Multi-cell battery charging circuit, multi-cell battery and electronic device

Abstract

The present invention provides a charging method for a multi-cell battery, a charging circuit for the multi-cell battery, a multi-cell battery, a terminal device, and an electronic device, which relate to the field of battery technology. The charging method for the multi-cell battery includes: acquiring a negative electrode potential of each cell in the multi-cell battery; comparing the negative electrode potentials of each cell to determine a minimum negative electrode potential; and controlling the multi-cell battery to charge in a first mode if the minimum negative electrode potential is equal to or greater than a safe potential; and controlling the multi-cell battery to operate in a second mode if the minimum negative electrode potential is less than the safe potential. This method ensures a high charging rate while suppressing the occurrence of lithium precipitation.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from application number 202110834181.8, filed on July 20, 2021, and a Chinese patent application entitled "Battery Charging Method and Circuit, Multi-Cell Battery, Terminal Device and Electronic Device," the entire contents of which are incorporated herein by reference.

[0002] This application relates to the field of charging technology, Nima Multi-cell battery charging circuit, multi-cell battery Ikeo and electronic devices. [Background technology]

[0003] As the functionality of mobile devices continues to improve, the demand for battery capacity also increases. The use of multi-cell batteries has become one of the main methods to improve the overall capacity of conventional batteries and increase their flight time.

[0004] In the process of fast charging a conventional multi-cell battery, charging is generally performed at a fixed charging rate, and as long as the charging environment meets the fast charging conditions, fast charging will be performed at the fastest possible rate.

[0005] However, charging a multi-cell battery at the fastest possible rate over its entire life cycle can cause lithium deposition, accelerating battery degradation. Summary of the Invention

[0006] No. of this application 1In one aspect, a charging circuit for a multi-cell battery is provided. The charging circuit for the multi-cell battery includes a detection circuit and a control circuit. The detection circuit is configured to obtain a negative electrode potential of each cell in the multi-cell battery. The control circuit is configured to compare the negative electrode potentials of each cell to determine a minimum negative electrode potential, and control the multi-cell battery to charge in a first mode if the minimum negative electrode potential is equal to or greater than a safe potential, and control the multi-cell battery to operate in a second mode if the minimum negative electrode potential is less than the safe potential.

[0007] No. of this application 2 In an aspect, a multi-cell battery is provided. A charging circuit for a multi-cell battery, the charging circuit including at least one insulation measurement structure and a control circuit, the multi-cell battery including a plurality of cells, each insulation measurement structure being disposed between two adjacent cells and used to isolate the two adjacent cells, and used to measure negative electrode potentials of the cells of the multi-cell battery, the control circuit being connected to the at least one insulation measurement structure and used to obtain the negative electrode potentials from the at least one insulation measurement structure; determining a minimum negative electrode potential from the negative electrode potentials of the cells; controlling the multi-cell battery to charge in a first mode if the minimum negative electrode potential is equal to or greater than a safe potential; and controlling the multi-cell battery to operate in a second mode if the minimum negative electrode potential is less than the safe potential. .

[0008] No. of this application 3 In an aspect, an electronic device is provided. 1. An electronic device including a multi-cell battery, a processor, and a memory, the memory being adapted to store executable instructions for the processor, wherein execution of the executable instructions causes the processor to: obtain a negative electrode potential from at least one insulation measurement structure of the multi-cell battery; determine a minimum negative electrode potential from the negative electrode potentials of the cells; control the multi-cell battery to charge in a first mode if the minimum negative electrode potential is equal to or greater than a safe potential; and control the multi-cell battery to operate in a second mode if the minimum negative electrode potential is less than the safe potential. . [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a structural schematic diagram of a multi-cell battery according to an embodiment of the present invention; [Figure 2] 3 is a flowchart of a method for charging a multi-cell battery according to the present embodiment. [Figure 3] FIG. 2 is a diagram showing the relationship between the negative electrode potential and time during the charge / discharge process of the multi-cell battery according to the present embodiment. [Figure 4] 1 is a schematic diagram of a charging circuit for a multi-cell battery according to an embodiment of the present invention. [Figure 5] FIG. 10 is a front view of another multi-cell battery according to the present embodiment. [Figure 6] FIG. 6 is a cross-sectional schematic view of the multi-cell battery shown in FIG. 5. [Figure 7] FIG. 6 is a schematic vertical cross-sectional view of the multi-cell battery shown in FIG. 5. [Figure 8] 1 is a structural schematic diagram of an insulation measurement structure according to an embodiment of the present invention; [Figure 9] 1 is a structural schematic diagram of an electronic device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0010] Exemplary embodiments will now be described in detail with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in various forms and should not be construed as being limited to the examples set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to fully understand the embodiments of the present application. However, those skilled in the art will understand that the technical solutions of the present application can be implemented without one or more of the specific details, or by employing other methods, components, devices, steps, etc. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring aspects of the present application.

