Method for preparing dry-method electrode plate through glue spraying and coating

Abstract

The invention relates to the technical field of electrode plate preparation, and particularly discloses a method for preparing a dry-method electrode plate through glue spraying and coating, and the method comprises the following steps: S1, respectively pouring dry-method powder into two feeding mechanisms; s2, vertically unwinding the current collector by an unwinding mechanism; s3, cutting the head ends of the two dry-method self-supporting films which are longitudinally symmetrical along the current collector by a preliminary compounding mechanism; s4, the two attached dry-method self-supporting films and the current collector enter a rolling mechanism to be rolled to form a pole piece; and S5, guiding the pole piece into a single-section drying oven by a guide roller II for drying. The head end of the dry-method self-supporting film is cut off through the head end cutter, and when the dry-method self-supporting film is compounded with a current collector in a rolling mode, the head end of the dry-method self-supporting film is in a flush state, so that the head end of the pole piece formed in a rolling mode is kept in a flush state, and when the pole piece is put into use in the later period, the head end of the pole piece does not need to be cut; therefore, waste of the current collector is avoided.

Description

[0001] The present invention belongs to the technical field of electrode sheet preparation, and in particular relates to a method for preparing dry electrode sheets by spray coating. Background Art

[0002] With the continued exploitation and utilization of traditional fossil fuels such as coal, oil, and natural gas, humanity faces increasingly severe energy crises and environmental challenges. For the sustainable development of humanity and nature, clean energy sources such as wind, solar, and tidal energy are gradually increasing in proportion, potentially replacing traditional fossil fuels and alleviating the energy crisis. The utilization of new energy sources primarily involves converting mechanical energy into electrical energy. Due to time and space mismatches, the output power suffers from poor stability and sustainability. Therefore, the utilization of new energy sources is inseparable from the development of energy storage devices. Commercial lithium-ion batteries, the most mainstream energy storage device, have been developed for decades. However, traditional lithium-ion battery production relies on a wet process, which involves mixing active materials, conductive agents, and binders in a liquid phase in a stirring mechanism to achieve uniform dispersion. This slurry, which has a certain viscosity, is then coated onto metal foil using a coating machine and baked in a tens-of-meter-long oven to remove the solvent. This process requires significant equipment investment and is accompanied by enormous energy consumption. The cathode solvent, NMP (N-methylpyrrolidone), is a toxic organic solvent, posing potential hazards to both humans and the environment.

[0003] Because the dry process involves dry mixing of the powders without the addition of any solvent, it eliminates the solvent drying and recovery step in electrode preparation. This prevents the capillary action during solvent evaporation, which causes binders, conductive agents, and other materials to accumulate on the electrode surface as the solvent flows, thereby improving the uniformity of the electrode components. The lack of solvent also reduces the need for ovens, significantly reducing energy consumption during production. However, existing dry-process electrode production equipment can suffer from uneven rolling when rolling the raw powders.

