Battery and power consuming device

Abstract

This application provides a battery and an electrical device. The battery includes a cell, which is a wound core. The cell includes a positive electrode, a negative electrode, and a separator stacked together. The cell has a first surface and a second surface opposite each other along its thickness direction. A reference electrode includes a third current collector and an electrode material layer disposed on one side surface of the third current collector. The reference electrode is disposed on the first surface or the second surface of the cell. The reference electrode is used to form a test circuit with the positive electrode and / or the negative electrode to test the electrical parameters of the battery. An separator is disposed between the cell and the reference electrode. By setting a reference electrode on the surface of the cell, this battery can achieve high-accuracy real-time monitoring of the positive and negative electrode reaction states inside the battery, improving battery life and safety performance. The reference electrode does not affect the original capacity and charge / discharge performance of the battery, and the battery manufacturing process is simple, highly compatible with existing commercial battery production processes and equipment, and conducive to large-scale production.

Description

Batteries and electrical devices Technical Field

[0001] The present application relates to the technical field of batteries and electrical equipment, and in particular to a battery with a reference electrode and an electrical equipment comprising the battery. Background Art

[0002] In recent years, with the continuous improvement of parameters such as energy density, charge and discharge rate, and battery capacity of lithium-ion batteries, it has brought huge challenges to battery safety performance. The industry usually develops a set of inherent charge and discharge procedures for the charge and discharge process of lithium-ion batteries. This charge and discharge procedure is relatively safe in the early stages of battery use. However, when the battery ages or the battery abnormality causes the internal resistance to increase, the originally set charging procedure may cause lithium plating at the negative electrode, thereby causing safety problems. If the voltage, internal resistance, current and other electrical parameters that can reflect the internal positive and negative electrode reaction state of the lithium-ion battery can be monitored in real time, not only can the battery charge and discharge current be adjusted in time to improve the battery life, but also the abnormal behavior of the lithium-ion battery can be warned in time to avoid the occurrence of safety accidents. However, it is relatively difficult to monitor the electrical parameters that can reflect the internal positive and negative electrode reaction state of the lithium-ion battery in real time, and there is currently no mature commercial solution in the industry.

[0003] Summary of the Invention

[0004] In view of this, an embodiment of the present application provides a battery and an electrical device. By setting a reference electrode on the surface of the battery cell, the battery can achieve high-accuracy real-time monitoring of the positive and negative electrode reaction states inside the battery, thereby improving the battery's service life and safety performance; the reference electrode will not affect the battery's original capacity and charge and discharge performance, and the battery preparation process is simple, and has a high degree of compatibility with the existing commercial production process and production equipment of batteries, which is conducive to commercial large-scale production.

[0005] According to a first aspect of an embodiment of the present application, a battery is provided, comprising a cell and a reference electrode, and a separator disposed between the cell and the reference electrode for isolating the cell and the reference electrode, wherein the cell has a first surface and a second surface opposite to each other along its thickness direction; the reference electrode is disposed on the first surface or the second surface of the cell; the reference electrode comprises a third current collector and an electrode material layer disposed on one surface of the third current collector, wherein one side of the electrode material layer is disposed adjacent to the separator; and the reference electrode is configured to form a test circuit with the positive electrode sheet and / or the negative electrode sheet to test the electrical parameters of the battery. The battery can form a test circuit with the reference electrode, the positive electrode sheet, and the negative electrode sheet to achieve real-time monitoring of electrical parameters reflecting the reaction state of the positive and negative electrodes within the battery, and the test accuracy is high. Therefore, the battery's charging current, charging voltage, and other parameters can be adjusted in a timely manner based on the monitored electrical parameters to adjust the battery's charge and discharge state, thereby improving the battery's service life and safety performance, and avoiding excessive battery aging and safety accidents caused by abnormal battery charge and discharge. The battery with a reference electrode provided in the embodiment of the present application, the introduction of its reference electrode will not affect the original capacity and charge and discharge performance of the battery. In addition, the battery with a reference electrode provided in the embodiment of the present application can obtain the changing trend of the positive and negative electrode impedances after battery aging, thereby providing data reference for the subsequent design optimization of the battery. The battery with a reference electrode provided in the embodiment of the present application has a simple structure and setting process of the reference electrode, and has a high degree of matching with the commercial production process and production equipment of existing batteries. There is no need to change the existing battery cell preparation process, nor to add complex operating procedures and production equipment, which facilitates large-scale production based on existing production lines.

[0006] In the embodiment of the present application, the battery cell can be a wound core or a laminated core. In the embodiment of the present application, the electrode material layer includes a reference electrode active material, a conductive agent and a binder. In a battery with a wound core, the reference electrode active material can include lithium iron phosphate LiFePO4 and / or lithium titanate Li4Ti5O 12 In a battery with a laminated core, the reference electrode active material may include lithium titanate Li4Ti5O 12 LiFePO4 and Li4Ti5O 12 The material has the characteristics of good cycle stability, chemical stability and reversibility, and LiFePO4 and Li4Ti5O 12The reference electrode has a wide voltage platform during the lithium insertion and deintercalation reaction. It is used as the reference electrode active material to prepare the reference electrode. During the battery charging and discharging process, the change of the battery SOC (State of Charge) has very little effect on the platform voltage, which can enable the reference electrode to maintain a constant potential better during the battery cycle. Using this voltage platform as a reference voltage can effectively reflect the absolute voltage of the positive and negative electrodes, thereby obtaining more accurate electrode potential and impedance values.

[0007] In the embodiment of the present application, the LiFePO4 and Li4Ti5O 12 The D50 particle size is 1nm-100nm. The D50 particle size is the particle size corresponding to the cumulative particle size distribution percentage of a sample reaching 50%. D50 is also called the median diameter or median particle size. The reference electrode uses nano-scale lithium iron phosphate LiFePO4 and / or lithium titanate Li4Ti5O 12 The material has better cycle stability, chemical stability and reversibility, can significantly reduce the internal resistance of the reference electrode, eliminate the polarization effect of the reference electrode, and more accurately measure the potential, internal resistance and other parameters of the positive and negative electrodes inside the battery; and can be better adhered to the current collector by coating it with a binder, avoiding the phenomenon of active material falling off during the cycle.

[0008] In the embodiment of the present application, the thickness of the electrode material layer is 1 μm to 5 μm. The ultra-thin electrode material layer design facilitates its stable bonding to the surface of the third current collector, preventing distortion of electrical parameter measurements caused by the shedding of the reference electrode active material during battery cycling, and improving the stability and reliability of the reference electrode test.

[0009] In the embodiment of the present application, the third current collector comprises any one of copper foil, carbon-coated copper foil, copper mesh, nickel mesh, and carbon cloth. The reference electrode adopts a structure in which the third current collector carries the electrode material layer, which facilitates welding to form the reference electrode tab using the third current collector.

[0010] In the embodiment of the present application, the separator material includes any one of a polyolefin separator, a polyolefin aluminum oxide composite separator, and a polymer-based solid electrolyte. The above separator material is a conventional battery separator material, which is readily available and can effectively isolate the battery cell from the reference electrode.

[0011] In the embodiment of the present application, the orthographic projection of the reference electrode in the thickness direction of the battery cell is located within the orthographic projection of the first surface or the second surface where the reference electrode is located in the thickness direction of the battery cell. This design facilitates the fixing of the reference electrode to the battery cell and better matches the original size design of the battery.

[0012] In the embodiment of the present application, when the battery capacity is 1000mAh, the area of ​​the orthographic projection of the reference electrode in the thickness direction of the battery cell is greater than or equal to 30% of the area of ​​the orthographic projection of the first surface or second surface where the reference electrode is located in the thickness direction of the battery cell; when the battery capacity is (1000+C)mAh, the area of ​​the orthographic projection of the reference electrode in the thickness direction of the battery cell is greater than or equal to X% of the area of ​​the orthographic projection of the first surface or second surface where the reference electrode is located in the thickness direction of the battery cell, where C is greater than 0, and X% = 30% + (C / 1000) 10%. This design can better take into account the installation convenience and reliability of the reference electrode, as well as the total weight design and cost of the battery while accurately monitoring the battery electrical parameters.

[0013] In an embodiment of the present application, the reference electrode at least partially covers a central region of the first surface or the second surface where the reference electrode is located. Placing the reference electrode in the central region of the first surface or the second surface helps reduce the size of the reference electrode for easier positioning and installation, optimizes the weight of the battery, and ensures monitoring accuracy.

[0014] In an embodiment of the present application, the reference electrode at least partially covers the midline of the first surface or the second surface where the reference electrode is located, and the regions of the reference electrode located on either side of the midline are symmetrical relative to the midline, with the midline being perpendicular to the winding direction of the battery cell. This symmetrical design can better reduce the size of the reference electrode to optimize the weight of the battery while ensuring monitoring accuracy, thereby ensuring monitoring accuracy with a reference electrode design that is as small as possible.

