Battery electrode sheet, preparation method therefor and use thereof

Abstract

A battery electrode sheet, a preparation method therefor and a use thereof, relating to the technical field of new energy. The battery electrode sheet comprises a current collector, and active coatings and insulating coatings arranged on the surfaces of the current collector, each active coating and the corresponding insulating coating are in contact with each other on at least one edge. A raw material for preparing the insulating coatings comprises an insulating filler satisfying the following parameters: Dv10≥0.5 μm; Dv50 ranges from 0.8 to 2 μm; Dv90≤4 μm; specific surface area BET≤6.5 m2 / g; DSC endothermic peak position<600°C; and A=(Dv90-Dv10) / (Dv50×BET), and 0.22 g / m2≤A≤0.35 g / m2. The battery electrode sheet can effectively prevent burrs generated during laser die-cutting of pseudo-tabs and also avoids incomplete cutting problems in laser die-cutting. Also provided are the preparation method for the battery electrode sheet and the use of the battery electrode sheet.

Description

Battery pole piece, preparation method and application thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a battery pole piece, a preparation method and application thereof. BACKGROUND

[0002] The multi-pole ear and the lamination structure battery cell usually adopts zebra coating, and the edge of the material area is left with a blank foil, and then the laser or hardware knife die is used to die cut the edge blank foil to form a false pole ear. However, in the die cutting process, if the blank foil is directly die cut, burrs are easy to appear, thereby causing the burrs to pierce the diaphragm and cause internal short circuit of the battery. If cutting is performed on the material area, the pole ear on part of the coating will be caused, and due to the staggered positive and negative pole ears, the corresponding opposite polarity pole piece will not have the coating corresponding to it, and the safety problem is easy to be caused during the charging and discharging of the battery.

[0003] In order to improve the above die cutting problem, at present, a layer of non-metallic filler coating without pole is usually coated on the edge of the active coating as an insulating layer to insulate the burr lap joint short circuit of the cutting position, and to replace the coating pole ear during the die cutting of the false pole ear, thereby improving the safety problem of the battery cell.

[0004] However, the processing performance of the existing insulating coating needs to be improved, and the false pole ear coated with the insulating coating still has the poor technical effect that burrs are generated during the laser die cutting process.

[0005] SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a battery pole piece which can effectively improve the laser processing effect of the insulating coating, avoid the burrs generated during the laser die cutting of the false pole ear, and also avoid the problem of incomplete cutting during the laser die cutting.

[0007] The present application also provides a preparation method of the above-mentioned battery pole piece.

[0008] The present application also provides a secondary battery comprising the above-mentioned battery pole piece.

[0009] According to the embodiment of the first aspect of the present application, a battery pole piece is provided, which comprises:

[0010] a current collector;

[0011] an active coating, which is arranged on at least one side surface of the current collector;

[0012] an insulating coating, which is arranged on a region of the surface of the current collector not occupied by the active coating; and at least one side edge of the insulating coating and the active coating is connected;

[0013] The preparation raw material of the insulating coating comprises an insulating filler.

[0014] The insulating filler satisfies the following parameters:

[0015] (1) Dv10≥0.5 μm;

[0016] (2) Dv50 is 0.8-2 μm;

[0017] (3) Dv90≤4 μm;

[0018] (4) Specific surface area BET≤6.5 m 2 / g;

[0019] (5) DSC endothermic peak peak position <600℃;

[0020] (6) A=(Dv90-Dv10) / (Dv50x BET), and 0.22 g / m 2 ≤A≤0.35 g / m 2 .

[0021] The battery pole piece according to the embodiments of the present application has at least the following beneficial effects:

[0022] In the conventional technology, when laser die cutting is used on the current collector coated with an insulating coating, burrs are easily generated, and the cutting is also easily not broken, which seriously affects the overall performance such as safety of the obtained pole piece. The present application effectively overcomes the above problems by limiting the particle size, specific surface area and other parameters of the insulating filler, specifically:

[0023] The current collector of the battery pole piece is either an aluminum foil or a copper foil, and the minimum melting point is >600℃. By limiting the DSC endothermic peak position of the insulating filler, the present application can ensure that the current collector will not soften before the insulating coating is damaged during laser die cutting processing, improve the laser die cutting effect, and avoid the generation of burrs.

