Battery device, charging control method thereof and electric equipment

Abstract

The invention discloses a battery device, a charging control method thereof and electric equipment. The battery device comprises a box body, a plurality of battery monomers and a sampling assembly, the plurality of single batteries are arranged in the box body, the plurality of single batteries are arranged in the box body in an array along a first direction and a second direction, and the first direction is perpendicular to the second direction; the battery monomer comprises a shell, an electrode assembly accommodated in the shell, and a positive terminal and a negative terminal which are arranged on the shell, the electrode assembly comprises a positive plate and a negative plate, the positive terminal is electrically connected to the positive plate, and the negative terminal is electrically connected to the negative plate; at least one battery monomer located on the outermost side in the first direction further comprises a first reference electrode, the first end of the first reference electrode is arranged between the positive plate and the negative plate, and the second end of the first reference electrode extends out of the shell. The sampling assembly is electrically connected to the negative terminal and the second end of the first reference electrode and used for collecting potential information of the negative terminal and the first reference electrode.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a battery device and its charging control method, and an electrical device. Background Technology

[0002] Rechargeable batteries are batteries that can be recharged after being discharged to reactivate the active materials and continue to be used. Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, and drones.

[0003] The development of battery technology must take into account multiple design factors, such as energy density, cycle life, assembly efficiency, and processing technology, as well as battery reliability. Summary of the Invention

[0004] This application provides a battery device and its charging control method, as well as an electrical device, which can improve the reliability of the battery device.

[0005] According to a first aspect of this application, a battery device is provided, comprising a housing, a plurality of battery cells, and a sampling component. The plurality of battery cells are disposed within the housing and arranged in an array within the housing along a first direction and a second direction, the first and second directions being perpendicular. Each battery cell includes a housing, an electrode assembly housed within the housing, and a positive terminal and a negative terminal disposed within the housing. The electrode assembly includes a positive electrode plate and a negative electrode plate, the positive terminal being electrically connected to the positive electrode plate, and the negative terminal being electrically connected to the negative electrode plate. At least one battery cell located on the outermost side along the first direction further includes a first reference electrode, a first end of which is disposed between the positive and negative electrode plates, and a second end of which extends out of the housing. The sampling component is electrically connected to the negative terminal and the second end of the first reference electrode for collecting potential information from the negative terminal and the first reference electrode. Since lithium ion deposition requires certain potential conditions, namely, the negative electrode potential must be lower than the lithium ion electrode potential, the potential difference between the first reference electrode and the negative electrode can be used to determine whether lithium deposition occurs in the outermost battery cell. This is helpful in predicting and evaluating whether the entire battery device is operating normally, reducing the risk of abnormal operation and performance degradation of the battery device, and improving the reliability of the battery device.

[0006] In some embodiments, at least one battery cell located on the outermost side along both the first and second directions is provided with a first reference electrode. This allows for more accurate prediction of whether other battery cells will undergo lithium plating; that is, if a battery cell does not exhibit lithium plating, the likelihood of lithium plating in other battery cells is lower. This helps reduce the risk of abnormal operation and performance degradation of individual battery cells, further improving the reliability of the battery device.

[0007] In some embodiments, the battery device includes a battery management system electrically connected to the sampling component. The battery management system is used to calculate a first potential difference between a first reference electrode and a negative terminal, and adjust the charging rate of the battery device according to the first potential difference, so that the battery cells of the battery device always operate under good conditions, which is beneficial to improving the cycle life and capacity retention of the battery device.

[0008] In some embodiments, the electrode assembly includes a separator disposed between the positive electrode and the negative electrode, and a first end of the first reference electrode is disposed between the separator and the negative electrode. This facilitates more timely detection of lithium plating in individual battery cells, allows for timely adjustment of the battery device's charging rate, and reduces the probability of performance degradation in individual battery cells.

[0009] In some embodiments, the positive and negative electrode sheets are wound together; the first end of the first reference electrode is located between the innermost ring of the positive electrode sheet and the innermost ring of the negative electrode sheet; and / or, the first end of the first reference electrode is located between the outermost ring of the negative electrode sheet near the outer casing and the outermost ring of the positive electrode sheet near the outer casing. The first end of the first reference electrode is located at a position where lithium ions are more easily accumulated in the battery cell, which facilitates more timely detection of lithium plating in the battery cell, thereby allowing for timely adjustment of the charging rate of the battery device and reducing the probability of battery cell performance degradation.

[0010] In some embodiments, there are multiple positive and negative electrode sheets, which are alternately stacked. The first end of the first reference electrode is located between the outermost negative electrode sheet and the adjacent outermost positive electrode sheet. The first end of the first reference electrode is located at a position where lithium ions are more likely to accumulate in the battery cell, which is beneficial for timely detection of lithium plating in the battery cell, thereby adjusting the charging rate of the battery device in a timely manner and reducing the probability of battery cell performance degradation.

[0011] In some embodiments, the first end of the first reference electrode extends to the middle of the positive or negative electrode along the third direction Z, with the first direction, the second direction, and the third direction being perpendicular to each other. The lithium-ion distribution at the middle of the positive or negative electrode along the third direction Z can roughly characterize the average lithium-ion content between the positive and negative electrodes. Extending the first end of the first reference electrode to the middle of the positive or negative electrode along the third direction Z helps to improve the accuracy of lithium plating detection.

[0012] In some embodiments, the first reference electrode includes a main body and an insulating part. The insulating part surrounds and is fixed to the main body. The main body is electrically connected to the sampling assembly. The end of the main body located between the positive and negative electrode plates extends out of the insulating part. In the lithium-ion migration path, the insulating part occupies less space and has a smaller obstructive effect on lithium-ions, thus reducing the impact of the first reference electrode's placement on the lithium-ion migration rate. This is beneficial for further reducing the risk of lithium plating and improving the reliability of the battery cell.

[0013] In some embodiments, the material of the main body includes lithium titanate. Lithium titanate is a stable compound that is not easily affected by the positive electrode, negative electrode, and electrolyte. Furthermore, lithium titanate has a high intrinsic potential and is not easily oxidized or reduced by other substances during electrochemical reactions, making it relatively stable and beneficial for extending its service life.

[0014] In some embodiments, the housing includes a shell and an end cap. The shell has an opening, and the end cap closes to the opening. Both the positive and negative terminals are located on the end cap, and the second end of the first reference electrode extends out of the end cap and is positioned between the positive and negative terminals. This facilitates shortening the connection lines between the first reference electrode, the positive and negative terminals, and the sampling assembly, simplifying the structure. Furthermore, the space between the positive and negative terminals can be fully utilized to bring out the first reference electrode, which helps improve the rationality of the structural layout and reduces the risk of interference or mutual influence between the first reference electrode and the positive and negative terminals.