[0015] In an embodiment of the present application, the reference electrode includes a first end and a second end that are opposite each other in a direction perpendicular to the bottom seal surface or the top seal surface of the cell, with at least one of the first end and the second end extending close to the bottom seal surface or the top seal surface of the cell. This design facilitates simultaneous securing of the reference electrode to the cell using the top seal layer and / or the bottom seal layer when performing top and bottom seals on the cell.

[0016] In an embodiment of the present application, the positive electrode sheet includes a positive electrode collector and a positive electrode active layer arranged on the surface of the positive electrode collector, and the negative electrode sheet includes a negative electrode collector and a negative electrode active layer arranged on the surface of the negative electrode collector; the positive electrode sheet also includes a positive electrode tab electrically connected to the positive electrode collector, the negative electrode sheet also includes a negative electrode tab electrically connected to the negative electrode collector, and the reference electrode also includes a reference electrode tab electrically connected to the third current collector.

[0017] In the embodiment of the present application, the positive electrode tab and the negative electrode tab are arranged at the ends of the battery cell, and the reference electrode tab is arranged at the end of the reference electrode to facilitate connection with an external circuit.

[0018] In an embodiment of the present application, the battery further includes a battery protection board, the positive electrode tab, the negative electrode tab, and the reference electrode tab are respectively welded to the battery protection board, and the battery protection board is connected to the positive electrode tab and the reference electrode tab to form the test circuit, and / or the battery protection board is connected to the negative electrode tab and the reference electrode tab to form the test circuit to obtain the electrical parameters of the battery. After obtaining the real-time electrical parameters of the battery, the battery protection board can timely adjust the charge and discharge status of the battery, thereby protecting the battery.

[0019] In the embodiment of the present application, the battery protection board is also used to adjust the charge and discharge state of the battery according to the electrical parameters of the battery. By timely adjusting the charge and discharge state of the battery, the service life of the battery can be increased and the occurrence of short circuits and other phenomena can be avoided.

[0020] In the embodiment of the present application, a positive electrode contact point, a negative electrode contact point and a reference electrode contact point are provided on the battery protection board, and the positive electrode tab, the negative electrode tab and the reference electrode tab are electrically connected to the positive electrode contact point, the negative electrode contact point and the reference electrode contact point respectively.

[0021] In the embodiment of the present application, the battery further comprises an adhesive layer, which is used to fix the reference electrode, the separator and the battery cell together. The adhesive layer is used for fixing, which is convenient to operate.

[0022] In the embodiment of the present application, the battery further comprises a housing, wherein the battery cell, the reference electrode, and the separator are housed in the housing. The housing can protect the battery cell and the like housed therein.

[0023] In an embodiment of the present application, the battery further includes an electrolyte, and the electrolyte is contained in the housing.

[0024] A second aspect of an embodiment of the present application provides a method for preparing a battery having a reference electrode, comprising:

[0025] preparing an electrode active layer and a reference electrode tab on the third current collector to obtain a reference electrode;

[0026] Arrange an isolator on one side surface of the battery cell in the thickness direction, and then place the reference electrode on the isolator;

[0027] The battery cell, the separator, and the reference electrode are fixed together.

[0028] In the embodiment of the present application, the preparation method further comprises:

[0029] The battery core, the separator and the reference electrode fixed together are packaged with a shell material, and an electrolyte is injected to obtain a packaged battery core, and the packaged battery core is welded to a battery protection board to obtain the battery.

[0030] The battery preparation method provided in the embodiments of the present application has a simple process and is highly compatible with the commercial production process and production equipment of existing batteries. There is no need to change the existing battery cell preparation process, nor is there any need to add complex operating procedures and production equipment, which facilitates large-scale production based on existing production lines.

[0031] The present application also provides an electrical device comprising an electrical module and the battery described in the first aspect of the present application, wherein the battery is used to power the electrical module. The use of such a battery facilitates the electrical device to monitor battery health, determine appropriate parameters such as charging voltage, charging current, charging speed, and charging time, and predict battery life, thereby improving the safety and reliability of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic structural diagram of a battery 100 provided in one embodiment of the present application;

[0033] FIG2 is a schematic structural diagram of a battery 100 provided in one embodiment of the present application;

[0034] FIG3A is a schematic diagram of the cross-sectional structure of the reference electrode 20 according to an embodiment of the present application;

[0035] FIG3B is a schematic diagram of the stacking position of the reference electrode 20 and the battery cell 10 in an embodiment of the present application;

[0036] FIG4 is a schematic structural diagram of a battery 100 provided in another embodiment of the present application;

[0037] FIG5 is a schematic structural diagram of a battery 100 provided in another embodiment of the present application;

[0038] FIG6 is a schematic structural diagram of a battery 100 provided in another embodiment of the present application;

[0039] FIG7 is a schematic structural diagram of a battery 100 provided in another embodiment of the present application;

[0040] FIG8 is a schematic structural diagram of a battery 100 provided in one embodiment of the present application;

[0041] FIG9 is a schematic diagram of the arrangement of the tabs at the end of the winding core according to an embodiment of the present application;

[0042] FIG10 is a schematic diagram of the arrangement of terminal tabs at the ends of a laminated battery cell according to an embodiment of the present application;

[0043] FIG11 is a schematic structural diagram of a reference electrode 20 in one embodiment of the present application;

[0044] FIG12 is a schematic diagram of the arrangement of the tabs at the end of the winding core according to another embodiment of the present application;

[0045] FIG13 is a schematic diagram of the arrangement of the tabs at the end of the winding core provided by another embodiment of the present application;

[0046] FIG14 is a schematic diagram of the arrangement of the tabs at the end of the winding core provided by another embodiment of the present application;

[0047] FIG15 is a flow chart of a method for preparing a battery provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0049] The reaction state of the positive and negative electrodes inside the lithium-ion battery directly determines the health status and safety performance of the battery. Real-time monitoring of the reaction state of the positive and negative electrodes inside the battery can not only timely adjust the battery's charge and discharge current and other parameters to avoid rapid aging of the battery and increase the battery's service life, but also timely warn of abnormal behavior of the lithium-ion battery, thereby avoiding the occurrence of safety accidents. However, it is relatively difficult to monitor in real time the electrical parameters that can reflect the internal positive and negative electrode reaction state of the lithium-ion battery during operation, and there is currently no mature commercial solution in the industry. In order to solve the above problems, an embodiment of the present application provides a battery, which can achieve high-accuracy real-time monitoring of the positive and negative electrode reaction state inside the battery by setting a reference electrode on the surface of the winding core, thereby improving the battery's service life and safety performance; the reference electrode will not affect the original capacity and charge and discharge performance of the battery, and the battery preparation process is simple, and has a high degree of compatibility with the commercial production process and production equipment of existing batteries, which is conducive to commercial large-scale production.

[0050] 1 and 2 , FIG1 is a schematic structural diagram of a battery 100 provided in one embodiment of the present application, and FIG2 is a schematic structural diagram of a battery 100 provided in another embodiment of the present application. The battery 100 includes:

[0051] The battery cell 10 has a first surface 110 and a second surface 120 opposite to each other along its thickness direction;

[0052] In the embodiment shown in FIG1 , the battery cell 10 is a wound core, and the battery cell 10 includes a positive electrode sheet 101, a negative electrode sheet 102, and a separator 103 that are stacked and wound. The separator 103 is disposed between the positive electrode sheet 101 and the negative electrode sheet 102 to separate the positive electrode sheet 101 from the negative electrode sheet 102. In the embodiment shown in FIG2 , the battery cell 10 is a laminated battery cell, and the battery cell 10 includes a positive electrode sheet 101, a negative electrode sheet 102, and a separator 103 that are stacked. The separator 103 is disposed between the positive electrode sheet 101 and the negative electrode sheet 102 to separate the positive electrode sheet 101 from the negative electrode sheet 102.

[0053] A reference electrode 20 is disposed on the first surface 110 or the second surface 120 of the battery cell 10 ; the reference electrode 20 is used to form a test circuit with the positive electrode sheet 101 and / or the negative electrode sheet 102 to test the electrical parameters of the battery 100 ;

[0054] The separator 30 is disposed between the battery cell 10 and the reference electrode 20 to isolate the battery cell 10 from the reference electrode 20 .

[0055] The battery 100 with a reference electrode provided in the embodiment of the present application can form a test circuit through the reference electrode 20 and the positive electrode sheet 101 and the negative electrode sheet 102 to achieve real-time monitoring of electrical parameters reflecting the positive and negative electrode reaction states inside the battery 100, and the test accuracy is relatively high. Therefore, the battery's charging current, charging voltage and other parameters can be adjusted in time based on the monitored electrical parameters to adjust the battery's charge and discharge state, thereby improving the battery's service life and safety performance, and avoiding rapid aging of the battery and the occurrence of safety accidents caused by abnormal battery charging and discharging.

