CN117772041B

CN117772041B - Auxiliary dissolution mixing device and preparation process of high-conductivity flexible carbon nanofiber interlayer

Info

Publication number: CN117772041B
Application number: CN202410207896.4A
Authority: CN
Inventors: 宋英泽; 王奎又; 宋丽贤; 魏锡均; 张青春; 万琦
Original assignee: Southwest University Of Science And Technology Sichuan Tianfu New Area Innovation Research Institute
Current assignee: Southwest University Of Science And Technology Sichuan Tianfu New Area Innovation Research Institute
Priority date: 2024-02-26
Filing date: 2024-02-26
Publication date: 2024-05-07
Anticipated expiration: 2044-02-26
Also published as: CN117772041A

Abstract

The invention relates to the field of lithium-sulfur batteries, in particular to an auxiliary dissolution mixing device and a preparation process of a high-conductivity flexible carbon nanofiber interlayer. The auxiliary dissolution mixing device judges dissolution conditions according to the light intensity detected by the light beam receiver, so that whether the solute is completely dissolved or not can be judged. Similarly, the dissolution of different solute-solvent systems can be detected. In addition, the controller controls the first driver to drive the screw rod to enable the detection ring to reciprocate along the guide rod, so that the dissolution condition in the whole inner container can be detected, and the dissolution condition in the whole inner container can be judged conveniently. The preparation process of the conductive flexible carbon nanofiber interlayer comprises the steps of dissolving polyacrylonitrile powder in a solvent to obtain a precursor solution, forming a film by using an electrostatic spinning technology, and sequentially carrying out low-temperature pre-oxidation treatment in air and high-temperature annealing treatment in protective gas to obtain the interlayer. The interlayer has the properties of flexible conductive reinforcing materials and high specific surface area and porosity.

Description

Auxiliary dissolution mixing device and preparation process of high-conductivity flexible carbon nanofiber interlayer

Technical Field

The invention relates to the field of lithium-sulfur batteries, in particular to an auxiliary dissolution mixing device and a preparation process of a high-conductivity flexible carbon nanofiber interlayer.

Background

In the preparation of interlayers for batteries, it is a common practice to prepare a precursor solution by dissolving a specific solute with a specific solvent. At present, when preparing the precursor liquid, whether the solute is completely dissolved is basically judged by manpower, so that misjudgment is easy to be caused, and a large burden is brought to staff. On the other hand, in order to overcome the limitation of manual observation, the stirring and mixing time can be set, and the time is equal to the time when the dissolution is complete, in this case, the set stirring and mixing time is often obviously longer than the time required by the actual dissolution to be complete, and the production efficiency is greatly slowed down.

In view of this, the present application has been made.

Disclosure of Invention

The first object of the present invention is to provide an auxiliary dissolution mixing device, which can effectively control the mixing dissolution progress, monitor the dissolution condition in real time, and send a notification at the first time after the dissolution is completed, thereby not only ensuring the sufficiency of dissolution, but also effectively reducing the time waste, ensuring the production efficiency, and simultaneously not bringing additional burden to the staff.

The second object of the present invention is to provide a process for preparing a highly conductive flexible carbon nanofiber sandwich, in which the diameter distribution of the carbon nanofibers of the prepared highly conductive flexible carbon nanofiber sandwich is uniform, the pore structure among the fibers is widely distributed, the microscopic surface of the fiber film is rough, and the fiber film has high conductivity characteristics similar to the surface structure of common interlayers such as carbon cloth. The carbon nanofiber composite material has the characteristics of high specific surface area and high porosity while showing the properties of the flexible conductive reinforced material, and has good application prospect in the aspect of carbon nanofiber interlayers for lithium-sulfur batteries.

Embodiments of the present invention are implemented as follows:

An auxiliary dissolution mixing apparatus, comprising: the device comprises an outer barrel, a cover body, an inner container, a detection ring, a light beam emitter, a light beam receiver, a magnetic stirring assembly, a magnetic stirrer and a controller.

The outer cylinder is provided with a containing cavity for containing the inner container, the cover body is used for sealing the containing cavity, and the inner container is made of light-transmitting materials. The recessed area is formed in the inner side wall of the accommodating cavity, extends continuously to form a ring shape along the circumferential direction of the accommodating cavity and extends along the depth direction of the accommodating cavity.

The concave area is internally provided with a guide rod and a screw rod which are arranged along the depth direction of the accommodating cavity, the detection ring is annularly arranged on the inner container, the detection ring is slidably matched with the guide rod, and the screw rod is in transmission fit with the detection ring and is driven by the first driver.

The beam emitter and the beam receiver are respectively arranged on two opposite sides of the inner annular wall of the detection ring, the beam emitter is arranged towards the beam receiver, and the beam receiver is used for receiving a beam signal sent by the beam emitter and detecting the light intensity.

The magnetic stirring assembly is arranged at the bottom of the accommodating cavity, and the magnetic stirrer is used for being placed in the inner container.

The controller stores light transmittance data for the liner and associated reagents.

The light beam emitter, the light beam receiver, the magnetic stirring assembly and the first driver are electrically connected with the controller. The controller is used for judging the dissolution condition according to the light intensity detected by the light beam receiver, and is also used for controlling the first driver to drive the screw rod to enable the detection ring to reciprocate along the guide rod, so that the dissolution condition in the whole liner is detected.

Further, when stirring is started, the controller controls the magnetic stirring assembly to drive the magnetic stirrer to stir at a speed lower than a preset rotating speed. When the condition that the condition near the liquid level meets the dissolution requirement is detected, the controller controls the magnetic stirring assembly to drive the magnetic stirrer to stir at a preset rotating speed. When detecting that the inner wall of the inner container is adhered with materials, the controller controls the magnetic stirring assembly to drive the magnetic stirrer to stir at a speed higher than a preset rotating speed.

Further, two groups of guide rods are respectively arranged on two opposite sides of the inner container and are respectively arranged at intervals with the inner container, two groups of screw rods are respectively arranged on two opposite sides of the inner container and are respectively arranged at intervals with the inner container, and the two groups of guide rods and the two groups of screw rods are alternately arranged at uniform intervals along the circumferential direction of the inner container.

Further, the auxiliary dissolution mixing apparatus further includes: an annular cylinder.

The annular cylinder is arranged on the detection ring, the inner diameter of the annular cylinder is larger than the outer diameter of the detection ring, the annular cylinder and the detection ring are coaxially arranged, and the annular cylinder is rotatably matched with the concave area and driven by the second driver. The annular cylinder has a push piece extending toward the detection ring, the push piece extending in an axial direction of the annular cylinder.

The detection ring comprises an upper ring piece, a lower ring piece, an inner ring body and an outer ring body. The upper ring piece, the lower ring piece, the inner ring body and the outer ring body are coaxially arranged and all encircle the inner container, the upper ring piece and the lower ring piece are arranged along the depth direction interval of the accommodating cavity, the outer diameter of the inner ring body is smaller than the inner diameter of the outer ring body, and the inner ring body and the outer ring body are matched between the upper ring piece and the lower ring piece.