[0015] In some embodiments, at least one battery cell located in the middle along a first direction and / or a second direction has a second reference electrode. The second reference electrode has opposing third and fourth ends. The third end is disposed between the positive and negative electrode plates, and the fourth end extends out of the housing and is electrically connected to a sampling assembly. The sampling assembly is used to collect the potential information of the second reference electrode. Based on the potential difference between the second reference electrode and the negative electrode plate, it can be determined whether the middle battery cell has experienced structural collapse, thereby predicting whether other battery cells will experience structural collapse. That is, if the middle battery cell does not experience structural collapse, the probability of other battery cells experiencing structural collapse is relatively small. This is beneficial for predicting and evaluating the structural stability of the entire battery device, further improving the reliability of the battery device.

[0016] In some embodiments, the battery device includes a heat exchange plate and a battery management system; the heat exchange plate is disposed between multiple battery cells and a housing, and a heat exchange channel is provided in the heat exchange plate for circulating a heat exchange medium; the battery management system is electrically connected to the sampling component, and the battery management system is used to calculate a second potential difference between a second reference electrode and a negative terminal, and adjust the flow rate of the heat exchange medium in the heat exchange channel according to the second potential difference, which is beneficial to improving the structural stability of the battery cells and the reliability of the battery device.

[0017] In some embodiments, the electrode assembly includes a separator disposed between the positive and negative electrode plates, and a third end of the second reference electrode is disposed between the separator and the negative electrode plate. The third end of the second reference electrode is located at the position where lithium ions are most likely to accumulate, which facilitates more timely detection of lithium plating caused by structural collapse of the battery cell.

[0018] In some embodiments, the positive and negative electrode sheets are wound together; the battery cell with a second reference electrode includes an electrode assembly, and the third end of the second reference electrode is located between the innermost ring of the positive electrode sheet and the innermost ring of the negative electrode sheet; or, the battery cell with a second reference electrode includes two electrode units stacked together, each electrode unit including at least one electrode assembly, and the third end of the second reference electrode is located between the negative electrode sheet and the positive electrode sheet of one electrode unit closest to the outermost ring of the other electrode unit. The third end of the second reference electrode is located at a position where the battery cell is more prone to structural collapse, which facilitates more timely detection of lithium plating caused by structural collapse, thereby allowing for timely adjustment of the flow rate of the heat exchange medium, further improving the structural stability of the battery cell and the reliability of the battery device.

[0019] According to a second aspect of this application, embodiments of this application provide a charging control method for a battery device according to any embodiment of the first aspect of this application, comprising: when the battery device is in a charging state, acquiring a first potential of the negative terminal of a battery cell having a first reference electrode and a second potential of the first reference electrode; calculating a first potential difference between the second potential and the first potential; and adjusting the charging rate of the battery device according to the first potential difference. This allows the battery cells of the battery device to always operate under good conditions, which is beneficial for improving the cycle life and capacity retention of the battery device.

[0020] In some embodiments, multiple battery cells are arranged in an array within a housing along a first direction and a second direction. At least one battery cell located in the middle along both the first and second directions has a second reference electrode. The second reference electrode has opposing third and fourth ends. The third end is disposed between a positive electrode and a negative electrode, and the fourth end extends out of the housing and is electrically connected to a sampling component. The battery device includes a heat exchange plate disposed between the multiple battery cells and the housing. A heat exchange channel is provided within the heat exchange plate for circulating a heat exchange medium. The charging control method further includes: when the battery device is in a charging state, acquiring the third potential of the negative terminal of the battery cell with the second reference electrode and the fourth potential of the second reference electrode; calculating the second potential difference between the fourth potential and the third potential; and adjusting the flow rate of the heat exchange medium in the heat exchange channel according to the second potential difference, which is beneficial to improving the structural stability of the battery cells and the reliability of the battery device.

[0021] According to a third aspect of this application, embodiments of this application also provide an electrical device, which includes a battery device provided in any embodiment of this application, the battery device being used to provide electrical energy. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0024] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0025] Figure 3 This is a partial structural schematic diagram of a battery device provided in some other embodiments of this application.

[0026] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0027] Figure 5 This is a cross-sectional structural schematic diagram of the electrode assembly of a battery device provided in some embodiments of this application.

[0028] Figure 6 This is a partial structural block diagram of a battery device provided in some embodiments of this application.

[0029] Figure 7 This is a schematic diagram of the winding of the electrode assembly of a battery device provided in some embodiments of this application.

[0030] Figure 8 This is a cross-sectional structural diagram of a battery cell of a battery device provided in some embodiments of this application.

[0031] Figure 9 for Figure 8 The diagram shows the winding structure of the electrode assembly of the battery cell.

[0032] Figure 10 This is a schematic diagram of the stacked structure of the electrode assembly of a battery device provided in some embodiments of this application.

[0033] Figure 11 This is a cross-sectional schematic diagram of some electrode components of the battery device provided in some embodiments of this application.

[0034] Figure 12 This is a cross-sectional view of the heat exchange plate of a battery device provided in some embodiments of this application.

[0035] Figure 13 This is a schematic diagram of the winding of the electrode assembly of a battery device provided in some other embodiments of this application.

[0036] Figure 14 This is a cross-sectional structural diagram of a battery cell of a battery device provided in some other embodiments of this application.

[0037] Figure 15 This is a schematic flowchart illustrating a charging control method for a battery device provided in some embodiments of this application.

[0038] Figure 16 A schematic flowchart illustrating a charging control method for a battery device provided in other embodiments of this application.

[0039] In the attached image:

[0040] Vehicle 1, battery unit 2, controller 3, motor 4, housing 5, battery cell 6, sampling assembly 7, battery management system 8, heat exchange plate 9;

[0041] Electrode assembly 10, electrode unit 10a, positive electrode 11, positive electrode body 111, positive electrode tab 112, negative electrode 12, negative electrode body 121, negative electrode tab 122, separator 13, outer shell 20, housing 21, opening 211, end cap 22, positive terminal 31, negative terminal 32, first reference electrode 40, first end 40a, second end 40b, body part 41, insulating part 42, second reference electrode 50, third end 50a, fourth end 50b, first housing part 5a, second housing part 5b, accommodating space 5c, heat exchange channel 91, steps S10, S20, S30, S40, S50, S60, first direction X, second direction Y, third direction Z. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0044] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0046] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0047] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0048] In this application, "multiple" means two or more (including two).

[0049] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0050] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0051] A battery cell typically includes a casing and an electrode assembly disposed within the casing. The electrode assembly includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. For example, the electrode assembly also includes a separator disposed between the positive and negative electrodes. The separator serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0052] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0053] As an example, the battery cell can be a prismatic battery cell or a battery cell of other shapes. Prismatic battery cells include square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0054] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0055] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0056] A battery device typically includes a housing for encapsulating one or more individual battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0057] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by fixing the battery module within the housing. As an example, the housing can include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, creating a closed space inside the housing to house the battery cell assembly.

[0058] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0059] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0060] Battery devices typically consist of multiple individual cells to meet the voltage requirements of electrical devices. Generally, within a certain temperature range, higher temperatures result in better charging capabilities and faster charging of individual cells. However, after prolonged use, the uniformity of individual cells deteriorates. Cells at the edges of the battery network have lower temperatures and poorer charging capabilities. If these cells are consistently charged at a uniform rate, exceeding their actual charging capacity, lithium ions cannot be deposited into the anode in time, accumulating on the anode surface and causing lithium plating, which affects the reliability of the battery device.

