Electrode plate, battery, battery pack and energy storage system

Abstract

The utility model provides an electrode plate, a battery, a battery pack and an energy storage system. The electrode plate of the battery provided by the utility model comprises a current collector layer, and a bottom material layer and an active material layer which are arranged on at least one surface of the current collector layer. The bottom material layer is arranged on the surface of the current collector layer and comprises a plurality of protrusions arranged at intervals. The active material layer covers the bottom material layer, the active material layer comprises at least one pit, and the projection of each pit is at least partially overlapped with the projection of at least one bulge along the direction from the active material layer to the current collector layer. By adopting the design mode of the electrode plate of the battery provided by the invention, the surface area of the active material layer is increased under the condition that the size of the electrode plate is fixed, so that the ion exchange efficiency between the electrode plate and the electrolyte is improved, the cycle capability of the battery is improved, and the service life of the battery is prolonged. And the rapid charging capability of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of energy technology, and in particular to an electrode plate, a battery, a battery pack and an energy storage system. Background Art

[0002] Since lithium batteries and sodium batteries have high energy density and long service life, they are widely used in the field of energy storage. The bare cells of lithium batteries and sodium batteries are usually wound structures or laminated structures. After the bare cells are immersed in the electrolyte, they can be charged and discharged. The initial activation charging process is that the lithium ions of lithium batteries or the sodium ions of sodium batteries are released from the positive electrode material into the electrolyte, and the lithium ions or sodium ions in the electrolyte are embedded in the negative electrode from the electrolyte. The discharge process is the reverse process of the charging process.

[0003] As users have higher and higher requirements for battery charging capacity, the fast charging capability of lithium batteries and sodium batteries has attracted great attention, which has become one of the key evaluation indicators of battery performance in the current battery development process. However, the battery charging process is affected by ambient temperature, current size and battery state of charge (SOC), and its charging rate cannot be increased indefinitely. Utility Model Content

[0004] The present application provides an electrode plate, a battery, a battery pack and an energy storage system to enhance the fast charging capability of the battery.

[0005] In the first aspect, the present application provides a battery, which includes an electrode plate, wherein the electrode plate includes a current collector layer and an underlying material layer and an active material layer disposed on at least one surface of the current collector layer. The underlying material layer is disposed on the surface of the current collector layer, and the underlying material layer includes a plurality of protrusions disposed at intervals. The active material layer covers the underlying material layer, and the active material layer includes at least one pit, and along the direction from the active material layer to the current collector layer, the projection of each pit overlaps at least part of the projection of at least one protrusion. Since in the electrode plate of the battery provided in the present application, the active material layer includes at least one pit, this is conducive to increasing the surface area of ​​the active material layer when the size of the electrode plate is constant. In addition, due to the presence of the pits in the active material layer, it is conducive to improving the electrolyte storage capacity of the electrode plate, thereby helping to improve the efficiency of ion exchange between the electrode plate and the electrolyte, which is conducive to improving the cycle capacity of the battery, and thus can improve the fast charging capacity of the battery.

[0006] In a possible implementation of the present application, the spacing between any two adjacent protrusions of the bottom material layer is greater than or equal to 2 mm and less than or equal to 20 mm. In this way, the spacing between any two adjacent protrusions can be smaller, so that when the size of the current collector layer is constant, it is convenient to set more protrusions on the current collector layer, which can be beneficial to increase the number of pits in the active material layer, thereby increasing the surface area of ​​the active material layer, and is beneficial to improving the electrolyte storage capacity of the electrode plate, so as to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0007] In addition, the diameter of each protrusion of the bottom material layer projected on the surface of the current collector layer is greater than or equal to 20 μm and less than or equal to 200 μm. Each protrusion of the bottom material layer occupies a smaller area on the current collector layer, so more protrusions can be arranged on the current collector layer of equal area.

[0008] In the present application, the active material layer includes a plurality of pits, and the distance between any two adjacent pits is greater than or equal to 3 mm and less than or equal to 20 mm. This can help the active material layer to form a greater number of pits, thereby effectively increasing the surface area of ​​the active material layer.

[0009] In a possible implementation of the present application, the depth h of the pit and the thickness H of the active material layer satisfy: 10% H≤h≤50% H. This ensures that the portion of the current collector layer used to set the active material layer can be completely covered by the active material layer, which can make the setting area of ​​the active material layer of the current collector layer larger, thereby facilitating the increase of the effective area of ​​the electrode plate, so as to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0010] In a possible implementation of the present application, the active material layer includes a plurality of pits, and the plurality of pits are arranged in a one-to-one correspondence with the plurality of protrusions, and along the direction from the active material layer to the current collector layer, the projection of each pit overlaps at least part of the projection of a protrusion. This can help increase the surface area of ​​the active material layer and help improve the electrolyte storage capacity of the electrode plate, thereby helping to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0011] In a possible implementation of the present application, the material of the bottom material layer includes one or more of animal fats, mineral oils, butyl rubber, isoprene rubber, EPDM rubber, fluororubber, polysiloxane, siloxane copolymers and siloxane crosslinkers to ensure that the surface tension of the bottom material layer in a liquid state is small.