[0011] Furthermore, the drawings are merely schematic diagrams of the present application and are not necessarily drawn to scale. In the drawings, the same reference numerals indicate the same or corresponding parts, and redundant explanations are omitted. Some of the block diagrams shown in the drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor and / or microcontroller devices.

[0012] The flowcharts shown in the drawings are merely illustrative and do not necessarily include all steps. For example, some steps may be separated, merged, or partially combined, so that the order of actual execution may vary depending on actual circumstances. Furthermore, the terms "first" and "second" below are for distinction purposes only and should not be used to limit the present application.

[0013] During the charging process of a lithium-ion battery, lithium ions (Li+) are released from the positive electrode and embedded in the negative electrode. However, under some abnormal circumstances, such as insufficient space for Li+ to be embedded in the negative electrode, too much resistance to Li+ embedding in the negative electrode, or Li+ being released from the positive electrode too quickly and not being embedded in the same amount in the negative electrode, the Li+ that is not embedded in the negative electrode will deposit only on the surface of the negative electrode, forming silvery-white lithium ions, which is called lithium deposition.

[0014] Lithium deposition is a detrimental condition in lithium-ion batteries. It not only degrades battery performance and significantly shortens cycle life, but also limits the battery's fast charging capacity and can lead to catastrophic consequences such as combustion and explosion. If lithium deposition on the negative electrode can be controlled, battery degradation during charging can be minimized.

[0015] During research, the applicant has found that slight lithium deposition generally has a reversible process, that is, newly generated lithium metal element can be reconverted to Li+ and embedded in the negative electrode, which not only suppresses lithium deposition in the negative electrode but also ensures a high charging rate and improves charging efficiency.

[0016] Based on this, exemplary embodiments of the present application provide a method for charging a multi-cell battery. The method for charging a multi-cell battery can be applied to lithium batteries. Lithium batteries include lithium ion batteries and lithium metal batteries, and exemplary embodiments of the present application are not particularly limited thereto.

[0017] Before describing the multi-cell battery charging method, it is necessary to briefly explain the multi-cell battery to which the charging method is applied.

[0018] In an exemplary embodiment of the present application, referring to Figure 1, a multi-cell battery is provided. The multi-cell battery includes a plurality of cells 110 and an insulation measurement structure 120.

[0019] The plurality of cells 110 may be connected in parallel or in series. In the embodiment of the present application, the plurality may be two. or Two or more cells 110 may be connected in parallel or in series. When there are more than two cells 110, a mixed connection may be realized. That is, the embodiment of the present application does not particularly limit the connection method of the cells 110 in the multi-cell battery.

[0020] The cell 110 further includes a positive electrode tab and a negative electrode tab 111. The positive and negative electrodes of the cell 110 are made of compounds that reversibly release and embed lithium ions. The positive electrode is typically made of a transition metal oxide, such as LiCoO2, LiNiO2, LiMn2O4, or LiFePO4, which has a potential greater than 3 V relative to lithium and in which lithium can be stably embedded in air. The negative electrode is typically made of a compound that has a potential as close as possible to the lithium potential and can embed lithium, such as various carbon materials or metal oxides. Carbon materials include natural graphite, synthetic graphite, carbon fiber, and mesophase carbon. Metal oxides include SnO, SnO2, and tin composite oxides.

[0021] The insulation measurement structure is placed between two adjacent cells 110 . In one example, one insulation measurement structure is placed between every two adjacent cells 110 .The insulation measuring structure 120 is used to isolate adjacent cells 110 and measure the negative electrode potential of the cells 110. That is, the insulation measuring structure 120 not only measures the negative electrode potential of the cells 110 but also provides isolation between the cells 110, thereby preventing short circuits caused by electrical contact between the cells 110. The specific structure of the insulation measuring structure 120 will be described in detail in a later embodiment.

[0022] The insulating measurement structure 120 includes an insulating layer 121 and a measurement layer. The insulating layer 121 is disposed between two adjacent cells 110 in the multi-cell battery, and the measurement layer is disposed on the side of the insulating layer 121 that is closer to the cells 110. A reference tab 122 is further disposed on the measurement layer, and the negative electrode potential of the cell 110 can be obtained by measuring the potential difference between the reference tab 122 and the negative electrode tab 111.

[0023] In the exemplary embodiment of the present application, it is necessary to dispose an isolation layer between the measurement layer and the cell to avoid electrical conduction due to contact between the measurement layer and the cell, which may affect the accuracy of the measured negative electrode potential. The isolation layer can be used to insulate the measurement layer from the cell.