[0061] In view of this, this application provides a technical solution by setting a first reference electrode between the positive and negative electrodes of at least one outermost battery cell, and electrically connecting the first reference electrode and the negative terminal of the battery cell to a sampling component. The sampling component can collect the potential information of the first reference electrode and the negative terminal, thereby obtaining the potential difference between the first reference electrode and the negative electrode. Since lithium ion deposition requires certain potential conditions, namely, the negative electrode potential is lower than the lithium ion electrode potential, the potential difference between the first reference electrode and the negative electrode can be used to determine whether lithium deposition has occurred in the outermost battery cell. This is beneficial for predicting and evaluating whether the entire battery device is operating normally, reducing the risk of abnormal operation and performance degradation of the battery device, and improving the reliability of the battery device.

[0062] The technical solutions improved in the embodiments of this application can be used in battery devices and electrical equipment that uses battery devices as power sources or various energy storage systems that use battery devices as energy storage elements.

[0063] Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0064] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0065] Figure 1 This is a schematic diagram of the vehicle structure provided for some embodiments of this application. (Refer to...) Figure 1 The vehicle 1 includes a battery device 2, which may be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0066] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0067] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0068] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application. Figure 3 This is a partial structural schematic diagram of a battery device provided for other embodiments of this application. (Refer to...) Figure 2 and Figure 3 The battery device 2 includes a housing 5 and multiple battery cells 6, which are housed within the housing 5.

[0069] The housing 5 is used to house the battery cell 6, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the battery cell 6. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.

[0070] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0071] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0072] In the battery device 2, multiple battery cells 6 can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 6 is housed in the housing 5. Alternatively, multiple battery cells 6 can first be connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole assembly, which is then housed in the housing 5.

[0073] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. Figure 5 This is a cross-sectional structural schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application. (Refer to...) Figure 3 This application provides a battery cell 6, which includes a housing 20 and an electrode assembly 10, with the electrode assembly 10 housed within the housing 20.

[0074] There can be one electrode assembly 10 or multiple electrode assemblies.

[0075] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 6, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. Optionally, the electrode assembly 10 also includes a separator disposed between the positive and negative electrodes, which can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0076] The outer casing 20 is used to encapsulate the electrode assembly 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0077] In some embodiments, the positive electrode includes a positive electrode sheet. The positive electrode sheet may include a positive electrode current collector and a layer of positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0078] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0079] In some embodiments, the negative electrode includes a negative electrode sheet. The negative electrode sheet may include a negative electrode current collector and a layer of negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0080] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0081] In some embodiments, the electrode assembly 10 further includes a separator for separating the positive and negative electrode plates. The separator can reduce the risk of short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0082] In some embodiments, the separator includes a separator membrane. The separator membrane in this application can be any known porous structure separator membrane with good chemical and mechanical stability.

[0083] In some embodiments, the electrode assembly 10 is a wound structure. Exemplarily, both the positive and negative electrode sheets are strip structures, and the positive electrode sheet, the separator, and the negative electrode sheet are wound into a wound structure.

[0084] In some embodiments, the electrode assembly 10 has a stacked structure.

[0085] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0086] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0087] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0088] In some embodiments, the electrode assembly 10 may be cylindrical, flat, or polygonal, etc.

[0089] In some embodiments, refer to Figures 2 to 5 The battery device 2 includes a housing 5, multiple battery cells 6, and a sampling assembly 7. The multiple battery cells 6 are disposed within the housing 5 and arranged in an array along a first direction X and a second direction Y, with the first direction X and the second direction Y perpendicular to each other. Each battery cell 6 includes a housing 20, an electrode assembly 10 housed within the housing 20, and a positive terminal 31 and a negative terminal 32 disposed within the housing 20. The electrode assembly 10 includes a positive electrode plate 11 and a negative electrode plate 12, with the positive terminal 31 electrically connected to the positive electrode plate 11 and the negative terminal 32 electrically connected to the negative electrode plate 12. At least one battery cell 6 located on the outermost side along the first direction X also includes a first reference electrode 40. The first end 40a of the first reference electrode 40 is disposed between the positive electrode plate 11 and the negative electrode plate 12, and the second end 40b of the first reference electrode 40 extends out of the housing 20. The sampling component 7 is electrically connected to the second end 40b of the negative terminal 32 and the first reference electrode 40, and is used to collect the potential information of the negative terminal 32 and the first reference electrode 40.

[0090] Multiple battery cells 6 can be arranged in multiple rows along the first direction X and in at least one column along the second direction Y. Optionally, multiple battery cells 6 can be arranged along both the first direction X and the second direction Y.

[0091] In some examples, the first direction X can be the length direction of the box 5, and the second direction Y can be the width direction of the box 5. In other examples, the first direction X can also be the width direction of the box 5, and the second direction Y can be the length direction of the box 5.

[0092] There can be one or more battery cells 6 having the first reference electrode 40. When there are multiple battery cells 6 having the first reference electrode 40, all of the multiple battery cells 6 having the first reference electrode 40 are located on the outermost side along the first direction X.

[0093] In the battery cell 6, the first reference electrode 40 can be one or more.

[0094] The positive electrode 11 may include a positive electrode body 111 and a positive electrode tab 112 extending from the positive electrode body 111, with the positive terminal 31 electrically connected to the positive electrode tab 112.

[0095] The negative electrode 12 may include a negative electrode body 121 and a negative electrode tab 122 extending from the negative electrode body 121, with the negative terminal 32 electrically connected to the negative electrode tab 122.

[0096] The positive terminal 31 can be directly electrically connected to the positive electrode 11, or indirectly electrically connected to the positive electrode 11 through other structures (such as adapter pieces). The positive terminal 31 can also be electrically connected to the sampling component 7 so that the sampling component 7 can collect the potential of the positive terminal 31.

[0097] The negative terminal 32 can be directly electrically connected to the negative electrode 12, or it can be indirectly electrically connected to the negative electrode 12 through other structures (such as adapter pieces).

[0098] The positive terminal 31 and the negative terminal 32 can be located on the same side of the housing 20 or on different sides of the housing 20. Optionally, the positive terminal 31 and the negative terminal 32 can be located on the same housing wall of the housing 20 along the third direction Z, or the positive terminal 31 and the negative terminal 32 can be located on two opposite housing walls of the housing 20 along the third direction Z, with the first direction X, the second direction Y, and the third direction Z being perpendicular to each other.

[0099] The sampling component 7 may include a flexible circuit board, in which the sampling circuit is integrated. The flexible circuit board is small in size, easily deformable, and convenient to connect to the first reference electrode 40, the negative terminal 32, and the positive terminal 31.

[0100] A portion of the first reference electrode 40 may be disposed between the positive electrode 11 and the negative electrode 12, and be insulated from and isolated from the positive electrode 11 and the negative electrode 12. Along the arrangement direction of the positive electrode 11 and the negative electrode 12, the portion of the first reference electrode 40 located between the positive electrode 11 and the negative electrode 12 may be closer to the positive electrode 11 or closer to the negative electrode 12.