[0024] When the particle size of the insulating filler is too small, the thickness of the insulating coating cannot meet the requirements, and the molten bead burrs generated after laser die cutting exceed the thickness of the insulating coating, resulting in safety risks. At the same time, when the particle size of the insulating filler is too small, the contact area between the particles of the insulating filler and the particles increases, the internal density of the insulating coating is high, and the laser die cutting processing effect is poor.

[0025] When the particle size of the insulating filler is too large, it will cause the stability of the insulating filler to decrease during pulping, and the slurry to settle; at the same time, the particle size is too large, which will cause the insulating coating to be scraped during coating, affecting the processing. In addition, the coating thickness uniformity is poor, and the upper and lower fluctuations are large, the laser power required for different coating thicknesses is different, the place with low thickness is easy to appear large laser power, the current collector molten bead is large, and the thickness of the molten bead exceeds the thickness of the insulating coating.

[0026] When the specific surface area of the insulating filler is too large, the viscosity of the slurry for preparing the insulating coating is too large to be coated (when the solid content is constant), and when the specific surface area of the insulating filler is too small, the viscosity of the slurry for preparing the insulating coating is too small, the stability of the slurry decreases, and the thickness consistency of the obtained insulating coating is poor.

[0027] The present application proposes a relationship between the particle size and the specific surface area of the insulating filler, wherein (Dv90-Dv10) / Dv50 is the particle size concentration degree. When the particle size concentration degree is larger, i.e., (Dv90-Dv10) / Dv50 is larger, it indicates that the particle size of the insulating filler is more dispersed, the thickness uniformity of the insulating coating after coating is poorer, and the laser power is more likely to be larger in the places where the thickness is low, the current collector bead is large, and the thickness of the bead exceeds the thickness of the insulating coating to form burrs. Overall, formula A comprehensively considers the influence of the particle size and the specific surface area on the die cutting effect of the insulating coating, and formula A can be used to screen the parameters of the insulating filler to ensure the die cutting effect of the insulating coating.

[0028] Therefore, by designing the physical parameters of the insulating filler, the present application improves the processing performance of the insulating coating and the laser die cutting effect of the part of the battery pole piece coated with the insulating coating.

[0029] According to some embodiments of the present application, the insulating filler comprises at least one of aluminum hydroxide, magnesium hydroxide, boehmite, zinc hydroxide, and calcium hydroxide.

[0030] According to some embodiments of the present application, the insulating filler satisfies at least one of the following parameters:

[0031] (1) Dv10 0.52-1.2 μm;

[0032] For example, it can be about 0.53 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, or about 1.15 μm.

[0033] (2) Dv50 1.85-2 μm;

[0034] For example, it can be about 0.9 μm, 1.0 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.75 μm, 1.8 μm, 1.85 μm, 1.9 μm, or about 1.95 μm.

[0035] (3) Dv90 1.7-3.7 μm;

[0036] For example, it can be about 1.75 μm, 1.8 μm, 2.0 μm, 2.5 μm, 2.7 μm, 2.8 μm, 2.85 μm, 2.9 μm, 3.0 μm, 3.2 μm, 3.5 μm, 3.6 μm, or about 3.65 μm.

[0037] (4) Specific surface area BET 3.4-6.2 m2 / g 2 / g;

[0038] For example, it can be about 3.5 m2 / g 2 / g, 3.8 m2 / g 2 / g, 3.9 m2 / g 2 / g, 4.0 m2 / g 2 / g, 5.0 m2 / g 2 / g, 5.5 m2 / g 2 / g, 6.0 m2 / g 2 / g, 6.1 m2 / g 2 / g, or about 6.15 m2 / g 2 / g.

[0039] (5) DSC endothermic peak position 250-550°C; for example, it can be about 300°C, 350°C, 400°C, or about 450°C.

[0040] (6) A value 0.23-0.33 g / m2 2 For example, it can be about 0.24 g / m2 2 , 0.25 g / m2 2 , 0.3 g / m2 2 , 0.31 g / m2 2 , or about 0.32 g / m2 2 .