[0012] In the present application, the current collector layer is copper foil or aluminum foil, which can be specifically selected according to the type of electrode plate provided by the present application.

[0013] The material of the active material in the active material layer is not limited in the present application, and illustratively may include at least one of graphite, soft carbon, hard carbon, silicon alloy and tin alloy.

[0014] The binder of the active material layer may include at least one of polyvinylidene fluoride, polytetrafluoroethylene, polyamide, styrene-butadiene rubber, styrene-propylene rubber and polyacrylic acid.

[0015] In addition, the dispersant of the active material layer may include at least one of sodium carboxymethylcellulose, lithium carboxymethylcellulose, and cellulose nanofibers.

[0016] The conductive agent of the active material layer may include at least one of conductive carbon, carbon nanotubes, graphene, carbon fiber, vapor-grown carbon fiber, activated carbon, porous carbon, acetylene black and Ketjen black.

[0017] Each component in the above active material layer can be specifically selected according to the specific application scenario of the electrode plate.

[0018] In a second aspect, the present application further provides a battery pack, the battery pack comprising a plurality of batteries according to the first aspect, any two of the plurality of batteries being connected in series or in parallel. The battery pack provided by the present application has better charge and discharge performance.

[0019] In the third aspect, the present application also provides an energy storage system, which includes an energy storage converter and an energy storage cabinet, wherein the energy storage cabinet includes one or more battery packs as in the second aspect, and the energy storage converter is electrically connected to the energy storage cabinet, and is used to convert the AC power output by an external power source into DC power and then provide it to the energy storage cabinet, or to convert the DC power from the energy storage cabinet into AC power and output it to an external device. Since the battery pack of the energy storage system provided by the present application has a relatively reliable charging and discharging performance, it is conducive to improving the operational reliability of the energy storage system.

[0020] In a fourth aspect, the present application also provides an electrode plate, which can be either a positive electrode plate of a battery or a negative electrode plate of a battery. When the electrode plate is specifically configured, it includes a current collector layer and a bottom material layer and an active material layer disposed on at least one surface of the current collector layer. The bottom material layer is disposed on the surface of the current collector layer, and the bottom material layer includes a plurality of protrusions disposed at intervals. The active material layer covers the bottom material layer, and the active material layer includes at least one pit, and along the direction from the active material layer to the current collector layer, the projection of each pit overlaps at least part of the projection of at least one protrusion. Since in the electrode plate provided in the present application, the active material layer includes at least one pit, this is conducive to increasing the surface area of ​​the active material layer when the size of the electrode plate is constant. In addition, due to the presence of the pits in the active material layer, it is conducive to improving the electrolyte storage capacity of the electrode plate, thereby facilitating the improvement of the efficiency of ion exchange between the electrode plate and the electrolyte.

[0021] In a possible implementation of the present application, the spacing between any two adjacent protrusions of the bottom material layer is greater than or equal to 2 mm and less than or equal to 20 mm. In this way, the spacing between any two adjacent protrusions can be smaller, so that when the size of the current collector layer is constant, it is convenient to set more protrusions on the current collector layer, which can be beneficial to increase the number of pits in the active material layer, thereby increasing the surface area of ​​the active material layer, and is beneficial to improving the electrolyte storage capacity of the electrode plate, so as to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0022] In addition, the diameter of each protrusion of the bottom material layer projected on the surface of the current collector layer is greater than or equal to 20 μm and less than or equal to 200 μm. Each protrusion of the bottom material layer occupies a smaller area on the current collector layer, so more protrusions can be arranged on the current collector layer of equal area.

[0023] In the present application, the active material layer includes a plurality of pits, and the distance between any two adjacent pits is greater than or equal to 3 mm and less than or equal to 20 mm. This can help the active material layer to form a greater number of pits, thereby effectively increasing the surface area of ​​the active material layer.