[0101] The first reference electrode 40 has a first end 40a and a second end 40b disposed opposite to each other. The first end 40a can be located at any position between the positive electrode 11 and the negative electrode 12, as long as it can contact the electrolyte. The second end 40b can pass through the housing 20 and extend out of the housing 20 for electrical connection with the sampling assembly 7. Exemplarily, the housing 20 may be provided with a through hole through which the second end 40b of the first reference electrode 40 can extend out of the housing 20.

[0102] The second end 40b of the first reference electrode 40 can extend out of the outer casing 20 through the shell wall where the negative terminal 32 is located, or it can extend out of the outer casing 20 through other shell walls of the outer casing 20.

[0103] The battery device 2 provided in this application embodiment provides a first reference electrode 40 disposed between the positive electrode 11 and the negative electrode 12 of at least one outermost battery cell 6. The first reference electrode 40 and the negative terminal 32 of the battery cell 6 are electrically connected to a sampling component 7. The sampling component 7 can collect the potential information of the first reference electrode 40 and the negative terminal 32, thereby obtaining the potential difference between the first reference electrode 40 and the negative electrode 12. Since the precipitation of lithium ions requires certain potential conditions, namely, the negative electrode potential is lower than the lithium ion electrode potential, the potential difference between the first reference electrode 40 and the negative electrode 12 can be used to determine whether lithium deposition occurs in the outermost battery cell 6. This is beneficial for predicting and evaluating whether the overall operating status of the battery device 2 is normal, reducing the risk of abnormal operation and performance degradation of the battery device 2, and improving the reliability of the battery device 2.

[0104] In some embodiments, at least one battery cell 6 located on the outermost side along both the first direction X and the second direction Y is provided with a first reference electrode 40.

[0105] The battery cell 6 located on the outermost side along both the first direction X and the second direction Y can be one, two, three, or four.

[0106] At least one battery cell 6, located on the outermost side along both the first direction X and the second direction Y, is situated at a corner of the array formed by multiple battery cells 6. The number of other battery cells 6 adjacent to this cell 6 is minimal, resulting in less heat accumulation and a relatively lower temperature, making it more susceptible to lithium plating degradation. In this embodiment, a first reference electrode 40 is provided in this battery cell 6, which can more accurately predict whether other battery cells 6 will plaque lithium. That is, if this battery cell 6 does not exhibit lithium plating, the likelihood of lithium plating in other battery cells 6 is lower, which helps reduce the risk of abnormal operation and performance degradation of individual battery cells 6, further improving the reliability of the battery device 2.

[0107] Figure 6 This is a partial structural block diagram of a battery device provided in some embodiments of this application. In some embodiments, reference is made to... Figure 6 The battery device 2 includes a battery management system 8, which is electrically connected to the sampling component 7. The battery management system 8 is used to calculate the first potential difference between the first reference electrode 40 and the negative terminal 32, and adjust the charging rate of the battery device 2 according to the first potential difference.

[0108] In a single battery cell 6, when there are multiple first reference electrodes 40, the first potential difference is the difference between the average potential of the multiple first reference electrodes 40 and the potential of the negative terminal 32.

[0109] The potential information of the first reference electrode 40 and the potential information of the negative terminal 32 collected by the sampling component 7 can be sent to the battery management system 8. The battery management system 8 calculates the first potential difference between the two based on the received potential information of the first reference electrode 40 and the potential information of the negative terminal 32.

[0110] If the first potential difference reaches the first preset potential difference (the first preset potential difference is greater than zero), it indicates that there are accumulated lithium ions between the positive electrode 11 and the negative electrode 12, and lithium plating occurs in the battery cell 6 with the first reference electrode 40 and the negative terminal 32. The battery management system 8 can automatically reduce the charging rate of the battery device 2 so that the charging rate of the battery device 2 matches the charging capacity of the battery cell 6, which helps to reduce the risk of lithium plating in the battery cell 6.

[0111] In this embodiment, the charging rate of the battery device 2 is intelligently adjusted based on the first potential difference between the first reference electrode 40 and the negative terminal 32 of the outermost battery cell 6, so that the battery cells 6 of the battery device 2 always operate under good conditions, which is beneficial to improving the cycle life and capacity retention of the battery device 2.

[0112] In some embodiments, the electrode assembly 10 includes an isolator 13 disposed between the positive electrode 11 and the negative electrode 12, and the first end 40a of the first reference electrode 40 is disposed between the isolator 13 and the negative electrode 12.

[0113] The separator 13 can separate the positive electrode 11 and the negative electrode 12 to reduce the risk of short circuit between the positive and negative electrodes. Optionally, the separator 13 may include a separator membrane.

[0114] When the battery device 2 is charging, if the temperature of the battery cell 6 is low, the lithium ions migrated from the positive electrode 11 cannot be inserted into the negative electrode 12 in time and tend to accumulate on the surface of the negative electrode 12. Therefore, the number of lithium ions on the surface of the negative electrode 12 is relatively large, and lithium plating is most likely to occur or is most obvious.

[0115] In this embodiment, the first end 40a of the first reference electrode 40 is located between the separator 13 and the negative electrode 12, which is the location where lithium ions are most likely to accumulate. This facilitates the timely detection of lithium plating in the battery cell 6, and makes it easier to adjust the charging rate of the battery device 2 in a timely manner, thereby reducing the probability of performance degradation of the battery cell 6.

[0116] Figure 7 This is a schematic diagram of the winding of an electrode assembly for a battery device provided in some embodiments of this application. In some embodiments, refer to... Figure 7 The positive electrode 11 and the negative electrode 12 are wound together. The first end 40a of the first reference electrode 40 is located between the innermost ring of the positive electrode 11 and the innermost ring of the negative electrode 12.

[0117] Optionally, the first end 40a of the first reference electrode 40 may be located between the innermost ring of the separator 13 and the innermost ring of the negative electrode 12. The innermost ring of the separator 13 is located between the innermost ring of the positive electrode 11 and the innermost ring of the negative electrode 12.

[0118] The positive electrode 11 and the negative electrode 12 are wound around the winding center, and a central hole is usually formed at the winding center. Therefore, the innermost ring of the positive electrode 11 and the innermost ring of the negative electrode 12 are relatively loose, and the migration distance of lithium ions is relatively longer, making lithium plating more likely to occur.

[0119] In this embodiment, the first end 40a of the first reference electrode 40 is located between the innermost ring of the positive electrode 11 and the innermost ring of the negative electrode 12. The first end 40a of the first reference electrode 40 is located in a position where lithium ions are more likely to accumulate in the battery cell 6, which is beneficial to detect the lithium plating phenomenon of the battery cell 6 more timely, thereby adjusting the charging rate of the battery device 2 in a timely manner and reducing the probability of performance degradation of the battery cell 6.

[0120] Figure 8 This is a cross-sectional structural diagram of a battery cell in a battery device provided in some embodiments of this application. Figure 9 for Figure 8 The diagram shows a schematic of the winding structure of the electrode assembly of a single battery cell. In some embodiments, the positive electrode 11 and the negative electrode 12 are wound together. The first end 40a of the first reference electrode 40 is located between the outermost ring of the negative electrode 12 near the outermost ring of the housing 20 and the outermost ring of the positive electrode 11 near the outermost ring of the housing 20.

