An electrode sheet, a method of manufacturing an electrode sheet, a secondary battery, and an electric device

Abstract

The application discloses a pole piece, a preparation method of the pole piece, a secondary battery and an electric device, and relates to the technical field of secondary batteries. The edge of the active coating is attached with solidified insulating glue, and the insulating glue at the edge can be bonded with the negative electrode (or the positive electrode) under high pressure. When the positive electrode is charged and discharged, the problem of poor cycle performance caused by volume change of the positive pole piece during the charging and discharging process can be effectively relieved, and the cycle performance of the battery is improved. In addition, the problem of edge material falling of the positive pole piece can be effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of secondary batteries, in particular to a pole piece, a preparation method of the pole piece, a secondary battery and a power utilization device. BACKGROUND

[0002] With the rapid development of lithium batteries, the traditional liquid battery using liquid electrolyte has been unable to meet people's pursuit of high energy density and high safety batteries. Full solid-state batteries, due to their high specific energy and high safety, are the main trend of the development of lithium ion batteries. As a new type of battery, the biggest difference from traditional batteries is the use of solid-state electrolyte, so there are great differences in the manufacturing process of electrodes and battery cells compared with traditional batteries. For the preparation of full solid-state batteries, most of them are cut and stacked. At present, in order to obtain high energy density, high load pole pieces are needed, and high efficiency ion and power channels also need to be maintained. The binder in the pole piece cannot be too much, which causes the pole piece edge to easily drop material. More importantly, during the charging and discharging process of the positive electrode, there is a volume change, and the interface separation problem caused by the volume change will lead to battery performance degradation. Therefore, this method has many problems for the continuous preparation of the pole piece of the later solid-state battery and the good performance expression.

[0003] Overall, the current full solid-state battery preparation process has the following problems: (1) After cutting the high-load positive electrode, the edge is easy to drop material during transportation and stacking, causing battery defects, reducing assembly success rate, and being not conducive to large-scale manufacturing; (2) In the full solid-state pole piece, the positive pole piece size is designed to be smaller than the negative pole piece size to prevent short circuit, and during the assembly of the solid-state battery, the pole piece needs to be pressed under a large pressure. During the pressing process, due to the smaller size of the positive electrode than the negative electrode, the edge part will be broken due to the large pressure, thereby causing a short circuit; (3) The existing pole piece does not address the problems of separation and performance degradation caused by the volume change of the positive electrode (such as cycle performance degradation). The adhesion between the existing material and the pole piece is poor, and the pole piece cannot form an effective bond to address the separation caused by the volume change.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The purpose of the present application is to provide a pole piece, a preparation method of the pole piece, a secondary battery and a power utilization device, aiming to improve the cycle performance of the battery and reduce the pole piece edge dropping material.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides a pole piece comprising a current collector and an active coating attached to the current collector, and an insulating glue after solidification attached to the current collector at the edge of the active coating.

[0008] In an optional embodiment, the cured insulating adhesive is attached around the periphery of the active coating layer;

[0009] Preferably, the width of the cured insulating adhesive is 0.5-1.5 μm.

[0010] In an optional embodiment, the raw material of the insulating adhesive comprises a first binder and a viscoelastic material, and the viscoelastic material is selected from at least one of thermoplastic adhesive and thermosetting adhesive;

[0011] Preferably, the first binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile;

[0012] Preferably, the mass ratio of the first binder to the viscoelastic material is 1:(0.5-1.5).

[0013] Preferably, the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, polyester, epoxy resin, polyurethane, polybutadiene acid, silicone resin, styrene-butadiene copolymer, polyester imide and polyimide.

[0014] In an optional embodiment, the active coating layer comprises an active material, a second binder and a conductive agent;

[0015] Preferably, the second binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile; more preferably, the first binder and the second binder contain the same component.

[0016] Preferably, the active coating layer is attached on both sides of the current collector, and the edges of the active coating layers on both sides are attached with the cured insulating adhesive;

[0017] Preferably, the active coating layer further comprises an electrolyte, and the electrolyte is selected from at least one of sulfide electrolyte, oxide electrolyte and halide electrolyte.