[0024] In a possible implementation of the present application, the depth h of the pit and the thickness H of the active material layer satisfy: 10% H≤h≤50% H. This ensures that the portion of the current collector layer used to set the active material layer can be completely covered by the active material layer, which can make the setting area of ​​the active material layer of the current collector layer larger, thereby facilitating the increase of the effective area of ​​the electrode plate, so as to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0025] In a possible implementation of the present application, the active material layer includes a plurality of pits, and the plurality of pits are arranged in a one-to-one correspondence with the plurality of protrusions, and along the direction from the active material layer to the current collector layer, the projection of each pit overlaps at least part of the projection of a protrusion. This can help increase the surface area of ​​the active material layer and help improve the electrolyte storage capacity of the electrode plate, thereby helping to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0026] In a possible implementation of the present application, the material of the bottom material layer includes one or more of animal fats, mineral oils, butyl rubber, isoprene rubber, EPDM rubber, fluororubber, polysiloxane, siloxane copolymers and siloxane crosslinkers to ensure that the surface tension of the bottom material layer in a liquid state is small.

[0027] In the present application, the current collector layer is copper foil or aluminum foil, which can be specifically selected according to the type of electrode plate provided by the present application.

[0028] The material of the active material in the active material layer is not limited in the present application, and illustratively may include at least one of graphite, soft carbon, hard carbon, silicon alloy and tin alloy.

[0029] The binder of the active material layer may include at least one of polyvinylidene fluoride, polytetrafluoroethylene, polyamide, styrene-butadiene rubber, styrene-propylene rubber and polyacrylic acid.

[0030] In addition, the dispersant of the active material layer may include at least one of sodium carboxymethylcellulose, lithium carboxymethylcellulose, and cellulose nanofibers.

[0031] The conductive agent of the active material layer may include at least one of conductive carbon, carbon nanotubes, graphene, carbon fiber, vapor-grown carbon fiber, activated carbon, porous carbon, acetylene black and Ketjen black.

[0032] Each component in the above active material layer can be specifically selected according to the specific application scenario of the electrode plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the structure of an electrode plate provided in an embodiment of the present application;

[0034] Figure 2 A schematic diagram of a configuration of a bottom material layer on the surface of a current collector layer provided in an embodiment of the present application;

[0035] Figure 3 for Figure 2 A magnified view of the local structure at A of the structure shown in FIG.

[0036] Figure 4 A top view of an electrode sheet provided in an embodiment of the present application;

[0037] Figure 5 for Figure 4 A cross-sectional view of the electrode sheet at BB shown in FIG.

[0038] Figure 6 A cross-sectional view of another structure of an electrode plate provided in an embodiment of the present application;

[0039] Figure 7 A cross-sectional view of another structure of an electrode plate provided in an embodiment of the present application;

[0040] Figure 8 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0041] Fig. 9 for Figure 8 An enlarged view of the local structure at C of the battery cell shown in FIG.

[0042] Fig.10 A schematic diagram of the structure of a battery provided in an embodiment of the present application;

[0043] Fig.11 A schematic diagram of the structure of an energy storage cabinet provided in an embodiment of the present application.

[0044] Reference numerals:

[0045] 100-battery pack; 10-battery; 1-battery cell; 101-electrode plate; 101a-positive electrode plate; 101b-negative electrode plate; 1011-current collector layer;

[0046] 1012-bottom material layer; 10121-protrusion; 1013-active material layer; 10131-pit; 102-diaphragm; 2-battery shell;

[0047] 200-Energy storage cabinet. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as being limited to the embodiments described herein. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted. The words expressing position and direction described in the embodiments of the present application are all illustrated by taking the accompanying drawings as examples, but changes may be made as needed, and the changes made are all included in the scope of protection of the present application. The drawings of the embodiments of the present application are only used to illustrate the relative position relationship, and they do not represent the true proportion.

[0049] It should be noted that specific details are described in the following description to facilitate understanding of the present application. However, the present application can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific implementation methods disclosed below.

[0050] In order to facilitate the understanding of the electrode plates and batteries provided in the embodiments of the present application, their application scenarios are first introduced below. When an electronic device is in use, a power supply device is usually required to power it. At present, various electronic devices, such as consumer electronic products (such as mobile phones, tablets or wearable devices) and electric vehicles, etc., can usually choose secondary batteries such as lithium batteries, lead-acid batteries, sodium batteries, magnesium batteries, aluminum batteries and potassium batteries as power supply devices. In addition, batteries are also used as basic units for energy storage systems such as energy storage base stations to realize charging and discharging functions. In this application, secondary batteries (rechargeable batteries) are also called rechargeable batteries, power batteries or storage batteries, which refer to batteries that can be activated by charging after the battery is discharged and continue to be used. In the following embodiments of the present application, unless otherwise specified, the batteries mentioned refer to secondary batteries.

