with a discharge port;

the rotation driving structure is fixedly arranged on a furnace body of the sintering furnace and is used for driving the rotation shaft to rotate;

the temperature sensor is arranged inside the sintering furnace and used for sensing the sintering temperature;

the second electromagnet is fixedly connected to the furnace cover and used for adsorbing the screw rod sleeve to lift and fix the screw rod sleeve;

the controller is used for controlling the heating unit to heat, the temperature sensor senses that the internal temperature of the sintering furnace is T, and the controller judges whether T is greater than a preset temperature T; if the second electromagnet is controlled to be closed by the controller, the spiral blade descends under the action of gravity, the screw rod sleeve rotates relative to the rotating shaft and moves axially and downwards, the bottom of the spiral blade is in contact with the upper surface of the precursor, and the rotating shaft drives the spiral blade to rotate to scrape the upper surface of the precursor, so that the precursor forms fine particles and is in contact with the spiral blade to heat; the controller judges whether T is greater than a preset temperature T'; if so, the controller controls the rotary driving piece to drive the rotary shaft to rotate reversely; lifting the spiral blade to press the precursor for heat preservation and sintering; after sintering is finished, the controller controls the heating unit to be closed, controls the interface of the condensing agent valve to enable nitrogen to enter the spiral blade, controls the rotating shaft to rotate in the forward direction, and enables the spiral blade to rotate to scrape the upper surface of the precursor, so that the precursor forms fine particles to be in contact with the spiral blade to be cooled; the controller judges whether T is less than a preset temperature T', if so, the controller controls the discharge of the sintered precursor.

Preferably: the sintering furnace comprises a furnace body and a furnace cover, wherein the furnace body is of a cylindrical structure; the furnace cover is a disc-shaped structure and is used for covering the top of the furnace body to form a sealed sintering space.

Preferably: the lower surface edge of the furnace cover is fixedly provided with an interference ring, and when the furnace cover is covered on the top of the furnace body, the interference ring covers the periphery of the top of the furnace body.

Preferably: the inner wall of screw rod cover includes smooth portion and thread groove portion, and thread groove portion passes through the ball cooperation with the axis of rotation outer wall, and smooth portion is in the both ends of thread groove portion, and a plurality of first thru holes have been seted up radially to the axis of rotation, and the second thru hole has been seted up on the screw rod cover, second thru hole and helical blade intercommunication.

Preferably: the bottom of the helical blade is arranged to be in a circular arc structure.

Preferably: the smooth portion can pass through seal cover sealing fit with the outer wall of axis of rotation.

Preferably: the rotary driving structure comprises a driven belt pulley, a driving belt pulley and a motor, the motor is fixedly installed on the outer wall of the furnace body, the output shaft of the motor is fixedly connected with the driving belt pulley in a coaxial mode, the rotating shaft is fixedly connected with the driven belt pulley in a coaxial mode, and the driven belt pulley and the driving belt pulley are connected through a belt.

Preferably: the rotary shaft is coaxially and fixedly connected with a threaded sleeve, the furnace cover is embedded on the threaded sleeve in a matching manner, at least one rotation limiting unit is arranged between the furnace cover and the furnace body, and the rotation of the furnace cover is limited through the rotation limiting unit.

Preferably: the rotation limiting unit comprises a guide rod, a limiting cap and a first electromagnet, and the guide rod is circumferentially fixed on the outer side wall of the furnace body; the top fixedly connected with spring of guide bar, the guide bar slides and passes the outer edge of bell, and the nested spring that has on the guide bar is in between bell and the furnace body.

The invention has the technical effects and advantages that: through the cooperation of the helical blade and the helical groove of the rotating shaft, the automatic adjustment of feeding and scraping can be carried out, the precursor can be heated and cooled better, the heating is uniform and the cooling is rapid, the uniformity of precursor dispersion is improved, and the sintering quality of the precursor is improved.

Drawings

Fig. 1 is a schematic perspective view of a precursor sintering device for preparing a positive electrode of a sodium-ion battery according to the present invention.

Fig. 2 is a schematic top view of a precursor sintering device for preparing a positive electrode of a sodium-ion battery according to the present invention.

Fig. 3 isbase:Sub>A partial sectional structural view of the sectionbase:Sub>A-base:Sub>A in fig. 2.