[0018] In a second aspect, the present application provides a method for preparing the electrode tab of any one of the preceding embodiments, comprising: providing an electrode tab substrate, the electrode tab substrate comprising a current collector and an active coating layer attached to the current collector;

[0019] According to the size of the electrode tab product, a mark is made on the active coating layer to form a mark groove, the insulating adhesive is injected into the mark groove, and is cured and formed; after the curing and forming, the electrode tab is die-cut at the position of the insulating adhesive.

[0020] In an optional embodiment, the insulating adhesive is coated around the periphery of the active coating layer, and is cured and formed.

[0021] In an optional embodiment, the indentation groove has a length direction and a width direction, in the length direction, the indentation groove extends from one end of the active coating to the opposite end; the width of the indentation groove is 1mm-3mm.

[0022] In an optional embodiment, the pole piece substrate is prepared by a wet process or a dry process;

[0023] Preferably, when the pole piece substrate is prepared by a wet process, it comprises: mixing the active material, the conductive agent, the electrolyte, the second binder and the dispersing agent to obtain a slurry, coating the slurry on at least one side of the current collector, and then drying;

[0024] Preferably, when the pole piece substrate is prepared by a dry process, it comprises: mixing the active material, the conductive agent, the electrolyte and the second binder to fiberize, preparing a sheet by rolling, and adhering to the current collector.

[0025] In a third aspect, the present application provides a secondary battery comprising the pole piece of any one of the preceding embodiments or the pole piece prepared by the preparation method of any one of the preceding embodiments.

[0026] In a fourth aspect, the present application provides an electric device comprising the secondary battery of the preceding embodiments.

[0027] The present application has the following beneficial effects: by attaching the cured insulating adhesive to the edge of the active coating, the insulating adhesive of the edge can be bonded to the negative electrode (or the positive electrode) under high pressure, when the positive electrode is charged and discharged, the problem of poor cycle performance caused by the volume change of the positive electrode pole piece during charging and discharging can be effectively alleviated, and the cycle performance of the battery can be improved; and the problem of edge material falling off of the positive electrode pole piece can also be effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 is a top view of the pole piece after indentation;

[0030] Figure 2 is a sectional view of the pole piece after indentation;

[0031] Figure 3 is a sectional view of the pole piece after injection of adhesive;

[0032] Figure 4 is a schematic view of the pole piece product obtained after die cutting of the pole piece. DETAILED DESCRIPTION

[0033] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. If specific conditions are not indicated in the embodiments, conventional conditions or manufacturer recommended conditions are adopted. If the used reagents or instruments are not indicated by manufacturers, they are all conventional products that can be purchased in the market.

[0034] The embodiments of the present application provide a preparation method of an electrode sheet, which can be a preparation method of a positive electrode sheet or a negative electrode sheet, comprising the following steps:

[0035] S1, preparing an electrode sheet substrate

[0036] The active coating layer is formed on the current collector, and a solid composite positive electrode can be prepared by using a wet process or a dry process, or a negative electrode sheet substrate can be prepared by using an existing preparation process of a negative electrode sheet.

[0037] In some embodiments, when the wet process is used to prepare the positive electrode sheet substrate, the specific steps include: mixing an active material, a conductive agent, an electrolyte, a second binder and a dispersing agent to obtain a positive electrode slurry, coating the positive electrode slurry on at least one side of the positive electrode current collector, and then drying. The specific types of the active material, the conductive agent, the electrolyte, the second binder and the dispersing agent are not limited, and they can be conventional raw materials used in the preparation of the positive electrode sheet, all of which are within the protection scope of the present application.

[0038] In some embodiments, when the dry process is used to prepare the positive electrode sheet substrate, the specific steps include: mixing an active material, a conductive agent, an electrolyte and a second binder to be fibrous, using a rolling method to prepare a positive electrode sheet, and adhering the positive electrode sheet to the positive electrode current collector, or using other dry processes that exist, which are not limited to the above method. The specific types of the active material, the conductive agent, the electrolyte and the second binder are not limited, and they can be conventional raw materials used in the preparation of the positive electrode sheet, all of which are within the protection scope of the present application. The amounts of the components are not limited, and the raw material ratio followed in the existing preparation process of the positive electrode sheet can be referred to, which is not limited herein.