[0051] With the rapid development of electronic devices, users have put forward higher requirements for electronic devices. Among them, the problem of fast charging of batteries for electronic devices has become a key issue of concern. However, the charging process of the battery is affected by the ambient temperature, current size and battery state of charge (SOC), and its charging rate cannot be increased indefinitely. In order to improve the fast charging capability of the battery, some solutions in this field currently consider increasing the surface area of ​​the active material layer of the electrode plate to increase the number of ion exchanges between the electrode plate and the electrolyte per unit time, thereby improving the charging performance of the battery. However, the existing solutions for increasing the surface area of ​​the active material layer of the electrode plate have poor feasibility and insufficient lifespan, and it is difficult to meet the actual use requirements of the battery.

[0052] In view of this, the electrode plate provided in the present application utilizes the principle that two slurries with a surface tension difference will shrink and produce pits during the solidification process, so as to achieve the purpose of increasing the surface area of ​​the active material layer of the electrode plate. The implementation process of this scheme has high controllability, and the adhesion reliability of the active material layer is good, which is conducive to extending the service life of the electrode plate. In addition, since the surface area of ​​the active material layer of the electrode plate is large, it is conducive to improving the charging performance of the battery using the electrode plate. The electrode plate provided in the embodiment of the present application will be described in detail below in conjunction with the accompanying drawings.

[0053] Reference Figure 1 , Figure 1 A schematic diagram of the structure of the electrode plate 101 provided in the embodiment of the present application. The electrode plate 101 includes a current collector layer 1011 and a bottom material layer 1012 and an active material layer 1013 disposed on at least one surface of the current collector layer 1011. The bottom material layer 1012 is disposed on the surface of the current collector layer 1011, and the active material layer 1013 covers the bottom material layer 1012. Figure 1It can be seen that in the electrode plate 101 provided in the present application, the active material layer 1013 includes at least one pit 10131, which is conducive to increasing the surface area of ​​the active material layer 1013 when the size of the electrode plate 101 is constant. In addition, due to the presence of the pit 10131 of the active material layer 1013, it is conducive to improving the electrolyte storage capacity of the electrode plate 101, thereby helping to improve the efficiency of ion exchange between the electrode plate 101 and the electrolyte.

[0054] In the present application, the pits 10131 of the active material layer 1013 are generated during the preparation of the electrode plate 101, because the surface tension of the bottom material layer 1012 in a liquid state is less than the surface tension of the active material layer 1013 in a liquid state, so as to utilize the surface tension difference between the bottom material layer 1012 in a liquid state and the active material layer 1013. In order to facilitate the understanding of the electrode plate 101 provided by the present application, the specific structure of the electrode plate 101 provided by the embodiment of the present application is described below in combination with the introduction of the preparation process of the electrode plate 101.

[0055] Reference Figure 2 , Figure 2 A schematic diagram of a setting method of the bottom material layer 1012 provided in an embodiment of the present application on the surface of the current collector layer 1011. The bottom material layer 1012 includes a plurality of protrusions 10121 arranged at intervals. In the present application, the bottom material layer 1012 can be formed on the surface of the current collector by coating. Specifically, a mold including a hollow pattern can be placed on the surface of the current collector layer 1011, and then the bottom material layer 1012 in a liquid state can be coated on the mold, and formed on the surface of the current collector layer 1011 through the hollow pattern on the mold. Finally, the bottom material layer 1012 in a liquid state is dried so that the bottom material layer 1012 condenses into a solid form and adheres to the surface of the current collector layer 1011.

[0056] The specific shape of the protrusion 10121 of the bottom material layer 1012 is not limited in the present application. For example, reference may be made to Figure 3 , Figure 3 for Figure 2 A magnified view of the local structure at A of the structure shown in FIG. Figure 3 In the embodiment, the cross-sectional shape of the protrusion 10121 of the bottom material layer 1012 is a trapezoid. In some other possible embodiments, the protrusion 10121 of the bottom material layer 1012 may also be a hemispherical shape or other possible shapes, which can be realized by selecting a suitable mold according to the needs of specific application scenarios, and they are not listed one by one here.

[0057] You can continue to refer to Figure 3In the present application, the diameter D of the projection of each protrusion 10121 of the underlying material layer 1012 on the surface of the current collector layer 1011 may be greater than or equal to 20 μm and less than or equal to 200 μm, so that each protrusion 10121 of the underlying material layer 1012 occupies a smaller area on the current collector layer 1011, so that more protrusions 10121 can be set on the current collector layer 1011 of equal area.