[0121] Optionally, the first end 40a of the first reference electrode 40 is located between the outermost ring of the negative electrode 12 near the outermost ring of the housing 20 and the outermost ring of the separator 13 near the outermost ring of the housing 20.

[0122] In some examples, the electrode assembly 10 can be a single unit, with each segment of the outermost ring of the positive electrode 11 and the outermost ring of the negative electrode 12 close to the housing 20.

[0123] In another example, there may be multiple electrode assemblies 10, which are stacked together. The outermost ring of the positive electrode 11 and the outermost ring of the negative electrode 12 of each electrode assembly 10 are partially close to the housing 20, and the other part is close to the adjacent electrode assembly 10. The part close to the adjacent electrode assembly 10 is located in the middle of the entire battery cell 6 and has a relatively higher temperature.

[0124] The negative electrode 12 is located near the outermost edge of the outer casing 20, and the positive electrode 11 is located near the outermost edge of the outer casing 20, which is close to the edge of the entire battery cell 6. The temperature is relatively low, the migration speed of lithium ions is relatively low, and lithium plating is more likely to occur.

[0125] In this embodiment, the first end 40a of the first reference electrode 40 is located between the outermost ring of the negative electrode 12 near the outermost ring of the outer shell 20 and the outermost ring of the positive electrode 11 near the outermost ring of the outer shell 20. The first end 40a of the first reference electrode 40 is located in a position where lithium ions are more likely to accumulate in the battery cell 6, which is beneficial to detect the lithium plating phenomenon of the battery cell 6 more timely, thereby adjusting the charging rate of the battery device 2 in a timely manner and reducing the probability of performance degradation of the battery cell 6.

[0126] In some embodiments, the number of first reference electrodes 40 is at least two, wherein at least one first reference electrode 40 has a first end 40a disposed between the innermost ring of the positive electrode 11 and the innermost ring of the negative electrode 12, and the other at least one first reference electrode 40 has a first end 40a disposed between the outermost ring of the negative electrode 12 near the outermost ring of the outer casing 20 and the outermost ring of the positive electrode 11 near the outermost ring of the outer casing 20.

[0127] The first ends 40a of at least two first reference electrodes 40 are located at different positions where lithium ions are more likely to accumulate in the battery cell 6. This facilitates the timely and comprehensive detection of lithium plating in the battery cell 6, thereby allowing for timely adjustment of the charging rate of the battery device 2 and reducing the probability of performance degradation in the battery cell 6.

[0128] Figure 10 This is a schematic diagram of the stacked structure of the electrode assembly of a battery device provided in some embodiments of this application. In some embodiments, refer to... Figure 10 There are multiple positive electrode plates 11 and multiple negative electrode plates 12, which are stacked alternately. The first end 40a of the first reference electrode 40 is located between the outermost negative electrode plate 12 and the adjacent outermost positive electrode plate 11.

[0129] Optionally, an isolation member 13 is provided between the positive electrode 11 and the negative electrode 12, and the first end 40a of the first reference electrode 40 is located between the outermost negative electrode 12 and the adjacent isolation member 13.

[0130] The outermost positive electrode 11 and the adjacent outermost negative electrode 12 are close to the edge of the entire battery cell 6, where the temperature is relatively low, the migration rate of lithium ions is relatively low, and lithium plating is more likely to occur.

[0131] In this embodiment, the first end 40a of the first reference electrode 40 is located between the outermost positive electrode 11 and the adjacent outermost negative electrode 12. The first end 40a of the first reference electrode 40 is located in a position where lithium ions are more likely to accumulate in the battery cell 6, which is beneficial to detect the lithium plating phenomenon of the battery cell 6 more timely, thereby adjusting the charging rate of the battery device 2 in a timely manner and reducing the probability of performance degradation of the battery cell 6.

[0132] In some embodiments, refer to Figure 5The first end 40a of the first reference electrode 40 extends to the middle of the positive electrode 11 or the negative electrode 12 along the third direction Z, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0133] The middle part of the positive electrode 11 along the third direction Z is the middle position of the positive electrode 11 along the third direction Z, and the middle part of the negative electrode 12 along the third direction Z is the middle position of the negative electrode 12 along the third direction Z.

[0134] Along the third direction Z, the lithium-ion distribution between the positive electrode 11 and the negative electrode 12 is not uniform. The lithium-ion distribution in the middle of the positive electrode 11 or the negative electrode 12 along the third direction Z can roughly characterize the average lithium-ion content between the positive electrode 11 and the negative electrode 12. Extending the first end 40a of the first reference electrode 40 to the middle of the positive electrode 11 or the negative electrode 12 along the third direction Z is beneficial to improving the accuracy of lithium plating detection.

[0135] In some embodiments, refer to Figure 5 The first reference electrode 40 includes a main body 41 and an insulating part 42. The insulating part 42 surrounds the main body 41 and is fixed to the main body 41. The main body 41 is electrically connected to the sampling assembly 7. The end of the main body 41 located between the positive electrode 11 and the negative electrode 12 extends out of the insulating part 42.

[0136] The insulating part 42 can cover a portion of the main body 41, which can insulate the main body 41 from the positive electrode 11, the negative electrode 12 and other components, reducing the risk of the first reference electrode 40 directly contacting the positive electrode 11, the negative electrode 12 or other components.

[0137] The end of the main body 41 located between the positive electrode 11 and the negative electrode 12 extends out of the insulating part 42 to contact the electrolyte, thereby detecting lithium ions. The other end of the main body 41 can extend out of the housing 20 and be electrically connected to the sampling assembly 7.

[0138] In this embodiment, the insulation between the first reference electrode 40 and the positive electrode 11 and the negative electrode 12 is achieved by enclosing an insulating portion 42 outside the main body 41. In the migration path of lithium ions, the insulating portion 42 occupies less space and has a smaller obstruction effect on lithium ions. This can reduce the impact of the setting of the first reference electrode 40 on the lithium ion migration rate, which is beneficial to further reduce the risk of lithium plating and improve the reliability of the battery cell 6.

[0139] In some embodiments, the material of the main body 41 includes lithium titanate.

[0140] Lithium titanate is a stable compound that is not easily affected by the positive electrode 11, the negative electrode 12, and the electrolyte. In addition, lithium titanate has a high potential and is not easily oxidized or reduced by other substances during the electrochemical reaction. Its stable properties are beneficial to improving its service life.

[0141] In some embodiments, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening 211, and the end cap 22 closing the opening 211. Both the positive terminal 31 and the negative terminal 32 are disposed on the end cap 22, and the second end 40b of the first reference electrode 40 extends out of the end cap 22 and is located between the positive terminal 31 and the negative terminal 32.

[0142] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0143] The housing 21 and the end cap 22 can be separate components. For example, an opening 211 can be provided on the housing 21, and the end cap 22 can be used to close the opening 211 to form an internal cavity for the battery cell 6.