[0004] In response to the above technical problems, the applicant has retrieved some existing technologies that have achieved uniform rolling of raw material powders. For example, the patent publication number is CN117936691A. Its main technical means is to design at least two hot pressing rollers. The hot pressing rollers in the existing technology are two. The function of the hot pressing gap is: when the raw material powder passes through the hot pressing gap, due to the rolling of the hot pressing rollers on both sides, pole pieces are formed. The two pole pieces form a finished product in the forming channel. The finished product is a lithium battery electrode. Therefore, there is only one hot pressing gap and it can only be rolled once. It is easy to roll unevenly once, resulting in a low yield. In this solution, three or more hot pressing rollers have two or more hot pressing gaps, and can perform multiple rolling. The second rolling can solve the uneven problem caused by the first rolling. The disadvantage of this technical solution is that after the electrode is rolled, the head end of the electrode is uneven when it is discharged, and it is not in a flat state. If the electrode sheets on both sides are directly rolled and compounded with the current collector, the head end of the electrode sheet will be uneven when it is rolled up. When it is put into use later, when the head end of the electrode sheet is used, the head end of the electrode sheet needs to be cut, which will cut off part of the current collector, resulting in a waste of resources. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the prior art and provide a method for preparing dry electrode sheets by spray coating, so as to solve the technical problem of uneven head ends of electrode sheets after roll-pressing and compounding.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a dry electrode sheet by spray coating comprises the following steps: Step S1: Pour the dry powder into two feeding mechanisms respectively, so that the powder evenly enters the corresponding multi-roller continuous rolling mechanism below the two feeding mechanisms, and is rolled into a dry self-supporting film of target thickness through multiple rollers; Step S2: The current collector is unwound vertically by an unwinding mechanism, and an electrostatic spraying mechanism is provided on each side of the current collector to spray the conductive adhesive onto both sides of the current collector; Step S3: The preliminary laminating mechanism cuts the head ends of the two dry-process self-supporting films symmetrically along the longitudinal direction of the current collector, and laminates the two dry-process self-supporting films on both sides of the current collector respectively; Step S4: the two laminated dry-process self-supporting films and the current collector enter a rolling mechanism for rolling to form a pole piece; Step S5: The electrode is guided into a single-section oven for drying by the second guide roller, and then enters the winding mechanism for winding; The method for preparing dry-process electrode pole pieces by spraying glue is applied to a device for preparing dry-process electrode pole pieces by spraying glue, and the device includes: an unwinding mechanism for winding up a current collector; an electrostatic spraying mechanism located on both sides of the current collector after being discharged; a feeding mechanism and a multi-roller continuous rolling mechanism, wherein the material is fed into the multi-roller continuous rolling mechanism through the feeding mechanism, and the feeding position is between the first steel roller and the second steel roller in the multi-roller continuous rolling mechanism, and the feeding mechanism and the multi-roller continuous rolling mechanism are each provided with two groups, and the two groups of feeding mechanisms and multi-roller continuous rolling mechanisms are symmetrical along the vertically discharged current collector; a preliminary compounding mechanism, wherein two dry-process self-supporting films and the current collector pass through the preliminary compounding mechanism; a rolling mechanism, wherein the two dry-process self-supporting films and the current collector discharged from the preliminary compounding mechanism are then passed through the rolling mechanism for rolling; a single-section oven, wherein the roll-formed pole piece passes through the single-section oven; two guide rollers are provided between the single-section oven and the rolling mechanism; the roll-formed pole piece passing through the single-section oven is wound up by the unwinding mechanism.

[0007] As a preferred embodiment of the above technical solution, the preliminary composite structure includes: Guide roller 1, wherein two guide rollers are provided, and the two guide rollers are symmetrical along the vertically released current collector, and the dry self-supporting film is located between the guide roller 1 and the current collector on the same side; There are two vertical plates, one vertical plate and one guide roller. The two vertical plates are located between the two guide rollers and are in a vertical state. The two vertical plates are symmetrical along the vertically discharged current collector. The dry self-supporting film is located between the vertical plates and the current collector on the same side. The head end cutter is provided with two groups, and the two groups of head end cutters are symmetrical along the vertically released collector. The head end cutters are located between the vertical plate and the collector on the same side. The head end cutters move toward the vertical plate on the same side to cut the head end of the dry self-supporting film.

[0008] As a preferred embodiment of the above technical solution, the preliminary composite mechanism further includes: baffles, wherein two baffles are provided, and the two baffles are symmetrical along the vertically discharged current collector, and the discharged current collector is located between the two baffles, and the cut dry-process self-supporting film is guided to enter the position between the baffle and the current collector on the same side; A support plate is hinged at the bottom end of the baffle plate and is used to support the current collector located between the two baffle plates and the two cut dry self-supporting films.

[0009] As a preferred embodiment of the above technical solution, there is a preliminary composite plate between the baffle and the vertical plate on the same side, and a through hole is opened on the baffle. The two preliminary composite plates are respectively moved toward the baffle on the same side to pass through the through holes to extrude two dry self-supporting films and the current collector, and the two dry self-supporting films are respectively attached to both sides of the current collector.

[0010] As a preferred embodiment of the above technical solution, there is a guide plate between the two vertical plates and the current collector. The two guide plates are symmetrical along the vertically discharged current collector. The guide plates are in an inclined state, with their inclined tops facing the vertical plates on the same side, and their inclined bottoms facing the position between the current collector and the baffle on the same side.

[0011] As a preferred embodiment of the above technical solution, there is a protective plate above the guide plate, and the protective plate is in an inclined state, and its inclination direction is the same as the inclination direction of the guide plate on the same side, and the protective plate is parallel to the guide plate on the same side.