[0024] In practical applications, the multi-cell battery can be used in electrical devices, such as mobile phones, computers, drones, automobiles, etc., and the embodiments of the present application are not limited thereto.

[0025] The charging method for a multi-cell battery according to an exemplary embodiment of the present application will be specifically described below with reference to Fig. 2. As shown in Fig. 2, the charging method for a multi-cell battery can include:

[0026] Step S210: Obtain the negative electrode potential of each cell in the multi-cell battery.

[0027] In exemplary embodiments of the present application, a multi-cell battery is a battery that includes a plurality of cells, where plurality is 2 or more. In a multi-cell battery, the plurality of cells may be connected in parallel, in series, or in a mixed connection.

[0028] The negative electrode potential is an important indicator of lithium deposition on the negative electrode. When the negative electrode potential is less than 0 V, lithium deposition on the negative electrode occurs. In practical applications, there are various methods for obtaining the negative electrode potential. In the embodiment of the present application, the negative electrode potential can be obtained using the insulating measurement structure described above.

[0029] After obtaining the insulation measurement structure for measuring the negative electrode potential using the above method, the insulation measurement structure can be installed in a multi-cell battery and used to directly obtain the negative electrode potential of each cell, improving the convenience and accuracy of obtaining the negative electrode potential.

[0030] In an exemplary embodiment of the present application, in order to timely grasp the lithium ion accumulation status in the negative electrode, a method of acquiring the negative electrode potential of each cell in real time can be adopted, thereby realizing the lithium ion accumulation status in the negative electrode of each cell through the negative electrode potential in real time, and effectively managing the subsequent charging process. At the start of charging, the negative electrode potential is not yet low. This allows the multi-cell battery to be in the first preset state. Taden After being charged for a predetermined time based on the current, the negative electrode potential can be obtained based on a predetermined cycle. The specific predetermined time and the predetermined cycle can be determined based on the actual situation, as long as the desired negative electrode potential can be obtained in a timely manner, and the exemplary embodiments of the present application are not limited thereto.

[0031] Step S220: Compare the negative electrode potentials of the cells to determine the minimum negative electrode potential.

[0032] In an exemplary embodiment of the present application, after obtaining the negative electrode potential of each cell in a multi-cell battery, the negative electrode potential of each cell needs to be compared, thereby determining the minimum negative electrode potential among the plurality of negative electrode potentials.

[0033] In practical applications, there are several methods for comparing the negative electrode potentials of the cells to determine the minimum negative electrode potential. For example, the negative electrode potentials of two cells can be compared to determine the minimum negative electrode potential in stages. The exemplary embodiments of the present application are not limited to the method for determining the minimum negative electrode potential.

[0034] Step S230: if the minimum negative electrode potential is equal to or greater than the safe potential, control the multi-cell battery to be charged in the first mode.

[0035] In an exemplary embodiment of the present application, the safe potential is the critical potential at which the cells of the multi-cell battery can be charged according to the first mode. The minimum negative electrode potential is If the negative electrode potential is lower than the safe potential, irreversible lithium deposition may occur in the cell. If the minimum negative electrode potential among the negative electrode potentials of the multiple electrodes is equal to or higher than the safe potential, all cells can be charged in the first mode, and lithium deposition will not occur. Even if lithium deposition does occur, the lithium deposition process is reversible.

[0036] To ensure that the occurrence of lithium deposition is within a reversible range while reducing the charge rate, i.e., the current used for charging, as much as possible, in an exemplary embodiment of the present invention, the safe potential may be any value or range between −100 mV and −0.05 V. For example, if the safe potential is −10 mV, the multi-cell battery can be controlled to be charged in a first mode, e.g., a fast charge mode, as long as the minimum negative electrode potential of each cell of the multi-cell battery is −10 mV or higher.

[0037] In one embodiment of the present application, the first mode of charging may be a fast charge mode, in which the multi-cell battery is charged at a first preset current. The first preset current may use a current greater than the cells can tolerate for faster charging. At this current, the cells do not undergo side reactions, and the fast charge is maximized without adversely affecting the cell's lifespan or performance.

[0038] In practical applications, the magnitude of the first preset current can be determined according to actual conditions. For example, the first preset current may range from 2C to 10C, where C is the total capacity of the cells. Assuming that the total capacity of the cells is 1000mAh, the first preset current may range from 2000mA to 10A.