Along the circumference of the detection ring, the inner ring body and the outer ring body are rotatably matched between the upper ring piece and the lower ring piece. Along the axial direction of the guide rod, the inner ring body and the outer ring body are fixedly matched between the upper ring piece and the lower ring piece.

The guide rod and the screw rod penetrate through the upper ring piece and the lower ring piece and are positioned between the inner ring body and the outer ring body, and any one of the upper ring piece and the lower ring piece is in transmission fit with the screw rod.

The outer annular wall of the outer annular body is provided with a matching groove matched with the pushing piece, the inner annular wall of the outer annular wall is provided with a first radial blind hole, a first matching column is slidably matched in the first radial blind hole, and an elastic piece is abutted between the first matching column and the bottom of the first radial blind hole. The outer end of the first mating post has a protrusion.

The outer annular wall of the inner annular body is provided with a second radial blind hole, a second matching column is slidably matched in the second radial blind hole, and an elastic piece is abutted between the second matching column and the bottom of the second radial blind hole. The outer end of the second mating post has a recess for mating with the protrusion.

Under the natural state, the end parts of the first matching column and the second matching column are propped against, and the bulge is matched with the groove, so that the outer ring body and the inner ring body are fixedly matched in the circumferential direction.

Along the direction of the outer ring body of the annular cylinder drive, the front side walls of the first matching column and the second matching column are provided with guide grooves, the guide grooves penetrate through the outer end walls of the first matching column and the second matching column, the inner ends of the guide grooves point to the outer end direction, and the concave depth of the guide grooves increases progressively.

When the first matching column and the second matching column are contacted with the guide rod/screw rod, the guide rod/screw rod is simultaneously abutted in the guide grooves of the first matching column and the second matching column, so that the first matching column and the second matching column are respectively pushed into the first radial blind hole and the second radial blind hole, the first matching column and the second matching column are separated, and the guide rod/screw rod can pass through the first matching column and the second matching column.

Further, along the circumference of the outer ring body, a plurality of matching grooves are uniformly arranged at intervals.

The annular cylinder is provided with a mounting opening for mounting the push plate, the mounting opening penetrates through the annular cylinder along the radial direction of the annular cylinder, the mounting opening extends along the axial direction of the annular cylinder, and a plurality of mounting openings are uniformly arranged at intervals along the circumferential direction of the annular cylinder.

A pushing piece is arranged in each mounting opening, a rotating shaft is fixedly connected to the edge of one side of the pushing piece, which is far away from the detection ring, and the rotating shaft is arranged along the axial direction of the annular cylinder, and is rotatably arranged in the mounting opening and far away from the detection ring.

The first guide way and the second guide way have been seted up to one side that the detection ring was kept away from to the pivot, and the axial extension of pivot is followed to first guide way, and the second guide way communicates with the one end of first guide way, and the second guide way is still kept away from first guide way step by step along the axial of pivot when the circumference of pivot extends.

The annular cylinder is also sleeved with a control ring, the control ring is slidably matched with the annular cylinder and driven by a third driver, the inner annular wall of the control ring is fixedly connected with a positioning column, and the positioning column is slidably matched with the first guide groove or the second guide groove.

The control ring has a first sliding dead point and a second sliding dead point. When the control ring is positioned at the first sliding dead point, the positioning column is positioned in the first guide groove, and the pushing piece is arranged along the radial direction of the annular cylinder and is matched in the matching groove. When the control ring is positioned at the second sliding dead point, the positioning column is positioned in the second guide groove, the pushing piece deflects towards the reverse direction of the rotating direction of the annular cylinder, and the pushing piece withdraws from the matching groove.

Further, along the direction of the outer ring body of the annular cylinder driving, the front end wall of the matching groove is arranged along the radial direction of the outer ring body, and the rear end wall of the matching groove is obliquely arranged to give way for the pushing piece to leave the matching groove.

A process for preparing a highly conductive flexible carbon nanofiber sandwich, comprising:

Acquiring light transmittance data of a mixed phase of polyacrylonitrile powder with a target proportion fully dispersed in a solvent;

Adding solvent and polyacrylonitrile powder in a corresponding proportion into the liner of the auxiliary dissolution mixing device, and stirring and dispersing the polyacrylonitrile powder in the solvent by using a magnetic stirrer;

the method comprises the steps of receiving a light beam signal sent by a light beam emitter by using a light beam receiver, detecting light intensity, and when the detected light intensity is matched with light transmittance data when the light intensity is fully dispersed, indicating that polyacrylonitrile powder is fully dispersed in a solvent to obtain an electrostatic spinning precursor liquid;

preparing a polyacrylonitrile fiber membrane by an electrostatic spinning method, and drying the polyacrylonitrile fiber membrane;

and (3) pre-oxidizing the dried polyacrylonitrile fiber membrane in air at low temperature, and then annealing in a protective gas at high temperature to obtain the high-conductivity flexible carbon nanofiber interlayer.

Further, the solvent is: n, N-dimethylformamide. The mass fraction of the polyacrylonitrile is 8.3-12.5 wt%.

Further, in the electrostatic spinning method, the electrostatic spinning voltage is 16 kV-20 kV, the electrostatic spinning distance is 40 cm-80 cm, the electrostatic spinning flow is 0.6-0.8 mL/h, and the volume of the electrostatic spinning precursor solution is 6 mL-10 mL.

Further, in the low-temperature pre-oxidation treatment in the air, the temperature of the low-temperature pre-oxidation is 250-280 ℃, the temperature rising rate of the low-temperature pre-oxidation is 1-3 ℃/min, and the heat preservation time of the low-temperature pre-oxidation is 120min.

And during the high-temperature annealing treatment in the protective gas, the heating rate of the high-temperature annealing is 2-5 ℃/min, the temperature of the high-temperature annealing is 600-800 ℃, and the heat preservation time of the high-temperature annealing is 120min.

The technical scheme of the embodiment of the invention has the beneficial effects that:

The controller of the auxiliary dissolution mixing device provided by the embodiment of the invention can judge dissolution conditions according to the light intensity detected by the light beam receiver, for example, when sodium chloride is dissolved by water, the light intensity of the light beam emitted by the light beam emitter received by the light beam receiver when the sodium chloride solution with corresponding concentration is placed in the inner container is stored in the controller. When sodium chloride is not completely dissolved, sodium chloride particles are also present in the solution system, and the light beam can be more obstructed when passing through the sodium chloride particles, so that the light intensity of the light beam received by the light beam receiver is lower than that of the light beam passing through the pure sodium chloride solution, and whether the sodium chloride is completely dissolved can be judged. In the same way, the dissolution of different solute-solvent systems can be detected. In addition, the controller is also used for controlling the first driver to drive the screw rod to enable the detection ring to reciprocate along the guide rod, so that the dissolution condition in the whole liner can be detected.