[0039] In some embodiments, the specific type of the active material is not limited, which can be NCM811 purchased in the market, but is not limited thereto.

[0040] In some embodiments, the second binder in the active coating layer is selected from at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyacrylic acid (PAA) and polyacrylonitrile (PAN), and the second binder can be any one or several of the above.

[0041] In some embodiments, the electrolyte is selected from at least one of a sulfide electrolyte, an oxide electrolyte and a halide electrolyte, and the electrolyte can be any one or several of the above, such as a sulfide electrolyte LPSC, but is not limited thereto. The conductive agent can be conductive carbon black, but is not limited thereto.

[0042] The active coating can be located on one side of the current collector, or active coatings can be formed on both sides of the current collector, which can be adjusted according to the requirements of the product.

[0043] S2, marking

[0044] A marking device is used to form a marking groove (such as Figure 1 and Figure 2 marking area in the middle) on the active coating. The active layer of the electrode piece material area is removed in size by laser or mechanical cleaning means.

[0045] Specifically, the marking device can remove the active coating on the surface of the current collector to form a regular groove, and the specific model is not limited. The marking device can be an existing laser cleaning device (such as a laser cleaning machine of Haimeixing), a current collector punching and peeling marking device and a mechanical cutter cleaning device, which can achieve micron-level precision marking without damaging the current collector, affecting the strength of the current collector and the winding of the electrode piece, and generating burrs. When the current collector has active coatings on both sides, a double-sided marking method is used, as shown in Figure 2 When the current collector has an active coating on one side, a single-sided marking method is used.

[0046] When double-sided marking is performed, the marking groove positions on the active coatings on both sides can correspond, and marking can be performed at the same position. The marking width can be the same or different, and the width is preferably the same.

[0047] As shown in Figure 1 and Figure 2 , the marking groove has a length direction and a width direction. In the length direction, the marking groove extends from one end of the active coating to the opposite end. The width of the marking groove is preferably 1 mm-3 mm, such as 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, etc.

[0048] Further, the depth of the marking groove is 80 μm-120 μm, and the depth of the marking groove is less than or equal to the thickness of the active coating. That is, the depth of the marking groove can be substantially the same as the thickness of the active coating, or slightly less than the thickness of the active coating.

[0049] S3, glue injection and die cutting

[0050] As shown in Figure 3 and Figure 4As shown, insulating glue is injected at the notch groove, and then cured and formed. After that, die cutting is performed at the position of the insulating glue to obtain Figure 4 The edge-coated pole piece product.

[0051] In some embodiments, while injecting insulating glue at the notch groove, insulating glue can also be coated around the periphery of the active coating and cured and formed. The size of the positive pole piece after coating with glue can be consistent with that of the negative pole piece, which can avoid high-pressure edge breakage and edge material dropping of the pole piece due to the size difference between the positive and negative pole pieces, resulting in battery defects. More importantly, the edge glue can adhere to the negative pole under high pressure, and when the positive pole is charged and discharged, it can suppress the positive pole interface from being detached by the volume change of the glue itself, thereby improving the cycle performance of the battery. The width of the insulating glue coated around the periphery of the active coating is 0.5 μm-1.5 μm, and the thickness of the cured insulating glue is less than or equal to the thickness of the active coating. By optimizing the width of the coating around the periphery, the size of the positive pole piece can be consistent with that of the negative pole piece, thereby avoiding battery defects caused by edge breakage of the pole piece during high-pressure process.

[0052] Specifically, the curing method is not limited, and different materials can be cured by light curing, thermal curing, etc. If a thermoplastic material is used, cooling and solidification can also be used.

[0053] In some embodiments, the notch area can be filled with insulating glue by a micropore glue injection method, and the notch area can be filled with insulating glue by a micropore glue injection method. After curing, the pole piece is cut at the glue injection position to prepare a new type of full-solid-state pole piece with edge coating. The whole process is efficient, the prepared pole piece has few defects, and can be used for continuous assembly and production of full-solid-state, thereby improving the cycle performance of the battery.