[0041] According to some embodiments of the present application, the insulation filler thermal decomposition temperature (DSC peak position) ≤ the melting point of the current collector. The melting points of the insulation coating and the current collector of the conventional technology are constructed in the relationship of high-low-high; thus, when laser cutting, a very high power is required to melt the outer layer of the insulation coating material, and then the inner layer of the current collector can be cut; but such parameters not only require a higher-power laser to be selected, but also cause the inner layer of the current collector to melt before the outer layer of the insulation coating material when laser processing, and if the parameters of the insulation filler are not selected properly, it will cause the flat burr of the insulation coating area to protrude, the heat-affected zone to be large, and the batch metal leakage problem to be prominent after cutting; in the preferred scheme provided by the present application, the structure of low-high-low is constructed, which can effectively improve the problems of flat burr protrusion of the insulation coating area, large heat-affected zone, and batch metal leakage affecting the safety of the battery when laser cutting; the limitation of temperature and the limitation of particle size, etc. can basically eliminate the burr generated during the cutting process of the insulation coating.

[0042] According to some embodiments of the present application, the heat absorption peak of the insulating filler is greater than 1 mW / mg. For example, it can be about 2 mW / mg, 3 mW / mg, 3.5 mW / mg, 4 mW / mg, 5 mW / mg, or about 5.5 mW / mg. In combination with the definition of the DSC heat absorption peak of the insulating filler, it can be ensured that when the insulating coating is laser cut, the insulating filler is first decomposed and destroyed by heat absorption before the current collector is melted, avoiding the temperature of the current collector being too high, softening and sticking the insulating filler, causing the die cutting to be difficult, and the die cutting burr to be out of standard. If the heat absorption peak of the insulating filler is higher than the melting point of the aluminum foil (positive current collector), a larger power needs to be used when laser cutting, at which time the inner layer current collector has been melted, and the heat affected zone of the insulating coating cutting edge after laser cutting is large, the bead is large, and burr is formed.

[0043] According to some embodiments of the present application, the raw material for preparing the insulating coating further comprises a binder.

[0044] According to some embodiments of the present application, the binder comprises at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polyacrylic acid (PAA, water-based adhesive).

[0045] According to some embodiments of the present application, the mass percentage of the insulating filler in the insulating coating is 65-95%. For example, it can be about 80%, 82%, 85%, 87%, 88%, 89%, 90%, or about 92%.

[0046] According to some embodiments of the present application, the thickness of the insulating coating is 10-60% of the thickness of the active coating. For example, it can be about 20%, 30%, or about 40%. By limiting the thickness ratio between the insulating coating and the active coating, the melting of the current collector during laser cutting can be significantly avoided, and the bead exceeding the insulating coating and forming burr can be avoided, which affects the safety performance of the battery cell. That is, the limitation of this parameter can significantly improve the safety performance of the battery pole piece.

[0047] According to some embodiments of the present application, the raw material for preparing the insulating coating further comprises a solvent.

[0048] According to some embodiments of the present application, the solvent comprises at least one of water, NMP, dimethylformamide, dimethylacetamide, and tetrahydrofuran. The selection of the solvent is determined according to the application environment of the electrode pole piece, the type of the binder, whether the raw material for preparing the electrode pole piece reacts with the solvent, and the like.

[0049] According to some embodiments of the present application, the thickness range of the insulating coating is less than or equal to 3.5 μm. For example, it can be about 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, or about 3.0 μm.

[0050] According to some embodiments of the present application, the battery pole piece comprises at least one of a positive pole and a negative pole.

[0051] According to some embodiments of the present application, when the battery pole piece is a positive pole, the active coating comprises a positive pole active material.

[0052] According to some embodiments of the present application, the positive pole active material comprises at least one of a polyanion material, a layered material and a spinel material.

[0053] The polyanion material comprises at least one of lithium iron phosphate, lithium manganese phosphate and lithium manganese iron phosphate.

[0054] The layered material has a general formula of LiMO2, wherein M comprises at least one of nickel, cobalt and manganese.

[0055] In the layered material, M further comprises a doping element; the doping element comprises at least one of aluminum, zirconium, magnesium, titanium, boron and fluorine.

[0056] The spinel material comprises lithium manganate (spinel phase).

[0057] Preferably, the positive pole active material is selected from lithium cobaltate.

[0058] According to some embodiments of the present application, the positive pole coating further comprises a conductive agent and a binder. In the positive pole coating, the mass percentage of the positive pole active material is 90-98%. The mass ratio of the conductive agent to the binder is 1:0.8-1.2; for example, it can be about 1:1.

[0059] According to some embodiments of the present application, when the battery pole piece is a negative pole, the active coating comprises a negative pole active material.

