Battery preparation method

Abstract

The present application provides a method for preparing a battery, and relates to the field of battery technology. Among them, the battery includes a shell, a plurality of pole pieces arranged in the shell, and a diaphragm located between adjacent pole pieces, and the pole piece includes a current collector and a first insulating layer. The first insulating layer is stacked on at least one side of the current collector along the thickness direction of the current collector, so that the first insulating layer is at the end side edge of the current collector, and the first insulating layer can cover the end side edge of the current collector. The first insulating layer includes a first insulating material, and the density of the first insulating material is greater than the density of aluminum oxide, so that the density of the first insulating layer is relatively large, so that when the battery is inspected by a CT device, without increasing the X-ray exposure on the end side of the current collector, the part of the pole piece covered with the first insulating layer can be imaged clearly, so that the position and morphological condition of the end side of the current collector can be accurately obtained, so as to achieve the purpose of efficient detection of the pole piece and the application of the pole piece.

Description

Technical Field

[0001] The present application relates to a method for preparing a battery, and belongs to the technical field of batteries. Background Art

[0002] As the demand for new energy markets continues to grow, the demand for battery production continues to grow. The battery is mainly composed of a shell, a positive electrode sheet, a negative electrode sheet, and a diaphragm between the positive and negative electrodes. The shell can also be filled with an electrolyte solution. When preparing the battery, it is necessary to alternately stack multiple positive electrode sheets and multiple negative electrode sheets in sequence. During the stacking process, some electrode sheets may be skewed, curled, there are too many electrode sheets, and some electrode sheets may be missing. Therefore, it is necessary to use CT (Computed Tomography) to detect the internal condition of the battery in order to understand the stacking condition of the electrode sheets. However, due to the influence of the material of the electrode sheet itself, the imaging effect of the electrode sheet in CT detection is not good.

[0003] At present, in order to improve the detection effect of batteries in CT detection, the electrode display can be made clear by increasing the X-ray exposure of CT. Correspondingly, the battery detection time will be increased, resulting in low battery detection efficiency. Summary of the invention

[0004] The present application provides a battery preparation method, which solves the problem of low efficiency of battery pole piece detection in the related art.

[0005] The present application provides a battery preparation method, comprising:

[0006] A battery is provided, the battery comprising a housing, a diaphragm and a plurality of pole pieces, the plurality of pole pieces are arranged in the housing at intervals, the diaphragm is arranged between adjacent pole pieces, the pole piece comprises a current collector and a first insulating layer, the first insulating layer is superimposed on at least one side edge of the current collector along a thickness direction of the current collector, the first insulating layer comprises a first insulating material, and the density of the first insulating material is greater than the density of aluminum oxide;

[0007] Sending X-rays to the battery through a CT device to obtain an image of the pole piece;

[0008] Whether the battery is qualified is determined based on the image of the electrode piece.

[0009] In some embodiments, the first insulating material is a metal oxide.

[0010] In some embodiments, the atomic number of the metal element in the first insulating material is greater than the atomic number of the aluminum element.

[0011] In some embodiments, the first insulating material includes at least one of zirconium oxide, bismuth oxide, and barium oxide.

[0012] In some embodiments, the pole piece further includes an active layer, the active layer is stacked on at least one side surface along the thickness direction of the current collector, and the active layer is connected to the first insulating layer.

[0013] In some embodiments, the thickness of the active layer is the same as the thickness of the first insulating layer.

[0014] In some embodiments, the first insulating layer has a thickness of 50 μm-80 μm.

[0015] In some embodiments, the pole piece further includes a pole tab and a second insulating layer, the pole tab is connected to the current collector, the second insulating layer is stacked on at least one side surface along the thickness direction of the pole tab, and the second insulating layer is spaced apart from an end of the pole tab away from the current collector.

[0016] In some embodiments, the second insulating layer includes a second insulating material having a density greater than a density of aluminum oxide.

[0017] In some embodiments, the second insulating material is the same as the first insulating material.

[0018] In some embodiments, the thickness of the second insulating layer is no greater than 20 μm.

[0019] In some embodiments, the first insulating layer is stacked on an edge of the current collector adjacent to the electrode tab, and the first insulating layer is also stacked on an edge of the current collector away from the electrode tab.