[0039] In the fast charge mode, lithium deposition occurs on the negative electrode within the cell, so the exemplary embodiment of the present application provides a safe potential so that a multi-cell battery can be charged using the fast charge mode only when the minimum negative electrode potential is equal to or greater than the safe potential, thereby ensuring reversible lithium deposition while using the maximum possible fast charge current. By suppressing lithium deposition, the probability of a slowdown in the charge rate is reduced, improving the user experience.

[0040] An exemplary embodiment of the present application obtains the minimum negative electrode potential of a cell, and controls a multi-cell battery to charge in a first mode if the minimum negative electrode potential is equal to or greater than the safe potential. This ensures that all battery cells operate within a safe potential range during fast charging. When the battery cell corresponding to the minimum negative electrode potential can be fast charged, lithium deposition in other cells is naturally eliminated, and even if it does occur, it is within a reversible range. This prevents irreversible lithium deposition in all cells, ensuring a high charge rate while reducing the degradation rate of the multi-cell battery.

[0041] Step S240: If the minimum negative electrode potential is less than the safe potential, control the multi-cell battery to operate in the second mode.

[0042] In an exemplary embodiment of the present application, if the minimum negative electrode potential is lower than the safe potential, continuing to charge in the first mode, for example, when charging using a fast charging method, may cause irreversible lithium deposition in the cell, thereby accelerating battery degradation and affecting the overall battery life. Therefore, if the minimum negative electrode potential is lower than the safe potential, the occurrence of irreversible lithium deposition can be avoided by controlling the multi-cell battery to operate in another mode, i.e., the second mode, so that the lithium metal element generated during reversible lithium deposition during charging in the first mode can be converted to Li+ and embedded in the negative electrode, thereby avoiding the generation of inactive lithium metal element.

[0043] In an exemplary embodiment of the present application, there are multiple implementations for controlling a multi-cell battery to operate in the second mode.

[0044] In the first method, the multi-cell battery can be controlled to remain in a discharged state until the minimum negative electrode potential is equal to or greater than a safe potential.

[0045] Charging at a large current can cause elemental lithium metal to deposit on the surface of the negative electrode, lowering the negative electrode potential and further causing lithium deposition problems. Therefore, in an exemplary embodiment of the present application, when the minimum negative electrode potential is lower than the safe potential, a discharge, i.e., reverse charge process can be used to return at least a portion of the deposited elemental lithium metal to the positive electrode, thereby reversing lithium deposition and increasing the negative electrode potential, and when the negative electrode potential is higher than the potential for lithium deposition, the lithium deposition phenomenon can be avoided.

[0046] In an exemplary embodiment of the present application, after the multi-cell battery has been in a discharge state for a certain period of time, if the minimum negative electrode potential of the cells is equal to or greater than the safe potential, the discharge can be stopped and the battery can be further charged in the first mode, and the above process can be repeated until the battery is fully charged.

[0047] It should be noted that while the negative electrode potential of a certain cell is determined to be the minimum negative electrode potential during charging, the minimum negative electrode potential after discharge is not necessarily the negative electrode potential of the cell, i.e., the minimum negative electrode potential needs to be updated in real time and is not necessarily the negative electrode potential of a specific cell.

[0048] 3, which shows the relationship between the negative electrode potential and time during the charge and discharge process of a multi-cell battery according to an exemplary embodiment of the present application, first charges the multi-cell battery with a large first preset current. As the charging process progresses, the negative electrode potential decreases. When the negative electrode potential decreases to a safe potential, i.e., at time T1, the multi-cell battery is discharged with a small current (e.g., 0.01 C to 1 C). As the discharging process progresses, the negative electrode potential increases until the minimum negative electrode potential reaches time T2. The battery can then be charged with the first preset current, and the above process is repeated until the multi-cell battery is fully charged.

[0049] An exemplary embodiment of the present application provides a first mode and a second mode, in which a multi-cell battery is charged using a large first preset current, and when the minimum negative electrode potential is lower than the safe potential, the multi-cell battery is controlled to be discharged to increase the negative electrode potential, and after the minimum negative electrode potential is higher than the safe potential, the multi-cell battery is charged again, thereby realizing a charge-discharge cycle process that can achieve maximum rapid charging while ensuring reversible lithium deposition.

[0050] In an exemplary embodiment of the present application, determining whether the multi-cell battery is fully charged may include: obtaining a voltage between the positive and negative terminals of the multi-cell battery, and determining whether the multi-cell battery is fully charged based on the voltage between the positive and negative terminals of the multi-cell battery; when the voltage between the positive and negative terminals reaches a full voltage set for the multi-cell battery, it indicates that the multi-cell battery is fully charged; and stopping charging of the multi-cell battery when the multi-cell battery is fully charged.

[0051] In the second type method, the multi-cell battery can be controlled to remain in a stationary state until the minimum negative electrode potential reaches or exceeds the safe potential.