[0058] It can be understood that, when the size of the current collector layer 1011 is constant, the distance between two adjacent protrusions 10121 of the bottom material layer 1012 has an important influence on the number of protrusions 10121 of the bottom material layer 1012. Based on this, Figure 3 As shown, in the present application, the spacing L1 between any two adjacent protrusions 10121 of the underlying material layer 1012 is greater than or equal to 2 mm and less than or equal to 20 mm, and the spacing between any two adjacent protrusions 10121 is smaller, so as to facilitate setting a larger number of protrusions 10121 on the current collector layer 1011 of equal area.

[0059] In addition, in the present application, the multiple protrusions 10121 of the bottom material layer 1012 can be arranged in a matrix or linear manner on the surface of the current collector layer 1011, which is beneficial to improve the compactness of the layout of the multiple protrusions 10121, thereby helping to increase the number of protrusions 10121.

[0060] From the above description of the structure of the electrode plate 101, it can be known that the active material layer 1013 covers the bottom material layer 1012. After the bottom material layer 1012 is dried and condensed into a solid, the active material layer 1013 can be coated on the surface of the bottom material layer 1012. Specifically, a mold including a hollow pattern can be placed on the surface of the bottom material layer 1012, and then the active material layer 1013 in a liquid state can be coated on the mold, and formed on the surface of the bottom material layer 1012 through the hollow pattern on the mold. Finally, the active material layer 1013 in a liquid state is dried.

[0061] Since the surface tension of the active material layer 1013 in a liquid state is greater than the surface tension of the bottom material layer 1012 in a liquid state, during the drying process of the active material layer 1013, due to the surface tension difference, the portion of the active material layer 1013 in a liquid state corresponding to the protrusion 10121 of the bottom material layer 1012 will shrink to form a pit 10131. Figure 4 , Figure 4A top view of an electrode plate 101 provided in an embodiment of the present application. In the present application, the active material layer 1013 covers a plurality of protrusions 10121 of the bottom material layer 1012. Ideally, during the drying process, the active material layer 1013 in a liquid state can form a pit 10131 at a portion corresponding to each protrusion 10121. The more protrusions 10121 of the bottom material layer 1012, the more pits 10131 formed in the active material layer 1013, so that the active material layer 1013 can include a plurality of pits 10131, and the plurality of pits 10131 are arranged in a one-to-one correspondence with the plurality of protrusions 10121. In addition, along the direction from the active material layer 1013 to the current collector layer 1011, the projection of each pit 10131 at least partially overlaps with the projection of a protrusion 10121, which can help increase the surface area of ​​the active material layer 1013 and improve the electrolyte retention capacity of the electrode plate 101, thereby helping to improve the efficiency of ion exchange between the electrode plate 101 and the electrolyte.

[0062] However, in the actual production process, due to the influence of material selection and preparation conditions, the number of pits 10131 in the active material layer 1013 may be less than the number of protrusions 10121 in the underlying material layer 1012. However, compared with the active material layer 1013 with a flat surface in the prior art, since the active material layer 1013 of the electrode plate provided in the present application includes at least one pit 10131, its surface area is also significantly increased, which can also improve the electrolyte storage capacity of the electrode plate 101, thereby achieving the purpose of improving the ion exchange efficiency between the electrode plate 101 and the electrolyte.

[0063] You can continue to refer to Figure 4 In the present application, the spacing L2 between any two adjacent pits 10131 in the multiple pits 10131 of the active material layer 1013 is greater than or equal to 3 mm and less than or equal to 20 mm, which is conducive to the active material layer 1013 forming a larger number of pits 10131 to effectively increase the surface area of ​​the active material layer 1013.

[0064] It is understandable that the shape of the pit 10131 of the active material layer 1013 is closely related to the material of the active material layer 1013, the surface tension difference between the active material layer 1013 and the underlying material layer 1012, and the drying conditions. Therefore, the specific shape of the pit 10131 of the active material layer 1013 is not limited in the present application. Figure 5 , Figure 5 for Figure 4 A cross-sectional view of the electrode plate 101 at BB is shown in FIG. Figure 5In FIG. 1 , the pits 10131 of the active material layer 1013 are hemispherical pits 10131. Figure 6 , Figure 6 This is a cross-sectional view of another structure of the electrode plate 101 provided in the embodiment of the present application. Figure 6 In FIG. 1 , the pits 10131 of the active material layer 1013 are conical pits 10131. Figure 7 In the structure shown, Figure 7 FIG. 1 is a cross-sectional view of another structure of the electrode plate 101 provided in an embodiment of the present application. The pit 10131 of the active material layer 1013 is also a hemispherical pit 10131, but different from FIG. Figure 5 Compared with the pits 10131 of the active material layer 1013 shown in Figure 7 The diameter of the pits 10131 of the middle active material layer 1013 is larger.