In general, the auxiliary dissolution mixing device provided by the embodiment of the invention can effectively control the mixing dissolution progress, monitor the dissolution condition in real time, and send a notification at the first time after the dissolution is completed, so that the dissolution sufficiency is ensured, the time waste is effectively reduced, the production efficiency can be ensured, and meanwhile, no additional burden is brought to staff.

The carbon nanofiber diameter of the high-conductivity flexible carbon nanofiber sandwich prepared by the preparation process of the high-conductivity flexible carbon nanofiber sandwich provided by the embodiment of the invention is uniformly distributed, the pore structure among the fibers is widely distributed, the microscopic surface of the fiber film is rough, the fiber film is similar to the surface structure of common sandwich such as carbon cloth, and the fiber film shows the characteristic of high conductivity. The carbon nanofiber composite material has the characteristics of high specific surface area and high porosity while showing the properties of the flexible conductive reinforced material, and has good application prospect in the aspect of carbon nanofiber interlayers for lithium-sulfur batteries.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the overall structure of an auxiliary dissolution mixing apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic illustration of the cooperation of the control ring, annular cylinder, detection ring and bladder of the auxiliary dissolution mixing apparatus of FIG. 1;

FIG. 3 is a schematic view of the inner structure of the detection ring of FIG. 2;

FIG. 4 is a schematic view of the process of the screw passing through the first and second mating posts;

FIG. 5 is a schematic view of another arrangement of mating grooves of the outer ring;

FIG. 6 is a schematic view of the internal structure of the annular cylinder;

FIG. 7 is a schematic view of a side of the shaft away from the liner;

FIG. 8 is a schematic view of the pusher tab of the annular cartridge as it deflects;

FIG. 9 is a schematic illustration of the engagement of the pusher tab of the annular cartridge with the outer ring when deflected;

FIG. 10 is a contrast image of the high conductivity flexible carbon nanofiber interlayers prepared in example 2, example 3 and example 4 by scanning electron microscopy;

FIG. 11 is an X-ray diffraction pattern of the highly conductive flexible carbon nanofiber interlayers prepared in example 2, example 3, and example 4;

Fig. 12 is a cycle-specific capacity curve at 0.2C of the lithium sulfur batteries prepared in example 2, example 3, example 4 and comparative example.

Reference numerals illustrate:

Auxiliary dissolution mixing device 1000; an outer cylinder 100; a receiving chamber 110; a recessed region 120; a guide bar 130; a screw 140; a cover 150; an inner container 200; a detection ring 300; an upper ring plate 310; a lower ring piece 320; an inner ring 330; a second mating post 331; a groove 332; an outer ring 340; a fitting groove 341; a first mating post 342; a protrusion 343; an elastic member 350; a guide groove 360; a beam emitter 410; a beam receiver 420; a magnetic stirring assembly 510; magnetic stirrer 520; an annular cylinder 600; a pushing piece 610; a mounting port 620; a rotation shaft 630; a first guide groove 631; a second guide groove 632; a control loop 700; positioning posts 710.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The terms "first," "second," "third," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "parallel," "perpendicular," and the like, do not denote that the components are required to be absolutely parallel or perpendicular, but may be slightly inclined. For example, "parallel" merely means that the directions are more parallel than "perpendicular" and does not mean that the structures must be perfectly parallel, but may be slightly tilted.

In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Example 1

Referring to fig. 1 to 9, the present embodiment provides an auxiliary dissolution mixing apparatus 1000, the auxiliary dissolution mixing apparatus 1000 includes: the outer cylinder 100, the cover 150, the inner container 200, the detection ring 300, the beam emitter 410, the beam receiver 420, the magnetic stirring assembly 510, the magnetic stirrer 520 and a controller (not shown).

The outer tub 100 has a receiving chamber 110 for receiving the inner tub 200, and a depth direction of the receiving chamber 110 is disposed in a vertical direction. In this embodiment, the accommodating chamber 110 has a cylindrical shape. The cover 150 is used for closing the accommodating cavity 110, and the cover 150 is detachably covered on the opening of the accommodating cavity 110 of the outer cylinder 100.

The bladder 200 is made of a light transmissive material including, but not limited to, glass. In this embodiment, the liner 200 is adapted to the receiving chamber 110. The liner 200 is used to provide space for the miscibility of solutes and solvents.

The inner sidewall of the accommodating chamber 110 is provided with a recessed area 120, and the recessed area 120 continuously extends in a ring shape along the circumferential direction of the accommodating chamber 110 and simultaneously extends in the depth direction of the accommodating chamber 110. Wherein, a space is left between the concave area 120 and the mouth of the accommodating cavity 110.

The concave region 120 is provided with a guide bar 130 and a screw 140 arranged along the depth direction of the accommodating cavity 110, and the guide bar 130 and the ground sensing are arranged in parallel and at intervals. The guide rod 130 is fixedly matched with the concave area 120, and the screw rod 140 is rotatably matched with the concave area 120. The detection ring 300 is arranged around the liner 200, the detection ring 300 and the liner 200 are coaxially arranged, and the inner diameter of the detection ring 300 is larger than the outer diameter of the liner 200.

Along the axial direction of the guide bar 130, the sensing ring 300 is slidably fitted to the guide bar 130, and the screw 140 is in driving engagement with the sensing ring 300 and driven by a first driver (not shown). The detection ring 300 is provided with a through hole matched with the guide rod 130, and is provided with a threaded through hole matched with the screw rod 140 to form a screw rod 140 mechanism.

The beam emitter 410 and the beam receiver 420 are separately disposed at opposite sides of the inner circumferential wall of the detection ring 300, the beam emitter 410 is disposed toward the beam receiver 420, and the beam receiver 420 is used for receiving the beam signal emitted from the beam emitter 410 and detecting the light intensity of the received beam. The optical path of the beam emitter 410 is arranged along the radial direction of the detection ring 300.

The magnetic stirring assembly 510 is disposed at the bottom of the accommodating cavity 110, and the magnetic stirrer 520 is disposed in the inner container 200. When the liner 200 is placed in the receiving cavity 110, the bottom of the liner 200 is attached to the magnetic stirring assembly 510.

The controller maintains light transmittance data for bladder 200 and associated reagents, including, but not limited to: the light intensity of the light beam emitted from the light beam emitter 410 received by the light beam receiver 420 when the inner container 200 is not placed in the accommodating chamber 110; the light intensity of the light beam emitted from the light beam emitter 410 received by the light beam receiver 420 when the empty liner 200 is placed in the accommodating chamber 110; the light intensity of the light beam emitted from the light beam emitter 410 received by the light beam receiver 420 when the inner container 200 filled with only the solvent is placed in the accommodating chamber 110 (may be further classified according to the kind of solvent); the light intensity of the light beam emitted from the light beam emitter 410 received by the light beam receiver 420 when the inner container 200 only containing the solute is placed in the accommodating cavity 110 (can be further classified according to the solute type); the light intensity of the light beam emitted from the light beam emitter 410 received by the light beam receiver 420 when the mixed-phase liner 200 in which the solute has been completely dissolved by the solvent is placed in the accommodating chamber 110 (may be further classified according to the kind of solvent, the kind of solute, and the concentration).