[0052] Compared to the first method, the second method switches the discharge state to a static state, without charging or discharging, and waits for lithium ions to fully enter the negative electrode, returning at least a portion of the lithium metal deposited by the static process to the positive electrode, thereby achieving the goal of reversible lithium deposition. Fast charging continues at the first preset current until it is detected that the minimum negative electrode potential is greater than the safe potential, and the above process is repeated until the multi-cell battery is fully charged.

[0053] Unlike the Type 1 method, the time it takes for the minimum negative electrode potential to rise above the safe voltage from point T1 to point T2 in the static state is longer, which increases the overall charging time, but it ensures that the fastest possible charging is achieved while making lithium deposition reversible.

[0054] In a third mode, the multi-cell battery can be controlled to be charged with a second preset current, and the second preset current is smaller than the first preset current.

[0055] In an exemplary embodiment of the present application, when fast charging is performed according to a first preset current so that the minimum negative electrode potential is lower than the safe potential, slow charging can be performed using a smaller second preset current, which does not cause lithium deposition during the slow charging process and provides enough time for lithium ions to enter the negative electrode of the multi-cell battery, ensuring that the lithium metal elements deposited during fast charging return to the positive electrode and achieving the purpose of reversible lithium deposition.Fast charging is continued at the first preset current until it is detected that the minimum negative electrode potential is higher than the safe potential, and the above process is repeated until the multi-cell battery is fully charged.

[0056] Compared with the first and second types of methods, this method requires the safe potential to be set higher, for example, to any value between −10 mV and 0.05 V. This is to prevent the negative electrode potential from becoming difficult to increase when charging with the second preset current.

[0057] The charging method for a multi-cell battery provided by the exemplary embodiments of the present application controls the charging process of the multi-cell battery based on the minimum negative electrode potential of each cell, thereby achieving fast charging and avoiding the occurrence of lithium deposition, thereby ensuring the safety of the multi-cell battery and improving the charging efficiency.

[0058] Based on the above multi-cell battery charging method, an exemplary embodiment of the present application further provides a multi-cell battery charging circuit. Figure 4 is a schematic diagram of the multi-cell battery charging circuit of the exemplary embodiment of the present application. As shown in Figure 4, the multi-cell charging circuit 300 includes a detection circuit and a control circuit 310.

[0059] Here, the detection circuit can be used to obtain the negative electrode potential of each cell in the multi-cell battery 400.

[0060] To facilitate the detection circuit to acquire the negative electrode potential of each cell of the multi-cell battery, in an exemplary embodiment of the present application, the detection circuit may include an insulation measurement structure 410 and a plurality of connecting wires 420. Here, the insulation measurement structure 410 may be installed between two adjacent cells of the multi-cell battery 400. Among the plurality of connecting wires 420, one end of each connecting wire 420 is electrically connected to one of the positive electrode tab, the negative electrode tab, or the reference tab of the insulation measurement structure 410 of the cell, and the other end of the connecting wire 420 is electrically connected to the control circuit 310. The negative electrode potential of the cell can be obtained by collecting the potential difference between the negative electrode tab and the reference tab.

[0061] In an exemplary embodiment of the present application, the insulation measurement structure 410 can include an insulation layer, a measurement layer, and an isolation layer, where the insulation layer is placed between two adjacent cells of a multi-cell battery. A measurement layer may be arranged on at least one side of the insulating layer close to the cell. Each measuring layer corresponds to one cell and is used to measure the negative electrode potential of the cell. A separating layer is disposed between the measuring layer and the cell and is used to insulate the measuring layer from the cell. The specific arrangement of the measuring layer will be described in detail in the subsequent embodiment of a multi-cell battery, and will not be described here.

[0062] Specifically, in the detection process, the detection circuit is used to obtain the negative electrode potential of each cell in real time, or the multi-cell battery is first preset Taden The detection circuit is used to obtain the negative electrode potential based on a preset period after charging for a preset time based on the current. The detection frequency and detection start time of the detection circuit can be set according to actual needs, and detailed description thereof will be omitted here.

[0063] In an exemplary embodiment of the present application, a communication connection may be formed between the detection circuit and the control circuit 310, and the detection circuit may transmit the detected negative electrode potential of each cell to the control circuit 310. The communication connection between the detection circuit and the control circuit 310 may be a wired connection or a wireless connection, and the embodiment of the present application is not limited thereto.

[0064] After receiving the negative electrode potential of each cell detected by the detection circuit, the control circuit 310 is used to compare the negative electrode potential of each cell and determine the minimum negative electrode potential; if the minimum negative electrode potential is equal to or greater than the safe potential, control the multi-cell battery to charge in the first mode; if the minimum negative electrode potential is less than the safe potential, control the multi-cell battery to operate in the second mode.