[0144] The housing 21 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 10. The housing 21 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, aluminum-plastic film, steel-plastic film, etc.

[0145] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 22 is not easily deformed when subjected to compression and impact, so that the battery cell 6 can have higher structural strength and improve reliability.

[0146] The end cap 22 is connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0147] The housing 21 may be open at one end or open at both ends. In some examples, the housing 21 may be a structure with an opening on one side, and one end cap 22 is provided to cover the housing 21. In other examples, the housing 21 may also be a structure with openings on both sides, and two end caps 22 are provided, with the two end caps 22 respectively covering the two openings of the housing 21.

[0148] The positive terminal 31 and the negative terminal 32 can be located on the same end cap 22. The second end 40b of the first reference electrode 40 extends out of the end cap 22 where the positive terminal 31 and the negative terminal 32 are located, and is located between the positive terminal 31 and the negative terminal 32.

[0149] The second end 40b of the first reference electrode 40 extends out of the end cap 22 and is located between the positive terminal 31 and the negative terminal 32. This facilitates shortening the connection lines between the first reference electrode 40, the positive terminal 31, the negative terminal 32, and the sampling assembly 7, simplifying the structure. Furthermore, the space between the positive terminal 31 and the negative terminal 32 can be fully utilized to bring out the first reference electrode 40, which helps improve the rationality of the structural layout and reduces the risk of interference or mutual influence between the first reference electrode 40 and the positive and negative terminals 31 and 32.

[0150] Figure 11 This is a cross-sectional schematic diagram of some electrode components of a battery device provided in some embodiments of this application. In some embodiments, at least one battery cell 6 located in the middle along a first direction X and / or a second direction Y has a second reference electrode 50. The second reference electrode 50 has opposing third ends 50a and fourth ends 50b. The third end 50a is disposed between the positive electrode 11 and the negative electrode 12, and the fourth end 50b extends out of the housing 20 and is electrically connected to the sampling component 7. The sampling component 7 is used to collect potential information of the second reference electrode 50.

[0151] In some examples, the number of battery cells 6 arranged along the first direction X is greater than the number of battery cells 6 arranged along the second direction Y, and the battery cell 6 having the second reference electrode 50 is located approximately in the middle along the first direction X.

[0152] In other examples, the number of battery cells 6 arranged along the first direction X is less than the number of battery cells 6 arranged along the second direction Y, and the battery cell 6 having the second reference electrode 50 is located approximately in the middle along the second direction Y.

[0153] In some other examples, the number of battery cells 6 arranged along the first direction X is the same as the number of battery cells 6 arranged along the second direction Y, and the battery cell 6 having the second reference electrode 50 is located approximately in the middle along the second direction Y.

[0154] The battery cell 6 having the second reference electrode 50 can be one or more.

[0155] In the battery cell 6, there may be one or more second reference electrodes 50.

[0156] A portion of the second reference electrode 50 may be disposed between the positive electrode 11 and the negative electrode 12, and shall be insulated from and isolated from the positive electrode 11 and the negative electrode 12. Along the arrangement direction of the positive electrode 11 and the negative electrode 12, the portion of the second reference electrode 50 located between the positive electrode 11 and the negative electrode 12 may be closer to the positive electrode 11 or closer to the negative electrode 12.

[0157] The third end 50a can be located at any position between the positive electrode 11 and the negative electrode 12, as long as it can contact the electrolyte. The fourth end 50b can pass through the housing 20 and extend out of the housing 20 for electrical connection with the sampling assembly 7. For example, the housing 20 can be provided with a through hole through which the fourth end 50b can extend out of the housing 20.

[0158] The fourth end 50b of the second reference electrode 50 can extend out of the outer casing 20 through the shell wall where the negative terminal 32 is located, or it can extend out of the outer casing 20 through other shell walls of the outer casing 20.

[0159] The battery cell 6 that is in the middle along both the first direction X and the second direction Y refers to the battery cell 6 that is not on the outermost side along both the first direction X and the second direction Y.

[0160] Optionally, the battery cell 6 having the second reference electrode 50 may be located at or near the center of an array formed by multiple battery cells 6.

[0161] When the temperature of battery cell 6 exceeds a certain range, the chemical bonds of the positive electrode material are prone to endothermic breakage and the formation of new chemical bonds, leading to the destruction and collapse of the original structure, which in turn results in lithium plating. Battery cell 6, located in the middle along both the first direction X and the second direction Y, is surrounded by numerous other battery cells 6, making heat dissipation difficult and resulting in a relatively high temperature. This makes it more susceptible to structural collapse, exacerbating lithium plating.

[0162] In this embodiment, a second reference electrode 50 is provided in the battery cell 6 located in the middle along both the first direction X and the second direction Y. The sampling component 7 can collect the potential information of the second reference electrode 50 and the negative terminal 32, thereby obtaining the potential difference between the second reference electrode 50 and the negative electrode 12. Based on the potential difference between the second reference electrode 50 and the negative electrode 12, it can be determined whether the battery cell 6 located in the middle has experienced structural collapse, thereby predicting whether other battery cells 6 will experience structural collapse. That is, if the battery cell 6 located in the middle has not experienced structural collapse, the possibility of other battery cells 6 experiencing structural collapse is relatively small. This is beneficial for predicting and evaluating the structural stability of the entire battery device 2, further improving the reliability of the battery device 2.

[0163] In some embodiments, the battery device 2 includes a heat exchange plate 9 and a battery management system 8. Figure 12 This is a cross-sectional structural schematic diagram of the heat exchange plate of a battery device provided in some embodiments of this application. (Refer to...) Figure 2 , Figure 6 and Figure 12A heat exchange plate 9 is disposed between multiple battery cells 6 and the housing 5. The heat exchange plate 9 has a heat exchange channel 91 for circulating the heat exchange medium. The battery management system 8 is electrically connected to the sampling component 7. The battery management system 8 is used to calculate the second potential difference between the second reference electrode 50 and the negative terminal 32, and adjust the flow rate of the heat exchange medium in the heat exchange channel 91 according to the second potential difference.

[0164] In a single battery cell 6, when there are multiple second reference electrodes 50, the second potential difference is the difference between the average potential of the multiple second reference electrodes 50 and the potential of the negative terminal 32.

[0165] The potential information of the second reference electrode 50 and the potential information of the negative terminal 32 collected by the sampling component 7 can be sent to the battery management system 8. The battery management system 8 calculates the second potential difference between the two based on the received potential information of the second reference electrode 50 and the potential information of the negative terminal 32.

[0166] If the second potential difference reaches the second preset potential difference (the first preset potential difference is greater than zero), it indicates that there are accumulated lithium ions between the positive electrode 11 and the negative electrode 12, and the battery cell 6 with the second reference electrode 50 and the negative terminal 32 exhibits lithium plating due to structural collapse. The battery management system 8 can automatically increase the flow rate of the heat exchange medium to accelerate the heat dissipation efficiency of the battery cell 6, which helps to reduce the temperature of the battery cell 6 and decreases the possibility of further structural damage or collapse of the battery cell 6.