[0020] In the battery provided by the present application, the first insulating layer of the pole piece is superimposed on at least one side edge of the current collector along the thickness direction of the current collector, so that the first insulating layer is at the end side edge of the current collector, and the first insulating layer can cover the end side edge of the current collector. When the pole piece is used in a battery, there are other pole pieces on both sides of the current collector of the pole piece, and the first insulating layer can prevent the end side of the current collector from contacting other electrodes and short-circuiting, thereby protecting the pole piece. The density of the first insulating layer is greater than the density of aluminum oxide, so that the density of the first insulating layer is relatively large, so that when the battery is inspected by a CT device, without increasing the X-ray exposure of the end side of the current collector, the part of the pole piece covered with the first insulating layer can be clearly imaged, so that the position and morphology of the end side of the current collector can be accurately known, and the purpose of efficient inspection of the pole piece and the application of the pole piece is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other purposes, features and advantages of the embodiments of the present application will become more easily understood through the following detailed description with reference to the accompanying drawings. In the accompanying drawings, multiple embodiments of the present application will be described in an exemplary and non-limiting manner, wherein:

[0022] Figure 1 A schematic diagram of a battery according to an embodiment of the present application;

[0023] Figure 2 A schematic diagram of a pole piece according to an embodiment of the present application;

[0024] Figure 3 A schematic diagram of a pole piece according to an embodiment of the present application being stacked with other adjacent pole pieces;

[0025] Figure 4 A schematic diagram showing a gap between the first insulating layer and the second insulating layer of a pole piece according to an embodiment of the present application;

[0026] Figure 5 A schematic diagram of a pole piece of an embodiment of the present application being stacked on an adjacent pole piece in another implementation manner;

[0027] Figure 6 A schematic diagram of a pole piece according to an embodiment of the present application in another implementation manner;

[0028] Figure 7 for Figure 6 A cross-sectional view of the internal structure of the middle pole piece;

[0029] Figure 8 A schematic diagram of the spacing between the second insulating layer and the first insulating layer in the pole piece of an embodiment of the present application;

[0030] Fig. 9 for Figure 8 Cross-sectional view of the internal structure of the middle pole piece.

[0031] Reference numerals:

[0032] 10-Pole piece,

[0033] 100 - current collector, 110 - first side, 120 - second side,

[0034] 200-ear, 210-third side, 220-fourth side, 230-welding area,

[0035] 300- first insulating layer,

[0036] 400-active layer,

[0037] 500- second insulation layer,

[0038] 20-housing,

[0039] 30-Diaphragm. DETAILED DESCRIPTION

[0040] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0041] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0043] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0046] As the demand for new energy markets continues to grow, the demand for battery production continues to grow. The battery is mainly composed of a shell, a positive electrode sheet, a negative electrode sheet, and a separator between the positive electrode sheet and the negative electrode sheet. The shell can also be filled with an electrolytic solution. When preparing the battery, it is necessary to alternately stack multiple positive electrode sheets and multiple negative electrode sheets in sequence. In order to prevent the positive electrode sheets from contacting the negative electrode sheets and causing a short circuit, an insulating layer can be provided on the end side of the negative electrode sheet between adjacent positive and negative electrode sheets. In the process of stacking the positive and negative electrode sheets, some of the electrode sheets may be skewed, the electrode sheets may be curled, the number of electrode sheets may be too large, and some electrode sheets may be missing. Therefore, it is necessary to detect the internal condition of the battery by CT (Computed Tomography) detection to understand the stacking condition of the electrode sheets.

[0047] The negative electrode of the battery can be made of copper material, the positive electrode of the battery can be made of aluminum material, and the insulating layer covering the positive electrode can be made of alumina ceramic coating. During the CT detection process, the negative electrode made of copper has a better absorption effect on X-rays, making the image of the negative electrode bright and clear. The positive electrode made of aluminum and the alumina ceramic coating have a poor absorption effect on X-rays, resulting in darker imaging of the end side of the positive electrode and poor effect, especially when the positive electrode is between the bright negative electrode, making the image of the positive electrode dim, and the relative position relationship between the end side of the positive electrode and the negative electrode cannot be accurately obtained.

[0048] At present, in order to improve the detection effect of batteries in CT detection, the positive electrode can be displayed clearly by increasing the X-ray exposure of CT. Correspondingly, the battery detection time will be increased, resulting in low battery detection efficiency.