[0056] Among them, the electrical parameters may include the positive electrode absolute potential, the negative electrode absolute potential, the positive electrode AC impedance, the negative electrode AC impedance, the positive electrode DC impedance, the negative electrode DC impedance, etc. The positive electrode absolute potential and the negative electrode absolute potential can reflect the battery status information that the positive and negative electrode voltage difference cannot reflect. The positive electrode absolute potential and the negative electrode absolute potential are too high, which is not conducive to safe charging. By monitoring the positive electrode absolute potential or the negative electrode absolute potential in real time, it is beneficial to improve the monitoring accuracy of the battery status, better and more timely regulate the battery status, reduce the possibility of being charged too fast, avoid the negative electrode absolute potential being lower than 0V, resulting in lithium precipitation and short circuit, and the positive electrode absolute potential exceeding the preset value, resulting in irreversible damage to the positive electrode material and battery bulging, which is beneficial to delaying the aging of the battery and improving the battery safety. Specifically, for example, when the battery is charging, when it is monitored that the current negative electrode absolute potential of the battery is greater than the preset potential, the charging current of the battery can be reduced to return the battery to a safe charging state.

[0057] The battery 100 with a reference electrode provided in the embodiment of the present application has a reference electrode 20 that is not arranged between the positive electrode 101 and the negative electrode 102 of the battery cell 10. There is no problem of lithium ions being deposited on the surface of the reference electrode 20 during the battery charging and discharging process, which affects the original capacity and balance of the battery. That is, the introduction of the reference electrode 20 of the present application will not affect the original capacity, internal resistance, voltage, charge and discharge performance, cycle life, safety performance, etc. of the battery. In addition, the battery 100 with a reference electrode provided in the embodiment of the present application can obtain the status of the battery 100 throughout its life cycle, and can obtain the changing trend of the positive and negative electrode impedances after battery aging, thereby providing data reference for subsequent design optimization of the battery. The battery 100 with a reference electrode provided in the embodiment of the present application has a simple structure and setting process of the reference electrode 20, which is highly compatible with the commercial production process and production equipment of existing batteries. There is no need to change the existing battery cell preparation process, nor to add complex operating procedures and production equipment, which facilitates large-scale production based on existing production lines.

[0058] Referring to Figure 1, the battery cell 10 is a roll core, which is a wound battery cell. In this embodiment, the battery cell 10 includes a flat area 10a and a bending area 10b connected to both ends of the flat area 10a. The thickness direction of the battery cell 10 itself is the stacking direction of the positive electrode sheet 101, the separator 103, and the negative electrode sheet 102 in the flat area 10a. The electrode sheet and separator of the wound battery cell are continuous and integrated, with high manufacturing efficiency, few edges, easy to control burrs, and improved safety. The wound battery cell can make the battery smaller, with high energy density, good stability, and good heat dissipation performance.

[0059] Referring to Figure 2 , the battery cell 10 is a laminated battery cell. In this embodiment, the thickness direction of the battery cell 10 itself is the stacking direction of the positive electrode sheet 101, the separator 103, and the negative electrode sheet 102. The laminated battery cell can include multiple layers of alternating positive and negative electrode sheets 101, 102, and a separator 103 disposed between the positive and negative electrode sheets 101, 102.

[0060] Referring to Figures 3A and 3B, Figure 3A is a schematic diagram of the cross-sectional structure of the reference electrode 20 of an embodiment of the present application, and Figure 3B is a schematic diagram of the stacking position of the reference electrode 20 and the battery cell 10 in an embodiment of the present application. The reference electrode 20 includes a third current collector 201 and an electrode material layer 202 arranged on the surface of one side of the third current collector 201, wherein one side of the electrode material layer 202 of the reference electrode 20 is arranged close to the separator 30. The structure of the reference electrode 20 of the present application is similar to that of a conventional positive and negative electrode. It can be obtained by coating the electrode material layer 202 on the surface of the third current collector 201. This structure can be conveniently welded to form a reference electrode ear through the third current collector 201, thereby forming a tight and reliable welding connection with the battery protection plate; this structure is also conducive to cutting the reference electrode into various shapes and sizes as needed during the actual production process for easy use.

[0061] The battery 100 of the present application may specifically be a lithium-ion battery.

[0062] In the embodiment of the present application, the electrode material layer 202 includes a reference electrode active material. In a battery with a wound core, the reference electrode active material may include lithium iron phosphate LiFePO4 and / or lithium titanate Li4Ti5O 12 In a battery with a laminated core, the reference electrode active material may include lithium titanate Li4Ti5O 12 LiFePO4 and Li4Ti5O 12 The material has the characteristics of good cycle stability, chemical stability and reversibility, and LiFePO4 and Li4Ti5O 12 The reference electrode has a wide voltage platform during the lithium insertion and deintercalation reaction. It is used as the reference electrode active material to prepare the reference electrode. During the battery charging and discharging process, the change of the battery SOC (State of Charge) has very little effect on the platform voltage, which can enable the reference electrode to maintain a constant potential better during the battery cycle. Using this voltage platform as a reference voltage can effectively reflect the absolute voltage of the positive and negative electrodes, thereby obtaining more accurate electrode potential and impedance values.

[0063] In the embodiment of the present application, LiFePO4 and Li4Ti5O 12 With nanoscale size, LiFePO4 and Li4Ti5O 12 The D50 particle size can be 1nm-100nm. In some embodiments, LiFePO4 and Li4Ti5O 12The D50 particle size can be, but is not limited to, 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, and 100 nm. The reference electrode 20 is made of nanometer-sized lithium iron phosphate LiFePO4 and / or lithium titanate Li4Ti5O 12 The material has better cycle stability, chemical stability and reversibility, can greatly reduce the internal resistance of the reference electrode 20, eliminate the polarization effect of the reference electrode 20, and more accurately measure the internal positive electrode absolute potential, negative electrode absolute potential, positive electrode AC impedance, negative electrode AC impedance, positive electrode DC impedance, negative electrode DC impedance and other electrical parameters of the battery; and through the adhesive coating on the current collector, it can better adhere to avoid the phenomenon of active material falling off during the cycle.

[0064] In the embodiment of the present application, the thickness of the electrode material layer 202 may be 1 μm to 5 μm. In some embodiments, the thickness of the electrode material layer 202 may be, but is not limited to, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, or 5 μm. The ultra-thin electrode material layer 202 design facilitates its stable bonding to the surface of the third current collector 201, preventing distortion of electrical parameter measurements caused by the shedding of the reference electrode active material during battery cycling, and improving the stability and reliability of the reference electrode in battery electrical parameter testing.

[0065] In the embodiment of the present application, the third current collector 201 is made of a conductive material and is used to collect current. The third current collector 201 can be any of copper foil, carbon-coated copper foil, copper mesh, nickel mesh, and carbon cloth. The thickness of the third current collector 201 can be 5μm-10μm, specifically but not limited to 5μm, 6μm, 7μm, 8μm, 9μm, and 10μm. The reference electrode 20 adopts the structure of the third current collector 201 supporting the electrode material layer 202. The third current collector 201 is made of the above materials to facilitate the use of the third current collector 201 to weld and form the reference electrode tab.

[0066] In the embodiment of the present application, the electrode material layer 202 further includes a conductive agent and a binder. The conductive agent may be, but is not limited to, any one or more of conductive carbon black, carbon nanotubes, graphene, and Ketjen black. The binder may be, but is not limited to, any one or more of polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyacrylic acid (PAA), cyanoacrylate binder (CA), and polyacrylonitrile (PAN). In the electrode material layer 202, the reference electrode active material, the conductive agent, and the binder are uniformly mixed and distributed. The conductive agent is used to construct a conductive network, and the binder is used to bond the components together. In an embodiment of the present application, in the electrode material layer 202, the mass percentage of the reference electrode active material may be 90%-96%, such as, but not limited to, 90%, 91%, 92%, 93%, 94%, 95%, or 96%. The mass percentage of the conductive agent may be 1%-10%, such as, but not limited to, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. The mass percentage of the binder may be 1%-10%, such as, but not limited to, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. In some embodiments, the mass ratio of the reference electrode active material, the conductive agent, and the binder may be, but not limited to, 90:5:5, 90:6:4, or 90:7:3.

[0067] In the present application, the structural design of the reference electrode 20 is the same as that of conventional positive and negative electrodes, and can be prepared using the same operations as the positive and negative electrodes without the need for additional equipment.

[0068] In the embodiment of the present application, the first surface 110 and the second surface 120 in the thickness direction of the battery cell 10 are planes. Referring to Figures 1, 2, 4, 5, 6 and 7, Figures 4, 5, 6 and 7 are schematic structural diagrams of a battery 100 provided in another embodiment of the present application. In the embodiment of the present application, the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 is located within the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10. In other words, the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 may be less than or equal to the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10. This design facilitates the fixation of the reference electrode 20 to the battery cell 10 and can better match the original size design of the battery.

[0069] The size, design, and placement of the reference electrode 20 will, to a certain extent, affect the accuracy of battery electrical parameter monitoring based on the reference electrode 20 and the difficulty of positioning and installation. A larger reference electrode 20 can avoid voltage jumps caused by uneven localized active material coating, allowing for more accurate measurement of the absolute voltages at the positive and negative electrodes. A smaller reference electrode 20 allows for better positioning and installation during the manufacturing process and is more conducive to optimizing the overall battery weight.