The beam emitter 410, the beam receiver 420, the magnetic stirring assembly 510, and the first driver are all electrically connected to the controller. The controller may control the turning on and off of the beam emitter 410, the beam receiver 420, the magnetic stirring assembly 510, and the first driver.

In the mixing and dissolving process, the first driver can drive the screw 140 to make the detection ring 300 reciprocate along the guide rod 130, so as to judge the dissolving condition of the mixed phases at different depth positions in the liner 200.

The controller can determine the dissolution condition according to the light intensity detected by the light beam receiver 420, for example, when sodium chloride is dissolved by water, the controller stores the light intensity of the light beam emitted by the light beam emitter 410 received by the light beam receiver 420 when the sodium chloride solution with the corresponding concentration is placed in the liner 200. When sodium chloride is not completely dissolved, sodium chloride particles are also present in the solution system, and the light beam is more obstructed when passing through the sodium chloride particles, so that the light intensity of the light beam received by the light beam receiver 420 is lower than that of the pure sodium chloride solution, and whether the sodium chloride is completely dissolved can be judged. In the same way, the dissolution of different solute-solvent systems can be detected.

In addition, the controller is further used for controlling the first driver to drive the screw 140 to enable the detection ring 300 to reciprocate along the guide rod 130, so that the dissolution condition in the whole liner 200 can be detected.

In general, the auxiliary dissolution mixing device 1000 provided in this embodiment can effectively control the mixing dissolution progress, monitor the dissolution situation in real time, and send a notification at the first time after the dissolution is completed, so that not only is the sufficiency of dissolution ensured, but also the time waste is effectively reduced, the production efficiency can be ensured, and meanwhile, no additional burden is brought to staff.

Further, in this embodiment, when stirring is started, the controller controls the magnetic stirring assembly 510 to drive the magnetic stirrer 520 to stir at a speed lower than the preset rotation speed, so as to effectively avoid that the solute which is not dissolved yet is thrown up and adheres to the inner wall of the liner 200 above the liquid level. The duration of stirring at this low speed can be flexibly set according to actual needs.

With the start of dissolution of the solute, when it is detected that the solute near the liquid surface reaches the dissolution requirement, that is, when it is detected that the solute near the liquid surface (for example, the solute is sufficiently dissolved in the area 30mm below the liquid surface, but not limited thereto, the size of the area can be flexibly set according to actual needs), the controller controls the magnetic stirring assembly 510 to drive the magnetic stirrer 520 to stir at a preset rotation speed, normal stirring is performed at this time, and the solute is not easily adhered to the inner wall of the liner 200 above the liquid surface.

When detecting that the inner wall of the liner 200 is adhered with materials, if the solute in the liquid phase system is completely dissolved, the controller controls the magnetic stirring assembly 510 to drive the magnetic stirring rod 520 to stir at a speed higher than the preset rotating speed, so that the liquid level near the inner wall of the liner 200 is conveniently raised (under the action of centrifugal force) to wash away and dissolve away the adhered solute, on one hand, the solute loss is avoided, and on the other hand, the concentration of the finally obtained solution is ensured to meet the requirement.

In this embodiment, the two sets of guide rods 130 are respectively disposed on two opposite sides of the inner container 200 and are spaced from the inner container 200, the two sets of screw rods 140 are respectively disposed on two opposite sides of the inner container 200 and are spaced from the inner container 200, and the two sets of guide rods 130 and the two sets of screw rods 140 are alternately disposed at equal intervals along the circumferential direction of the inner container 200.

Further, the auxiliary dissolution mixing apparatus 1000 further includes: an annular cartridge 600.

The annular cylinder 600 is disposed around the detection ring 300, the inner diameter of the annular cylinder 600 is larger than the outer diameter of the detection ring 300, the annular cylinder 600 is disposed coaxially with the detection ring 300, and the annular cylinder 600 is rotatably fitted in the recess 120 and driven by a second driver (not shown). The annular cylinder 600 has a push piece 610 extending toward the detection ring 300, the push piece 610 extending in the axial direction of the annular cylinder 600.

The sense ring 300 includes an upper ring piece 310, a lower ring piece 320, an inner ring body 330, and an outer ring body 340.

The upper ring piece 310, the lower ring piece 320, the inner ring body 330 and the outer ring body 340 are coaxially arranged and all encircle the liner 200. The inner diameter and the outer diameter of the upper ring piece 310 and the lower ring piece 320 are equal, the upper ring piece 310 and the lower ring piece 320 are spaced apart in the depth direction of the accommodating chamber 110, and the upper ring piece 310 is positioned above the lower ring piece 320.

The outer diameter of the inner ring 330 is smaller than the inner diameter of the outer ring 340, the inner diameter of the inner ring 330 is larger than the outer diameter of the liner 200, and the inner ring 330 and the outer ring 340 are both matched between the upper ring piece 310 and the lower ring piece 320.

Along the circumference of the detection ring 300, the inner ring body 330 and the outer ring body 340 are rotatably fitted between the upper ring piece 310 and the lower ring piece 320. Along the axial direction of the guide bar 130, the inner ring body 330 and the outer ring body 340 are fixedly fitted between the upper ring piece 310 and the lower ring piece 320.

The guide rod 130 and the screw 140 penetrate through the upper ring piece 310 and the lower ring piece 320 and are positioned between the inner ring body 330 and the outer ring body 340, and any one of the upper ring piece 310 and the lower ring piece 320 is in transmission fit with the screw 140.

The outer annular wall of the outer annular body 340 is provided with a matching groove 341 for matching with the pushing piece 610, the pushing piece 610 can be matched with the matching groove 341, and the annular cylinder 600 can drive the outer annular body 340 through the pushing piece 610 when rotating.

The inner annular wall of the outer annular wall is provided with a first radial blind hole, a first matching column 342 is slidably matched in the first radial blind hole, and an elastic piece 350 is abutted between the first matching column 342 and the bottom of the first radial blind hole. The outer end of the first fitting post 342 has a protrusion 343.

The outer annular wall of the inner annular body 330 is provided with a second radial blind hole, a second matching column 331 is slidably matched in the second radial blind hole, and an elastic piece 350 is abutted between the second matching column 331 and the bottom of the second radial blind hole. The outer end of the second fitting post 331 has a groove 332 for fitting with the protrusion 343.

Under the action of the elastic member 350, the first mating post 342 extends from the first radial blind hole, the second mating post 331 extends from the second radial blind hole, the ends of the first mating post 342 and the second mating post 331 abut against each other, and the protrusion 343 is mated with the groove 332, so that the outer ring 340 and the inner ring 330 are fixedly mated in the circumferential direction. Based on this, when the outer ring 340 is driven by the annular cylinder 600, the outer ring 340 can indirectly drive the inner ring 330 to rotate synchronously through the first and second mating posts 342 and 331.