[0049] In the pole piece proposed in the present application, the first insulating layer is superimposed on at least one side edge of the current collector along the thickness direction of the current collector, so that the first insulating layer is at the end side edge of the current collector, and the first insulating layer can cover the end side edge of the current collector. When the pole piece is used in a battery, there are other pole pieces on both sides of the current collector of the pole piece, and the first insulating layer can prevent the end side of the current collector from contacting other electrodes and short-circuiting, thereby protecting the pole piece. The density of the first insulating layer is greater than the density of aluminum oxide, so that the density of the first insulating layer is relatively large, so that when the battery is inspected by a CT device, without increasing the X-ray exposure of the end side of the current collector, the part of the pole piece covered with the first insulating layer can be clearly imaged, so that the position and morphology of the end side of the current collector can be accurately known, and the purpose of efficient inspection of the pole piece and the application of the pole piece is achieved.

[0050] In the battery proposed in the present application, the pole piece is applied to the battery, and when the battery is subjected to CT inspection, a clear image of the end side of the current collector in the pole piece can be obtained, thereby improving the inspection efficiency of the battery.

[0051] The electrode, battery and electrical equipment provided by the present application are described in detail below in conjunction with specific embodiments.

[0052] An embodiment of the present application provides an electrical device, comprising a plurality of batteries, wherein the plurality of batteries can be stacked along a preset direction and the plurality of batteries are electrically connected.

[0053] The present application embodiment proposes a battery, referring to Figure 1 As shown, it includes a housing 20 , a plurality of pole pieces 10 and a diaphragm 30 .

[0054] The housing 20 is a basic component of the battery of the present application. The housing 20 can provide a mounting base for at least some of the other components of the battery and protect at least some of the other components. The housing 20 can be made of a metal material, so that the housing 20 has a better structural strength, thereby making the durability and reliability of the housing 20 better. Of course, the housing 20 can also be made of a composite material, so that the housing 20 has a certain structural strength and is relatively light in weight.

[0055] Multiple pole pieces 10 are all disposed in the housing 20. Multiple pole pieces 10 can be stacked in the housing 20 in a spaced manner along one direction, and adjacent pole pieces 10 are disposed opposite to each other, and the diaphragm 30 is disposed between adjacent pole pieces 10. Among the multiple pole pieces 10, the housing 20 can also be filled with electrolyte. Multiple pole pieces 10 can be electrically connected to an external electrical connection structure, and ions are transferred between adjacent pole pieces 10 through the electrolyte, thereby realizing the charging and discharging function of the battery.

[0056] Among them, some of the multiple pole pieces 10 are negative pole pieces, and the material of the negative pole pieces can be copper foil. When the stacking of the pole pieces 10 inside the battery is detected by CT equipment, the pole pieces 10 made of copper have a better absorption effect on X-rays, so that the image of this part of the pole pieces 10 is clear. Another part of the pole pieces 10 are positive pole pieces, and the material of this part of the pole pieces 10 can be aluminum foil. The pole pieces 10 made of aluminum foil have a poor absorption effect on X-rays, which leads to unclear images of this part of the pole pieces 10, so it is difficult to clearly observe the position and state of the pole pieces 10 made of aluminum.

[0057] To this end, the present application also proposes a pole piece 10, referring to Figures 2 to 5 As shown, the pole piece 10 comprises a current collector 100, a pole tab 200, a first insulating layer 300 and an active layer 400. The pole piece 10 can be applied to the battery of the present application.

[0058] The current collector 100 is a basic component of the pole piece 10. The current collector 100 can provide a mounting base for at least some other components of the pole piece 10. The current collector 100 is made of metal, specifically aluminum foil, so that the preparation cost of the pole piece 10 is relatively low. The tab 200 is connected to one end of the current collector 100. The current collector 100 is electrically connected to other structures of the battery through the tab 200, specifically, it can be connected to the pole of the battery, and is electrically connected to the outside through the pole.