[0012] As a preferred embodiment of the above technical solution, the side of the head end cutter away from the vertical plate on the same side is in an inclined state, with its inclined top facing the vertical plate on the same side, and its inclined bottom facing the guide plate on the same side. After the head end cutter moves toward the vertical plate on the same side and cuts the head end of the dry self-supporting film, the inclined bottom of the head end cutter coincides with the inclined top of the guide plate.

[0013] As a preferred embodiment of the above technical solution, two groups of side cutters are provided between the two guide rollers 1, the two groups of side cutters are symmetrical along the vertically discharged current collector, and the side cutters and guide roller 1 on the same side are used in conjunction with each other.

[0014] As a preferred embodiment of the above technical solution, a side cutter is provided on the inner side of the guide roller.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, the head end of the dry-process self-supporting film is cut off by a head end cutter. In this way, when the dry-process self-supporting film is roll-pressed and compounded with the current collector, the head end of the dry-process self-supporting film is in a flush state. In this way, the head end of the roll-formed pole piece is also kept in a flush state. When the pole piece is put into use later, there is no need to cut the head end of the pole piece, so as not to waste the current collector. 2. In the present invention, the baffle and the support plate are used to make the bottom of the current collector and the two dry-process self-supporting films on both sides thereof flush, thus ensuring that the first end of the pole piece after roll-pressing and compounding is flush; at the same time, the preliminary composite plates on both sides make the two dry-process self-supporting films further adhere to the two sides of the current collector, so that the two dry-process self-supporting films and the bottom of the current collector can be kept flush before entering the rolling mechanism. In this way, after the two dry-process self-supporting films and the current collector are rolled, the two dry-process self-supporting films and the bottom of the current collector remain flush, thereby further ensuring that the first end of the pole piece after roll-pressing and compounding is flush. When the pole piece is put into use later, there is no need to cut the first end of the pole piece, so as to avoid waste of the current collector; 3. In the present invention, the dry-process self-supporting film is placed in a bent state rather than a straightened state by means of the vertical plates and the guide plates, so that the dry-process self-supporting film has a buffer area, thereby being able to keep up with the displacement speed of the current collector. This allows the thickness of the dry-process self-supporting film to be uniform when compounded with the current collector. In the subsequent roll-pressing compounding, the thickness of the dry-process self-supporting film on both sides of the produced electrode is the same, effectively avoiding the different displacement speeds of the dry-process self-supporting film and the current collector, effectively avoiding the dry-process self-supporting film compounded on the current collector being thin in some places and thick in others, and effectively avoiding the dry-process self-supporting film from being broken or wrinkled. 4. In the present invention, the two sides of the dry-process self-supporting film are trimmed by a side cutter, thereby cutting off the uneven parts of the two sides of the dry-process self-supporting film, effectively avoiding the waste of resources caused by cutting off part of the collector when cutting the two sides after the electrode is formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 Schematic diagram of the front structure before the dry process self-supporting film and current collector are initially composited; Figure 3 Schematic diagram of the three-dimensional structure of the dry process self-supporting film before preliminary composite with the current collector; Figure 4 for Figure 2 A in the middle is an enlarged structural diagram; Figure 5 Schematic diagram of the front structure after the dry process self-supporting film and current collector are initially composited; Figure 6 Schematic diagram of the three-dimensional structure after the dry process self-supporting film and current collector are initially composited; Figure 7 for Figure 6 Enlarged structural diagram at point B in the middle.

