CN116967120A - Natural graphite screening device for preparing negative electrode material of power lithium battery - Google Patents

Abstract

The invention relates to a screening device, in particular to a natural graphite screening device for preparing a negative electrode material of a power lithium battery. The invention provides a natural graphite screening device for preparing a negative electrode material of a power lithium battery, which can remove metal impurities in graphite. The invention provides a natural graphite screening device for preparing a power lithium battery cathode material, which comprises a bottom plate, fixing sleeves and sliding frames, wherein the tops of the two bottom plates are fixedly connected with the two fixing sleeves, the sliding frames are arranged between the two fixing sleeves on the front side in a sliding manner, and the sliding frames are also arranged between the two fixing sleeves on the rear side in a sliding manner. Graphite constantly moves and contacts with the magnetic rod in the screening process, and under the action of the magnetic rod, metal impurities mixed in the graphite can be adsorbed, so that the function of removing the metal impurities in the graphite is realized, and the quality of the prepared cathode material can be improved.

Description

Natural graphite screening device for preparing negative electrode material of power lithium battery

Technical Field

The invention relates to a screening device, in particular to a natural graphite screening device for preparing a negative electrode material of a power lithium battery.

Background

The negative electrode material is a carrier of lithium ions and electrons in the charging process of the battery, plays roles in storing and releasing energy, and is widely applied to the preparation of the negative electrode material because the graphite has the advantages of high electron conductivity, large lithium ion diffusion coefficient, high lithium intercalation capacity, low lithium intercalation potential and the like.

Patent grant bulletin number CN 206527058U's patent discloses a high-efficient graphite screening plant, the on-line screen storage device comprises a base, be fixed with the installing support on the base, cylindrical first screening room that from top to bottom set gradually on the installing support, square second screening room and vibration third screening room, first screening room middle part is provided with first screen cloth, first screen cloth middle part is provided with the rotating electrical machines, the rotating electrical machines rotates and is connected with first screen cloth scraper blade, second screening room middle part is provided with the second screen cloth, second screen cloth upper portion slip is provided with the second screen cloth brush, third screening room middle part is provided with the third screen cloth, third screen cloth upper portion slip is provided with the third screen cloth brush, third screening room bottom is installed on installing support upper portion through the spring, third screening room one side is connected with vibrating component, although above-mentioned patent is when sieving graphite, can clear up the screen cloth simultaneously, but above-mentioned patent does not possess the function of getting rid of metal impurity in the graphite, lead to metal impurity to the metal impurity to mix in graphite, thereby influence the quality of making negative pole material.

Therefore, it is necessary to invent a natural graphite screening device for preparing a negative electrode material of a power lithium battery, which can remove metal impurities in graphite, so as to solve the above problems.

Disclosure of Invention

In order to overcome the defect that the quality of the prepared negative electrode material is affected by mixing metal impurities in graphite due to the fact that the patent does not have a function of removing the metal impurities in the graphite, the invention provides a natural graphite screening device for preparing the negative electrode material of a power lithium battery, which can remove the metal impurities in the graphite.

The invention is realized by the following technical approaches: the utility model provides a power class lithium cell negative pole material preparation is with natural graphite screening plant, including the bottom plate, fixed cover, the carriage, the guide bar, the slider, the unloading frame, the discharging frame, the screen cloth, pushing mechanism and edulcoration mechanism, two fixed covers of all rigid couplings at two bottom plate tops, be provided with the carriage between two fixed covers of front side, also be provided with the carriage between two fixed covers of rear side, carriage upper portion rigid coupling has the guide bar, the sliding type is provided with two sliders on the guide bar, the rigid coupling has the unloading frame between four sliders, the rigid coupling has three discharging frame in the unloading frame, all the rigid coupling has the screen cloth in the discharging frame of left side and intermediate position, be provided with the pushing mechanism that is used for promoting unloading frame removal on the carriage, be provided with the edulcoration mechanism that is used for getting rid of metal impurity on the unloading frame.