Fig. 4 is a partially enlarged structural diagram of a in fig. 3.

Description of reference numerals: the furnace comprises a furnace body 1, a furnace cover 2, a limiting cap 3, a guide rod 4, a spring 5, a first electromagnet 6, a threaded sleeve 7, a driven belt pulley 8, a condensing agent valve interface 9, a driving belt pulley 10, a motor 11, a discharge port 12, a rotating shaft 13, a screw rod sleeve 14, a spiral blade 15, a second electromagnet 16, a smooth part 17, a first through hole 18, a second through hole 19 and a sealing sleeve 20.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention have been presented for purposes of illustration and description, and are not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Example 1

Referring to fig. 1 to fig. 3, in this embodiment, a precursor sintering apparatus for preparing a positive electrode of a sodium-ion battery is provided, which is used for calcining a precursor of the positive electrode of the sodium-ion battery, and includes:

the fritting furnace, inside sealed sintering space that forms, sintering space can be cylindrical structure, and the fritting furnace can include furnace body 1 and bell 2, and furnace body 1 can be cask type structure, has better rigidity and thermal insulation performance, can be provided with the heat preservation on the furnace body 1 to increase furnace body 1's heat preservation ability, do not specifically do here and describe repeatedly. The furnace cover 2 may be a disk-shaped structure and may cover the top of the furnace body 1, thereby forming a sealed sintering space. The side wall of the bottom of the sintering furnace is provided with a discharge opening 12, and the discharge opening 12 is provided with a control valve. The precursor raw material can be added into the sintering furnace by opening the furnace cover 2, and the precursor is discharged from the discharge port 12 after sintering. The lower surface edge portion of bell 2 can be fixed and be provided with the interference circle, and when bell 2 lid was at the furnace body 1 top, the interference circle can cover at the top periphery of furnace body 1 to increase the leakproofness of connecting. The furnace body 1 bottom can be provided with a plurality of supporting legs, the supporting leg can be provided with threely, the even circumference of three supporting leg is fixed in the bottom of furnace body 1 to make furnace body 1 be in the horizontality. Certainly, the bottom of the supporting leg can be provided with a universal wheel and/or a rolling wheel, the rolling wheel is a wheel which can not change the rotating direction, and the universal wheel and/or the rolling wheel are/is provided with a braking clamping plate, so that the precursor sintering device can be conveniently moved and fixed. Certainly, the bottom of the supporting leg can also be fixedly connected with a base plate, and the base plate enables the supporting leg to be placed stably.

The inside of fritting furnace rotates and is provided with axis of rotation 13, and axis of rotation 13 can coaxial rotation set up in the inside of furnace body 1, and axis of rotation 13 is hollow structure, and the top of axis of rotation 13 stretches out the fritting furnace and is provided with condensing agent valve interface 9 in the communication, can communicate and the control flow with the nitrogen cylinder through condensing agent valve interface 9. The screw sleeve 14 is nested on the rotating shaft 13, and can be matched with a ball through a spiral groove, which is not described herein. The screw rod sleeve 14 is fixedly provided with a spiral blade 15, the friction force between the rotating shaft 13 and the screw rod sleeve 14 is smaller than the sum of the gravity of the screw rod sleeve 14 and the gravity of the spiral blade 15, a heating unit and a cavity are arranged inside the spiral blade 15, and the cavity inside the spiral blade 15 can be in sliding communication with the rotating shaft 13.