[0070] In order to better ensure the accuracy of electrical parameter detection, the size of the reference electrode 20 can be designed according to the capacity of the battery 100. In some embodiments of the present application, when the capacity of the battery 100 is 1000 mAh, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 is greater than or equal to 30% of the area of ​​the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10. In some embodiments, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 can be greater than or equal to 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95% of the area of ​​the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10.

[0071] In other embodiments of the present application, when the battery capacity is (1000+C) mAh, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 is greater than or equal to X% of the area of ​​the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10, where X% = 30% + (C / 1000) 10%, and C is a capacity value greater than 0. In this embodiment, the maximum value of X% is 100%. It can be understood that when X% is calculated to be a value less than 100%, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 can be any value within the range of X% to 100% relative to the area of ​​the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10. For example, when the battery capacity is 5000 mAh, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 is greater than or equal to 70% of the area of ​​the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10; in actual production, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 relative to the area of ​​the orthographic projection of the first surface 110 or the second surface 120 where the reference electrode 20 is located in the thickness direction of the battery cell 10 can be any value within the range of 70%-100%, including but not limited to 70%, 80%, and 90%. In some embodiments, the value of C is within the range of 0-7000.

[0072] The size of the reference electrode 20 is designed so that the area of ​​its orthographic projection in the thickness direction of the battery cell 10 is smaller than the area of ​​its orthographic projection in the thickness direction of the battery cell 10 on the first surface 110 or the second surface 120. This can better monitor the battery electrical parameters accurately while taking into account the installation convenience and reliability of the reference electrode, as well as the total weight design and cost of the battery. In some embodiments, the area of ​​the orthographic projection of the reference electrode 20 in the thickness direction of the battery cell 10 is equal to the area of ​​the orthographic projection of the first surface 110 or the second surface 120 on which the reference electrode 20 is located in the thickness direction of the battery cell 10. The size of the reference electrode 20 is designed so that the area of ​​its orthographic projection in the thickness direction of the battery cell 10 is equal to the area of ​​the orthographic projection of the first surface 110 or the second surface 120 on which the reference electrode 20 is located in the thickness direction of the battery cell 10. While ensuring high monitoring accuracy, it can be directly cut according to the shape and size of the first surface 110 and the second surface 120. The solution is simple.

[0073] Continuing to refer to Figures 1, 2, 4, 5, 6 and 7, in order to reduce the size of the reference electrode for easy positioning and installation, and to optimize the weight of the battery while ensuring monitoring accuracy, in some embodiments of the present application, the reference electrode 20 at least partially covers the middle area of ​​the first surface 110 or the second surface 120 where the reference electrode 20 is located, that is, at least a portion of the reference electrode 20 is located in the middle area of ​​the first surface 110 or the second surface 120 where the reference electrode 20 is located. In some embodiments, the entire reference electrode 20 is located in the middle area of ​​the first surface 110 or the second surface 120 where it is located to improve monitoring accuracy. As shown in Figures 4 to 7, the middle area here can be the center line M of the first surface 110 or the second surface 120 and the areas on both sides near the center line M. Among them, the center line M is perpendicular to the top end face 130 or the bottom end face 140 of the battery cell 10. The top seal end face 130 refers to the end face of the battery cell 10 corresponding to the top seal end of the battery 100, and the bottom seal end face 140 refers to the end face of the battery cell 10 corresponding to the bottom seal end of the battery 100. For batteries in which the battery cell 10 is a roll core, the top seal end face 130 or the bottom seal end face 140 of the battery cell 10 is the winding end face of the battery cell 10, that is, the end face perpendicular to the winding direction of the roll core. In this case, the center line M is perpendicular to the winding direction of the battery cell 10. The direction from the top seal end face 130 to the bottom seal end face 140 of the battery cell 10 is defined as the length direction of the battery cell 10, and the direction perpendicular to the length direction is the width direction of the battery cell 10. The center line M is along the length direction of the battery cell 10. For batteries in which the battery cell 10 is a roll core, the length direction of the battery cell 10 is perpendicular to the winding direction of the battery cell 10. The reference electrode 20 covers the middle area of ​​the surface of the battery cell 10. On the one hand, it facilitates the uniform entry of lithium ions and electrons into the reference electrode 20 to obtain an accurate reference voltage. On the other hand, it facilitates the layout of the tabs of the reference electrode 20 at the end of the battery and the welding with the battery protection plate.

[0074] In some embodiments of the present application, the reference electrode 20 at least partially covers the midline M of the first surface 110 or the second surface 120 where the reference electrode 20 is located, and the regions of the reference electrode 20 located on both sides of the midline M are symmetrical relative to the midline M. This symmetrical design can better reduce the size of the reference electrode to optimize the weight of the battery while ensuring monitoring accuracy, thereby ensuring monitoring accuracy with a design of the reference electrode 20 with the smallest possible size.

[0075] Continuing to refer to Figures 1, 2, 4, 5, 6 and 7, in the embodiment of the present application, the reference electrode 20 includes a first end 21 and a second end 22 that are relatively perpendicular to the winding direction of the battery cell 10 in a direction perpendicular to the top seal end surface 130 or the bottom seal end surface 140 of the battery cell 10, and at least one of the first end 21 and the second end 22 of the reference electrode 20 extends to a position close to the top seal end surface 130 or the bottom seal end surface 140 of the battery cell 10. This design facilitates the use of the top seal layer and / or the bottom seal layer to simultaneously fix the reference electrode 20 to the battery cell 10 when the battery cell 10 is top-sealed and bottom-sealed, thereby simplifying the process. As shown in Figures 1 and 2, the top seal layer and the bottom seal layer are used to fix the reference electrode 20 to the battery cell 10; as shown in Figures 4 and 6, the top seal layer is used to fix the reference electrode 20 to the battery cell 10. In the embodiment of the present application, the first end 21 of the reference electrode 20 may extend to the top sealed end surface 130 close to the battery cell 10, or the second end 22 of the reference electrode 20 may extend to the bottom sealed end surface 140 close to the battery cell 10, or the first end 21 of the reference electrode 20 may extend to the top sealed end surface 130 close to the battery cell 10, and the second end 22 of the reference electrode 20 may extend to the bottom sealed end surface 140 close to the battery cell 10.

[0076] In the embodiment of the present application, the battery 100 further includes an adhesive layer 40, which is used to fix the reference electrode 20, the separator 30 and the battery cell 10 together. The location of the adhesive layer 40 is not limited. As shown in Figures 1, 2, 4 to 7, the adhesive layer 40 can be at the end of the reference electrode 20 or in the middle, as long as the reference electrode 20 and the battery cell 10 are firmly fixed. In some embodiments, as shown in Figure 1, for ease of operation, the reference electrode 20 and the battery cell 10 can be directly fixed by using the top sealing adhesive layer and the bottom sealing adhesive layer for the top and bottom sealing of the battery cell. This is convenient to operate, saves the amount of adhesive used, and achieves firm fixation.

[0077] In the embodiment of the present application, the material of the separator 30 includes any one of a polyolefin separator, a polyolefin aluminum oxide composite separator, and a polymer-based solid electrolyte, and is used to isolate the battery cell 10 from the reference electrode 20. The size of the separator 30 is greater than or equal to the size of the reference electrode 20. The above separator materials are conventional battery separator materials, are easily available, and can effectively isolate the battery cell from the reference electrode. Polyolefin separators may include, for example, PE (polyethylene) separators, PP (polypropylene) separators, or PE and PP composite separators. Polyolefin aluminum oxide composite separators may include, for example, PE and Al2O3 composite separators, or PP and Al2O3 composite separators. Polymer-based solid electrolytes may include, for example, PEO (polyethylene oxide) and lithium salt composite gel electrolytes, PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene) and lithium salt composite gel electrolytes, PAN (polyacrylonitrile) and lithium salt composite gel electrolytes, MPEGA (polyethylene glycol methyl ether acrylate) and PEGDA (polyethylene glycol diacrylate) and lithium salt composite gel electrolytes, PEO and LATP (lithium aluminum titanium phosphate) and lithium salt composite electrolytes, PEO and PVDF, LLZO (lithium lanthanum zirconium oxide) and lithium salt composite electrolytes. The thickness of separator 30 may be 5 μm to 20 μm. In some embodiments, the thickness of the separator 30 may be, but is not limited to, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 16 μm, 18 μm, or 20 μm.

[0078] The reference electrode 20 of the present application is independently arranged on the surface of the battery cell 10 and is not arranged between the positive electrode sheet 101 and the negative electrode sheet 102. Therefore, lithium ions will not be deposited on the surface of the reference electrode 20 when passing through the reference electrode 20, thereby affecting the original capacity and balance of the battery; and the potential of the reference electrode can be kept constant during the battery cycle.