[0065] In one implementation of the exemplary embodiment of the present application, the control circuit 310 is used to control the multi-cell battery to charge at a first preset current when the minimum negative electrode potential is equal to or greater than the safety potential.

[0066] In one implementation of the exemplary embodiment of the present application, the control circuit 310 is used to control the multi-cell battery to charge at a second preset current when the minimum negative electrode potential is lower than the safe potential, and the second preset current is lower than the first preset current.

[0067] In one implementation of the exemplary embodiment of the present application, when the minimum negative electrode potential is lower than the safe potential, the control circuit 310 is used to control the multi-cell battery to remain in a rest state until the minimum negative electrode potential is equal to or higher than the safe potential.

[0068] In one implementation of the exemplary embodiment of the present application, when the minimum negative electrode potential is less than the safe potential, the control circuit 310 is used to control the multi-cell battery to stay in the discharge state until the minimum negative electrode potential is equal to or greater than the safe potential.

[0069] In one implementation mode of the exemplary embodiment of the present application, the control circuit 310 is further used for obtaining a voltage between the positive terminal and the negative terminal of the multi-cell battery, and determining whether the multi-cell battery is fully charged according to the voltage between the positive terminal and the negative terminal of the multi-cell battery; and stopping charging of the multi-cell battery when the multi-cell battery is fully charged.

[0070] Although the various steps of the methods in this application are described in a particular order in the figures, this does not require or imply that the steps must be performed in that particular order, or that all steps shown must be performed to achieve a desirable result. Additionally or alternatively, some steps can be omitted, multiple steps can be combined and performed in a single step, and / or a single step can be divided into multiple steps, etc.

[0071] The present application describes a charging method and a charging circuit for a multi-cell battery, which includes a plurality of cells, an insulation measurement structure, and a housing.

[0072] The plurality of cells is connected in parallel or in series. In the embodiment of the present application, the plurality is two. or The term "multi-cell battery" refers to two or more cells. Two of the multiple cells may be connected in parallel or in series. When there are more than two cells, a mixed connection can be realized. That is, the exemplary embodiments of the present application are not particularly limited to the connection method of the cells in the multi-cell battery.

[0073] An insulation measuring structure is installed between two adjacent cells, and is used to isolate the adjacent cells and measure the negative electrode potential of the cells. That is, the insulation measuring structure not only measures the negative electrode potential of the cells, but also isolates the cells, preventing short circuits due to electrical contact between the cells.

[0074] A housing is used to encase the plurality of cells and insulating measurement structures, thereby forming an integral battery structure.

[0075] The above multi-cell battery will be described below by taking a battery including three cells as an example.

[0076] 5 to 7, the multi-cell battery 400 includes a first cell 401, a second cell 402, and a third cell 403. Here, the first cell 401, the second cell 402, and the third cell 403 each include a positive electrode tab 404 and a negative electrode tab 405, and the positive electrode tab 404 and the negative electrode tab 405 each penetrate a housing 406 and are exposed to the outside. The first cell 401 and the second cell 402 may be connected in series or in parallel, and the second cell 402 and the third cell 403 may be connected in series or in parallel, and this is not a limitation.

[0077] In an exemplary embodiment of the present application, an insulation measurement structure 410 is installed between the first cell 401 and the second cell 402, and an insulation measurement structure 410 is also installed between the second cell 402 and the third cell 403. Referring to Figure 8, a structural schematic diagram of the insulation measurement structure is shown. The insulation measurement structure 410 includes an insulating layer 411, a measurement layer 412, and an isolation layer 413.

[0078] The insulating layer 411 is installed between two adjacent cells in a multi-cell battery, i.e., in this embodiment, the insulating layer 411 is installed between the first cell 401 and the second cell 402, or between the second cell 402 and the third cell 403.

[0079] A measurement layer 412 is disposed on at least one side of the insulating layer 411 close to the cell. Each measurement layer 412 corresponds to one cell, and is used to measure the negative electrode potential of the cell. In a battery including only two cells, there is only one insulation measurement structure 410, with the measurement layer 412 on both sides of the insulating layer 411. However, when there are more than two cells, for example, three cells as shown in FIG. 7 , two insulation measurement structures 410 are required, with the measurement layer 412 on both sides of the insulating layer 411 of one of the insulation measurement structures 410, and the measurement layer 412 may be on only one side of the insulating layer 411 of the other insulation measurement structure 410. This ensures that each cell corresponds to one measurement layer 412, and that the measurement layer 412 can detect the negative electrode potential of the cell. Here, the measurement layer 412 may be at least one of lithium metal and lithium titanate, and is mainly used to provide a reference voltage and corresponds to a ground connection for the cell. Furthermore, the thickness of the measurement layer 412 may be any value between 1 μm and 100 μm, and specifically can be determined based on the actual conditions of the cell.