Along the driving direction of the outer ring 340 driven by the annular cylinder 600, the front side walls of the first and second fitting columns 342 and 331 are provided with guide grooves 360, the guide grooves 360 penetrate through the outer end walls of the first and second fitting columns 342 and 331, the inner ends of the first and second fitting columns 342 and 331 are directed to the outer ends, and the concave depths of the guide grooves 360 are respectively in incremental change.

During the rotation of the outer ring 340 and the inner ring 330 together, when the first and second fitting posts 342 and 331 are in contact with the guide rod 130/screw 140, the guide rod 130/screw 140 is simultaneously abutted in the guide grooves 360 of the first and second fitting posts 342 and 331, so that the first and second fitting posts 342 and 331 are pushed into the first and second radial blind holes, respectively, to separate the first and second fitting posts 342 and 331, and the guide rod 130/screw 140 can pass through the first and second fitting posts 342 and 331. In this embodiment, the surfaces of the first mating post 342, the protrusion 343, and the second mating post 331 are all smooth.

Through the above design, the outer ring 340 and the inner ring 330 can smoothly rotate under the driving of the ring cylinder 600.

Further, a plurality of mating grooves 341 are uniformly spaced along the circumference of the outer ring 340. Alternatively, the mating grooves 341 may be densely arranged along the circumferential direction of the outer ring 340, that is, the front and rear ends of the mating grooves 341 are sequentially connected, as shown in fig. 5.

The annular cylinder 600 is provided with mounting openings 620 for mounting the push plates 610, the mounting openings 620 penetrate the annular cylinder 600 in the radial direction of the annular cylinder 600, the mounting openings 620 extend in the axial direction of the annular cylinder 600, and the plurality of mounting openings 620 are uniformly arranged at intervals in the circumferential direction of the annular cylinder 600.

A pushing piece 610 is installed in each installation opening 620, a rotating shaft 630 is fixedly connected to an edge of one side of the pushing piece 610 far away from the detection ring 300, the rotating shaft 630 is arranged along the axial direction of the annular cylinder 600, and the rotating shaft 630 is rotatably installed in the installation opening 620 and far away from the detection ring 300.

The side of the rotating shaft 630 far away from the detecting ring 300 is provided with a first guiding groove 631 and a second guiding groove 632, the first guiding groove 631 extends along the axial direction of the rotating shaft 630, the second guiding groove 632 is communicated with one end of the first guiding groove 631, and the second guiding groove 632 extends along the circumferential direction of the rotating shaft 630 and also gradually extends along the axial direction of the rotating shaft 630 far away from the first guiding groove 631, namely, the second guiding groove 632 extends in a spiral shape.

The annular cylinder 600 is further sleeved with a control ring 700, the control ring 700 is slidably matched with the annular cylinder 600 and driven by a third driver (not shown in the figure), a positioning column 710 is fixedly connected to the inner annular wall of the control ring 700, the positioning column 710 is arranged along the radial direction of the control ring 700, and the positioning column 710 is slidably matched in the first guide groove 631 or the second guide groove 632.

When the third driver drives the control ring 700 to move, the control ring 700 has a first sliding dead point and a second sliding dead point.

When the control ring 700 is positioned at the first sliding dead point, the positioning column 710 is positioned in the first guiding groove 631, the pushing piece 610 is arranged along the radial direction of the annular cylinder 600 and is matched in the matching groove 341, and the pushing piece 610 is attached to the front end surface of the matching groove 341. At this time, the outer ring 340 is driven to rotate together when the ring cylinder 600 rotates.

When the control ring 700 is positioned at the second sliding dead point, the positioning post 710 slides into the second guiding groove 632 from the first guiding groove 631, the positioning post 710 is positioned in the second guiding groove 632, the positioning post 710 pushes the rotating shaft 630 to rotate the pushing piece 610, the pushing piece 610 deflects in the opposite direction to the rotating direction of the annular cylinder 600, and the pushing piece 610 withdraws from the rear end of the matching groove 341, as shown in fig. 8 and 9. At this time, the outer ring 340 is not driven when the ring cylinder 600 rotates.

Through the above design, the driving relationship between the annular cylinder 600 and the outer ring 340 can be adjusted by using the control ring 700, so as to achieve the purpose that the outer ring 340 and the inner ring 330 can rotate at different rotation speeds, and simultaneously, the outer ring 340 and the inner ring 330 can be decelerated, accelerated and started and stopped as required. In this way, the light beam emitter 410 can generate various rotation speed differences (phase differences) with the rotation of the liquid phase (stirred by the magnetic stirrer 520) in the circumferential direction of the liner 200, so that undissolved solutes can be prevented from being missed, particularly undissolved solutes can be effectively prevented from being missed when the solutes are about to be completely dissolved, the dissolution sufficiency is ensured, and meanwhile, too long dissolution time is not caused.

On the above basis, a certain space is reserved around the liner 200 due to the existence of the depression 120. An input pipe (not shown) and an output pipe (not shown) communicating with the depression 120 may be additionally provided.

The input and output pipes are normally closed, and a heat transfer medium may be injected into the recessed area 120, including but not limited to: air, heat transfer fluid, and the like. By this design, since the concave region 120 belongs to the closed space, the temperature around the liner 200 can be ensured to be more uniform, and the local temperature difference is prevented from being too large, so that the solute can be better dissolved. In addition, in the process of driving the outer ring 340 by the ring cartridge 600, the pushing piece 610 can also push the heat-conducting medium to flow, so that the temperature is more uniform, and local heat accumulation is avoided.

Particularly, for the dissolution process with obvious heat absorption or heat release, the heat is quickly homogenized by using a heat conducting medium, or the heat is led out by matching with an input pipe and an output pipe, so that the dissolution can be more smooth.

In this embodiment, along the direction in which the annular cylinder 600 drives the outer ring 340, the front end wall of the engagement groove 341 is disposed along the radial direction of the outer ring 340, and the rear end wall of the engagement groove 341 is disposed obliquely to give way for the push piece 610 to leave the engagement groove 341.

Illustratively, the auxiliary dissolution mixing apparatus 1000 may be used for the preparation of an electrospinning precursor solution, comprising:

(1) Acquiring light transmittance data of a mixed phase of polyacrylonitrile powder with a target proportion fully dispersed in a solvent;

(2) Adding solvent and polyacrylonitrile powder in a corresponding proportion into the liner 200 of the auxiliary dissolution mixing device 1000, and stirring and dispersing the polyacrylonitrile powder in the solvent by using a magnetic stirrer 520;

(3) The beam receiver 420 of the auxiliary dissolution mixing apparatus 1000 is used to receive the beam signal emitted from the beam emitter 410 and detect the light intensity, and when the detected light intensity matches with the light transmittance data at the time of full dispersion, it indicates that the polyacrylonitrile powder has been fully dispersed in the solvent, and then the stirring can be stopped as long as the standard of the stirring time is satisfied, so as to obtain the electrospinning precursor liquid.