[0059] The first insulating layer 300 is superimposed on at least one side edge of the current collector 100 along the thickness direction of the current collector 100, that is, the first insulating layer 300 is located at the end side edge of the current collector 100, and the active layer 400 is also superimposed on the current collector 100 along the thickness direction of the current collector 100, and is located on the portion of the current collector 100 where the first insulating layer 300 is not provided, that is, the active layer 400 is located in the middle part of the current collector 100, so that the active layer 400 and the first insulating layer 300 can cover the current collector 100. The active layer 400 can be specifically lithium iron phosphate or a ternary material, so that the battery is a lithium battery. Among them, the first insulating layer 300 and the active layer 400 can be superimposed on the current collector 100 by coating. It should be understood that in the battery of the present application, a plurality of pole pieces 10 are stacked in sequence, so that both sides of any current collector 100 have other pole pieces 10, and if the end side edge of the current collector 100 contacts other pole pieces 10, a short circuit will occur. Therefore, by providing the first insulating layer 300 on the current collector 100, even if the end edge of the current collector 100 contacts other pole pieces 10, the two will not be conductive, thereby avoiding the occurrence of a short circuit. The first insulating layer 300 is superimposed on at least one side edge of the current collector 100, so that the first insulating layer 300 can be distributed along the edge of the current collector 100, so that when the pole piece 10 in the battery is detected by a CT device, the image displayed by the first insulating layer 300 corresponds to the structural morphology of the portion on one side of the edge of the current collector 100.

[0060] The first insulating layer 300 includes a first insulating material, and the density of the first insulating material is greater than that of alumina, so that the density of the first insulating layer 300 is relatively large, so that the first insulating layer 300 has a better absorption effect on X-rays, so that when the battery is inspected by a CT device, the portion of the current collector 100 stacked with the first insulating layer 300 can have a clear image, that is, the end side edge of the current collector 100 has a clear image. In this way, the relative position relationship between the end side edge of the current collector 100 and other adjacent pole pieces 10 can be clearly understood to achieve the purpose of accurately detecting the position of the pole piece 10 in the battery. Accordingly, it is not necessary to increase the energy intensity of the X-ray irradiated on the current collector 100, which reduces the detection time of the CT device and improves the efficiency of the battery of the present application when it is detected by the CT device.

[0061] In some embodiments, it is understood that reference Figure 7 and Fig. 9As shown, the pole tab 200 and the current collector 100 in the present application can be set as an integrated structure, that is, the current collector 100 and the pole tab 200 are both made of aluminum foil, the part of the aluminum foil coated with the active layer 400 and the first insulating layer 300 can constitute the current collector 100, and the remaining part of the aluminum foil can constitute the pole tab 200, and the side of the pole tab 200 away from the current collector 100 can be electrically connected to the pole of the battery. In this way, it is not necessary to prepare the current collector 100 and the pole tab 200 separately and then connect them, which reduces the difficulty and cost of the preparation process of the pole piece 10. Specifically, a welding area 230 can be set on the side of the pole tab 200 away from the current collector 100, and the welding area 230 is the part where the pole tab is welded to the pole.

[0062] In some embodiments, the first insulating material of the first insulating layer 300 of the present application can specifically be a metal oxide material, that is, the first insulating layer 300 is a metal oxide coating, and the density of the metal oxide is greater than the density of aluminum oxide, so that the first insulating layer 300 has a better absorption effect on X-rays.

[0063] Specifically, in the metal oxide material used in the first insulating material of the first insulating layer 300, the atomic number of the metal element is greater than the atomic number of the aluminum element. In this way, the density of the metal oxide material used in the first insulating material of the first insulating layer 300 is greater than the density of aluminum oxide, so that the first insulating layer 300 has a better absorption effect on X-rays, and the part of the current collector 100 adjacent to the pole ear 200 has a clear image in the CT equipment detection.

[0064] In some embodiments, the first insulating material of the first insulating layer 300 in the present application may specifically be at least one of zirconium oxide, bismuth oxide, and barium oxide. Among them, zirconium oxide, bismuth oxide, and barium oxide are all insulating materials, so that the first insulating layer 300 has insulating properties. The atomic numbers of zirconium, bismuth, and barium are all higher than the atomic number of aluminum. Accordingly, the densities of zirconium oxide, bismuth oxide, and barium oxide are all greater than the density of aluminum oxide, so that the first insulating layer 300 has a better absorption effect on X-rays, and thus the portion of the current collector 100 adjacent to the pole ear 200 has a clear image in the CT device detection.