[0080] That is, to avoid the number of measurement layers 412 being greater than the number of cells, A measurement layer 412 may be disposed on at least one side of the insulating layer 411 close to the cell., and one measuring layer 412 corresponds to one cell. By providing one measuring layer 412 for one cell, the negative electrode potential of each cell 412 in a multi-cell battery can be measured, providing technical support for charging control of the multi-cell battery.

[0081] The isolation layer 413 is disposed between the measuring layer 412 and the cell, and serves to insulate the measuring layer 412 from the cell, thereby preventing electrical connection between the measuring layer 412 and the cell from affecting the measurement results. Here, the isolation layer 412 may be a thin isolation film as long as it can achieve isolation.

[0082] Unlike the isolation layer 413, the insulating layer 411 not only serves to isolate the measuring layer 412 but also to support the measuring layer 412. In practical applications, the insulating layer 411 may be a composite material layer that is resistant to electrolyte corrosion and non-conductive. For example, the insulating layer 411 may be a composite material layer made of at least one of polypropylene, polyethylene, polyimide film, polyamide film, polyethylene terephthalate, spandex, or aramid film. The thickness of the insulating layer 411 may be any value between 0.1 and 1000 μm, and the specific thickness of the insulating layer 411 can be determined according to the actual conditions of the cell.

[0083] In the exemplary embodiment of the present application, to facilitate measurement of the negative electrode potential, a reference tab 414 needs to be disposed on the measurement layer 412, and the negative electrode potential is measured by measuring the potential difference between the negative electrode tab 405 and the reference tab 414. Here, the material of the reference tab 414 and the material of the negative electrode tab 405 may be the same, and may be, for example, at least one of aluminum, copper, nickel, cobalt, tungsten, tin, lead, iron, silver, gold, platinum, or an alloy thereof. The embodiment of the present application is not particularly limited thereto.

[0084] In an embodiment of the present application, FIG. 5As shown in Figure 1, the reference tab 414 and the negative tab 405 can be located on the same side of the multi-cell battery 400 to facilitate hardwired measurement of the negative electrode potential.

[0085] In the exemplary embodiment of the present application, the insulating layer 411 may be configured to have different dimensions for different connection methods between cells. Specifically, when two adjacent cells are connected in parallel, the surface area of ​​the insulating layer 411 on the side closest to the cells is 1 / 2 times the surface area of ​​the side of the cells. Surface area of can be matched with

[0086] However, when two adjacent cells are connected in series, Fig. 6 As shown in Fig. 1, the lateral area of ​​the insulating layer 411 is larger than that of the cell, and the insulating layer 411 and the housing 406 are packaged to form a space for accommodating a plurality of single cells, which is used to accommodate one single cell, thereby achieving the purpose of completely isolating each cell and preventing electrical conduction between the cells.

[0087] In practical installation, the insulating layer 411 and the housing 406 can be packaged by a heat sealing process. The insulating layer 411 and the housing 406 need to be sealed at all peripheries.

[0088] In the exemplary embodiment of the present application, there is no particular limitation on the size of the measurement layer 412. The lateral area of ​​the measurement layer 412 can be set to be the same as the lateral area of ​​the core, or can be smaller than the lateral area of ​​the cell, and can be determined according to actual circumstances, and the exemplary embodiment of the present application is not limited thereto.

[0089] Furthermore, the lateral area of ​​the isolation layer 413 must be the same as the lateral area of ​​the measurement layer 412 in order to insulate the measurement layer 412 and the cell.

[0090] In an exemplary embodiment of the present application, to realize the charging control of the multi-cell battery, the multi-cell battery 400 further includes a control assembly, which can be connected to the positive electrode tab 404, the negative electrode tab 405 and the reference tab 414, and can collect the negative electrode potential of each cell in the multi-cell battery 400 and control the charging of the multi-cell battery. 400 It is used to control the state of charge of the battery.

[0091] In practical application, the control assembly may be installed inside the housing 406 of the multi-cell battery 400, or may be installed outside the housing 406 in another device, such as a charger for charging the multi-cell battery, but the embodiments of the present application are not limited thereto.

[0092] An exemplary embodiment of the present application further provides a terminal device, which includes the above-mentioned multi-cell battery, where the specific structure of the multi-cell battery has already been described in detail in the above embodiment, and therefore will not be described again here.