[0054] In some embodiments, the raw material of the injected insulating glue includes a first binder and a viscoelastic material, and the viscoelastic material is selected from at least one of thermoplastic glue and thermosetting glue, which can be any one or several of the above. The prepared composite material can be well bonded with the pole piece, and has good viscoelasticity, which can effectively alleviate the problem of cycle performance decline caused by volume change of the pole piece during charging and discharging, and has very strong operability, thereby providing a very feasible method for large-scale manufacturing of full-solid-state.

[0055] In some embodiments, the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, polyester, epoxy resin, polyurethane, polybutadiene acid, silicone resin, styrene-butadiene copolymer, polyester imine, and polyimide. The viscoelastic material can be any one or several of the above, which can make the cured glue have good viscoelasticity.

[0056] In some embodiments, the first binder in the insulating glue is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile, and the first binder in the insulating glue can be any one or several of the above. Preferably, the first binder in the insulating glue and the second binder in the active coating preferably contain the same component. "Contain the same component" means that the same binder component is contained in both binders, such as polyacrylic acid, but other components can also be contained, which can be the same or different.

[0057] Further, the mass ratio of the first binder to the viscoelastic material is 1:(0.5-1.5), and the mass ratio of the first binder to the viscoelastic material is preferably in this range, which can further alleviate the problem of cycle performance decline caused by volume change of the pole piece during charging and discharging. Specifically, the mass ratio of the first binder to the viscoelastic material can be 1:0.5, 1:0.8, 1:1.0, 1:1.2, 1:1.5, etc., and the insulating glue can be prepared by blending extrusion, but is not limited thereto. When injecting glue, the prepared insulating glue can be injected by injection molding, and the injection thickness is consistent with the thickness of the pole piece, or can be slightly smaller than the thickness of the pole piece. The injection position can be at the marking position, or can surround the active coating.

[0058] The embodiment of the present application also provides a pole piece, as shown in Figure 4 which comprises a current collector and an active coating attached to the current collector, and the cured insulating glue is attached to the current collector at the edge of the active coating. Through the adhesion of the glue layer to the positive electrode or the negative electrode under high pressure, the problem of poor cycle performance caused by volume change of the positive pole piece during charging and discharging can be effectively alleviated, and the cycle of the battery is improved.

[0059] In some embodiments, the cured insulating glue is attached around the active coating on the current collector, as shown in Figure 4 .

[0060] The embodiment of the present application also provides a secondary battery comprising the above-mentioned pole piece. When the above-mentioned pole piece is a positive pole piece, it can also comprise a negative pole piece; when the above-mentioned pole piece is a negative pole piece, it can also comprise a positive pole piece, forming a complete battery structure.

[0061] The embodiment of the present application also provides an electric device comprising the above-mentioned secondary battery, which is powered by the secondary battery, and the form of the electric device is not limited.

[0062] The features and properties of the present application are further described in detail below in conjunction with embodiments.

[0063] Embodiment 1

[0064] The embodiment provides a preparation method of a positive electrode tab, and a novel full-solid-state positive electrode tab with edge glue is prepared, including the following steps.

[0065] (1) Preparation of tab substrate

[0066] The positive electrode is prepared by using a dry process. NCM811 positive electrode material, conductive carbon black SP, sulfide electrolyte LPSC and binder PTFE and PAA are weighed in a proportion of 75:3:19:2:1 and fiberized after mixing, a positive electrode tab is prepared by rolling, and a carbon-coated aluminum foil current collector with a thickness of 14 microns is laminated to prepare a full-solid-state composite positive electrode. The thickness of the positive electrode active coating is 100 microns.

[0067] (2) Positive electrode marking

[0068] The laser marking method is used to adjust the laser energy, and the tab is marked on both sides, the marking width is 2 mm, and the depth is 100 microns.

[0069] (3) Glue injection and die cutting

[0070] A microporous glue injection machine is used, and EVA+PAA=1:1 is used as the insulating glue (EVA is ethylene-vinyl acetate copolymer material, and PAA is polyacrylic acid). The glue is injected at the marking position and around the tab, the thickness is 100 microns, the glue injection width at the tab marking position is 2 mm, the surrounding glue injection width is 1 mm, and the positive electrode tab is prepared by solidification and die cutting at the marking position.