Referring to fig. 4, the inner wall of the screw sleeve 14 may include a smooth portion 17 and a screw groove portion, the screw groove portion is matched with the outer wall of the rotating shaft 13 through balls, the smooth portion 17 is located at two ends of the screw groove portion, the smooth portion 17 and the outer wall of the rotating shaft 13 may be hermetically attached through a sealing sleeve 20, and of course, may also be directly attached to the outer wall of the rotating shaft 13, a plurality of first through holes 18 are radially formed in the rotating shaft 13, a second through hole 19 is formed in the screw sleeve 14, and the second through hole 19 is communicated with the helical blade 15. When the screw sleeve 14 axially slides and rotates relative to the rotating shaft 13, the first through hole 18 and the second through hole 19 can be always communicated, so that nitrogen inside the rotating shaft 13 can enter the inside of the helical blade 15, and the precursor inside the sintering furnace can be heated and cooled through the helical blade 15. The helical blade 15 may be made of a material with good thermal conductivity, such as copper, aluminum-copper alloy, graphite, and the like, which will not be described herein. The heating unit may be an electric heating wire structure or a heating agent introduced through a condensing agent valve interface 9, which is not described herein in detail. The bottom of the sintering furnace is provided with a discharge port 12, and the precursor sintered in the sintering furnace can be discharged through the discharge port 12. The bottom of the helical blade 15 can be set to be in an arc structure, and when the material needs to be discharged, the helical blade 15 rotates along with the screw rod sleeve 14, and the arc structure can push the precursor inside the sintering furnace to discharge the material to the periphery. Of course, the discharge opening 12 may be disposed at the bottom of the sintering furnace, and the precursor may be directly discharged from the discharge opening 12, which is not described herein.

Rotate the drive structure, can fixed mounting on the furnace body 1 of fritting furnace, be used for driving axis of rotation 13 to rotate, the rotation drive structure can include driven pulley 8, drive pulley 10 and

motor

11, 11 fixed mounting of motor can two-way drive on the outer wall of furnace body 1, the coaxial fixedly connected with drive pulley 10 of the output shaft of motor 11, the coaxial fixedly connected with driven pulley 8 of axis of rotation 13, driven pulley 8 and drive pulley 10 are connected through the belt, 11 drive pulley 10 of motor rotate, drive pulley 10 drives driven pulley 8 through the belt and rotates, accomplish axis of rotation 13 with this and rotate. Of course, the motor 11 and the rotating shaft 13 can also be driven by a gear combination, which is not described herein in detail.

The rotary shaft 13 can be coaxially and fixedly connected with the threaded sleeve 7, the furnace cover 2 is nested on the threaded sleeve 7 in a matched mode, at least one rotation limiting unit can be arranged between the furnace cover 2 and the furnace body 1, the furnace cover 2 is limited to rotate through the rotation limiting unit, when the rotary shaft 13 rotates in the forward direction, the rotary shaft 13 drives the threaded sleeve 7 to rotate, the threaded sleeve 7 drives the furnace cover 2 to descend, so that the furnace cover 2 covers the top of the furnace body 1, the furnace cover 2 is separated from the threaded sleeve 7 at the moment, and the threaded sleeve 7 presses the furnace cover 2 downwards to complete sealing of the sintering furnace. When the rotating shaft 13 rotates reversely, the threaded sleeve 7 can drive the furnace cover 2 to lift, so that the furnace cover 2 is separated from the furnace body 1, and the precursor is conveniently added into the sintering furnace. The rotating shaft 13 rotates until the furnace cover 2 is separated from the threaded sleeve 7, and then the furnace cover stops lifting. When the rotating shaft 13 rotates forwards, the furnace cover 2 is sleeved on the threaded sleeve 7 under the action of gravity and is matched with the threaded sleeve, and the furnace cover 2 descends to cover the furnace body 1. The rotation limiting unit can comprise a guide rod 4, a limiting cap 3 and a first electromagnet 6, wherein the guide rod 4 is circumferentially fixed on the outer side wall of the furnace body 1. The top fixedly connected with spring 5 of guide bar 4, guide bar 4 slide and pass the outer edge of bell 2, and nested spring 5 has on the guide bar 4, and spring 5 is in between bell 2 and the furnace body 1. The furnace cover 2 can be lifted upwards and nested on the threaded sleeve 7 under the action of the spring 5. The fixed first electro-magnet 6 that is provided with in top of bell 2, first electro-magnet 6 can adsorb furnace body 1 under the on-state to make the sealed lid of bell 2 at 1 top of furnace body, and make bell 2 break away from with furnace body 1, bell 2 is provided with the iron sheet for iron, stainless steel material or bell 2 corresponding position this moment, furnace body 1 and bell 2 can also carry out fixed connection through the bolt certainly, specifically do not give unnecessary detail here.

And the temperature sensor is arranged inside the sintering furnace and used for sensing the sintering temperature.

And the second electromagnet 16 can be fixedly connected to the furnace cover 2 and is used for adsorbing the screw rod sleeve 14, so that the screw rod sleeve 14 is lifted and fixed.