It should be noted that the above is only one example of an application scenario of the auxiliary dissolution mixing apparatus 1000, and is not limited thereto, and the auxiliary dissolution mixing apparatus 1000 may be applied to mixing between other material reagents as well.

Example 2

The embodiment provides a preparation process of a high-conductivity flexible carbon nanofiber interlayer, which specifically comprises the following steps:

(1) Weighing 1g of polyacrylonitrile powder in a reagent bottle, adding 12g of N, N-dimethylformamide, then magnetically stirring and dispersing by using the auxiliary dissolution mixing device 1000 provided in the embodiment 1 at a rotating speed of 600rpm (preset rotating speed), wherein the stirring temperature is 26 ℃, the time is set to 2 hours, and the mass fraction of the polyacrylonitrile is 8.3wt% of an electrostatic spinning precursor solution, and the electrostatic spinning precursor solution is marked as 8.3% PAN;

(2) The distance between a spinning needle head of the electrostatic spinning and a receiving device is 12cm, the voltage of the electrostatic spinning is set to be 16kV, the electrostatic spinning is carried out by using electrostatic spinning precursor liquid of 8.3% PAN, the amount of the spinning precursor liquid is 6mL, the flow parameter is 0.6mL/h, the distance parameter is 40cm, and the time is set to be 10 hours;

(3) Taking down the prepared fiber membrane, and putting the fiber membrane into a 60 ℃ oven for drying for 6 hours;

(4) Cutting the dried fiber membrane sample, and then preserving the heat for 2 hours at 250 ℃ in an air atmosphere (low-temperature pre-oxidation in air) by using a tube furnace, wherein the heating rate is 3 ℃ per minute, and then preserving the heat for 2 hours at 600 ℃ in an argon atmosphere (high-temperature annealing in protective gas), and the heating rate is 5 ℃ per minute;

(5) Cooling along with the furnace to obtain the high-conductivity flexible carbon nanofiber interlayer;

(6) Preparation of a positive plate: mixing active material sulfur, conductive carbon nano tube MWCNT and PVDF in a mass ratio of 6:3:1, dropwise adding 2g N-methylpyrrolidone into the mixed material, and stirring for 6 hours to obtain anode slurry; coating positive electrode slurry on the surface of an aluminum foil, wherein the thickness of a wet film formed by the positive electrode slurry on the surface of the aluminum foil is 250 mu m; drying at 60 ℃ for 12 hours in vacuum, and cutting into positive plates with the diameter of 13mm by a cutting machine;

(7) Preparation of lithium-sulfur battery: in a MIKROUNA glove box filled with argon gas and dried, the positive electrode, the interlayer, the diaphragm, the lithium sheet, the gasket and the elastic sheet are assembled in sequence. The interlayer is the high-conductivity flexible carbon nanofiber interlayer prepared by the embodiment. The battery accessory is a 2032 button type battery, and the diaphragm is Celgrad2500; the electrolyte used for battery assembly is lithium sulfur electrolyte prepared by dissolving 1M lithium bis (trifluoromethyl) sulfonate imide (LiTFSI) containing 2wt.% LiNO ₃ in ethylene glycol dimethyl ether and 1, 3-dioxolane in a volume ratio of 1:1. The amount of the electrolyte and the active material sulfur used was 12. Mu.L.mg ^-1.

Example 3

(1) 1g of polyacrylonitrile powder is weighed into a reagent bottle, 10g of N, N-dimethylformamide is added, then magnetic stirring and dispersion are carried out by using the auxiliary dissolution mixing device 1000 provided in the embodiment 1 at a rotating speed of 400rpm (preset rotating speed), the stirring temperature is 27 ℃, the time is set to 4 hours, and the electrostatic spinning precursor liquid with the mass fraction of polyacrylonitrile of 10wt% is obtained and marked as 10% PAN;

(2) The distance between a spinning needle head of the electrostatic spinning and a receiving device is 12cm, the voltage of the electrostatic spinning is set to 18kV, the electrostatic spinning is carried out by using 10% PAN electrostatic spinning precursor liquid, the spinning precursor liquid amount is 8mL, the flow parameter is 0.7mL/h, the distance parameter is 60cm, and the time is set to 11 hours;

(3) Taking down the prepared fiber membrane, and putting the fiber membrane into a 60 ℃ oven for drying for 8 hours;

(4) Cutting the dried fiber membrane sample, and then preserving the heat for 2 hours at 260 ℃ in an air atmosphere (low-temperature pre-oxidation in air) by using a tube furnace, wherein the heating rate is 2 ℃ per minute, and then preserving the heat for 2 hours at 700 ℃ in an argon atmosphere (high-temperature annealing in protective gas), and the heating rate is 4 ℃ per minute;

(6) Preparation of a positive plate: the active substance sulfur and the conductive carbon nano tube MWCNT are mixed according to the mass ratio of 3:1 to prepare an S/C mixture. The total mass of the mixture is 0.45g, and sulfur is melted for 24 hours at 155 ℃ after the mixture is mixed. Mixing the mixture and LA133 in a mass ratio of 9:1, dropwise adding 1.3g of deionized water into the mixed material, and stirring in a deaeration machine for 1h in the mixing process to obtain anode slurry; coating positive electrode slurry on the surface of an aluminum foil, wherein the thickness of a wet film formed by the positive electrode slurry on the surface of the aluminum foil is 250 mu m; after vacuum drying, cutting into positive plates with the diameter of 13mm by a cutting machine;

Example 4

(1) 1g of polyacrylonitrile powder is weighed into a reagent bottle, 8g of N, N-dimethylformamide is added, then magnetic stirring and dispersion are carried out by using the auxiliary dissolution mixing device 1000 provided in the embodiment 1 at a rotating speed of 200rpm (preset rotating speed), the stirring temperature is 28 ℃, the time is set to 6 hours, and the electrospinning precursor liquid with the mass fraction of polyacrylonitrile of 12.5wt% is obtained and marked as 12.5% PAN;

(2) The distance between a spinning needle head of the electrostatic spinning and a receiving device is 12cm, the voltage of the electrostatic spinning is set to be 20kV, the electrostatic spinning is carried out by using electrostatic spinning precursor liquid of 12.5% PAN, the amount of the spinning precursor liquid is 10mL, the flow parameter is 0.8mL/h, the distance parameter is 80cm, and the time is set to be 12 hours;

(3) Taking down the prepared fiber membrane, and putting the fiber membrane into a 60 ℃ oven for drying for 10 hours;

(4) Cutting the dried fiber membrane sample, and then preserving the heat for 2 hours at 280 ℃ in an air atmosphere (low-temperature pre-oxidation in air) by using a tube furnace, wherein the heating rate is 1 ℃ per minute, and then preserving the heat for 2 hours at 800 ℃ in an argon atmosphere (high-temperature annealing in protective gas), and the heating rate is 2 ℃ per minute;

(6) Preparation of a positive plate: the S/C mixture is prepared by mixing active substance sulfur and conductive carbon black Super P according to a mass ratio of 3:1. The total mass of the mixture is 0.45g, and sulfur is melted for 24 hours at 155 ℃ after the mixture is mixed. Mixing the mixture and LA133 in a mass ratio of 9:1, dropwise adding 1.3g of deionized water into the mixed material, and stirring in a deaeration machine for 1h in the mixing process to obtain anode slurry; coating positive electrode slurry on the surface of an aluminum foil, wherein the thickness of a wet film formed by the positive electrode slurry on the surface of the aluminum foil is 250 mu m; after vacuum drying, cutting into positive plates with the diameter of 13mm by a cutting machine;

Comparative example

Comparative example no interlayer was added when assembling the lithium sulfur battery.