In one embodiment, the pushing mechanism comprises a mounting plate, a motor, a cam, a partition plate and a first elastic piece, wherein the mounting plate is fixedly connected between the right parts of the two sliding frames, the motor is mounted on the mounting plate, an output shaft of the motor is connected with the cam in a key manner, the cam rotates to extrude the blanking frame to move, two sliding grooves are formed in the front wall and the rear wall of the blanking frame, the partition plate is arranged between the two sliding grooves on the left side in a sliding manner, the partition plate is also arranged between the two sliding grooves on the right side in a sliding manner, the first elastic piece is connected between the sliding block and the sliding frame, and the first elastic piece is sleeved on the guide rod.

In one embodiment, the impurity removing mechanism comprises a mounting sleeve, sliding blocks, pull rods and magnetic rods, wherein the two mounting sleeves are detachably arranged at the top of the blanking frame, the sliding blocks are arranged in the mounting sleeves, the pull rods are fixedly connected to the front side and the rear side of each sliding block, the magnetic rods are fixedly connected to the bottoms of the sliding blocks at uniform intervals, and the magnetic rods are positioned in the blanking frame.

In one embodiment, the lifting mechanism for lifting the mounting sleeve further comprises a support, slide bars and a screw rod, wherein the support is fixedly connected between the tops of the two slide frames, the left side and the right side of the upper portion of the support are respectively provided with two slide bars in a sliding mode, the bottoms of the slide bars are connected with the tops of the similar mounting sleeves, the screw rods are respectively arranged on the left side and the right side of the upper portion of the support in a threaded mode, and the screw rods are rotatably connected with the tops of the similar mounting sleeves.

In one embodiment, the scraper mechanism for scraping the impurities on the magnetic rod comprises a mounting frame, a scraping frame, torsion springs and extrusion blocks, wherein two mounting frames are fixedly connected to the left side and the right side of the upper portion of the support, the scraping frame is rotatably arranged on the lower portion of the mounting frame, four torsion springs are connected between the scraping frame and the mounting frame, the torsion springs are sleeved on the scraping frame, two extrusion blocks are fixedly connected to the front side and the rear side of the top of the mounting sleeve, the extrusion blocks move upwards to extrude the scraping frame to rotate inwards, and the scraping frame rotates inwards to contact the magnetic rod.

In one embodiment, the blanking frame further comprises a shaking mechanism for shaking the blanking frame, the shaking mechanism comprises a convex plate and a top plate, the convex plate is fixedly connected to the front side and the rear side of the blanking frame, the top plate is fixedly connected between the two fixed sleeves on the front side, the top plate is fixedly connected between the two fixed sleeves on the rear side, and the convex plate can be extruded by the top plate to move upwards.

In one embodiment, the screen cleaning device further comprises a cleaning mechanism for cleaning the screen, the cleaning mechanism comprises a guide rail, sliding rods and brushes, the guide rail is fixedly connected to the front side and the rear side of the blanking frame, the sliding rods are arranged in the guide rail in a sliding mode, and the brushes are detached between the two sliding rods and are in contact with the screen.

In one embodiment, the sliding frame further comprises second elastic pieces, two second elastic pieces are connected between the sliding frame and the bottom plate, and the second elastic pieces are located in the fixing sleeve.

The design starting point, concept and advantages of the invention are as follows, as can be seen from the above description of the structure of the invention: 1. graphite constantly moves and contacts with the magnetic rod in the screening process, and under the action of the magnetic rod, metal impurities mixed in the graphite can be adsorbed, so that the function of removing the metal impurities in the graphite is realized, and the quality of the prepared cathode material can be improved.

2. Through rotating the screw rod for the installation cover upwards moves and drives extrusion piece upwards to move, and extrusion piece upwards moves and can extrude scraping the inward rotation card of frame on the magnetic pole, through continuing to rotate the screw rod, can make scraping the impurity on frame with the magnetic pole surface and scrape down, thereby can make impurity concentrate in the magnetic pole lower part, and then the staff of being convenient for clear up it.

3. Through the left-right movement slide bar, the slide bar moves left-right and drives the brush to move left-right for the brush can clean the screen cloth, so that the purpose of cleaning the screen cloth conveniently is achieved.

Drawings

Fig. 1 is a schematic perspective view of the present invention.

Fig. 2 is a schematic view of a partial perspective structure of the present invention.

Fig. 3 is a schematic view of a part of a pushing mechanism according to the present invention.

Fig. 4 is a schematic perspective view of a first part of the impurity removing mechanism of the present invention.

Fig. 5 is a schematic perspective view of a second part of the impurity removing mechanism of the present invention.