[0017] In the picture: 1. Unwinding mechanism; 2. Current collector; 3. Electrostatic spraying mechanism; 4. Feeding mechanism; 5. Multi-roller continuous rolling mechanism; 6. Dry self-supporting film; 7. Preliminary lamination mechanism; 71. Guide roller 1; 72. Vertical plate; 73. Head end cutter; 731. Telescopic part 1; 74. Guide plate; 741. Protective plate; 75. Baffle; 751. Through hole; 76. Support plate; 77. Preliminary lamination plate; 771. Telescopic part 2; 78. Side cutter; 8. Rolling mechanism; 9. Guide roller 2; 10. Single-section oven; 11. Winding mechanism. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] Example like Figure 1 As shown, a method for preparing a dry electrode sheet by spray coating includes the following steps: Step S1: Pour the dry powder into two feeding mechanisms 4 respectively, so that the powder evenly enters the corresponding multi-roller continuous rolling mechanism 5 below the two feeding mechanisms 4, and is rolled into a dry self-supporting film 6 of target thickness through multiple rollers; Step S2: The current collector 2 is unwound vertically by the unwinding mechanism 1, and an electrostatic spraying mechanism 3 is provided on each side of the current collector 2 to spray the conductive adhesive onto both sides of the current collector 2; Step S3: The preliminary laminating mechanism 7 cuts the front ends of the two dry-process self-supporting films 6 symmetrically along the longitudinal direction of the current collector 2 and laminates the two dry-process self-supporting films 6 onto both sides of the current collector 2 respectively; Step S4: the two laminated dry self-supporting films 6 and the current collector 2 enter the rolling mechanism 8 for rolling to form a pole piece; Step S5: The electrode is guided into the single-section oven 10 for drying by the guide roller 2 9, and then enters the winding mechanism 11 for winding; The method for preparing dry electrode sheets by spray coating is applied to a device for preparing dry electrode sheets by spray coating, the device comprising: an unwinding mechanism 1 for winding a current collector 2; an electrostatic spraying mechanism 3 located on both sides of the unwound current collector 2; a feeding mechanism 4 and a multi-roller continuous rolling mechanism 5, wherein the material is fed into the multi-roller continuous rolling mechanism 5 through the feeding mechanism 4, and the feeding position is between the first steel roller and the second steel roller in the multi-roller continuous rolling mechanism 5, and the feeding mechanism 4 and the multi-roller continuous rolling mechanism 5 are each provided with two groups, and the two groups of feeding mechanisms 4 and The multi-roller continuous rolling mechanism 5 is symmetrical along the vertically discharged current collector 2; the preliminary composite mechanism 7, the two dry self-supporting films 6 and the current collector 2 pass through the preliminary composite mechanism 7; the rolling mechanism 8, the two dry self-supporting films 6 and the current collector 2 discharged from the preliminary composite mechanism 7 are then passed through the rolling mechanism 8 for rolling; the single-section oven 10, the roll-formed electrode passes through the single-section oven 10; a guide roller 9 is provided between the single-section oven 10 and the rolling mechanism 8; the roll-formed electrode passing through the single-section oven 10 is wound up by the winding mechanism 11.

[0020] In one case of this embodiment, the unwinding mechanism 1 is composed of an unwinding roller and a device for driving the unwinding roller, which is used to unwind the wound current collector 2; the electrostatic spraying mechanism 3 is responsible for evenly spraying the conductive glue on the surface of the current collector 2; the feeding mechanism 4 is similar to a funnel, feeding the material to the multi-roller continuous rolling mechanism 5, and the feeding position is between the first steel roller and the second steel roller; the multi-roller continuous rolling mechanism 5 is composed of three or more steel rollers and a device for driving the steel rollers to rotate, and can perform multiple rolling presses. After the powder enters the mechanism, it is rolled into a film by the first rolling, and is thinned by the subsequent rolling to obtain a dry self-supporting film 6 of the target thickness; the roller press The structure 8 is composed of two rolling rollers and a device that drives the rolling rollers to rotate. The rolling mechanism 8 is responsible for rolling the two dry self-supporting films 6 and the current collector 2 into a composite electrode; the single-section oven 10 is used to dry a small amount of solvent in the conductive glue; the winding mechanism 11 is composed of a winding roller and a device that drives the winding roller to rotate, and is used to wind up the formed electrode; the unwinding mechanism 1, the electrostatic spraying mechanism 3, the multi-roller continuous rolling mechanism 5, the rolling mechanism 8, the single-section oven 10 and the winding mechanism 11 are all prior art, and this application does not improve them. Therefore, there is no need to disclose their specific mechanical structure and circuit structure, which does not affect the integrity of this application; The dry powder is composed of an active material, a conductive agent (superconducting carbon black: SP), and a binder (polytetrafluoroethylene: PTFE) mixed in a mass ratio of 92:3:5 (the mass ratio is adjustable). The active materials in the dry powder are lithium iron phosphate, ternary lithium, lithium cobalt oxide, graphite, hard carbon, etc., which are the main raw materials in batteries and an important component of the dry powder. The binder in the dry powder is PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), etc. The current collector 2 is a common lithium battery foil, with aluminum foil as the positive electrode and copper foil as the negative electrode, and does not require special processing. The conductive glue is a mixture of PTFE / PVDF emulsion, SP (superconducting carbon black), CNT (carbon nanotube), and graphene in a ratio of 85:5:5:5 (the ratio is variable), and the conductive glue spraying thickness range is 0.1-3μm. In addition, there is no need to use a special current collector with a hot-melt conductive adhesive coating. The current collector 2 is compatible with traditional aluminum foil and copper foil, and there is no need to pre-treat the foil, which reduces the cost of raw materials. The electrostatic spraying mechanism 3 adopts an electrostatic spraying process, which can evenly spray the conductive adhesive on the surface of the foil with an extremely thin thickness and high consistency. The rolling mechanism 8 does not need to be heated, but needs to be temperature controlled and maintained at 25°C, thereby improving the cleanliness of the surface of the roll-formed pole piece. In this way, there is no need for a hot roller process, and the two sides can be dry-supported by direct rolling through the rolling mechanism 8. The supporting film 6 is compounded with the current collector 2 through the conductive adhesive, which reduces energy consumption and production costs; the single-section oven 10 is one section with a length of 1-2m, and the oven drying temperature range is 60-120°C. It is equipped with a solvent recovery system. Since the conductive adhesive contains a small amount of solvent that needs to be dried, only one section of the single-section oven 10 is designed, which can evaporate the liquid in the conductive adhesive. During the volatilization process, part of the conductive adhesive will move with the liquid and further combine with the dry self-supporting film 6, thereby improving the adhesion between the dry self-supporting film 6 and the current collector 2.