[0079] In the embodiment of the present application, the positive electrode sheet 101 includes a positive electrode current collector and a positive electrode active layer disposed on the surface of the positive electrode current collector, and the negative electrode sheet 102 includes a negative electrode current collector and a negative electrode active layer disposed on the surface of the negative electrode current collector.

[0080] Wherein, the positive electrode current collector can be any one of aluminum foil, porous aluminum foil, and aluminum polymer composite current collector, and the thickness of the positive electrode current collector can be 5μm-10μm, for example, but not limited to 5μm, 6μm, 7μm, 8μm, 9μm, and 10μm. The thickness of the positive electrode active layer can be 5μm-200μm, for example, but not limited to 5μm, 10μm, 15μm, 20μm, 30μm, 40μm, 50μm, 60μm, 80μm, 100μm, 120μm, 150μm, 180μm, and 200μm. The positive electrode active layer includes a positive electrode active material, a conductive agent, and a binder, wherein the positive electrode active material can be various materials with the ability to embed and deintercalate lithium ions, including but not limited to LiCoO2, LiMnO2, LiNiO2, LiFePO4, LiNi 0.8 Co 0.1 Mn 0.1 O2(NCM811), LiNi 0.5 Co 0.2 Mn 0.3 O2(NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O2(NCM622), LiNiCoMnO2(NCM111), LiNi 0.8 Co 0.15 Al 0.05 O2(NCA)). The selection of the conductive agent and the binder can refer to the selection of the conductive agent and the binder in the reference electrode 20, which will not be repeated here. In the embodiment of the present application, in the positive electrode active layer, the mass percentage of the positive electrode active material can be 90%-97%, for example, but not limited to 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, the mass percentage of the conductive agent can be 1%-10%, for example, but not limited to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, the mass percentage of the binder can be 1%-10%, for example, but not limited to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%. In some embodiments, in the positive electrode active layer, the mass ratio of the positive electrode active material, the conductive agent, and the binder can be, but not limited to, 95:3:2 or 96:2:2.

[0081] The negative electrode current collector can be any one of copper foil, porous copper foil, copper-polymer composite current collector, and carbon-coated copper foil. The thickness of the negative electrode current collector can be 5μm-10μm, for example, but not limited to, 5μm, 6μm, 7μm, 8μm, 9μm, and 10μm. The thickness of the negative electrode active layer can be 5μm-300μm, for example, but not limited to, 5μm, 10μm, 15μm, 20μm, 30μm, 40μm, 50μm, 60μm, 80μm, 100μm, 120μm, 150μm, 180μm, 200μm, 250μm, and 300μm. The negative electrode active layer includes a negative electrode active material, a conductive agent, and a binder. The negative electrode active material can be any material capable of intercalating and deintercalating lithium ions, including but not limited to one or more of graphite, silicon, silicon-carbon compounds, and silicon-oxygen compounds. The selection of the conductive agent and the binder can refer to the selection of the conductive agent and the binder in the reference electrode 20, and will not be repeated here. In the embodiment of the present application, in the negative electrode active layer, the mass percentage of the negative electrode active material can be 90%-96%, for example, but not limited to 90%, 91%, 92%, 93%, 94%, 95%, 96%, the mass percentage of the conductive agent can be 1%-10%, for example, but not limited to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and the mass percentage of the binder can be 1%-10%, for example, but not limited to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%. In some embodiments, in the negative electrode active layer, the mass ratio of the negative electrode active material, the conductive agent, and the binder can be, but not limited to, 94:2:4 or 94:3:3.

[0082] In the embodiment of the present application, the separator constituting the battery cell 10 can be any one of a polyolefin separator and a polyolefin aluminum oxide composite separator. The polyolefin separator and the polyolefin aluminum oxide composite separator are described above. The separator constituting the battery cell 10 and the separator 30 can be made of the same material or different materials.

[0083] Referring to Figures 8, 9 and 10, Figure 8 is a schematic diagram of the structure of the battery 100 provided in one embodiment of the present application; Figure 9 is a schematic diagram of the arrangement of the end tabs of the roll core provided in one embodiment of the present application; and Figure 10 is a schematic diagram of the arrangement of the end tabs of the laminated battery cell provided in one embodiment of the present application. The end of the battery cell 10 where the tabs are arranged may be the top seal end of the battery 100, that is, the tabs may be the end where the top seal end surface of the battery cell 10 is located. In the embodiment of the present application, the positive electrode sheet 101 further includes a positive electrode tab 104 electrically connected to the positive electrode current collector, the negative electrode sheet 102 further includes a negative electrode tab 105 electrically connected to the negative electrode current collector, and the reference electrode 20 further includes a reference electrode tab 203 electrically connected to the third current collector 201.

[0084] As shown in Figure 3A and Figure 11, Figure 11 is a schematic structural diagram of the reference electrode 20 in one embodiment of the present application (top view); the reference electrode tab 203 can be formed by welding on the surface of the third current collector 201 that is not covered with the electrode material layer 202, 205 is a welding point, and 204 is tab glue, which is used to protect the battery cell to prevent short circuit. The reference electrode tab 203 is set at the edge of the reference electrode 20, and the specific position of the edge can be designed according to actual needs. Similarly, the positive electrode tab 104 can be formed by welding on the surface of the positive current collector that is not covered with the positive active layer; the negative electrode tab 105 can be formed by welding on the surface of the negative current collector that is not covered with the negative active layer.

[0085] Continuing to refer to Figures 8 and 9, for ease of preparation and connection between the battery and an external circuit, in the embodiment of the present application, the positive electrode tab 104 and the negative electrode tab 105 are arranged at the ends of the battery cell 10, specifically, they can be the top seal end or the bottom seal end of the battery cell 10, the top seal end is the end where the top seal end surface 130 is located, and the bottom seal end is the end where the bottom seal end surface 140 is located. The reference electrode tab 203 is arranged at the end of the reference electrode 20. For batteries in which the battery cell 10 is a wound core, the positive electrode tab 104 and the negative electrode tab 105 are arranged at the ends of the battery cell 10 perpendicular to the winding direction, and the reference electrode tab 203 is arranged at the end of the reference electrode 20 perpendicular to the winding direction of the battery cell 10. The positive electrode tab 104 and the negative electrode tab 105 can be arranged at the end of the battery cell 10 where the top end face 130 is located, or at the end where the bottom end face 140 is located. The reference electrode tab 203 can be arranged at the first end 21 or the second end 22 of the battery cell 10. In actual preparation, the reference electrode tab 203 can be arranged at the same end of the battery cell 100 as the positive electrode tab 104 and the negative electrode tab 105; or the reference electrode tab 203 can be arranged at one end of the battery cell 100, and the positive electrode tab 104 and the negative electrode tab 105 can be arranged at the other end of the battery cell 100. In some embodiments, the reference electrode tab 203, the positive electrode tab 104, and the negative electrode tab 105 are arranged at the same end of the battery 100 (top seal 601 or bottom seal 602), and the direction from the top seal 601 to the bottom seal 602 of the battery 100 is defined as the length direction of the battery 100 (that is, the length direction of the battery cell 10), and the direction perpendicular to the length direction is the width direction of the battery 100 (that is, the width direction of the battery cell 10), and the reference electrode tab 203, the positive electrode tab 104, and the negative electrode tab 105 of the battery cell 10 are spaced apart along the width direction of the battery cell 10.

[0086] For the battery cell 10, it has a stacked structure of multiple layers of positive electrode sheets 101, separators 103, and negative electrode sheets 102 in the thickness direction. The positive electrode tab 104 can be set on the positive electrode collector of the positive electrode sheet 101 in any layer in the thickness direction of the battery cell 10. Similarly, the negative electrode tab 105 can also be set on the negative electrode collector of the negative electrode sheet 102 in any layer in the thickness direction of the battery cell 10. Referring to Figures 9, 10, 12, 13 and 14, Figures 12, 13 and 14 are schematic diagrams of the arrangement of the tabs at the end of the winding core. The reference electrode tab 203 can be set at any position of the reference electrode 20 along the width direction of the battery cell 10. In some embodiments, the reference electrode tab 203 can be set in the middle of the reference electrode 20 along the width direction of the battery cell 10, which is convenient for preparation and also convenient for subsequent welding of the battery protection plate. In some embodiments, in a battery with a wound core, the positive electrode tab 104 and the negative electrode tab 105 can be located at the starting end of the winding of the positive electrode sheet 101 and the negative electrode sheet 102 in the innermost circle of the battery cell 10, or at the middle of the winding of the positive electrode sheet 101 and the negative electrode sheet 102 in the middle circle of the battery cell 10, or at the end of the winding of the positive electrode sheet 101 and the negative electrode sheet 102 in the outermost circle of the battery cell 10; there can be one positive electrode tab 104 and one negative electrode tab 105, or multiple positive electrode tabs 104 and 105. As shown in Figure 9, the positive electrode tab 104 and the negative electrode tab 105 are located in the middle of the winding of the positive electrode sheet 101 and the negative electrode sheet 102 in the middle circle of the battery cell 10; as shown in Figure 12, the positive electrode tab 104 and the negative electrode tab 105 are located at the starting end of the winding of the positive electrode sheet 101 and the negative electrode sheet 102 in the innermost circle of the battery cell 10. As shown in Figures 9 and 12, the number of positive electrode tabs 104 and negative electrode tabs 105 is one each. The single-pole tab design helps ensure the rated capacity of the battery, reduces packaging difficulty, and avoids potential risks such as battery short circuits, flatulence, and leakage caused by poor packaging. As shown in Figure 13, the number of positive electrode tabs 104 is two, and the two positive electrode tabs 104 are spaced apart along the width direction of the battery cell 10. As shown in Figure 14, the number of positive electrode tabs 104 and negative electrode tabs 105 is five each, and the five positive electrode tabs 104 are aligned along the thickness direction of the battery cell 10, and the five negative electrode tabs 105 are aligned along the thickness direction of the battery cell 10. The multi-pole tab design helps improve the battery's rate performance and reduce the charge and discharge temperature rise, making it more suitable for high-power equipment.