Fig. 6 is a schematic view of a part of a three-dimensional structure of the lifting mechanism of the invention.

Fig. 7 is a schematic view showing a first partial perspective structure of the scraping mechanism of the present invention.

Fig. 8 is a schematic view of a second partial perspective of the scraping mechanism of the present invention.

Fig. 9 is a schematic partial perspective view of the dithering mechanism of the present invention.

Fig. 10 is a schematic view of a partially cut-away perspective structure of the dithering mechanism of the present invention.

Fig. 11 is a schematic view showing a partial perspective structure of the cleaning mechanism of the present invention.

Marked in the figure as: 1_floor, 2_stationary sleeve, 3_carriage, 4_guide bar, 5_slider, 6_blanking frame, 7_blanking frame, 8_screen, 9_mechanism, 901_mounting plate, 902_motor, 903_cam, 904_runner, 905_spacer, 906_first elastic member, 10_edulcoration mechanism, 1001_mounting sleeve, 1002_slider, 1003_pull bar, 1004_magnetic bar, 11_lifting mechanism, 1101_bracket, 1102_slide bar, 1103_screw, 12_scraping mechanism, 1201_mounting frame, 1202_scraping frame, 1203_torsion spring, 1204_pressing block, 13_shaking mechanism, 1301_convex plate, 1302_roof, 1303_second elastic member, 14_cleaning mechanism, 1401_guide rail, 1402_slide bar, 1403_brush.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

Example 1

The utility model provides a natural graphite screening plant is used in preparation of power class lithium cell negative pole material, see fig. 1-5, including bottom plate 1, fixed cover 2, carriage 3, guide bar 4, slider 5, unloading frame 6, discharging frame 7, screen cloth 8, pushing mechanism 9 and edulcoration mechanism 10, both sides all are provided with fixed cover 2 through welded mode around two bottom plate 1 tops, be provided with carriage 3 between two fixed covers 2 of front side, also be provided with carriage 3 between two fixed covers 2 of rear side, carriage 3 upper portion rigid coupling has guide bar 4, the last sliding type of guide bar 4 is provided with two sliders 5, rigid coupling has unloading frame 6 between four sliders 5, rigid coupling has three discharging frame 7 in the unloading frame 6, all rigid coupling has screen cloth 8 in left side and the discharging frame 7 of intermediate position, be provided with pushing mechanism 9 on the carriage 3, pushing mechanism 9 is used for promoting unloading frame 6 and removes the edulcoration mechanism 10 on the unloading frame 6, edulcoration mechanism 10 is used for getting rid of metal impurity.

Referring to fig. 1 and 3, the pushing mechanism 9 includes a mounting plate 901, a motor 902, a cam 903, a partition 905 and a first elastic member 906, wherein the mounting plate 901 is fixedly connected between the right parts of the two sliding frames 3, the motor 902 is mounted on the mounting plate 901, the cam 903 is connected to the output shaft of the motor 902 in a key manner, the rotation of the cam 903 can extrude the blanking frame 6 to move, two sliding grooves 904 are respectively formed in the front wall and the rear wall of the blanking frame 6, the partition 905 is slidably arranged between the two sliding grooves 904 on the left side, the partition 905 is also slidably arranged between the two sliding grooves 904 on the right side, the first elastic member 906 is connected between the sliding blocks 5 and the sliding frames 3, and the first elastic member 906 is sleeved on the guide rod 4.

Referring to fig. 1, 4 and 5, the impurity removing mechanism 10 includes a mounting sleeve 1001, a sliding block 1002, a pull rod 1003 and a magnetic rod 1004, two mounting sleeves 1001 are detachably arranged at the top of the blanking frame 6, the sliding block 1002 is slidably arranged in the mounting sleeve 1001, the pull rod 1003 is fixedly connected to the front side and the rear side of the sliding block 1002, the magnetic rods 1004 are fixedly connected to the bottom of the sliding block 1002 at uniform intervals, and the magnetic rods 1004 are positioned in the blanking frame 6.