[0021] like Figure 1-Figure 7 As shown, a method for preparing dry electrode sheets by spray coating provided by the present invention, the preliminary composite mechanism 7 includes: The preliminary composite structure 7 includes: There are two guide rollers 71, which are symmetrical along the vertically released current collector 2. The dry self-supporting film 6 is located between the guide roller 71 and the current collector 2 on the same side. There are two vertical plates 72, one vertical plate 72 is used in conjunction with a guide roller 1 71, and the two vertical plates 72 are located between the two guide rollers 1 71 and are in a vertical state. The two vertical plates 72 are symmetrical along the vertically discharged current collector 2, and the dry self-supporting film 6 is located between the vertical plates 72 and the current collector 2 on the same side; The head end cutter 73 is provided with two groups, and the two groups of head end cutters 73 are symmetrical along the vertically released collector 2. The head end cutters 73 are located between the vertical plate 72 and the collector 2 on the same side. The head end cutters 73 move toward the vertical plate 72 on the same side to cut the head end of the dry self-supporting film 6.

[0022] In one case of this embodiment, the guide roller 71 is connected to an external driving device to rotate the guide roller 71, and the vertical plate 72 is flush with the vertical tangent of the side close to the guide roller 71 on the same side, so that the dry self-supporting film 6 passing through the guide roller 71 is vertically attached to the surface of the vertical plate 72; the head end cutter 73 is connected to the telescopic part 731, and the telescopic part 731 can be a cylinder, and of course it can also be a component that can drive the head end cutter 73 to move.

[0023] In actual application of this embodiment, when the dry self-supporting film 6 passes through the guide roller 71 and moves vertically downward, the telescopic member 731 is used to move the head end cutter 73 toward the vertical plate 72 on the same side, thereby cutting off the uneven part of the head end of the dry self-supporting film 6. During the cutting process, the vertical plate 72 presses against the head end cutter 73, making it easier for the head end cutter 73 to cut off the head end of the dry self-supporting film 6. After the head end of the dry self-supporting film 6 is cut off, when it is roll-pressed and compounded with the collector 2, the head end of the dry self-supporting film 6 is in a flush state, so that the head end of the roll-formed pole piece is also kept in a flush state. When the pole piece is put into use later, there is no need to cut the head end of the pole piece, so that there will be no waste of the collector 2.

[0024] Furthermore, the preliminary composite mechanism 7 further includes: Baffle 75, there are two baffles 75, the two baffles 75 are symmetrical along the vertically discharged current collector 2, the discharged current collector 2 is located between the two baffles 75, and the cut dry-process self-supporting film 6 is guided to enter the position between the baffle 75 and the current collector 2 on the same side; Support plate 76 : A support plate 76 is hingedly connected to the bottom end of the baffle 75 , and is used to support the current collector 2 and the two cut dry self-supporting films 6 located between the two baffles 75 .

[0025] In one case of this embodiment, the support plate 76 is rotatable, and the support plate 76 can be driven to rotate by an electrically controlled rotating shaft, or it can be a component that can drive the support plate 76 to rotate; in addition, the position of the baffle 75 is adjustable, so that it can adapt to dry self-supporting films 6 of different thicknesses; the baffle 75 is slightly tilted to facilitate the dry self-supporting film 6 to enter between the baffle 75 and the current collector 2, and the baffle 75 is tilted with the top facing the guide plate 74 on the same side, and the bottom facing the support plate 76 on the same side.