[0071] Example 2

[0072] The embodiment provides a preparation method of a positive electrode tab, and a novel full-solid-state positive electrode tab with edge glue is prepared, including the following steps:

[0073] (1) Preparation of tab substrate

[0074] The positive electrode is prepared by using a wet process. NCM811 positive electrode material, conductive carbon SP, sulfide electrolyte LPSC and binder SBR are weighed in a proportion of 75:3:19:3 and mixed, then butyl butyrate is added as a dispersion medium, the solid content concentration is adjusted to 60%, and ultrasonic dispersion treatment is performed for 2 minutes to obtain a positive electrode slurry. The positive electrode slurry is coated on both sides of a carbon-coated aluminum foil current collector with a thickness of 14 microns, and a composite positive electrode tab is obtained after drying. The thickness of the positive electrode active coating is 100 microns.

[0075] (2) Positive electrode marking

[0076] The laser marking method is used to adjust the laser energy, and the tab is marked on both sides, the marking width is 2 mm, and the depth is 100 microns.

[0077] (3) Glue injection and die cutting

[0078] The micro-hole injection machine is used, the insulating glue is SEBS (hydrogenated styrene-butadiene block copolymer) + SBR = 1:1, the glue is injected at the notch position and around the pole piece, the thickness is 100 μm, the glue injection width at the notch position of the pole piece is 2 mm, the glue injection width around is 1 mm, and the die cutting machine is used to die cut at the notch position to prepare the positive pole piece.

[0079] Example 3

[0080] The present embodiment provides a preparation method of a positive pole piece, and a new type of full solid-state positive pole piece with edge glue is prepared, which comprises the following steps:

[0081] (1) Preparation of pole piece matrix

[0082] The positive pole is prepared by a wet process. NCM811 positive material, conductive carbon SP, sulfide electrolyte LPSC and binder SBR are weighed and mixed in a proportion of 75:3:19:3, then a dispersion medium butyl butyrate is added, the solid content concentration is adjusted to 60%, and ultrasonic dispersion treatment is performed for 2 minutes to obtain a positive pole slurry. The slurry is coated on both sides of a carbon-coated aluminum foil current collector with a thickness of 14 μm, and a composite positive pole piece is obtained after drying. The thickness of the positive active coating is 100 μm.

[0083] (2) Positive pole notch

[0084] The laser notch method is used to adjust the laser energy to notch the pole piece on both sides, the notch width is 2 mm, and the depth is 100 μm.

[0085] (3) Glue injection and die cutting

[0086] The micro-hole injection machine is used, the insulating glue is polyester elastomer (TPEE) + SBR = 1:1, the glue is injected at the notch position and around the pole piece, the thickness is 100 μm, the glue injection width at the notch position of the pole piece is 2 mm, the glue injection width around is 1 mm, and the die cutting machine is used to die cut at the notch position to prepare the positive pole piece.

[0087] Example 4

[0088] The difference from Example 2 is only that the insulating glue is single SBR.

[0089] Example 5

[0090] The difference from Example 2 is only that the insulating glue is single SEBS.

[0091] Comparative Example 1

[0092] The positive pole piece is prepared in this comparative example, and the difference from Example 2 is only that steps (2) and (3) are not performed.

[0093] Test Example 1

[0094] The test examples and comparative examples were prepared to obtain the assembly success rate and electrochemical performance of the positive electrode plate, and the results are shown in Table 1.

[0095] Test method: (1) Assembly success rate: after the battery is assembled, it is continuously connected, that is, the assembly is successful. (2) Cycle performance: the soft package battery is assembled by lamination, and continuously charged and discharged at 0.5C rate under the condition of 45 DEG C until the capacity retention rate is 80%.

[0096] Table 1 Assembly success rate and electrochemical performance test results of the positive electrode plate

[0097] Sample Assembly success rate Cycling (80% capacity retention) Example 1 95％ 800 cycles Example 2 94％ 780 cycles Example 3 95％ 750 cycles Example 4 90％ 700 cycles Example 5 89％ 680 cycles Comparative Example 1 80％ 500 cycles

[0098] In summary, the application provides an electrode plate, a preparation method of the electrode plate, a secondary battery and an electric device. According to the size of the electrode plate, high-precision control of laser, mechanical cutter or mechanical punching peeling is used to realize micro-level precision marking. Then, the marked area is filled with insulating glue with viscoelasticity by micro-hole glue injection at the edge of the marked area. After curing, the electrode plate is cut at the glue injection position to prepare a new full-solid-state electrode plate with edge glue coating. The application has the following advantages:

[0099] (1) By the adhesion of the glue layer to the negative electrode under high pressure, the cycle performance difference caused by the volume change of the electrode plate during charging and discharging can be effectively alleviated, and the cycle of the battery can be improved.