[0065] The above embodiments are merely some exemplary descriptions of the possible shapes of the pits 10131 of the active material layer 1013. In other embodiments of the present application, the pits 10131 of the active material layer 1013 may also be in other shapes, which are not listed here one by one, and in the same electrode plate 101, the shapes and sizes of the pits 10131 of the active material layer 1013 may be the same or different, which should be understood to fall within the protection scope of the present application.

[0066] You can continue to refer to Figure 5 In the present application, the depth h of the pit 10131 and the thickness H of the active material layer 1013 satisfy 10%H≤h≤50%H. This ensures that the portion of the current collector layer 1011 used to set the active material layer 1013 can be completely covered by the active material layer 1013, which can make the setting area of ​​the active material layer 1013 of the current collector layer 1011 larger, thereby facilitating the increase of the effective area of ​​the electrode plate, so as to improve the efficiency of ion exchange between the electrode plate and the electrolyte.

[0067] In the present application, the materials of the bottom material layer 1012 and the active material layer 1013 are not limited. Exemplarily, the material of the bottom material layer 1012 includes one or more of animal fat, mineral oil, butyl rubber, isoprene rubber, EPDM rubber, fluororubber, polysiloxane, siloxane copolymer and siloxane crosslinker. In addition, the bottom material layer 1012 may also include other possible ester, rubber or silicone materials, which are not listed here one by one, but they should all be understood to fall within the protection scope of the present application.

[0068] The solvent of the active material layer 1013 in a liquid state is usually water. In addition, the material of the active material layer 1013 can be selected according to the specific design requirements of the electrode plate 101. Exemplarily, the active material layer 1013 includes at least one of graphite, soft carbon, hard carbon, silicon alloy and tin alloy; the adhesive of the active material layer 1013 includes at least one of polyvinylidene fluoride, polytetrafluoroethylene, polyamide, styrene-butadiene rubber, styrene-propylene rubber and polyacrylic acid; the dispersant of the active material layer 1013 includes at least one of sodium carboxymethyl cellulose, lithium carboxymethyl cellulose and cellulose nanofibers; the conductive agent of the active material layer 1013 includes at least one of conductive carbon, carbon nanotubes, graphene, carbon fiber, vapor-grown carbon fiber, activated carbon, porous carbon, acetylene black and Ketjen black.

[0069] The above is only some exemplary explanations on the selection of materials for the underlying material layer 1012 and the active material layer 1013, but the materials for the underlying material layer 1012 and the active material layer 1013 are not limited thereto. As long as the surface tension of the underlying material layer 1012 in a liquid state is smaller than the surface tension of the active material layer 1013 in a liquid state, so as to satisfy the condition for the active material layer 1013 to form the pit 10131, they will not be listed one by one here, but they should all be understood to fall within the scope of protection of this application.

[0070] It is worth mentioning that the electrode plate 101 provided in the present application, when applied to a battery, can be specifically applied to a battery cell, and the battery cell may include a positive electrode plate and a negative electrode plate, and the electrode plate 101 provided in the present application can be used as both a positive electrode plate and a negative electrode plate, that is, at least one of the positive electrode plate and the negative electrode plate of the battery is the electrode plate 101 provided in the present application, and the current collector layer 1011 and the active material layer 1013 of the electrode plate 101 can be specifically designed according to the usage requirements in the specific application scenario.

[0071] Exemplarily, in a specific embodiment, the electrode plate 101 provided in the present application is applied to a sodium battery and is used as a negative electrode plate of a sodium battery. The current collector layer 1011 of the electrode plate 101 is aluminum foil, the material of the bottom material layer 1012 is styrene-butadiene rubber, the active material of the active material layer 1013 is hard carbon, the adhesive is styrene-butadiene rubber, the dispersant is sodium carboxymethyl cellulose, and the conductive agent is superconducting carbon. In addition, the coating width of the bottom material layer 1012 on the current collector layer 1011 can be 200 mm, and the active material layer 1013 completely covers the bottom material layer 1012. After the electrode plate 101 is prepared and dried, the diameter of the projection of the protrusion 10121 of the bottom material layer 1012 on the current collector layer 1011 is 120 μm, and the spacing between two adjacent protrusions 10121 is 2.5 μm, and the pit 10131 of the active material layer 1013 can be a hemispherical pit 10131.