[0060] According to some embodiments of the present application, the negative pole active material comprises at least one of a carbon-based material, a silicon-based material, a lithium-based material and a titanium-based material.

[0061] The carbon-based material comprises at least one of artificial graphite and natural graphite.

[0062] The silicon-based material comprises at least one of silicon-oxygen material and silicon-carbon material.

[0063] The lithium-based material comprises at least one of lithium monomer and lithium metal alloy.

[0064] The titanium-based material comprises lithium titanate.

[0065] According to some embodiments of the second aspect of the present application, a preparation method of the battery pole piece is provided, and the preparation method comprises the following steps:

[0066] S1. configuring an active slurry and an insulating slurry;

[0067] S2. coating the active slurry and the insulating slurry on the surface of the current collector, and drying;

[0068] S3. laser die cutting the component obtained in step S2.

[0069] Since the preparation method adopts all the technical solutions of the battery pole piece in the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments. Further, compared with the traditional mechanical die cutting method, the laser die cutting method significantly improves the die cutting efficiency and die cutting effect.

[0070] According to some embodiments of the present application, the preparation of the insulating slurry comprises mixing the insulating filler and the binder, and then mixing the obtained mixture with the solvent. In this way, the preparation time of the insulating slurry can be significantly saved.

[0071] According to some embodiments of the present application, the solid content of the insulating slurry is 20-50%. For example, it can be about 30%, 31%, 32%, 33%, 34%, 35%, 36%, 38%, 39%, 40%, 42% or about 45%.

[0072] According to some embodiments of the present application, the preparation of the active slurry comprises mixing the raw materials for preparing the active coating.

[0073] According to some embodiments of the present application, in step S2, the coating comprises simultaneously coating the active slurry and the insulating slurry on the surface of the current collector; or coating the active slurry first, drying, and then coating the insulating slurry again.

[0074] According to some embodiments of the present application, in step S2, the coating method comprises at least one of extrusion coating and dispensing coating.

[0075] According to some embodiments of the present application, in step S2, it further comprises rolling and slitting after the drying. The purpose of the slitting is to cut the obtained component into the required size (profile); in step S3, the function of the laser die cutting is mainly to die cut the shape of the dummy tab.

[0076] According to some embodiments of the present application, in step S3, in the laser die cutting, the power of the laser used is 30-80%. For example, it can be about 35%, 40%, 45%, 50%, 60% or about 70%. Unless otherwise specified, the laser used in the present application has a total power of 250W.

[0077] According to some embodiments of the present application, in step S3, the laser used in the laser die cutting has a frequency of 200-1000 kHz. For example, it can be about 300 kHz, 400 kHz, 500 kHz, 600 kHz, 700 kHz, 800 kHz or about 900 kHz.

[0078] According to some embodiments of the present application, in step S3, the laser die cutting has a running speed of 30-50 m / min. For example, it can be about 35 m / min, 40 m / min or about 45 m / min.

[0079] According to embodiments of the third aspect of the present application, a secondary battery is provided, which comprises the battery pole piece as described.

[0080] Since the secondary battery adopts all the technical solutions of the battery pole piece of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments. That is, the obtained secondary battery has higher safety, life and electrochemical performance.

[0081] According to some embodiments of the present application, the secondary battery comprises at least one of a lithium ion secondary battery, a sodium ion secondary battery and a potassium ion secondary battery.

[0082] Unless otherwise specified, in the present application, DSC represents a differential scanning calorimeter, which is a measurement method for measuring the thermodynamic properties of a material.

[0083] Unless otherwise specified, in the present application, "about" actually means that the allowed error is within ±2%, for example, about 100 actually means 100±2%*100.

[0084] Unless otherwise specified, in the present application, "between" includes the numbers, for example, "between 2-3" includes the end values 2 and 3.

[0085] Other features and advantages of the present application will be set forth in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0086] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description that follows, including the appended drawings, in which:

[0087] Fig. 1 is a schematic view of a semi-finished product of a pole piece according to an embodiment of the present application.