When the device is to be used, a worker starts the motor 902, the output shaft of the motor 902 rotates to drive the cam 903 to rotate, when the cam 903 rotates to contact with the blanking frame 6, the cam 903 can press the blanking frame 6 to move leftwards, the blanking frame 6 moves leftwards to drive the sliding block 5 to move leftwards, the left first elastic piece 906 is compressed along with the left first elastic piece, the right first elastic piece 906 is stretched along with the right first elastic piece, when the cam 903 rotates to separate from the blanking frame 6, the first elastic piece 906 can reset to drive the blanking frame 6 to move rightwards to reset, and thus the blanking frame 6 can drive the screen 8 and the discharging frame 7 to move leftwards and rightwards, then the worker can pour graphite on the screen 8 on the left side, so that graphite can be screened, finely crushed can fall downwards through the discharging frame 7, the worker can collect the graphite by using a container, the graphite continuously moves to contact with the magnetic rod 1004 in the screening process, under the action of the magnetic rod 1004, metal impurities mixed in graphite can be adsorbed, under the action of the partition 905, graphite can be blocked, after the screening of graphite on the left screen 8 is completed, a worker withdraws the left partition 905 from the chute 904, so that graphite is not blocked any more, at the moment, the graphite can move rightwards on the screen 8 at the middle position, further screening can be performed again, smaller graphite can fall outwards, after the screening is completed, the worker withdraws the right partition 905 upwards, graphite moves rightwards to fall out through the discharge frame 7 at the right side, three different sizes of graphite can be screened out, further, the follow-up treatment of the graphite with unqualified size is facilitated, further screening efficiency and screening effect are improved, after the whole graphite falls out, the worker turns off the motor 902, then the staff replace the baffle 905, when the impurity on the magnetic rod 1004 needs to be cleaned, the staff removes the installation sleeve 1001 from the blanking frame 6, then the magnetic rod 1004 is cleaned, the sliding block 1002 and the magnetic rod 1004 can be taken out to be replaced by pulling the pull rod 1003, and the above operation is repeated, so that graphite can be screened again.

Example 2

On the basis of embodiment 1, referring to fig. 1 and 6, the lifting mechanism 11 is further included, the lifting mechanism 11 is used for lifting the installation sleeve 1001, the lifting mechanism 11 comprises a bracket 1101, two sliding rods 1102 and a screw 1103, the bracket 1101 is fixedly connected between the tops of the two sliding frames 3, two sliding rods 1102 are slidably arranged on the left side and the right side of the upper portion of the bracket 1101, the bottoms of the sliding rods 1102 are connected with the tops of the similar installation sleeves 1001, the screws 1103 are threadedly arranged on the left side and the right side of the upper portion of the bracket 1101, and the screws 1103 are rotatably connected with the tops of the similar installation sleeves 1001.

Referring to fig. 1, 7 and 8, the device further comprises a scraping mechanism 12, the scraping mechanism 12 is used for scraping impurities on the magnetic rod 1004, the scraping mechanism 12 comprises a mounting frame 1201, a scraping frame 1202, torsion springs 1203 and extrusion blocks 1204, two mounting frames 1201 are fixedly connected to the left side and the right side of the upper portion of the support 1101, the scraping frame 1202 is rotatably arranged on the lower portion of the mounting frame 1201, four torsion springs 1203 are connected between the scraping frame 1202 and the mounting frame 1201, the torsion springs 1203 are sleeved on the scraping frame 1202, two extrusion blocks 1204 are fixedly connected to the front side and the rear side of the top of the mounting sleeve 1001, the extrusion blocks 1204 move upwards to extrude the scraping frame 1202 to rotate inwards, and the scraping frame 1202 rotates inwards to be in contact with the magnetic rod 1004.