[0072] In addition, the electrode plate 101 provided in the present application can also be applied to other types of batteries, for example, the electrode plate 101 can be applied to lithium batteries, wherein when the electrode plate 101 is used as the negative electrode plate of the lithium battery, the current collector layer 1011 of the electrode plate 101 can be copper foil; and when the electrode plate 101 is used as the positive electrode plate of the lithium battery, the current collector layer 1011 of the electrode plate 101 can be aluminum foil. Various types of batteries to which the electrode plate 101 provided in the present application is applied are not introduced one by one here, but they should all be understood to fall within the protection scope of the present application.

[0073] In the battery, the battery cell 1 includes a separator in addition to the positive electrode sheet 101a and the negative electrode sheet 101b. In addition, the specific configuration of the battery cell 1 is not limited in the present application, and its exemplary configuration may be: Figure 8 The winding structure shown in the figure, the battery cell 1 is a positive electrode sheet 101a, a separator ( Figure 8 Not shown in the figure), a negative electrode sheet 101b and a separator are arranged in sequence and stacked and then wound up, and the production efficiency is high.

[0074] Reference Fig. 9 , Fig. 9 for Figure 8 The enlarged view of the local structure of the cell 1 at C is shown in FIG. Fig. 9 It can be seen that the separator 102 is located between the positive electrode sheet 101a and the negative electrode sheet 101b.

[0075] exist Figure 8 and Fig. 9 In the battery cell 1 shown, the negative electrode plate 101b adopts the design of the electrode plate 101 provided in the present application. Since the surface area of ​​the active material layer 1013 of the negative electrode plate 101b is large, and the pits 10131 of the active material layer 1013 have a certain electrolyte storage capacity, it is beneficial to improve the efficiency of ion exchange between the negative electrode plate 101b and the electrolyte of the battery, thereby improving the cycle capacity of the battery cell 1, and further improving the fast charging capacity of the battery using the battery cell 1.

[0076] In addition, since the underlying material layer 1012 and the active material layer 1013 are formed separately by coating and then drying during the preparation process of the electrode plate 101 provided in the present application, the adhesion reliability of the underlying material layer 1012 and the active material layer 1013 on the current collector layer 1011 is better, which is beneficial to extend the service life of the electrode plate 101, thereby helping to improve the charging stability of the battery using the electrode plate 101.

[0077] It is worth mentioning that the electrode plate 101 provided in the present application can also be applied to other battery cells 1, such as stacked cores. Since the preparation process of stacked cores is relatively mature, it will not be described in detail. However, since the stacked core is applied with the electrode plate 101 provided in the present application, the efficiency of ion exchange between it and the electrolyte of the battery 10 is conducive to improving the cycle capacity of the battery cell 1, and further to improving the charging performance of the battery 10 applied with the battery cell 1.

[0078] Reference Fig.10 , Fig.10 A schematic diagram of the structure of a battery 10 provided in an embodiment of the present application. The battery 10 may further include a battery shell 2, and the battery core 1 to which the electrode plate 101 provided in the present application is applied may be accommodated in the battery shell 2.

[0079] The battery 10 provided in the embodiment of the present application can be applied to the energy storage system. In actual application, according to the different power requirements in different application scenarios, any two batteries 10 in the plurality of batteries 10 are usually connected in series or in parallel to form a battery pack for application in the energy storage system to provide appropriate voltage, capacity and power. In addition, the energy storage system may also include an energy storage inverter and an energy storage cabinet. Fig.11 , Fig.11 A schematic diagram of the structure of an energy storage cabinet 200 provided in an embodiment of the present application. The energy storage cabinet 200 includes one or more battery packs 100 composed of the batteries 10 provided in the above-mentioned embodiment. In addition, an energy storage inverter can be electrically connected to the battery pack 100 of the energy storage cabinet 200, and the energy storage inverter is used to convert the AC power output by an external power source into DC power and then provide it to the battery pack 100, or convert the DC power from the battery pack 100 into AC power and output it to an external device. Since the battery provided in the embodiment of the present application has a high energy density and production efficiency, and its structure and the reliability of the charge and discharge performance are better, it can be beneficial to reduce the cost of the energy storage system and improve the operational reliability of the energy storage system.

[0080] In addition, the energy storage system may also include a battery management system, which can effectively detect parameters such as the temperature, state of charge, and health status of the battery pack 100 in the energy storage cabinet 200, and can also effectively regulate the charging and discharging functions of the battery pack 100, thereby ensuring the normal operation of the energy storage system.

[0081] The battery 10 provided in the above embodiment of the present application can also be applied to a power supply system. In addition, the power supply system can also include a power generation device. The power generation device is electrically connected to the battery, and the power generation device can be used to store the electric energy generated by it in the battery. By applying the above battery 10, the cost of the power supply system can be effectively reduced.