[0087] In the embodiment of the present application, the positive electrode tab 104 may be made of aluminum strip, and may have a width of 6 mm to 7 mm and a thickness of 0.08 mm to 0.1 mm, specifically, for example, 6 mm wide and 0.08 mm thick, 7 mm wide and 0.08 mm thick, or 7 mm wide and 0.1 mm thick. The negative electrode tab 105 may be made of copper strip or copper-nickel-plated strip, and may have a width of 6 mm to 7 mm and a thickness of 0.08 mm to 0.1 mm, specifically, for example, 6 mm wide and 0.08 mm thick, 7 mm wide and 0.08 mm thick, or 7 mm wide and 0.1 mm thick. The material of the reference electrode tab 203 can be copper strip or copper nickel-plated strip; the width of the reference electrode tab 203 can be 6mm-8mm and the thickness can be 0.05mm-0.1mm, for example, 6mm wide / 0.08mm thick, 7mm wide / 0.1mm thick, 8mm wide / 0.1mm thick.

[0088] Continuing with FIG8 , in the embodiment of the present application, the battery 100 further includes a battery protection plate 50, to which the positive electrode tab 104, the negative electrode tab 105, and the reference electrode tab 203 are respectively welded. The battery protection plate 50 is fixedly connected to the battery cell 10 by being welded to the positive electrode tab 104, the negative electrode tab 105, and the reference electrode tab 203. To facilitate welding, the positive electrode tab 104, the negative electrode tab 105, and the reference electrode tab 203 can be bent and flattened until they are substantially flush, and then welded to the battery protection plate 50. The battery protection board 50 is an integrated circuit board used to protect the battery 100. The battery protection board 50 may include components such as a PCB, an anti-counterfeiting IC chip (Integrated Circuit Chip), a fuel gauge IC chip, a protection IC chip, capacitors, resistors, NTC (Negative Temperature Coefficient) thermistors, PTC (Positive Temperature Coefficient) thermistors, MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and fuses. The battery protection board 50 is used to monitor and protect the battery, preventing overcharging, over-discharging, overcurrent, overvoltage, undervoltage, and overtemperature in the battery cells, thereby maintaining the battery 100 in a safe operating state.

[0089] In the embodiment of the present application, the battery protection board 50 is provided with a positive electrode contact point, a negative electrode contact point, and a reference electrode contact point. The positive electrode tab 104, the negative electrode tab 105, and the reference electrode tab 203 are welded to the positive electrode contact point, the negative electrode contact point, and the reference electrode contact point, respectively. The battery protection board 50 can be connected to the mainboard of the electrical device via an FPC (Flexible Printed Circuit) connector or a BTB (Board-to-Board) connector.

[0090] In the embodiment of the present application, the battery protection board 50 is connected to the positive electrode tab 104 and the reference electrode tab 203 to form a test circuit, and / or the battery protection board 50 is connected to the negative electrode tab 105 and the reference electrode tab 203 to form a test circuit to obtain the electrical parameters of the battery 100. In some embodiments, the battery protection board 50 is connected to the positive electrode tab 104 and the reference electrode tab 203 to form a test circuit, so that the absolute potential and positive impedance of the positive electrode of the battery 100 can be monitored in real time. In some embodiments, the battery protection board 50 is connected to the negative electrode tab 105 and the reference electrode tab 203 to form a test circuit, so that the absolute potential and negative impedance of the negative electrode of the battery 100 can be monitored in real time. In some embodiments, the battery protection board 50 is connected to the positive electrode tab 104 and the reference electrode tab 203 to form a test circuit, and at the same time, the battery protection board 50 is connected to the negative electrode tab 105 and the reference electrode tab 203 to form a test circuit, so that the positive electrode absolute potential, negative electrode absolute potential, positive electrode impedance and negative electrode impedance of the battery 100 can be monitored in real time.

[0091] In some embodiments, the battery protection board 50 is further connected to the positive electrode tab 104 and the negative electrode tab 105 to form a test circuit to obtain electrical parameters of the battery 100 , such as monitoring the overall voltage and impedance of the battery 100 .

[0092] In the embodiment of the present application, the battery protection board 50 is also used to adjust the charge and discharge state of the battery 100 based on the monitored electrical parameters of the battery 100. The above-mentioned electrical parameters can well reflect the internal state information of the battery 100. Timely adjustment of the battery charge and discharge state based on these electrical parameters can improve the battery's service life and safety performance, and avoid the occurrence of safety accidents caused by abnormal charging and discharging of lithium-ion batteries. Specifically, for example, when the battery 100 is charging and the current absolute potential of the negative electrode of the battery is detected to be greater than a preset potential, the battery's charging current can be reduced to return the battery to a safe charging state.

[0093] Continuing with FIG8 , in an embodiment of the present application, the battery 100 further includes a housing 60 , in which the battery cell 10 , reference electrode 20 , and separator 30 are housed. In some embodiments, the battery 100 is a soft-pack battery, and the housing 60 can be made of various soft-pack materials, including but not limited to aluminum-plastic film. The positive electrode tab 104 , negative electrode tab 105 , and reference electrode tab 203 are exposed from the housing 60 to facilitate electrical connection to an external circuit. The battery protection board 50 is located outside the housing 60 .

[0094] In the embodiment of the present application, the battery 100 further includes an electrolyte, which is contained in the housing 60. In the embodiment of the present application, the electrolyte includes an organic solvent and an electrolyte lithium salt, and may further include additives as needed. The organic solvent may be a carbonate organic solvent, such as ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), etc. The electrolyte lithium salt may be, for example, lithium hexafluorophosphate.

[0095] 15 , an embodiment of the present application further provides a method for preparing the battery having the reference electrode, comprising the following steps:

[0096] S101, preparing an electrode active layer and a reference electrode tab on a third current collector to obtain a reference electrode;

[0097] In some embodiments, the preparation of the reference electrode may specifically include: mixing a reference electrode active material, a conductive agent, and a binder in a certain proportion, adding a solvent, and stirring to prepare a slurry; applying the prepared slurry to a third current collector by a single-layer extrusion coating method, drying in a vacuum oven at 80-120°C, and finally cutting into a desired shape and size; then removing a portion of the reference electrode active material from the third current collector and welding a reference electrode tab thereto to obtain the reference electrode. The solvent may be N-methylpyrrolidone (NMP).

[0098] S102, providing an insulator on one side surface of the battery cell in the thickness direction, and then placing the reference electrode on the insulator;

[0099] In some embodiments, the preparation of the battery cell may specifically include:

[0100] (1) Preparation of positive electrode sheet: The positive electrode active material, conductive agent, and binder are mixed in a certain proportion, and a solvent is added and stirred to prepare a slurry; the prepared slurry is coated on the positive electrode current collector by a double-layer extrusion coating method, and then dried in a vacuum oven at 80-120°C, and finally cut into the desired shape and welded to the positive electrode tab; wherein the solvent can be N-methylpyrrolidone (NMP);

[0101] (2) Preparation of negative electrode sheet: The negative electrode active material, conductive agent, and binder are mixed in a certain proportion, and a solvent is added and stirred to prepare a slurry; the prepared slurry is coated on the negative electrode current collector by a double-layer extrusion coating method, and then dried in a vacuum oven at 80-120°C, and finally cut into the desired shape and welded to the negative electrode tab; wherein the solvent can be deionized water or ultrapure water;

[0102] (3) The prepared positive electrode sheet, negative electrode sheet and separator are prepared into a battery cell by winding or stacking.

[0103] S103, fixing the battery cell, separator and reference electrode together.

[0104] In some embodiments, adhesive tape is used to secure the cell, separator, and reference electrode together. In some embodiments, adhesive tape can be used to secure the cell, separator, and reference electrode together when performing top and bottom sealing on the cell.

[0105] In some embodiments of the present application, the above preparation method further comprises:

[0106] S104 (not shown in the figure), use shell materials to package the battery cells, separators and reference electrodes fixed together, and inject electrolyte to obtain packaged battery cells, and weld the packaged battery cells to the battery protection board to obtain a battery.