[0065] In some embodiments, it should be understood that in the battery, the tabs 200 of the multiple pole pieces 10 are also stacked in sequence, and the multiple tabs 200 are all bent and electrically connected to the poles of the battery, which can reduce the space occupied by the tabs 200 of the multiple pole pieces 10 in the battery housing 20, making the battery structure more compact. Accordingly, the tabs 200 need to have a certain length so that the multiple tabs 200 can be stacked and bent. In order to prevent the tabs 200 in the pole piece 10 from contacting with the adjacent pole piece 10 and short-circuiting, an insulating layer can also be provided on the tabs 200 to prevent short-circuiting.

[0066] Specifically, refer to Figures 2 to 5 As shown, the pole piece 10 of the present application may also be provided with a second insulating layer 500, which is stacked on the pole piece 200 along the thickness direction of the pole piece 200, and the second insulating layer 500 is spaced from the end of the pole piece 200 away from the current collector 100. That is, the second insulating layer 500 is stacked on the other parts of the current collector 100 except the part of the pole piece 200 away from the current collector 100, wherein the second insulating layer 400 may be coated on the pole piece 200. The side of the pole piece 200 away from the current collector 100 is used to be electrically connected to the pole column of the battery, so the side of the pole piece 200 away from the current collector 100 is not stacked with the second insulating layer 500. The side of the pole piece 200 close to the current collector 100 is used to connect with the current collector 100, and the second insulating layer 500 is arranged on the part of the pole piece 200 close to the current collector 100, which can prevent this part of the pole piece 10 from directly contacting with the adjacent pole piece 10 and causing a short circuit.

[0067] The second insulating layer 500 is stacked on the side of the pole tab 200 adjacent to the current collector 100, so that the second insulating layer 500 can be distributed along the structural morphology of the side of the pole tab 200 adjacent to the current collector 100. In this way, when the pole tab 200 in the battery is detected by a CT device, the image displayed by the second insulating layer 500 corresponds to the structural morphology of the part of the side of the pole tab 200 adjacent to the current collector 100.

[0068] The second insulating layer 500 includes a second insulating material, and the density of the second insulating material is greater than that of alumina, so that the density of the second insulating layer 500 is relatively large, so that the second insulating layer 500 has a better absorption effect on X-rays, so that when the battery is inspected by a CT device, the portion of the tab 200 stacked with the second insulating layer 500 can have a clear image, that is, the portion of the tab 200 close to the current collector 100 has a clear image. In this way, the stacking form and bending form of the tab 200 can be clearly understood to achieve the purpose of accurately detecting the form of the tab 200 in the battery. Accordingly, it is not necessary to increase the energy intensity of the X-ray irradiated on the tab 200, which reduces the detection time of the CT device and improves the efficiency of the battery of the present application when it is detected by the CT device.

[0069] In some embodiments, the second insulating material of the second insulating layer 500 of the present application may specifically be a metal oxide material, that is, the second insulating layer 500 is a metal oxide coating, and the density of the metal oxide is greater than the density of aluminum oxide, so that the second insulating layer 500 has a better absorption effect on X-rays.

[0070] Specifically, in the metal oxide material used for the second insulating material of the second insulating layer 500, the atomic number of the metal element is greater than the atomic number of the aluminum element. In this way, the density of the metal oxide material used for the second insulating material of the second insulating layer 500 is greater than the density of aluminum oxide, so that the second insulating layer 500 has a better absorption effect on X-rays, and the part of the pole ear 200 adjacent to the current collector 100 has a clear image in the CT equipment detection.

[0071] In some embodiments, the second insulating material of the second insulating layer 500 in the present application may specifically be at least one of zirconium oxide, bismuth oxide, and barium oxide. Among them, zirconium oxide, bismuth oxide, and barium oxide are all insulating materials, so that the second insulating layer 500 has insulating properties. The atomic numbers of zirconium, bismuth, and barium are all higher than the atomic number of aluminum. Accordingly, the densities of zirconium oxide, bismuth oxide, and barium oxide are all greater than the density of aluminum oxide, so that the second insulating layer 500 has a better absorption effect on X-rays, and thus the portion of the tab 200 adjacent to the current collector 100 has a clear image in the CT device detection.