[0026] In actual application of this embodiment, the vertically released current collector 2 first enters the space formed by the two baffles 75 and the two support plates 76, and the bottom of the current collector 2 is against the middle position of the two support plates 76, and then the two cut dry self-supporting films 6 are guided so that the dry self-supporting film 6 enters the position between the baffle 75 and the current collector 2 on the same side, so that the dry self-supporting film 6 is against the support plate 76 on the same side, wherein the two baffles 75 slightly squeeze the current collector 2 and the two dry self-supporting films 6, so that the two dry self-supporting films 6 are initially attached to the two sides of the current collector 2, and the two support plates 76 make the current collector 2 and the bottom of the two dry self-supporting films 6 on both sides thereof flush, thereby ensuring that the head ends of the pole pieces are flush after roller pressing and compounding.

[0027] Furthermore, there is a preliminary composite plate 77 between the baffle 75 and the vertical plate 72 on the same side, and a through hole 751 is opened on the baffle 75. The two preliminary composite plates 77 move toward the baffle 75 on the same side through the through hole 751 to squeeze the two dry self-supporting films 6 and the collector 2, and respectively adhere the two dry self-supporting films 6 to both sides of the collector 2.

[0028] In one case of this embodiment, the preliminary composite plate 77 is connected to a second telescopic member 771 . The second telescopic member 771 may be a cylinder, or may be a member capable of driving the preliminary composite plate 77 to move.

[0029] In actual application of this embodiment, the preliminary composite plate 77 is made to pass through the through hole 751 on the same side baffle 75 through the telescopic part 2 771 to squeeze the two dry self-supporting films 6 and the collector 2, so that the two dry self-supporting films 6 are further adhered to the two sides of the collector 2, so that the two dry self-supporting films 6 and the bottom of the collector 2 can be kept flush before entering the rolling mechanism 8. In this way, after the two dry self-supporting films 6 and the collector 2 are rolled, the two dry self-supporting films 6 and the bottom of the collector 2 remain flush, thereby further ensuring that the head end of the electrode is flush after rolling and compounding.

[0030] like Figure 4 and Figure 7 As shown, a method for preparing dry electrode plates by spray coating provided by the present invention is provided. There is a guide plate 74 between the two vertical plates 72 and the current collector 2. The two guide plates 74 are symmetrical along the vertically discharged current collector 2. The guide plates 74 are in an inclined state, with their inclined tops facing the vertical plates 72 on the same side, and their inclined bottoms facing the position between the current collector 2 and the baffle 75 on the same side.

[0031] Furthermore, a protective plate 741 is provided above the guide plate 74 . The protective plate 741 is in an inclined state, and its inclination direction is the same as the inclination direction of the guide plate 74 on the same side, and the protective plate 741 is parallel to the guide plate 74 on the same side.

[0032] In one case of this embodiment, after the head end of the dry-process self-supporting film 6 is cut by the head end cutter 73 on the same side, the flush head end of the dry-process self-supporting film 6 after cutting is guided by the guide plate 74 on the same side to the position between the baffle 75 on the same side and the collector 2. The protective plate 741 guides the dry-process self-supporting film 6 on the one hand, and maintains the thickness of the dry-process self-supporting film 6 uniform on the other hand; in addition, the position of the protective plate 741 is adjustable to adapt to dry-process self-supporting films 6 of different thicknesses.

[0033] In actual application of this embodiment, the vertical plate 72 and the guide plate 74 put the dry self-supporting film 6 in a bent state rather than a straightened state, so that the dry self-supporting film 6 has a buffer area, so that it can keep up with the displacement speed of the current collector 2, so that the thickness of the dry self-supporting film 6 when compounded with the current collector 2 can be uniform. During the subsequent roller-pressing compounding, the thickness of the dry self-supporting film 6 on both sides of the electrode is the same, which effectively avoids the different displacement speeds of the dry self-supporting film 6 and the current collector 2, effectively avoids the dry self-supporting film 6 compounded on the current collector 2 being thin in some places and thick in other places, and effectively avoids the dry self-supporting film 6 being broken or wrinkled.