[0167] The embodiments of this application intelligently adjust the flow rate of the heat exchange medium based on the second potential difference between the second reference electrode 50 and the negative terminal 32 of the intermediate battery cell 6, which is beneficial to improving the structural stability of the battery cell 6 and the reliability of the battery device 2.

[0168] In some embodiments, the electrode assembly 10 includes an isolator 13 disposed between the positive electrode 11 and the negative electrode 12, and the third end 50a of the second reference electrode 50 is disposed between the isolator 13 and the negative electrode 12.

[0169] When the battery device 2 is charging, if the temperature of the battery cell 6 is too high, the structure of the positive electrode 11 will collapse, and lithium ions will not be able to completely return to the positive electrode 11. Excess lithium ions tend to accumulate on the negative electrode 12. Because the potential of the positive electrode 11 is relatively high, lithium ions cannot be reduced and can only be deposited on the surface of the negative electrode 12. Therefore, when the temperature of the battery cell 6 is too high, lithium deposition is most likely to occur or is most pronounced on the surface of the negative electrode 12.

[0170] In this embodiment, the third end 50a of the second reference electrode 50 is located between the separator 13 and the negative electrode 12, which is the location where lithium ions are most likely to accumulate. This facilitates the timely detection of lithium plating caused by structural collapse in the battery cell 6.

[0171] Figure 13 A schematic diagram of the winding of an electrode assembly of a battery device provided for other embodiments of this application. In some embodiments, refer to... Figure 13 The positive electrode 11 and the negative electrode 12 are wound together. The battery cell 6 having a second reference electrode 50 includes an electrode assembly 10, and the third end 50a of the second reference electrode 50 is located between the innermost ring of the positive electrode 11 and the innermost ring of the negative electrode 12.

[0172] The innermost rings of the positive electrode 11 and the negative electrode 12 are close to the center of the electrode assembly 10, where the temperature is relatively high. In this embodiment, the third end 50a of the second reference electrode 50 is located between the innermost rings of the positive electrode 11 and the negative electrode 12. The third end 50a of the second reference electrode 50 is located at a position where the battery cell 6 is more prone to structural collapse. This facilitates the timely detection of lithium plating caused by structural collapse in the battery cell 6, thereby allowing for timely adjustment of the flow rate of the heat exchange medium and further improving the structural stability of the battery cell 6 and the reliability of the battery device 2.

[0173] Figure 14 A cross-sectional structural schematic diagram of a battery cell for a battery device provided in other embodiments of this application. In some embodiments, refer to Figure 14 The positive electrode 11 and the negative electrode 12 are wound together. The battery cell 6 having the second reference electrode 50 includes two electrode units 10a stacked together. Each electrode unit 10a includes at least one electrode assembly 10. The third end 50a of the second reference electrode 50 is located between the negative electrode 12 and the positive electrode 11 of one electrode unit 10a, which are closest to the outermost ring of the other electrode unit 10a.

[0174] Each electrode unit 10a may include one electrode assembly 10 or more electrode assemblies 10.

[0175] Optionally, the two electrode units 10a may have the same number of electrode assemblies 10. The battery cell 6 includes an even number of electrode assemblies 10.

[0176] The inventors recognized that lithium plating in the middle battery cell 6 occurs due to the collapse of the electrode structure caused by high temperature, making the area with the highest temperature in battery cell 6 most prone to lithium plating. Since the overall temperature of the middle battery cell 6 is higher than that of the edge battery cells 6, it is unnecessary to detect the lowest temperature of the middle battery cell 6. That is, for the middle battery cell 6, detecting the potential of the second reference electrode 50 is to determine whether structural collapse has occurred in the battery cell 6; the second reference electrode 50 can be located at the position with the highest temperature in battery cell 6.

[0177] In the battery cell 6, the two adjacent electrode units 10a are located approximately at the center of the battery cell 6, where the temperature is relatively high. In this embodiment, the third end 50a of the second reference electrode 50 is located between the negative electrode 12 and the positive electrode 11 of one electrode unit 10a, which is closest to the outermost ring of the other electrode unit 10a. The third end 50a of the second reference electrode 50 is located approximately at a high temperature in the battery cell 6, which facilitates more timely detection of lithium plating caused by structural collapse in the battery cell 6. This allows for timely adjustment of the flow rate of the heat exchange medium, further improving the structural stability of the battery cell 6 and the reliability of the battery device 2.

[0178] In some embodiments, the structure of the second reference electrode 50 may be the same as that of the first reference electrode 40, which will not be described in detail here.

[0179] This application also provides a charging control method for a battery device 2 according to any embodiment of this application. Figure 15 A schematic flowchart illustrating the charging control method of a battery device provided in some embodiments of this application, with reference to... Figure 15 The charging control method provided in this application includes:

[0180] Step S10: While the battery device 2 is in a charging state, obtain the first potential of the negative terminal 32 of the battery cell 6 having the first reference electrode 40 and the second potential of the first reference electrode 40.

[0181] Step S20: Calculate the first potential difference between the second potential and the first potential; and

[0182] Step S30: Adjust the charging rate of battery device 2 according to the first potential difference.

[0183] In this embodiment, the charging rate of the battery device 2 is intelligently adjusted based on the first potential difference between the first reference electrode 40 and the negative terminal 32 of the outermost battery cell 6, so that the battery cells 6 of the battery device 2 always operate under good conditions, which is beneficial to improving the cycle life and capacity retention of the battery device 2.

[0184] In some embodiments, a plurality of battery cells 6 are arranged in an array within a housing 5 along a first direction X and a second direction Y. At least one battery cell 6 located in the middle along both the first direction X and the second direction Y has a second reference electrode 50. The second reference electrode 50 has a third end 50a and a fourth end 50b, which are located between the positive electrode 11 and the negative electrode 12. The fourth end 50b extends out of the housing 20 and is electrically connected to the sampling assembly 7. The battery device 2 includes a heat exchange plate 9, which is located between the plurality of battery cells 6 and the housing 5. The heat exchange plate 9 has a heat exchange channel 91 for circulating a heat exchange medium.

[0185] In these embodiments, reference is made to Figure 16 The charging control method in this application embodiment further includes:

[0186] Step S40: While the battery device 2 is in a charging state, obtain the third potential of the negative terminal 32 of the battery cell 6 having the second reference electrode 50 and the fourth potential of the second reference electrode 50.

[0187] Step S50: Calculate the second potential difference between the fourth and third potentials; and

[0188] Step S60: Adjust the flow rate of the heat exchange medium in the heat exchange channel 91 according to the second potential difference.

[0189] In some embodiments, steps S40, S50 and S60 may be performed before or after step S10.

[0190] The embodiments of this application intelligently adjust the flow rate of the heat exchange medium based on the second potential difference between the second reference electrode 50 and the negative terminal 32 of the intermediate battery cell 6, which is beneficial to improving the structural stability of the battery cell 6 and the reliability of the battery device 2.

[0191] This application also provides an electrical device, which includes a battery device 2 provided in any embodiment of this application. The battery device 2 is used to provide electrical energy.