[0088] Reference signs: current collector 100, active coating 200, insulating coating 300; die cutting line L; laser die cutting area A. DETAILED DESCRIPTION

[0089] The concept and the technical effects of the present application will be described clearly and completely in combination with the embodiments, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0090] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, in which the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0091] In the description of the present application, the description of the terms “one embodiment”, “some embodiments”, “exemplary embodiment”, “example”, “specific example”, or “some examples” means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0092] Embodiment 1

[0093] In this example, a battery positive electrode sheet is prepared, which comprises:

[0094] a current collector 100;

[0095] an active coating layer 200, which is arranged on both sides of the surface of the current collector 100;

[0096] an insulating coating layer 300, which is arranged on the surface of the current collector 100 in the region not occupied by the active coating layer 200; and the insulating coating layer 300 and the active coating layer 200 meet at one side edge. The thickness of the insulating coating layer 300 is 30% of the thickness of the active coating layer 200.

[0097] The preparation process of the battery positive electrode sheet is as follows:

[0098] S1. Preparation stage:

[0099] Preparation of active slurry: mix the positive active material lithium cobaltate, conductive agent: PVDF according to the mass ratio of 97%: 1.5%: 1.5%, and add NMP to homogenize, to obtain the active slurry.

[0100] Preparation of insulating slurry: insulating filler and PVDF were mixed in a mass ratio of 90:10, then mixed with NMP to obtain an insulating slurry with a solid content of 35%. The parameters of the insulating filler used in this example are shown in Tables 1-2.

[0101] S2. The active slurry and the insulating slurry were extrusion coated together on an aluminum current collector by an extrusion die, and after drying, the obtained component was rolled and cut. The structural schematic diagram of the component obtained in this step is shown in FIG. 1.

[0102] S3. The laser die-cutting area A was removed along the die-cutting line L by laser die-cutting to obtain a positive electrode sheet.

[0103] The conditions for laser die-cutting are shown in Table 3.

[0104] Example 2

[0105] In this example, a positive electrode sheet was prepared, which was different from Example 1 in that:

[0106] In step S1, the preparation process of the insulating slurry was as follows: the insulating filler and PVDF were mixed in a mass ratio of 88:12, then mixed with NMP to obtain an insulating slurry with a solid content of 40%. The parameters of the insulating filler used in this example are shown in Tables 1-2.

[0107] The conditions for laser die-cutting used in this example are shown in Table 3.

[0108] Example 3

[0109] In this example, a positive electrode sheet was prepared, which was different from Example 1 in that:

[0110] In step S1, the preparation process of the insulating slurry was as follows: the insulating filler and PVDF were mixed in a mass ratio of 85:15, then mixed with NMP to obtain an insulating slurry with a solid content of 38%. The parameters of the insulating filler used in this example are shown in Tables 1-2.

[0111] The conditions for laser die-cutting used in this example are shown in Table 3.

[0112] Comparative Examples 1-3 each prepared a positive electrode sheet, which was different from Example 1 in that:

[0113] Comparative Examples 4-6 each prepared a positive electrode sheet, which was different from Example 2 in that:

[0114] The parameters of the insulating filler were different, and the specific differences are shown in Tables 1-2.

[0115] Comparative Examples 7-11 each prepared a positive electrode sheet, which was different from Example 3 in that:

[0116] The parameters of the insulating fillers are different, and the specific differences are shown in Tables 1-2.

[0117] Table 1 Parameters of insulating fillers used in examples and comparative examples

[0118] Table 2 DSC parameters of insulating fillers used in examples and comparative examples

[0119] Table 3 Laser cutting parameters used in examples and comparative examples

[0120] The laser parameters in the comparative group are the parameters that have the best actual on-site debugging effect.

[0121] Test examples

[0122] In this example, the laser die cutting of the battery pole piece obtained from the examples and comparative examples is tested, and the test method is as follows: using a microscope with a measuring function (such as a Keyence 3D microscope), observing the end face of the pole piece after die cutting, and measuring the height of the bead exceeding the insulating coating; the test results are shown in Table 4.

[0123] Table 4 Laser die cutting effect of battery pole pieces obtained from examples and comparative examples

[0124] As can be seen from the results in Table 4, within the parameter range provided in the present application, the insulating filler is selected, and the insulating coating is sequentially set, and when laser die cutting is performed, a battery pole piece with no burr, smooth laser cutting, flat laser cutting port, and good effect can be obtained. Since laser die cutting can be used, the efficiency of die cutting can be significantly improved. Since the die cutting effect is good, the safety, life, and electrochemical performance of the secondary battery including the above battery pole piece can be significantly improved.