[0034] Furthermore, the side of the head end cutter 73 away from the vertical plate 72 on the same side is in an inclined state, with its inclined top facing the vertical plate 72 on the same side, and its inclined bottom facing the guide plate 74 on the same side. After the head end cutter 73 moves toward the vertical plate 72 on the same side and cuts the head end of the dry self-supporting film 6, the inclined bottom of the head end cutter 73 coincides with the inclined top of the guide plate 74.

[0035] In actual application of this embodiment, the inclined surface of the head end cutter 73 is connected to the inclined surface of the guide plate 74. In this way, after the head end of the dry self-supporting film 6 is cut, the flat head end of the dry self-supporting film 6 after cutting will be displaced along the inclined surface of the head end cutter 73 to the guide plate 74, and guided by the guide plate 74 to the position between the same side baffle 75 and the collector 2. The head end cutter 73 also plays a guiding role here, thereby making the entire process smoother.

[0036] like Figure 5 and Figure 6 As shown, two sets of side cutters 78 are provided between the two guide rollers 71. The two sets of side cutters 78 are symmetrical along the vertically discharged current collector 2. The side cutters 78 and the guide roller 71 on the same side are used in conjunction with each other.

[0037] In one case of this embodiment, the side cutter 78 is composed of a cutter and a positioning roller. The positioning roller is connected to an external driving device so that the positioning roller drives the cutter to rotate. The cutter is in contact with the surface of the guide roller 71 on the same side. The distance between the positioning roller and the guide roller 71 on the same side is equal to the thickness of the dry self-supporting film 6. There are multiple sizes of the cutter and the positioning roller to choose from, so as to adapt to dry self-supporting films 6 of different thicknesses. In addition, the positions of the cutters on both sides are adjustable, so as to adapt to dry self-supporting films 6 of different widths.

[0038] In actual application of this embodiment, the dry self-supporting film 6 passes through the guide roller 71, and the side cutter 78 will trim the two side edges of the dry self-supporting film 6, thereby cutting off the uneven parts of the two side edges of the dry self-supporting film 6, effectively avoiding the waste of resources caused by cutting off part of the collector 2 when cutting the two side edges after the electrode is formed.

[0039] In summary, it should be noted that the unwinding mechanism 1, the rolling mechanism 8 and the winding mechanism 11 have the same rotational speed, thereby effectively preventing the electrode from being pulled or squeezed during the winding process, and avoiding the occurrence of uneven electrode thickness.

[0040] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A method for preparing a dry electrode sheet by spray coating, characterized in that: The following steps are involved: Step S1: Pour the dry powder into two feeding mechanisms (4) respectively, so that the powder evenly enters the corresponding multi-roller continuous rolling mechanisms (5) below the two feeding mechanisms (4), and is pressed into a dry self-supporting film (6) of target thickness through multiple rollers; Step S2: the unwinding mechanism (1) unwinds the current collector (2) vertically, and an electrostatic spraying mechanism (3) is provided on each side of the current collector (2) to spray the conductive adhesive onto both sides of the current collector (2); Step S3: the preliminary composite mechanism (7) cuts the front ends of the two dry-process self-supporting films (6) symmetrically along the longitudinal direction of the current collector (2), and adheres the two dry-process self-supporting films (6) to the two sides of the current collector (2) respectively; Step S4: the two laminated dry-process self-supporting films (6) and the current collector (2) enter a rolling mechanism (8) for rolling to form a pole piece; Step S5: The electrode piece is introduced into the single-section oven (10) for drying by the guide roller 2 (9), and then enters the winding mechanism (11) for winding; The method for preparing a dry electrode sheet by spraying glue is applied to a device for preparing a dry electrode sheet by spraying glue, the device comprising: an unwinding mechanism (1) for winding a current collector (2); an electrostatic spraying mechanism (3) located on both sides of the unwound current collector (2); a feeding mechanism (4) and a multi-roller continuous rolling mechanism (5), wherein materials are fed into the multi-roller continuous rolling mechanism (5) through the feeding mechanism (4), and the feeding position is between the first steel roller and the second steel roller in the multi-roller continuous rolling mechanism (5), and the feeding mechanism (4) and the multi-roller continuous rolling mechanism (5) are each provided with two groups, and the two groups of the feeding mechanism (4) and the multi-roller continuous rolling mechanism (5) are respectively provided with two groups of the feeding mechanism (4) and the multi-roller continuous rolling mechanism (5). (5) symmetrically along the vertically discharged current collector (2); a preliminary composite mechanism (7), wherein the two dry self-supporting films (6) and the current collector (2) pass through the preliminary composite mechanism (7); a rolling mechanism (8), wherein the two dry self-supporting films (6) and the current collector (2) discharged from the preliminary composite mechanism (7) pass through the rolling mechanism (8) for rolling; a single-section oven (10), wherein the roll-formed pole piece passes through the single-section oven (10); a guide roller 2 (9) is provided between the single-section oven (10) and the rolling mechanism (8); the roll-formed pole piece passing through the single-section oven (10) is rolled up by a rolling mechanism (11).