And the controller is electrically or wirelessly connected with the rotary driving piece, the condensing agent valve interface 9, the heating unit, the second electromagnet 16, the first electromagnet 6 and the temperature sensor. The controller controls the first electromagnet 6 to be powered off, the furnace cover 2 is lifted to be in contact with the threaded sleeve 7 under the action of the spring 5, the controller controls the rotary driving piece to drive the rotary shaft 13 to rotate reversely, the threaded sleeve 7 drives the furnace cover 2 to be lifted, the furnace cover 2 and the furnace body 1 are separated, and a precursor can be conveniently added into the sintering furnace. The screw sleeve 14 can be manually raised and the second electromagnet 16 can be activated to attract the screw sleeve 14. Of course, the precursor addition can also be carried out directly by opening the bolt. When the controller controls the rotary driving piece to drive the rotary shaft 13 to rotate forwards, the rotary shaft 13 drives the threaded sleeve 7 to rotate, the threaded sleeve 7 drives the furnace cover 2 to descend, so that the furnace cover 2 covers the top of the furnace body 1, the furnace cover 2 is separated from the threaded sleeve 7 at the moment, the threaded sleeve 7 presses the furnace cover 2 downwards to complete sealing of the sintering furnace, and the controller controls the first electromagnet 6 to start and adsorb the furnace body 1 to complete sealing. Of course, the connection can also be made directly by means of screws. The controller controls the heating unit to heat, the temperature sensor senses that the internal temperature of the sintering furnace is T, the controller judges whether T is greater than a preset temperature T, T is the preheating temperature of the precursor, the design can be carried out according to actual needs, and if not, the heating unit continues to maintain; if yes, the controller controls the second electromagnet 16 to close, and the helical blade 15 descends under the action of gravity, or the helical blade may cooperate with the acceleration of the rotating shaft 13 through gravity, which is not described herein in detail. The screw rod sleeve 14 rotates relative to the rotating shaft 13 and moves axially downwards, the bottom of the spiral blade 15 is in contact with the upper surface of the precursor, the precursor has a barrier effect on the descending of the spiral blade 15, the rotating shaft 13 drives the spiral blade 15 to rotate to scrape the upper surface of the precursor, so that the precursor forms fine particles and is in contact with the spiral blade 15 to be heated, when the resistance of the precursor is smaller than the gravity of the spiral blade 15, the spiral blade 15 is axially fed to scrape the precursor, the dispersibility of the precursor is increased, and the uniformity of sintering is improved. The controller judges whether T is larger than a preset temperature T ', wherein T' is the sintering temperature of the precursor, if not, the controller continues to maintain, and if so, the controller controls the rotary driving piece to drive the rotary shaft 13 to rotate reversely. The resistance of the precursor to the helical blade 15 is larger than the gravity of the helical blade 15, the helical blade 15 is lifted, and the precursor is pressed down for heat preservation and sintering. After sintering is finished, the controller controls the heating unit to be closed, the condensing agent valve interface 9 is controlled to enable nitrogen to enter the spiral blade 15, the controller controls the rotating shaft 13 to rotate in the forward direction, the screw rod sleeve 14 rotates relative to the rotating shaft 13 and moves axially downwards, the bottom of the spiral blade 15 is in contact with the upper surface of the precursor, the precursor has a blocking effect on descending of the spiral blade 15, the rotating shaft 13 drives the spiral blade 15 to rotate to scrape the upper surface of the precursor, and therefore the precursor forms fine particles to be in contact with the spiral blade 15 to be cooled, and the cooling effect is good and rapid. The controller determines whether T is less than a preset temperature T ", where T" is the cooling temperature of the precursor, if not, the process continues to be maintained, and if so, the controller controls the discharge opening 12 to be opened and the sintered precursor to be discharged. Through the screw blade 15 and the screw groove cooperation of the rotating shaft 13, the automatic adjustment of feeding and scraping can be carried out, the precursor can be better heated and cooled, the heating is uniform and the cooling is rapid, the uniformity of precursor dispersion is improved, and the sintering quality of the precursor is improved.

It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by one of ordinary skill in the art and related arts based on the embodiments of the present invention without any creative effort, shall fall within the protection scope of the present invention. Structures, devices, and methods of operation not specifically described or illustrated herein are generally practiced in the art without specific recitation or limitation.