(1) Preparation of a positive plate: the S/C mixture is prepared by mixing active substance sulfur and conductive carbon black Super P according to a mass ratio of 3:1. The total mass of the mixture is 0.45g, and sulfur is melted for 24 hours at 155 ℃ after the mixture is mixed. Mixing the mixture and LA133 in a mass ratio of 9:1, dropwise adding 1.3g of deionized water into the mixed material, and stirring in a deaeration machine for 1h in the mixing process to obtain anode slurry; coating positive electrode slurry on the surface of an aluminum foil, wherein the thickness of a wet film formed by the positive electrode slurry on the surface of the aluminum foil is 250 mu m; after vacuum drying, cutting into positive plates with the diameter of 13mm by a cutting machine;

(2) Preparation of lithium-sulfur battery: in a MIKROUNA glove box filled with argon gas and dried, the positive electrode, the diaphragm, the lithium sheet, the gasket and the elastic sheet are assembled in sequence. The battery accessory is a 2032 button type battery, and the diaphragm is Celgrad2500; the electrolyte used for battery assembly is lithium sulfur electrolyte prepared by dissolving 1M lithium bis (trifluoromethyl) sulfonate imide (LiTFSI) containing 2wt.% LiNO ₃ in ethylene glycol dimethyl ether and 1, 3-dioxolane in a volume ratio of 1:1. The amount of the electrolyte and the active material sulfur used was 12. Mu.L.mg ^-1.

Fig. 10 is a scanning electron micrograph of the highly conductive flexible carbon nanofiber interlayers prepared in example 2, example 3 and example 4, example 2 corresponds to (a), example 3 corresponds to (b), and example 4 corresponds to (c).

Fig. 11 is an X-ray diffraction pattern of the highly conductive flexible carbon nanofiber interlayers prepared in example 2, example 3 and example 4, wherein example 2 corresponds to PAN-600, example 3 corresponds to PAN-700, and example 4 corresponds to PAN-800.

Fig. 12 is a cycle-specific capacity curve at 0.2C of the lithium sulfur batteries prepared in example 2, example 3, example 4 and comparative example, wherein example 2 corresponds to PAN-600, example 3 corresponds to PAN-700, example 4 corresponds to PAN-800, and comparative example corresponds to Without.

Therefore, the carbon nano fiber of the high-conductivity flexible carbon nano fiber interlayer has uniform diameter distribution, widely distributed hole structures among fibers, rough microscopic surface of the fiber film, similar to the surface structure of the common interlayer such as carbon cloth, and the like, and the fiber film shows the characteristic of high conductivity. The high-conductivity flexible carbon nanofiber interlayer prepared by the method has the characteristics of high specific surface area and high porosity while showing the properties of the flexible conductive reinforced material, and has good application prospect in the aspect of carbon nanofiber interlayers for lithium-sulfur batteries.

In summary, the auxiliary dissolution mixing device 1000 provided by the embodiment of the invention can effectively control the mixing dissolution progress, monitor the dissolution condition in real time, and send a notification at the first time after the dissolution is completed, thereby not only guaranteeing the sufficiency of dissolution, but also effectively reducing the time waste, ensuring the production efficiency, and simultaneously not bringing additional burden to the staff.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An auxiliary dissolution mixing apparatus, comprising: the device comprises an outer barrel, a cover body, an inner container, a detection ring, a light beam emitter, a light beam receiver, a magnetic stirring assembly, a magnetic stirrer and a controller;

The outer cylinder is provided with a containing cavity for containing the inner container, the cover body is used for closing the containing cavity, and the inner container is made of a light-transmitting material; the inner side wall of the accommodating cavity is provided with a concave area, and the concave area continuously extends along the circumferential direction of the accommodating cavity to form a ring shape and simultaneously extends along the depth direction of the accommodating cavity;

The concave area is internally provided with a guide rod and a screw rod which are arranged along the depth direction of the accommodating cavity, the detection ring is annularly arranged on the inner container, the detection ring is slidably matched with the guide rod, and the screw rod is in transmission fit with the detection ring and is driven by a first driver;

the light beam emitter and the light beam receiver are respectively arranged on two opposite sides of the inner annular wall of the detection ring, the light beam emitter is arranged towards the light beam receiver, and the light beam receiver is used for receiving light beam signals sent by the light beam emitter and detecting light intensity;

the magnetic stirring assembly is arranged at the bottom of the accommodating cavity, and the magnetic stirrer is used for being placed in the inner container;

The controller stores the light transmittance data of the inner container and related reagents;

The light beam emitter, the light beam receiver, the magnetic stirring assembly and the first driver are all electrically connected with the controller; the controller is used for judging the dissolution condition according to the light intensity detected by the light beam receiver, and is also used for controlling the first driver to drive the screw rod to enable the detection ring to reciprocate along the guide rod so as to detect the dissolution condition in the whole liner;

The auxiliary dissolution mixing apparatus further includes: an annular cylinder;

The annular cylinder is arranged on the detection ring in a surrounding manner, the inner diameter of the annular cylinder is larger than the outer diameter of the detection ring, the annular cylinder and the detection ring are coaxially arranged, and the annular cylinder is rotatably matched with the concave area and driven by a second driver; the annular cylinder is provided with a pushing piece extending towards the detection ring, and the pushing piece extends along the axial direction of the annular cylinder;

the detection ring comprises an upper ring piece, a lower ring piece, an inner ring body and an outer ring body; the upper ring piece, the lower ring piece, the inner ring body and the outer ring body are coaxially arranged and are all arranged in a ring shape in the inner container, the upper ring piece and the lower ring piece are arranged at intervals along the depth direction of the accommodating cavity, the outer diameter of the inner ring body is smaller than the inner diameter of the outer ring body, and the inner ring body and the outer ring body are matched between the upper ring piece and the lower ring piece;

Along the circumferential direction of the detection ring, the inner ring body and the outer ring body are rotatably matched between the upper ring piece and the lower ring piece; along the axial direction of the guide rod, the inner ring body and the outer ring body are fixedly matched between the upper ring piece and the lower ring piece;