[0082] In a specific embodiment, the power supply system may be a large power station or a micro power station, wherein the micro power station may be located in an industrial park or a community. Alternatively, the power supply system may also be a household power supply system or a power supply system for equipment such as a vehicle.

[0083] The power generation equipment can be, but is not limited to, photovoltaic power generation equipment, wind power generation equipment, etc., and the embodiments of the present application do not limit the specific type of the power generation equipment. In addition, in practical applications, the power generation equipment and the battery 10 can also be connected through a distribution cabinet. The distribution cabinet may include a DC-AC conversion device, or may also include devices such as a transformer, so as to effectively transmit the electric energy generated by the power generation equipment to the battery 10 for storage. In the specific setting, the number and type of devices in the distribution cabinet can be reasonably set according to actual needs, and the embodiments of the present application do not limit this.

[0084] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery, characterized in that: The battery comprises an electrode plate, wherein the electrode plate comprises a current collector layer and a bottom material layer and an active material layer arranged on at least one surface of the current collector layer, wherein: The bottom material layer is disposed on the surface of the current collector layer, and the bottom material layer includes a plurality of protrusions disposed at intervals; The active material layer covers the bottom material layer, and the active material layer includes at least one pit. Along the direction from the active material layer to the current collector layer, the projection of each of the pits at least partially overlaps with the projection of at least one of the protrusions.

2. The battery according to claim 1, characterized in that The distance between any two adjacent protrusions is greater than or equal to 2 mm and less than or equal to 20 mm.

3. The battery according to claim 1 or 2, characterized in that A diameter of a projection of each protrusion on the surface of the current collector layer is greater than or equal to 20 μm and less than or equal to 200 μm.

4. The battery according to claim 1 or 2, characterized in that The active material layer includes a plurality of the pits, and a distance between any two adjacent pits is greater than or equal to 3 mm and less than or equal to 20 mm.

5. The battery according to claim 1 or 2, characterized in that: The depth h of the pit and the thickness H of the active material layer satisfy the following relationship: 10%H≤h≤50%H.

6. The battery according to claim 1 or 2, characterized in that: The active material layer includes a plurality of the pits, and the plurality of the pits are arranged in one-to-one correspondence with the plurality of the protrusions, and in the direction from the active material layer to the current collector layer, the projection of each of the pits at least partially overlaps with the projection of one of the protrusions.

7. The battery according to claim 1 or 2, characterized in that: The material of the bottom material layer includes animal fat, mineral oil, butyl rubber, isoprene rubber, EPDM rubber, fluororubber, polysiloxane, siloxane copolymer or siloxane crosslinking agent.

8. The battery according to claim 1 or 2, characterized in that: The current collector layer is copper foil or aluminum foil.

9. The battery according to claim 1 or 2, characterized in that: The active material of the active material layer includes graphite, soft carbon, hard carbon, silicon alloy or tin alloy.

10. The battery according to claim 1 or 2, characterized in that: The binder of the active material layer includes polyvinylidene fluoride, polytetrafluoroethylene, polyamide, styrene-butadiene rubber, styrene-propylene rubber or polyacrylic acid.

11. The battery according to claim 1 or 2, characterized in that: The dispersant of the active material layer includes sodium carboxymethyl cellulose, lithium carboxymethyl cellulose or cellulose nanofiber.

12. The battery according to claim 1 or 2, characterized in that: The conductive agent of the active material layer includes conductive carbon, carbon nanotube, graphene, carbon fiber, vapor-grown carbon fiber, activated carbon, porous carbon, acetylene black or Ketjen black.

13. A battery pack, characterized in that: The method comprises a plurality of batteries according to any one of claims 1 to 12, wherein any two of the plurality of batteries are connected in series or in parallel.

14. An energy storage system, characterized in that: It comprises an energy storage inverter and an energy storage cabinet, wherein the energy storage cabinet comprises one or more battery packs as claimed in claim 13, and the energy storage inverter is electrically connected to the energy storage cabinet, and is used to convert the alternating current output by an external power supply into direct current and then provide it to the energy storage cabinet, or to convert the direct current from the energy storage cabinet into alternating current and output it to an external device.

15. An electrode plate, characterized in that: The invention comprises a current collector layer and a bottom material layer and an active material layer arranged on at least one surface of the current collector layer, wherein: The bottom material layer is disposed on the surface of the current collector layer, and the bottom material layer includes a plurality of protrusions disposed at intervals; The active material layer covers the underlying material layer, and the active material layer includes at least one pit. Along the direction from the active material layer to the current collector layer, the projection of each of the pits at least partially overlaps with the projection of at least one of the protrusions.

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