Claims

1. The utility model provides a precursor sintering device is used in positive preparation of sodium-ion battery, characterized in that, precursor sintering device includes for the positive preparation of sodium-ion battery:

the rotation driving structure is fixedly arranged on a furnace body of the sintering furnace and is used for driving the rotating shaft to rotate;

the temperature sensor is arranged inside the sintering furnace and is used for sensing the sintering temperature;

the controller is used for controlling the heating unit to heat, the temperature sensor senses that the internal temperature of the sintering furnace is T, and the controller judges whether T is greater than a preset temperature T; if the second electromagnet is controlled to be closed by the controller, the spiral blade descends under the action of gravity, the screw rod sleeve rotates relative to the rotating shaft and moves axially and downwards, the bottom of the spiral blade is in contact with the precursor, and the rotating shaft drives the spiral blade to rotate to scrape the upper surface of the precursor, so that the precursor forms fine particles and is in contact with the spiral blade to be heated; the controller judges whether T is greater than a preset temperature T'; if so, the controller controls the rotary driving piece to drive the rotary shaft to rotate reversely; lifting the spiral blade to press the precursor for heat preservation and sintering; after sintering is finished, the controller controls the heating unit to be closed, controls the interface of the condensing agent valve to enable nitrogen to enter the spiral blade, controls the rotating shaft to rotate in the forward direction, and rotates the spiral blade to scrape the precursor body so that the precursor body forms fine particles to be in contact with the spiral blade for cooling; the controller judges whether T is less than a preset temperature T', if yes, the controller controls the sintered precursor to be discharged.

2. The sintering device for the precursors for preparing the sodium-ion battery anode according to claim 1, wherein the sintering furnace comprises a furnace body and a furnace cover, and the furnace body is of a cylindrical structure; the furnace cover is a disc-shaped structure and is used for covering the top of the furnace body to form a sealed sintering space.

3. The sintering device for sodium-ion battery positive electrode precursor according to claim 2, wherein an interference ring is fixedly arranged at the edge of the lower surface of the furnace cover, and when the furnace cover is arranged at the top of the furnace body, the interference ring covers the periphery of the top of the furnace body.

4. The sintering device for precursors used in preparation of the positive electrode of the sodium-ion battery according to claim 1, wherein the inner wall of the screw sleeve comprises a smooth portion and a screw groove portion, the screw groove portion is engaged with the outer wall of the rotating shaft through balls, the smooth portion is disposed at two ends of the screw groove portion, a plurality of first through holes are radially formed in the rotating shaft, and a second through hole is formed in the screw sleeve and is communicated with the helical blade.

5. The sintering device for sodium-ion battery positive electrode precursor according to claim 1, wherein the bottom of the helical blade is configured to be a circular arc structure.

6. The sintering device for the precursor used in the preparation of the positive electrode of the sodium-ion battery as claimed in claim 4, wherein the smooth portion is hermetically attached to the outer wall of the rotating shaft by a sealing sleeve.

7. The sintering device for the precursor for preparing the positive electrode of the sodium-ion battery as claimed in claim 1, wherein the rotation driving structure comprises a driven pulley, a driving pulley and a motor, the motor is fixedly installed on the outer wall of the furnace body, the driving pulley is coaxially and fixedly connected with an output shaft of the motor, the driven pulley is coaxially and fixedly connected with a rotating shaft, and the driven pulley and the driving pulley are connected through a belt.

8. The sodium-ion battery anode preparation precursor sintering device according to claim 1, wherein the rotating shaft is coaxially and fixedly connected with a threaded sleeve, the furnace cover is fittingly nested on the threaded sleeve, at least one rotation limiting unit is arranged between the furnace cover and the furnace body, and the rotation of the furnace cover is limited by the rotation limiting unit.

9. The sintering device for the precursor for preparing the sodium-ion battery anode according to claim 8, wherein the rotation limiting unit comprises a guide rod, a limiting cap and a first electromagnet, and the guide rod is circumferentially fixed on the outer side wall of the furnace body; the top fixedly connected with spring of guide bar, the guide bar slides and passes the outer edge of bell, and the nested spring that has on the guide bar is in between bell and the furnace body.