[0107] It can be understood that the selection of the various components of the battery cell, separator, reference electrode, shell material, electrolyte, etc. involved in the above preparation method are as described above and will not be repeated here.

[0108] In a specific embodiment of the present application, a method for preparing a battery includes the following steps:

[0109] (1) Preparation of positive electrode sheet: LiCoO2, Ketjen black, and PVDF binder were added to NMP in a mass ratio of 96:2:2 and stirred to prepare a slurry. The slurry was then coated on a 7 μm thick aluminum foil by a double-layer extrusion coating method, and then dried in a vacuum oven at 100 °C. Finally, it was cut into the required shape and welded to the positive electrode tab (material: aluminum strip; size: width 6 mm / thickness 0.08 mm);

[0110] (2) Preparation of negative electrode sheet: Silicon carbon (SiC) composite material, Ketjen black, and polyacrylic acid (PAA) were added to deionized water in a mass ratio of 93:2:5 and stirred to prepare a slurry. The slurry was coated on a copper foil with a thickness of 5 μm by a double-layer extrusion coating method, and then dried in a vacuum oven at 80°C. Finally, it was cut into the desired shape and welded to the negative electrode tab (material: copper nickel-plated strip; size: width 6 mm / thickness 0.08 mm);

[0111] (3) Core preparation: The prepared positive electrode sheet, negative electrode sheet, and separator are wound into a core with a capacity of 8000 mAh using a winding machine;

[0112] (4) Preparation of reference electrode: Nanoscale lithium iron phosphate (LiFePO4), Cochin Black, and polyacrylic acid (PAA) were added to deionized water in a mass ratio of 90:5:5 and stirred to prepare a slurry. The slurry was then applied to a 5 μm thick copper foil by a single-layer extrusion coating method. The slurry coating thickness was 1-5 μm. The slurry was then dried in a vacuum oven (80°C) and finally cut into a shape with the same size as the upper surface of the core in the thickness direction. A scraper was used to remove part of the electrode slurry layer on the copper foil and welded to the reference electrode tab (material: nickel-plated copper strip; size: width 6 mm / thickness 0.08 mm);

[0113] (5) Battery Preparation: Place the reference electrode on the top surface of the core, place a separator between the core and the reference electrode, and then use tape to seal the top and bottom of the core to secure the core, separator, and reference electrode together. The core with the reference electrode is encapsulated with aluminum-plastic film, and electrolyte is injected to obtain an encapsulated cell. The encapsulated cell is then welded to the battery protection board to obtain a single cell.

[0114] In another specific embodiment of the present application, a method for preparing a battery includes the following steps:

[0115] (1) Preparation of positive electrode sheet: NCM811, Ketjen black, and PVDF binder were added to NMP in a mass ratio of 96:2:2 and stirred to prepare a slurry. The slurry was then coated on an aluminum foil with a thickness of 7 μm by a double-layer extrusion coating method, and then dried in a vacuum oven at 100 °C. Finally, it was cut into the required shape and welded to the positive electrode tab (material: aluminum strip; size: width 6 mm / thickness 0.08 mm);

[0116] (2) Preparation of negative electrode sheet: Graphite (Gr), Ketjen black, and polyacrylic acid (PAA) were added to deionized water in a mass ratio of 95:2:3 and stirred to prepare a slurry. The slurry was coated on a copper foil with a thickness of 5 μm by a double-layer extrusion coating method, and then dried in a vacuum oven at 80°C. Finally, it was cut into the desired shape and welded to the negative electrode tab (material: copper nickel-plated strip; size: width 6 mm / thickness 0.08 mm);

[0117] (3) Core preparation: The prepared positive electrode sheet, negative electrode sheet, and separator are wound into a core with a capacity of 5000 mAh using a winding machine;

[0118] (4) Reference electrode preparation: Nanoscale lithium iron phosphate (LiFePO4), Cochin Black, and polyacrylic acid (PAA) were added to deionized water in a mass ratio of 90:5:5 and stirred to prepare a slurry. The slurry was then applied to a 5 μm thick copper foil by a single-layer extrusion coating method. The slurry coating thickness was 1-5 μm. The slurry was then dried in a vacuum oven (80°C) and finally cut to a reference electrode area size of 70% of the area of ​​the upper surface in the thickness direction of the core. A scraper was used to remove part of the electrode slurry layer on the copper foil and the reference electrode tab (material: nickel-plated copper strip; size: 2 mm wide / 0.05 mm thick) was welded.

[0119] (5) Battery Preparation: Place the reference electrode on the upper surface of the core. The entire reference electrode is located in the middle area of ​​the upper surface of the core, and the reference electrode is located on both sides of the center line M perpendicular to the winding direction of the core, symmetrically relative to the center line M. Then, place an insulator between the core and the reference electrode, and use tape to seal the top and bottom of the core to fix the core, insulator, and reference electrode together. The core with the reference electrode fixed is encapsulated with aluminum plastic film, and the electrolyte is injected to obtain an encapsulated cell. The encapsulated cell is welded to the battery protection board to obtain a single cell.

[0120] In another specific embodiment of the present application, a method for preparing a battery includes the following steps:

[0121] (1) Preparation of positive electrode sheet: LiFePO4, Ketjen black, and PVDF binder were added to NMP in a mass ratio of 95:3:2 and stirred to prepare a slurry. The slurry was then coated on a 7 μm thick aluminum foil by a double-layer extrusion coating method, and then dried in a vacuum oven at 100 °C. Finally, it was cut into the required shape and welded to the positive electrode tab (material: aluminum strip; size: width 6 mm / thickness 0.08 mm);

[0122] (2) Preparation of negative electrode sheet: Graphite (Gr), Ketjen black, and CMC+SBR binder were added to deionized water in a mass ratio of 95:2:3 and stirred to prepare a slurry. The slurry was coated on a copper foil with a thickness of 5 μm by a double-layer extrusion coating method, and then dried in a vacuum oven at 80°C. Finally, it was cut into the required shape and welded to the negative electrode tab (material: copper nickel-plated strip; size: width 6 mm / thickness 0.08 mm);

[0123] (3) Core preparation: The prepared positive electrode sheet, negative electrode sheet, and separator are wound into a core with a capacity of 2000 mAh using a winding machine;

[0124] (4) Reference electrode preparation: Nanoscale lithium titanate (Li4Ti5O 12), Cogen Black, and polyacrylic acid (PAA) were added to deionized water in a mass ratio of 90:5:5 and stirred to prepare a slurry. The slurry was then applied to a 5μm thick copper foil via a single-layer extrusion coating method. The slurry coating thickness was 1-5μm. The foil was then dried in a vacuum oven (100°C) and cut to a reference electrode area that was 40% of the area of ​​the upper surface in the thickness direction of the core. A scraper was used to remove part of the electrode slurry layer on the copper foil and welded to the reference electrode tab (material: nickel-plated copper strip; size: 2mm wide / 0.05mm thick).

[0125] (5) Battery Preparation: Place the reference electrode on the upper surface of the core. The entire reference electrode is located in the middle area of ​​the upper surface of the core, and the reference electrode is located on both sides of the center line M perpendicular to the winding direction of the core, symmetrically relative to the center line M. Then, place an insulator between the core and the reference electrode, and use tape to seal the top and bottom of the core to fix the core, insulator, and reference electrode together. The core with the reference electrode fixed is encapsulated with aluminum plastic film, and the electrolyte is injected to obtain an encapsulated cell. The encapsulated cell is welded to the battery protection board to obtain a single cell.

[0126] In another specific embodiment of the present application, a method for preparing a battery includes the following steps:

[0127] (1) Preparation of positive electrode sheet: LiFePO4, Ketjen black, and PVDF binder were added to NMP in a mass ratio of 95:3:2 and stirred to prepare a slurry. The slurry was then coated on a 7 μm thick aluminum foil by a double-layer extrusion coating method, and then dried in a vacuum oven at 100 °C. Finally, it was cut into the required shape and welded to the positive electrode tab (material: aluminum strip; size: width 6 mm / thickness 0.08 mm);

[0128] (2) Preparation of negative electrode sheet: Graphite (Gr), Ketjen black, and CMC+SBR binder were added to deionized water in a mass ratio of 95:2:3 and stirred to prepare a slurry. The slurry was coated on a copper foil with a thickness of 5 μm by a double-layer extrusion coating method, and then dried in a vacuum oven at 80°C. Finally, it was cut into the required shape and welded to the negative electrode tab (material: copper nickel-plated strip; size: width 6 mm / thickness 0.08 mm);

[0129] (3) Preparation of laminated battery cells: The prepared positive electrode sheets, negative electrode sheets, and separators are prepared into laminated battery cells with a capacity of 5000 mAh through a laminating machine;

[0130] (4) Reference electrode preparation: Nanoscale lithium titanate (Li4Ti5O 12), Keqin Black, and polyacrylic acid (PAA) were added to deionized water in a mass ratio of 90:5:5 and stirred to prepare a slurry. The slurry was then applied to a 5μm thick copper foil via a single-layer extrusion coating method. The slurry coating thickness was 1-5μm. The slurry was then dried in a vacuum oven (100°C) and finally cut to a reference electrode area that was 70% of the area of ​​the upper surface of the laminated cell in the thickness direction. A scraper was used to remove part of the electrode slurry layer on the copper foil and welded to the reference electrode tab (material: nickel-plated copper strip; size: 2mm wide / 0.05mm thick);

[0131] (5) Battery Preparation: Place the reference electrode on the upper surface of the core. The entire reference electrode is located in the middle area of ​​the upper surface of the core, and the reference electrode is located on both sides of the center line M perpendicular to the winding direction of the core, symmetrically relative to the center line M. Then, place an insulator between the core and the reference electrode, and use tape to seal the top and bottom of the core to fix the core, insulator, and reference electrode together. The core with the reference electrode fixed is encapsulated with aluminum plastic film, and the electrolyte is injected to obtain an encapsulated cell. The encapsulated cell is welded to the battery protection board to obtain a single cell.