[0125] As can be seen from Comparative Example 1 and Comparative Example 1, Example 2 and Comparative Example 4, and Example 3 and Comparative Example 7, if the Dv10 of the insulating filler is too small and the A value is too large, i.e., the particle size distribution of the insulating filler is too dispersed, then the local cutting of the area where the insulating coating is located will be affected, and the process of the battery pole piece will be affected.

[0126] As can be seen from Comparative Example 1 and Comparative Example 2, Example 2 and Comparative Example 5, and Example 3 and Comparative Example 8, if the Dv50 of the insulating filler is not within the range required in the present application, then the thickness range of the insulating coating increases, and burrs appear at individual positions. The safety of the battery pole piece is affected.

[0127] As can be seen from Comparative Example 1 and Comparative Example 3, Example 2 and Comparative Example 6, and Example 3 and Comparative Example 9, if the Dv90 of the insulating filler is too large, then compared with Comparative Examples 2, 5, and 8, the thickness range of the insulating coating is further increased, and the burr phenomenon is more prominent.

[0128] From the comparative example and the comparative example 10, if the DSC peak position of the insulating filler is > 600℃, the molten beads will adhere to the insulating filler, the cutting end face will be uneven, and the degradation such as burr at individual positions will occur.

[0129] From the comparative example 1 and the comparative example 11, even if the particle size and the specific surface area are within the range provided in the present application, if the A value deviates from the required range of the present application, higher burrs will still occur, which can significantly negatively affect the safety performance of the obtained battery pole piece.

[0130] From the above, in the battery pole piece provided in the present application, through the synergistic effect of the particle size, specific surface area and other aspects of the insulating filler, the die cutting performance of the obtained battery pole piece can be significantly improved; finally, the safety performance, life and electrochemical performance of the secondary battery including the battery pole piece are significantly improved. Further, by limiting the A value, DSC parameters and the like, the selection of the raw materials such as the binder can be further widened, and further hidden dangers that may affect the safety performance are removed.

[0131] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge range possessed by those skilled in the art without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A battery electrode sheet, comprising: a current collector; an active coating layer disposed on at least one side surface of the current collector; an insulating coating layer disposed on a region of the surface of the current collector not occupied by the active coating layer; the insulating coating layer and the active coating layer being in contact with each other at least at one side edge; a raw material of the insulating coating layer comprising an insulating filler; the insulating filler satisfying the following parameters: (1) Dv10≥0.5 μm; (2) Dv50 is 0.8-2 μm; (3) Dv90≤4 μm; (4) a specific surface area BET < 6.5 m2 / g 2 / g; (5) DSC endothermic peak peak position <600℃; (6) A = (Dv90 - Dv10) / (Dv50 x BET), and 0.22 g / m 2 ≤ A ≤ 0.35 g / m 2 .

2. The battery pole piece of claim 1, wherein, the insulating filler comprising at least one of aluminum hydroxide, magnesium hydroxide, boehmite, zinc hydroxide and calcium hydroxide.

3. The battery pole piece of claim 1, wherein, the endothermic peak intensity of the insulating filler >1 mW / mg.

4. The battery pole piece of claim 1, wherein, the raw material of the insulating coating layer further comprising a binder; and / or, the binder comprising at least one of polyvinylidene fluoride, polytetrafluoroethylene and polyacrylic acid.

5. The battery pole piece of claim 1, wherein, the mass percentage of the insulating filler in the insulating coating layer is 65-95%; and / or, the thickness of the insulating coating layer is 10-60% of the thickness of the active coating layer.

6. The battery pole piece of any one of claims 1-5, wherein, the raw material of the insulating coating layer further comprising a solvent; and / or, the solvent comprising at least one of water, NMP, dimethylformamide, dimethylacetamide and tetrahydrofuran.

7. The battery pole piece of any one of claims 1-5, wherein, the battery electrode sheet comprising at least one of a positive electrode and a negative electrode.

8. A method of producing a battery electrode sheet as claimed in any one of claims 1 to 7, wherein, the preparation method comprising the following steps: S1. configuring an active slurry and an insulating slurry; S2. coating the active slurry and the insulating slurry on the surface of the current collector and drying; S3. laser die cutting the component obtained in step S2. 9.A secondary battery comprising the battery electrode sheet according to any one of claims 1-7.

10. The secondary battery according to claim 9, wherein the secondary battery comprising at least one of a lithium ion secondary battery, a sodium ion secondary battery and a potassium ion secondary battery.

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