2. The method for preparing dry electrode sheets by spray coating according to claim 1, characterized in that: The preliminary composite mechanism (7) comprises: A guide roller one (71), wherein two guide rollers (71) are provided, and the two guide rollers (71) are symmetrical along the vertically released current collector (2), and the dry process self-supporting film (6) is located between the guide roller one (71) and the current collector (2) on the same side; A vertical plate (72), wherein two vertical plates (72) are provided, one vertical plate (72) and one guide roller (71) are used in conjunction with each other, the two vertical plates (72) are located between the two guide rollers (71) and are in a vertical state, the two vertical plates (72) are symmetrical along the vertically released current collector (2), and the dry process self-supporting film (6) is located between the vertical plate (72) and the current collector (2) on the same side; The head end cutters (73) are provided with two groups, the two groups of head end cutters (73) are symmetrical along the vertically released current collector (2), the head end cutters (73) are located between the vertical plate (72) and the current collector (2) on the same side, and the head end cutters (73) move in the direction of the vertical plate (72) on the same side to cut the head end of the dry process self-supporting film (6).

3. The method for preparing dry electrode sheets by spray coating according to claim 2, characterized in that: The preliminary composite mechanism (7) further comprises: baffles (75), wherein two baffles (75) are provided, and the two baffles (75) are symmetrical along the vertically released current collector (2), the released current collector (2) is located between the two baffles (75), and the cut dry process self-supporting film (6) is guided to enter the position between the baffle (75) and the current collector (2) on the same side; A support plate (76), the bottom end of the baffle plate (75) is hingedly connected to the support plate (76), used to support the current collector (2) and the two cut dry-process self-supporting films (6) located between the two baffle plates (75).

4. The method for preparing dry electrode sheets by spray coating according to claim 3, characterized in that: A preliminary composite plate (77) is provided between the baffle plate (75) and the vertical plate (72) on the same side, and a through hole (751) is provided on the baffle plate (75). The two preliminary composite plates (77) are respectively moved toward the baffle plate (75) on the same side to pass through the through hole (751) to squeeze the two dry-process self-supporting films (6) and the current collector (2), and the two dry-process self-supporting films (6) are respectively attached to the two sides of the current collector (2).

5. The method for preparing dry electrode sheets by spray coating according to claim 3, characterized in that: There is a guide plate (74) between the two vertical plates (72) and the current collector (2). The two guide plates (74) are symmetrical along the vertically discharged current collector (2). The guide plates (74) are in an inclined state, with their inclined tops facing the vertical plates (72) on the same side and their inclined bottoms facing the position between the current collector (2) and the baffle (75) on the same side.

6. The method for preparing dry electrode sheets by spray coating according to claim 5, characterized in that: A protective plate (741) is provided above the guide plate (74); the protective plate (741) is in an inclined state, and its inclination direction is the same as the inclination direction of the guide plate (74) on the same side, and the protective plate (741) is parallel to the guide plate (74) on the same side.

7. The method for preparing dry electrode sheets by spray coating according to claim 6, characterized in that: The side of the head end cutter (73) away from the vertical plate (72) on the same side is in an inclined state, with its inclined top facing the vertical plate (72) on the same side, and its inclined bottom facing the guide plate (74) on the same side. After the head end cutter (73) moves toward the vertical plate (72) on the same side and cuts the head end of the dry process self-supporting film (6), the inclined bottom of the head end cutter (73) overlaps with the inclined top of the guide plate (74).

8. The method for preparing dry electrode sheets by spray coating according to claim 2, characterized in that: Two groups of side cutters (78) are provided between the two guide rollers (71); the two groups of side cutters (78) are symmetrical along the vertically discharged current collector (2); and the side cutters (78) and guide roller (71) on the same side are used in conjunction.

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