When the magnetic rod 1004 needs to be cleaned, a worker rotates the screw 1103, the screw 1103 rotates to drive the bracket 1101 and the sliding rod 1102 to move upwards, the sliding rod 1102 moves upwards to drive the installation sleeve 1001, the sliding block 1002 and the magnetic rod 1004 to move upwards, the installation sleeve 1001 moves upwards to drive the extrusion block 1204 to move upwards, when the extrusion block 1204 moves upwards to be in contact with the scraping frame 1202, the extrusion block 1204 can extrude the scraping frame 1202 to rotate inwards, the torsion spring 1203 deforms along with the extrusion block, the inward movement of the scraping frame 1202 can be clamped on the magnetic rod 1004, at the moment, the worker continues to rotate the screw 1103, so that the magnetic rod 1004 continues to move upwards, the upward movement of the magnetic rod 1004 can enable the scraping frame 1202 to scrape impurities on the surface of the magnetic rod 1004 downwards, so that the impurities are concentrated on the lower part of the magnetic rod 1004, and further the cleaning is convenient for the worker, after the cleaning is completed, the worker inverts the screw 1103, the screw rod 1103 inverts to drive the bracket 1101 and the sliding rod 1102 to move downwards, the sliding rod 1002 and the magnetic rod 1004 move downwards, the installation sleeve 1202 moves downwards, and the extrusion block 1204 is driven to move downwards, and the extrusion block 1202 moves downwards, and the sliding block 1202 is driven to move downwards, and the sliding block 1202, and moves downwards, and the sliding rod 1102, and moves so that the sliding rod is separated from the sliding block 1202, and is separated from the sliding rod, and is reset, and reset spring is driven.

Referring to fig. 1, 9 and 10, the blanking machine further comprises a dithering mechanism 13, the dithering mechanism 13 is used for dithering the blanking frame 6, the dithering mechanism 13 comprises a convex plate 1301, a top plate 1302 and second elastic elements 1303, the convex plate 1301 is fixedly connected to the front side and the rear side of the blanking frame 6, the top plate 1302 is fixedly connected between two fixed sleeves 2 on the front side, the top plate 1302 is fixedly connected between two fixed sleeves 2 on the rear side, the convex plate 1301 moves and can be extruded by the top plate 1302 to move upwards, two second elastic elements 1303 are connected between the sliding frame 3 and the bottom plate 1, and the second elastic elements 1303 are located in the fixed sleeves 2.

When the blanking frame 6 moves left and right, the blanking frame 6 can drive the convex plate 1301 to move left and right, when the convex plate 1301 moves left and right and is extruded by the top plate 1302, the convex plate 1301 can move upwards, the convex plate 1301 moves upwards to drive the blanking frame 6 to move upwards, the blanking frame 6 moves upwards to drive the sliding frame 3 to move upwards through the sliding block 5 and the guide rod 4, the second elastic element 1303 is stretched along with the sliding frame 6, when the convex plate 1301 is not extruded any more, the second elastic element 1303 can drive the sliding frame 3, the guide rod 4, the sliding block 5 and the blanking frame 6 to move downwards to reset, and the sliding frame 1301 reciprocates, so that the blanking frame 6 can move up and down continuously, the screen mesh 8 can move up and down continuously, and the screening speed of graphite can be accelerated.

Referring to fig. 1 and 11, the screen cleaning device further comprises a cleaning mechanism 14, the cleaning mechanism 14 is used for cleaning the screen 8, the cleaning mechanism 14 comprises a guide rail 1401, sliding rods 1402 and a brush 1403, the guide rail 1401 is fixedly connected to the front side and the rear side of the blanking frame 6, the sliding rods 1402 are arranged in the guide rail 1401 in a sliding mode, the brush 1403 is detached between the two sliding rods 1402, and the brush 1403 is in contact with the screen 8.

When the magnetic rod 1004 moves upwards and is no longer located in the discharging frame 7, a worker can move the sliding rod 1402 left and right, and the sliding rod 1402 moves left and right to drive the brush 1403 to move left and right, so that the brush 1403 can clean the screen 8, and the purpose of cleaning the screen 8 is achieved.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention.

Claims (8)

1. The utility model provides a natural graphite screening plant is used in preparation of power class lithium cell negative pole material, including bottom plate (1), fixed cover (2), carriage (3), guide bar (4), slider (5), unloading frame (6), ejection of compact frame (7) and screen cloth (8), two bottom plate (1) tops all rigid coupling have two fixed cover (2), sliding type is provided with carriage (3) between two fixed cover (2) of front side, also sliding type is provided with carriage (3) between two fixed cover (2) of rear side, carriage (3) upper portion rigid coupling has guide bar (4), sliding type is provided with two sliders (5) on guide bar (4), the rigid coupling has unloading frame (6) between four sliders (5), the rigid coupling has three ejection of compact frame (7) in unloading frame (6), all rigid coupling has screen cloth (8) in left side and the ejection of compact frame (7) of intermediate position, a serial communication port is provided with pushing mechanism (9) and impurity removal mechanism (10) on carriage (3), be provided with on pushing mechanism (6) removal impurity removal mechanism (10) that are used for pushing unloading frame (6).

2. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 1, wherein the pushing mechanism (9) comprises a mounting plate (901), a motor (902), a cam (903), a partition plate (905) and a first elastic piece (906), wherein the mounting plate (901) is fixedly connected between the right parts of the two sliding frames (3), the motor (902) is mounted on the mounting plate (901), the cam (903) is connected to an output shaft of the motor (902) in a key manner, the cam (903) can extrude the blanking frame (6) to move through rotation, two sliding grooves (904) are formed in the front wall and the rear wall of the blanking frame (6), the partition plate (905) is arranged between the two sliding grooves (904) on the left side in a sliding manner, the partition plate (905) is also arranged between the two sliding grooves (904) on the right side, the first elastic piece (906) is connected between the sliding block (5) and the sliding frames (3), and the first elastic piece (906) is sleeved on the guide rod (4).

3. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 2, wherein the impurity removing mechanism (10) comprises a mounting sleeve (1001), a sliding block (1002), a pull rod (1003) and a magnetic rod (1004), wherein two mounting sleeves (1001) are detachably arranged at the top of a blanking frame (6), sliding blocks (1002) are arranged in the mounting sleeve (1001), the pull rods (1003) are fixedly connected to the front side and the rear side of the sliding block (1002), the magnetic rods (1004) are fixedly connected to the bottom of the sliding block (1002) at uniform intervals, and the magnetic rods (1004) are positioned in the blanking frame (6).

4. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 3, further comprising a lifting mechanism (11) for lifting the mounting sleeve (1001), wherein the lifting mechanism (11) comprises a support (1101), sliding rods (1102) and a screw (1103), the support (1101) is fixedly connected between the tops of the two sliding frames (3), two sliding rods (1102) are slidably arranged on the left side and the right side of the upper portion of the support (1101), the bottoms of the sliding rods (1102) are connected with the tops of the similar mounting sleeves (1001), the screws (1103) are threadedly arranged on the left side and the right side of the upper portion of the support (1101), and the screws (1103) are rotatably connected with the tops of the similar mounting sleeves (1001).

5. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 4, further comprising a scraping mechanism (12) for scraping impurities on the magnetic rod (1004), wherein the scraping mechanism (12) comprises a mounting frame (1201), a scraping frame (1202), torsion springs (1203) and extrusion blocks (1204), two mounting frames (1201) are fixedly connected to the left side and the right side of the upper portion of the support (1101), the scraping frame (1202) is rotatably arranged at the lower portion of the mounting frame (1201), four torsion springs (1203) are connected between the scraping frame (1202) and the mounting frame (1201), the torsion springs (1203) are sleeved on the scraping frame (1202), two extrusion blocks (1204) are fixedly connected to the front side and the rear side of the top of the mounting sleeve (1001), the extrusion blocks (1204) move upwards to extrude the scraping frame (1202) to rotate inwards, and the scraping frame (1202) rotates inwards to be contacted with the magnetic rod (1004).

6. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 5, further comprising a shaking mechanism (13) for shaking the blanking frame (6), wherein the shaking mechanism (13) comprises a convex plate (1301) and a top plate (1302), the convex plate (1301) is fixedly connected to the front side and the rear side of the blanking frame (6), the top plate (1302) is fixedly connected between the two fixing sleeves (2) on the front side, the top plate (1302) is fixedly connected between the two fixing sleeves (2) on the rear side, and the convex plate (1301) can be extruded by the top plate (1302) to move upwards.

7. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 6, further comprising a cleaning mechanism (14) for cleaning the screen (8), wherein the cleaning mechanism (14) comprises a guide rail (1401), sliding rods (1402) and brushes (1403), the guide rail (1401) is fixedly connected to the front side and the rear side of the blanking frame (6), the sliding rods (1402) are arranged in the guide rail (1401) in a sliding mode, the brushes (1403) are detached between the two sliding rods (1402), and the brushes (1403) are in contact with the screen (8).

8. The natural graphite screening device for preparing the negative electrode material of the power lithium battery according to claim 7, further comprising second elastic elements (1303), wherein two second elastic elements (1303) are connected between the sliding frame (3) and the bottom plate (1), and the second elastic elements (1303) are positioned in the fixing sleeve (2).