[0100] (2) The size of the positive electrode plate and the negative electrode plate after glue coating can be consistent, which can avoid high-pressure edge breakage caused by the size difference between the positive electrode plate and the negative electrode plate, reduce the defects of the battery, and at the same time, the size of the positive electrode and the negative electrode can be consistent, which is convenient for the lamination of the positive electrode plate and the negative electrode plate.

[0101] (3) The insulating glue uses a composite elastomer, which can have good contact with the positive electrode and good flowability, so that the battery assembly success rate and cycle performance can be improved.

[0102] (4) The positive electrode prepared by the application has high edge strength, few defects, high size precision and good cycle performance, and can be used for the assembly of full-solid-state batteries by lamination method and Z-shaped lamination method, which has important significance for the continuous assembly of full-solid-state batteries in the later stage, and the method is also suitable for the preparation of negative electrode plates.

[0103] The above is only a preferred embodiment of the application and is not used to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A pole piece for a solid state battery, characterized by, The active coating is attached to the current collector, and the cured insulating glue is attached to the edge of the active coating on the current collector; The preparation process of the electrode tab comprises: providing an electrode tab substrate comprising a current collector and an active coating attached to the current collector; According to the size of the electrode tab product, a mark is made on the active coating to form a mark groove, the insulating glue is injected at the mark groove, and is cured and formed; after the curing and forming, die cutting is performed at the position of the insulating glue to obtain the electrode tab; The raw material of the insulating glue comprises a first binder and a viscoelastic material, the first binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile; the mass ratio of the first binder and the viscoelastic material is 1: (0.5-1.5); the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, hydrogenated styrene-butadiene block copolymer and polyester elastomer; The active coating comprises an active material, a second binder, a conductive agent and an electrolyte.

2. The pole piece of claim 1, wherein The width of the cured insulating glue is 0.5-1.5 μm.

3. The pole piece of claim 1, wherein The second binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile; the first binder and the second binder contain the same component.

4. The pole piece of claim 1, wherein The active coating is attached to both sides of the current collector, and the cured insulating glue is attached to the edge of the active coating on both sides.

5. The pole piece of claim 1, wherein The electrolyte is selected from at least one of sulfide electrolyte, oxide electrolyte and halide electrolyte.

6. A method of producing the pole piece according to any one of claims 1 to 5, characterized by, comprises: providing an electrode tab substrate comprising a current collector and an active coating attached to the current collector; According to the size of the electrode tab product, a mark is made on the active coating to form a mark groove, the insulating glue is injected at the mark groove, and is cured and formed; after the curing and forming, die cutting is performed at the position of the insulating glue to obtain the electrode tab.

7. The preparation method according to claim 6, characterized in that, The insulating glue is coated around the active coating, and is cured and formed.

8. The preparation method according to claim 6, characterized in that, The mark groove has a length direction and a width direction, in the length direction, the mark groove extends from one end of the active coating to the opposite end; the width of the mark groove is 1-3 mm.

9. The preparation method according to claim 6, characterized in that, The electrode tab substrate is prepared by a wet process or a dry process; when the electrode tab substrate is prepared by the wet process, the process comprises: mixing an active material, a conductive agent, an electrolyte, a second binder and a dispersant to obtain a slurry, coating the slurry on at least one side of the current collector, and then drying; when the electrode tab substrate is prepared by the dry process, the process comprises: mixing an active material, a conductive agent, an electrolyte and a second binder to form a fiber, preparing a sheet by rolling, and adhering the sheet to the current collector.

10. A secondary battery characterized by comprising: The secondary battery comprises the electrode tab prepared by the method of any one of claims 1-5 or the method of any one of claims 6-9.

11. An electrical device, characterized by The secondary battery comprises the electrode tab prepared by the method of any one of claims 1-5 or the method of any one of claims 6-9.

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