[0132] The battery preparation method provided in the embodiments of the present application has a simple process and is highly compatible with the commercial production process and production equipment of existing batteries. There is no need to change the existing core preparation process, nor is there any need to add complex operating procedures and production equipment, which facilitates large-scale production based on existing production lines.

[0133] The embodiment of the present application also provides an electric device, which includes an electric module and the battery described in the embodiment of the present application, and the battery is used to power the electric module. The electric device can be various electronic devices, vehicles, energy storage devices, etc. Among them, the electronic device can be, for example, various consumer electronic products, including but not limited to mobile phones, tablet computers, laptops, wearable devices (such as glasses, bracelets, watches, etc.), and vehicle-mounted devices.

[0134] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

[0135] It should be understood that the first, second and various numerical numbers involved in this document are only distinguished for the convenience of description and are not intended to limit the scope of this application.

[0136] In this application, "and / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the related objects are in an "or" relationship.

[0137] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0138] In this application, “-” represents a range value, including the endpoint values ​​at both ends. For example, the value of a can be 0.5-15, which means that the value of a can be between 0.5 and 15, and includes the endpoint values ​​0.5 and 15.

[0139] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A battery, characterized in that: include: A battery cell, the battery cell being a wound core, comprising a positive electrode sheet, a negative electrode sheet, and a separator stacked and wound, the separator being disposed between the positive electrode sheet and the negative electrode sheet; the battery cell having a first surface and a second surface facing each other along its thickness direction; A reference electrode, comprising a third current collector and an electrode material layer disposed on one side of the third current collector; the reference electrode is disposed on the first surface or the second surface of the battery cell; the reference electrode is used to form a test circuit with the positive electrode sheet and / or the negative electrode sheet to test the electrical parameters of the battery; A separator is provided between the battery cell and the reference electrode to isolate the battery cell from the reference electrode, wherein one side of the electrode material layer of the reference electrode is close to the separator.

2. The battery according to claim 1, characterized in that The electrode material layer includes a reference electrode active material, a conductive agent and a binder, and the reference electrode active material includes LiFePO4 and / or Li4Ti5O 12 .

3. The battery according to claim 2, characterized in that The LiFePO4 and Li4Ti5O 12 The D50 particle size is 1nm-100nm.

4. A battery, characterized in that: include: A battery cell, wherein the battery cell is a laminated battery cell, comprising a stacked positive electrode sheet, a negative electrode sheet, and a separator, wherein the separator is disposed between the positive electrode sheet and the negative electrode sheet; the battery cell has a first surface and a second surface opposite to each other along its thickness direction; A reference electrode, comprising a third current collector and an electrode material layer disposed on one side of the third current collector; the reference electrode is disposed on the first surface or the second surface of the battery cell; the reference electrode is used to form a test circuit with the positive electrode sheet and / or the negative electrode sheet to test the electrical parameters of the battery; a separator, disposed between the battery cell and the reference electrode to isolate the battery cell from the reference electrode, wherein the electrode material layer of the reference electrode is close to the separator; The electrode material layer includes a reference electrode active material, a conductive agent and a binder, and the reference electrode active material includes Li4Ti5O 12 .

5. The battery according to claim 4, characterized in that The Li4Ti5O 12 The D50 particle size is 1nm-100nm.

6. The battery according to any one of claims 1 to 5, characterized in that The thickness of the electrode material layer is 1 μm-5 μm.

7. The battery according to any one of claims 1 to 6, characterized in that: The third current collector includes any one of copper foil, carbon-coated copper foil, copper mesh, nickel mesh and carbon cloth.

8. The battery according to any one of claims 1 to 7, characterized in that: The material of the separator includes any one of a polyolefin separator, a polyolefin aluminum oxide composite separator, and a polymer-based solid electrolyte.

9. The battery according to any one of claims 1 to 8, characterized in that: The orthographic projection of the reference electrode in the thickness direction of the battery cell is located within the orthographic projection of the first surface or the second surface where the reference electrode is located in the thickness direction of the battery cell.

10. The battery according to claim 9, characterized in that When the battery capacity is 1000mAh, the area of the orthographic projection of the reference electrode in the thickness direction of the battery cell is greater than or equal to 30% of the area of the orthographic projection of the first surface or the second surface where the reference electrode is located in the thickness direction of the battery cell; when the battery capacity is (1000+C)mAh, the area of the orthographic projection of the reference electrode in the thickness direction of the battery cell is greater than or equal to X% of the area of the orthographic projection of the first surface or the second surface where the reference electrode is located in the thickness direction of the battery cell, where C is greater than 0, and X%=30%+(C / 1000)10%.

11. The battery according to any one of claims 1 to 10, characterized in that: The reference electrode at least partially covers a middle area of the first surface or the second surface where the reference electrode is located.

12. The battery according to any one of claims 1 to 11, characterized in that: The reference electrode at least partially covers the center line of the first surface or the second surface where the reference electrode is located, and the areas of the reference electrode located on both sides of the center line are symmetrical relative to the center line, and the center line is perpendicular to the bottom end surface or the top end surface of the battery cell.

13. The battery according to any one of claims 1 to 12, characterized in that: The reference electrode includes a first end and a second end opposite to each other in a direction perpendicular to the bottom seal surface or the top seal surface of the battery cell, and at least one of the first end and the second end extends to a position close to the bottom seal surface or the top seal surface of the battery cell.

14. The battery according to any one of claims 1 to 13, characterized in that: The positive electrode sheet includes a positive electrode collector and a positive electrode active layer arranged on the surface of the positive electrode collector, and the negative electrode sheet includes a negative electrode collector and a negative electrode active layer arranged on the surface of the negative electrode collector; the positive electrode sheet also includes a positive electrode tab electrically connected to the positive electrode collector, the negative electrode sheet also includes a negative electrode tab electrically connected to the negative electrode collector, and the reference electrode also includes a reference electrode tab electrically connected to the third current collector.

15. The battery according to claim 14, characterized in that The positive electrode tab and the negative electrode tab are arranged at the ends of the battery cell, and the reference electrode tab is arranged at the end of the reference electrode.

16. The battery according to claim 14 or 15, characterized in that The battery also includes a battery protection plate, and the positive electrode tab, the negative electrode tab and the reference electrode tab are respectively welded to the battery protection plate, and the battery protection plate is connected to the positive electrode tab and the reference electrode tab to form the test circuit, and / or the battery protection plate is connected to the negative electrode tab and the reference electrode tab to form the test circuit to obtain the electrical parameters of the battery.

17. The battery according to claim 16, characterized in that The battery protection board is also used to adjust the charge and discharge state of the battery according to the electrical parameters of the battery.

18. The battery according to claim 16 or 17, characterized in that The battery protection board is provided with a positive electrode contact point, a negative electrode contact point and a reference electrode contact point, and the positive electrode tab, the negative electrode tab and the reference electrode tab are welded to the positive electrode contact point, the negative electrode contact point and the reference electrode contact point respectively.

19. The battery according to any one of claims 1 to 18, characterized in that The battery further includes a glue layer, which is used to fix the reference electrode, the separator and the battery core together.

20. The battery according to any one of claims 1 to 19, characterized in that The battery further includes a shell, in which the battery cell, the reference electrode, and the separator are housed.

21. The battery according to claim 20, characterized in that The battery further includes an electrolyte, which is contained in the housing.

22. A method for preparing a battery having a reference electrode, characterized in that: include: preparing an electrode active layer and a reference electrode tab on the third current collector to obtain a reference electrode; Arrange an isolator on one side surface of the battery cell in the thickness direction, and then place the reference electrode on the isolator; The battery cell, the separator, and the reference electrode are fixed together.

23. The preparation method according to claim 22, characterized in that Also includes: The battery core, the separator and the reference electrode fixed together are packaged with a shell material, and an electrolyte is injected to obtain a packaged battery core, and the packaged battery core is welded to a battery protection board to obtain the battery.

24. An electrical device, characterized in that: The power-consuming device includes a power-consuming module and a battery according to any one of claims 1 to 22, and the battery is used to supply power to the power-consuming module.

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