[0072] In some embodiments, the first insulating layer 300 and the second insulating layer 500 of the present application can be made of the same material. In this way, when preparing the pole piece 10 of the present application, the same insulating coating can be applied to the current collector 100 and the pole ear 200, thereby reducing the preparation cost of the pole piece 10 of the present application.

[0073] In some embodiments, the number of the first insulating layers 300 of the present application may be set to two, and the two first insulating layers 300 may be disposed on opposite sides of the current collector 100, so that one of the first insulating layers 300 is adjacent to the pole tab 200, and the other first insulating layer 300 is away from the pole tab 200. Thus, the side of the current collector 100 away from the pole tab 200 can also be clearly displayed in the CT test.

[0074] In some embodiments, reference Figures 6 to 9 As shown, the thickness of the first insulating layer 300 in the present application can be set to be greater than the thickness of the second insulating layer 500, and accordingly, the thickness of the second insulating layer 500 is relatively small. It should be understood that in order to make the structure of the battery compact, the tab 200 needs to be bent before being electrically connected to the pole of the battery. By setting the thickness of the second insulating layer 500 stacked on the tab 200 to be smaller, the influence of the second insulating layer 500 on the bending performance of the tab 200 can be reduced, so that the tab 200 is easier to bend and the bending degree is greater, and finally the structure of the battery of the present application can be further compact.

[0075] In addition, there may be a gap or no gap between the first insulating layer 300 and the second insulating layer 500. Specifically, when there is no gap between the first insulating layer 300 and the second insulating layer 500, the first insulating layer 300 is directly connected to the second insulating layer 500. The spacing between the first insulating layer 300 and the second insulating layer 500 is affected by the process.

[0076] In some embodiments, reference Figures 6 to 9 As shown, in order to make the thickness of the first insulating layer 300 in the present application larger than the thickness of the second insulating layer 500, the thickness of the first insulating layer 300 can be set between 50 μm and 80 μm, and the thickness of the second insulating layer 500 is set to be no greater than 20 μm. In this way, the first insulating layer 300 can be stacked on the current collector 100 to have a good insulation effect, and the second insulating layer 500 can also be stacked on the tab 200 to have a good insulation effect. In addition, the first insulating layer 300 and the second insulating layer 500 can also have a better absorption effect on X-rays within the above-mentioned thickness range, so that the current collector 100 and the tab 200 can be clearly displayed.

[0077] In some embodiments, reference Figures 6 to 9 As shown, the first insulating layer 300 in the present application can be arranged on at least one side of the current collector 100 along the thickness direction of the current collector 100. Among them, the current collector 100 can be arranged to include a first side 110 and a second side 120 in its thickness direction, and the first side 110 and the second side 120 are opposite sides of the thickness direction of the current collector 100. The first insulating layer 300 can be arranged to be superimposed on the first side 110 or the second side 120 of the current collector 100, or the first insulating layer 300 can also be arranged to be superimposed on the first side 110 and the second side 120 of the current collector 100 at the same time. Specifically, among the multiple pole pieces 10 of the battery, the pole piece 10 located on the outermost side has only one side opposite and adjacent pole pieces 10. Accordingly, the first insulating layer 300 is arranged on the side of the current collector 100 facing the adjacent pole piece 10 to avoid the current collector 100 from directly contacting with the adjacent pole piece 10 and short-circuiting.

[0078] Among the multiple pole pieces 10 of the battery, the pole piece 10 located in the middle part has opposite and adjacent pole pieces 10 on both sides. Therefore, the first side 110 and the second side 120 of the current collector 100 are both stacked with the first insulating layer 300, which can prevent the first side 110 and the second side 120 of the pole piece 10 from directly contacting the opposite pole piece 10 and causing a short circuit, thereby further improving the safety and reliability of the battery.

[0079] In some embodiments, reference Figures 6 to 9As shown, the second insulating layer 500 in the present application can be arranged on at least one side of the pole tab 200 along the thickness direction of the pole tab 200. Among them, the pole tab 200 of the present application can be arranged to include a third side 210 and a fourth side 220 in its thickness direction, and the third side 210 and the fourth side 220 are opposite sides of the thickness direction of the pole tab 200. The second insulating layer 500 can be arranged to be superimposed on the third side 210 or the fourth side 220 of the pole tab 200, or the second insulating layer 500 can also be arranged to be superimposed on the third side 210 and the fourth side 220 of the pole tab 200 at the same time. Specifically, among the multiple pole pieces 10 of the battery, the pole piece 10 located on the outermost side has only one side opposite and adjacent pole pieces 10. Accordingly, the pole tab 200 is provided with a second insulating layer 500 on the side facing the adjacent pole piece 10 to avoid the pole tab 200 from directly contacting with the adjacent pole piece 10 and short-circuiting.