[0192] This application provides a battery device 2, which includes a housing 5, multiple battery cells 6, and a sampling assembly 7. The multiple battery cells 6 are disposed within the housing 5 and arranged in an array along a first direction X and a second direction Y, with the first direction X and the second direction Y being perpendicular. Each battery cell 6 includes a housing 20, an electrode assembly 10 housed within the housing 20, and a positive terminal 31 and a negative terminal 32 disposed within the housing 20. The electrode assembly 10 includes a positive electrode plate 11 and a negative electrode plate 12, with the positive terminal 31 electrically connected to the positive electrode plate 11 and the negative terminal 32 electrically connected to the negative electrode plate 12. At least one battery cell 6 located on the outermost side along the first direction X further includes a first reference electrode 40, with a first end 40a disposed between the positive electrode plate 11 and the negative electrode plate 12, and a second end 40b extending out of the housing 20. At least one battery cell 6, located in the middle along both the first direction X and the second direction Y, has a second reference electrode 50. The second reference electrode 50 has a third end 50a and a fourth end 50b, with the third end 50a disposed between the positive electrode 11 and the negative electrode 12, and the fourth end 50b extending out of the housing 20. A sampling component 7 is electrically connected to the negative terminal 32, the second end 40b of the first reference electrode 40, and the third end 50a of the second reference electrode 50, for collecting potential information from the negative terminal 32, the first reference electrode 40, and the second reference electrode 50.

[0193] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery device, characterized in that, include: Box; Multiple battery cells are disposed within the housing, and the multiple battery cells are arranged in an array within the housing along a first direction and a second direction, the first direction and the second direction being perpendicular; each battery cell includes a housing, an electrode assembly housed within the housing, and a positive terminal and a negative terminal disposed within the housing, the electrode assembly including a positive electrode plate and a negative electrode plate, the positive terminal being electrically connected to the positive electrode plate, and the negative terminal being electrically connected to the negative electrode plate; at least one battery cell located on the outermost side along the first direction further includes a first reference electrode, the first end of the first reference electrode being disposed between the positive electrode plate and the negative electrode plate, and the second end of the first reference electrode extending out of the housing; as well as The sampling component is electrically connected to the second end of the negative terminal and the first reference electrode, and is used to collect the potential information of the negative terminal and the first reference electrode.

2. The battery device according to claim 1, characterized in that, At least one of the battery cells located on the outermost side along both the first and second directions is provided with the first reference electrode.

3. The battery device according to claim 1 or 2, characterized in that, The battery device includes a battery management system electrically connected to the sampling component. The battery management system is used to calculate a first potential difference between the first reference electrode and the negative terminal, and to adjust the charging rate of the battery device according to the first potential difference.

4. The battery device according to any one of claims 1 to 3, characterized in that, The electrode assembly includes an isolator disposed between the positive electrode and the negative electrode, and the first end of the first reference electrode is disposed between the isolator and the negative electrode.

5. The battery device according to any one of claims 1-4, characterized in that, The positive electrode and the negative electrode are wound together. The first end of the first reference electrode is located between the innermost ring of the positive electrode and the innermost ring of the negative electrode; and / or, the first end of the first reference electrode is located between the outermost ring of the negative electrode near the outer shell and the outermost ring of the positive electrode near the outer shell.

6. The battery device according to any one of claims 1-4, characterized in that, There are multiple positive electrode plates and multiple negative electrode plates, which are alternately stacked. The first end of the first reference electrode is located between the outermost negative electrode and the adjacent outermost positive electrode.

7. The battery device according to any one of claims 1-6, characterized in that, The first end of the first reference electrode extends to the middle of the positive electrode or the negative electrode along a third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

8. The battery device according to any one of claims 1-7, characterized in that, The first reference electrode includes a main body and an insulating part. The insulating part surrounds and is fixed to the main body. The main body is electrically connected to the sampling assembly. The end of the main body located between the positive electrode and the negative electrode extends out of the insulating part.

9. The battery device according to claim 8, characterized in that, The material of the main body includes lithium titanate.

10. The battery device according to any one of claims 1-9, characterized in that, The housing includes a shell and an end cap. The shell has an opening, and the end cap closes to the opening. The positive terminal and the negative terminal are both disposed on the end cap. The second end of the first reference electrode extends out of the end cap and is located between the positive terminal and the negative terminal.

11. The battery device according to any one of claims 1-10, characterized in that, At least one of the battery cells located in the middle along the first direction and / or the second direction has a second reference electrode. The second reference electrode has a third end and a fourth end opposite to each other. The third end is disposed between the positive electrode and the negative electrode. The fourth end extends out of the housing and is electrically connected to the sampling component. The sampling component is used to collect the potential information of the second reference electrode.

12. The battery device according to claim 11, characterized in that, The battery device includes a heat exchange plate and a battery management system; The heat exchange plate is disposed between the plurality of battery cells and the housing, and the heat exchange plate is provided with heat exchange channels for circulating heat exchange medium. The battery management system is electrically connected to the sampling component. The battery management system is used to calculate the second potential difference between the second reference electrode and the negative terminal, and adjust the flow rate of the heat exchange medium in the heat exchange channel according to the second potential difference.

13. The battery device according to claim 11 or 12, characterized in that, The electrode assembly includes an isolator disposed between the positive electrode and the negative electrode, and the third end of the second reference electrode is disposed between the isolator and the negative electrode.

14. The battery device according to any one of claims 11-13, characterized in that, The positive electrode and the negative electrode are wound together. The battery cell having the second reference electrode includes one electrode assembly, with the third end of the second reference electrode disposed between the innermost ring of the positive electrode and the innermost ring of the negative electrode; or, the battery cell having the second reference electrode includes two electrode units stacked together, each electrode unit including at least one electrode assembly, with the third end of the second reference electrode disposed between the negative electrode and the positive electrode of one electrode unit closest to the outermost ring of the other electrode unit.

15. A charging control method for a battery device according to any one of claims 1-14, characterized in that, include: When the battery device is in a charging state, the first potential of the negative terminal of the battery cell having the first reference electrode and the second potential of the first reference electrode are obtained; Calculate the first potential difference between the second potential and the first potential; as well as The charging rate of the battery device is adjusted according to the first potential difference.

16. The charging control method according to claim 15, characterized in that, The plurality of battery cells are arranged in an array within the housing along a first direction and a second direction. At least one of the battery cells located in the middle along both the first and second directions has a second reference electrode. The second reference electrode has a third end and a fourth end opposite to each other. The third end is located between the positive electrode and the negative electrode, and the fourth end extends out of the housing and is electrically connected to the sampling component. The battery device includes a heat exchange plate disposed between the plurality of battery cells and the housing. The heat exchange plate has a heat exchange channel for circulating a heat exchange medium. The charging control method further includes: When the battery device is in a charging state, the third potential of the negative terminal of the battery cell having the second reference electrode and the fourth potential of the second reference electrode are obtained; Calculate the second potential difference between the fourth potential and the third potential; as well as The flow rate of the heat exchange medium in the heat exchange channel is adjusted according to the second potential difference.

17. An electrical appliance, characterized in that, Includes a battery device according to any one of claims 1-14, the battery device being used to provide electrical energy.

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