The guide rod and the screw rod penetrate through the upper ring piece and the lower ring piece and are positioned between the inner ring body and the outer ring body, and any one of the upper ring piece and the lower ring piece is in transmission fit with the screw rod;

The outer annular wall of the outer annular body is provided with a matching groove for matching with the pushing piece, the inner annular wall of the outer annular wall is provided with a first radial blind hole, a first matching column is slidably matched in the first radial blind hole, and an elastic piece is abutted between the first matching column and the bottom of the first radial blind hole; the outer end part of the first matching column is provided with a bulge;

The outer annular wall of the inner annular body is provided with a second radial blind hole, a second matching column is slidably matched in the second radial blind hole, and an elastic piece is abutted between the second matching column and the bottom of the second radial blind hole; the outer end part of the second matching column is provided with a groove used for matching with the bulge;

In a natural state, the ends of the first matching column and the second matching column are propped against, and the protrusion is matched with the groove, so that the outer ring body and the inner ring body are fixedly matched in the circumferential direction;

The front side walls of the first matching column and the second matching column are provided with guide grooves along the direction of driving the outer ring body by the annular cylinder, the guide grooves penetrate through the outer end walls of the first matching column and the second matching column, the inner ends of the guide grooves point to the outer end direction, and the concave depth of the guide grooves increases progressively;

When the first matching column and the second matching column are contacted with the guide rod/the screw rod, the guide rod/the screw rod is simultaneously abutted to the guide grooves of the first matching column and the second matching column, so that the first matching column and the second matching column are pushed into the first radial blind hole and the second radial blind hole respectively, the first matching column and the second matching column are separated, and the guide rod/the screw rod can pass through the first matching column and the second matching column.

2. The auxiliary dissolution mixing apparatus of claim 1, wherein the controller controls the magnetic stirring assembly to drive the magnetic stirrer to stir at a speed lower than a preset rotational speed when stirring is started; when the condition that the condition near the liquid level meets the dissolution requirement is detected, the controller controls the magnetic stirring assembly to drive the magnetic stirrer to stir at a preset rotating speed; when detecting that the inner wall of the inner container is adhered with materials, the controller controls the magnetic stirring assembly to drive the magnetic stirrer to stir at a speed higher than a preset rotating speed.

3. The auxiliary dissolution mixing device according to claim 1, wherein two groups of guide rods are respectively arranged on two opposite sides of the inner container and are respectively arranged at intervals with the inner container, two groups of screw rods are respectively arranged on two opposite sides of the inner container and are respectively arranged at intervals with the inner container, and two groups of guide rods and two groups of screw rods are alternately arranged at uniform intervals along the circumferential direction of the inner container.

4. The auxiliary dissolution mixing apparatus according to claim 1, wherein a plurality of the fitting grooves are provided at regular intervals along the circumferential direction of the outer ring body;

The annular cylinder is provided with a mounting opening for mounting the pushing piece, the mounting opening penetrates through the annular cylinder along the radial direction of the annular cylinder, the mounting opening extends along the axial direction of the annular cylinder, and a plurality of mounting openings are uniformly arranged at intervals along the circumferential direction of the annular cylinder;

Each mounting opening is internally provided with a pushing piece, one side edge of the pushing piece, far away from the detection ring, is fixedly connected with a rotating shaft, the rotating shaft is arranged along the axial direction of the annular cylinder, and the rotating shaft is rotatably mounted in the mounting opening and far away from the detection ring;

A first guide groove and a second guide groove are formed in one side, far away from the detection ring, of the rotating shaft, the first guide groove extends along the axial direction of the rotating shaft, the second guide groove is communicated with one end of the first guide groove, and the second guide groove extends along the circumferential direction of the rotating shaft and is gradually far away from the first guide groove along the axial direction of the rotating shaft;

The annular cylinder is also sleeved with a control ring, the control ring is slidably matched with the annular cylinder and driven by a third driver, the inner annular wall of the control ring is fixedly connected with a positioning column, and the positioning column is slidably matched with the first guide groove or the second guide groove;

The control ring is provided with a first sliding dead point and a second sliding dead point; when the control ring is positioned at the first sliding dead point, the positioning column is positioned in the first guide groove, and the pushing piece is arranged along the radial direction of the annular cylinder and is matched in the matching groove; when the control ring is positioned at the second sliding dead point, the positioning column is positioned in the second guide groove, the pushing piece deflects towards the reverse direction of the rotating direction of the annular cylinder, and the pushing piece withdraws from the matching groove.

5. The auxiliary dissolution mixing apparatus according to claim 4, wherein a front end wall of the fitting groove is provided in a radial direction when the outer ring body is provided in a direction in which the outer ring body is driven by the ring cylinder, and a rear end wall of the fitting groove is provided obliquely to give way for the pushing piece to leave the fitting groove.

6. The preparation process of the high-conductivity flexible carbon nanofiber interlayer is characterized by comprising the following steps of:

Adding solvent and polyacrylonitrile powder in a corresponding proportion into the inner container of the auxiliary dissolution mixing device according to any one of claims 1 to 5, and stirring and dispersing the polyacrylonitrile powder in the solvent by using the magnetic stirrer;

The beam receiver is used for receiving a beam signal sent by the beam emitter and detecting the light intensity, and when the detected light intensity is matched with the light transmittance data when the light intensity is fully dispersed, the polyacrylonitrile powder is fully dispersed in the solvent, so that the electrostatic spinning precursor liquid is obtained;

And (3) pre-oxidizing the dried polyacrylonitrile fiber membrane in air at low temperature, and then annealing in protective gas at high temperature to obtain the high-conductivity flexible carbon nanofiber interlayer.

7. The process for preparing a highly conductive flexible carbon nanofiber sandwich according to claim 6 wherein the solvent is: n, N-dimethylformamide; the mass fraction of the polyacrylonitrile is 8.3 to 12.5 percent.

8. The process for preparing the high-conductivity flexible carbon nanofiber interlayer according to claim 6, wherein in the electrostatic spinning method, the electrostatic spinning voltage is 16 kV-20 kV, the electrostatic spinning distance is 40 cm-80 cm, the electrostatic spinning flow is 0.6-0.8 mL/h, and the volume of the electrostatic spinning precursor solution is 6 mL-10 mL.

9. The process for preparing the high-conductivity flexible carbon nanofiber sandwich according to claim 6, wherein during low-temperature pre-oxidation treatment in air, the temperature of the low-temperature pre-oxidation is 250-280 ℃, the temperature rising rate of the low-temperature pre-oxidation is 1-3 ℃/min, and the heat preservation time of the low-temperature pre-oxidation is 120min;

And during high-temperature annealing treatment in the protective gas, the heating rate of the high-temperature annealing is 2-5 ℃/min, the temperature of the high-temperature annealing is 600-800 ℃, and the heat preservation time of the high-temperature annealing is 120min.