[0080] Among the multiple pole pieces 10 of the battery, the pole piece 10 located in the middle part has opposite and adjacent pole pieces 10 on both sides. Therefore, the third side 210 and the fourth side 220 of the pole ear 200 are both stacked with the second insulating layer 500, which can prevent the third side 210 and the fourth side 220 of the pole piece 10 from directly contacting the opposite pole piece 10 and causing a short circuit, thereby further improving the safety and reliability of the battery.

[0081] The present application also proposes a battery detection method, which can be used to detect the battery described above. The method comprises the following steps:

[0082] S100, providing a battery, the battery comprising a shell, a diaphragm and a plurality of pole pieces, the plurality of pole pieces are spaced apart in the shell, the diaphragm is disposed between adjacent pole pieces, the pole pieces comprise a current collector and a first insulating layer, the first insulating layer is superimposed on at least one side edge of the current collector along a thickness direction of the current collector, the first insulating layer comprises a first insulating material, and the density of the first insulating material is greater than the density of aluminum oxide.

[0083] S200, emitting X-rays to the battery through a CT device to obtain an image of the pole piece;

[0084] S300, judging whether the battery is qualified based on the image of the electrode piece.

[0085] In the above-mentioned battery testing method, a clear image of the inside of the battery can be obtained by emitting X-rays to the battery through the CT device, thereby obtaining a clear image of the pole piece. In this way, it is easier to judge whether the battery is qualified based on the image of the pole piece.

[0086] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned implementation modes, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned implementation modes can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation modes of the present application.

Claims

1. A method for preparing a battery, characterized in that: include: A battery is provided, the battery comprising a housing, a diaphragm and a plurality of pole pieces, the plurality of pole pieces are arranged in the housing at intervals, the diaphragm is arranged between adjacent pole pieces, the pole piece comprises a current collector and a first insulating layer, the first insulating layer is superimposed on at least one side edge of the current collector along a thickness direction of the current collector, the first insulating layer comprises a first insulating material, the density of the first insulating material is greater than the density of aluminum oxide, and the thickness of the first insulating layer is 50 μm-80 μm; Sending X-rays to the battery through a CT device to obtain an image of the pole piece; Whether the battery is qualified is determined based on the image of the electrode piece.

2. The battery preparation method according to claim 1, characterized in that: The first insulating material is metal oxide.

3. The battery preparation method according to claim 2, characterized in that: The atomic number of the metal element in the first insulating material is greater than the atomic number of the aluminum element.

4. The battery preparation method according to claim 3, characterized in that: The first insulating material includes at least one of zirconium oxide, bismuth oxide, and barium oxide.

5. The battery preparation method according to claim 1, characterized in that: The pole piece further includes an active layer, which is stacked on at least one side surface along the thickness direction of the current collector, and the active layer is connected to the first insulating layer.

6. The battery preparation method according to claim 5, characterized in that: The thickness of the active layer is the same as the thickness of the first insulating layer.

7. The method for preparing a battery according to any one of claims 1 to 6, characterized in that: The pole piece also includes a pole tab and a second insulating layer, wherein the pole tab is connected to the current collector, the second insulating layer is stacked on at least one side surface along the thickness direction of the pole tab, and the second insulating layer is spaced apart from an end of the pole tab away from the current collector.

8. The battery preparation method according to claim 7, characterized in that: The second insulating layer includes a second insulating material, and the density of the second insulating material is greater than that of aluminum oxide.

9. The battery preparation method according to claim 8, characterized in that: The second insulating material is the same as the first insulating material.

10. The battery preparation method according to claim 9, characterized in that: The thickness of the second insulating layer is no more than 20 μm.

11. The battery preparation method according to claim 7, characterized in that: The first insulating layer is stacked on an edge of the current collector adjacent to the electrode tab, and the first insulating layer is also stacked on an edge of the current collector away from the electrode tab.

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