[0093] An exemplary embodiment of the present application also provides a computer-readable storage medium having stored thereon a program product capable of implementing the above-described methods of the present application. In some possible embodiments, various aspects of the present application may also be realized in the form of a program product including program code. When the program product is executed on a terminal device, the program code is used to cause the terminal device to perform the steps of various exemplary embodiments of the present application described in the "Exemplary Methods" section above in this specification, for example, to perform any one or more steps of FIG. 1.

[0094] The program product may be stored on a portable compact disk read-only memory (CD-ROM) and may contain program code and be executable on a terminal device such as a personal computer. However, the program product of this application is not so limited, and as used herein, a readable storage medium may be any tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device.

[0095] The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system or device, or any combination thereof. More specific examples (not an exhaustive list) of readable storage media include an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0096] A computer-readable signal medium includes a propagated data signal in baseband or as part of a carrier wave, and the computer-readable signal medium carries readable program code. Such propagated data signals may take various forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. A readable signal medium may be any readable medium other than a readable storage medium. The readable medium may transmit, propagate, or transport a program for use by or in connection with an instruction execution system or device.

[0097] The program code contained in the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0098] Program code for carrying out the operations of the present application may be written in any combination of one or more programming languages. Programming languages ​​include object-oriented programming languages ​​such as Java, C++, etc., and may include conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may execute entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. When a remote computing device is involved, the remote computing device may be connected to the user computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., connected via the Internet using an Internet Service Provider).

[0099] An exemplary embodiment of the present application further provides an electronic device, which will be described below with reference to Fig. 9. It should be noted that the electronic device 800 shown in Fig. 9 is merely an example and is not limited to the function and scope of use of the embodiment of the present application.

[0100] 9, electronic device 800 is represented in the form of a general computing device. Components of electronic device 800 include, but are not limited to, at least one processing unit 810, at least one storage unit 820, a bus 830 connecting different system components (including storage unit 820 and processing unit 810), and a display unit 840.

[0101] Here, program code may be stored in the storage unit, and the program code may be executed by the processing unit 810, which may perform steps according to various exemplary embodiments of the present application as described above in the "Exemplary Method" section of this specification. For example, the processing unit 810 may perform the method steps shown in FIG. 2, etc.

[0102] The storage cells 820 may include volatile storage units such as a random access storage unit (RAM) 8201 and / or a cache storage unit 8202 , and may further include a read-only storage unit (ROM) 8203 .

[0103] The storage unit 820 may also include a program / utility 8204 having a set (at least one) program module 8205, such program module 8205 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may include implementation in a network environment.

[0104] The bus 830 may include a data bus, an address bus, and a control bus.

[0105] Electronic device 800 can also communicate with one or more external devices 870 (e.g., a keyboard, a pointing device, a Bluetooth device, etc.), and such communication can be performed via input / output (I / O) interface 850. Electronic device 800 also includes a display unit 840, connected to input / output (I / O) interface 850 and used for display. Electronic device 800 can also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network such as the Internet) via network adapter 860. As shown, network adapter 860 communicates with other modules of electronic device 800 via bus 830. Although not shown, other hardware and / or software modules may be used in conjunction with electronic device 800, including, but not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0106] Those skilled in the art will appreciate that various aspects of the present application may be embodied as a system, method, or program product. Accordingly, various aspects of the present application may be embodied in the following forms: an entirely hardware embodiment, an entirely software implementation (including firmware, microcode, etc.), or an embodiment combining hardware and software, which may be collectively referred to herein as a "circuit," "module," or "system."

[0107] Those skilled in the art will readily devise other embodiments of the present application upon consideration of this specification and practicing the disclosed invention. This application is intended to cover any variations, uses, or adaptations of the present application in accordance with its general principles, including common knowledge or customary technical means in the art that are not disclosed herein. The specification and embodiments should be considered exemplary, with the true scope and spirit of the present application being indicated by the following claims.

[0108] It should be understood that the present application is not limited to the exact construction described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope of the present application, which is defined solely by the appended claims.

Claims

1. 1. A charging circuit for a multi-cell battery, comprising at least one insulation measurement structure and a control circuit, the multi-cell battery includes a plurality of cells; each of the at least one insulation measurement structure is installed between two adjacent cells and is used to isolate the two adjacent cells, and is used to measure the negative electrode potential of the cell of the multi-cell battery; the control circuit is connected to the at least one insulation measurement structure and is used to obtain the negative electrode potential from the at least one insulation measurement structure; determine a minimum negative electrode potential from the negative electrode potential of the cell; control the multi-cell battery to charge at a first preset current if the minimum negative electrode potential is equal to or greater than a safe potential; and control the multi-cell battery to operate at a second preset current if the minimum negative electrode potential is less than the safe potential; the insulation measurement structure includes an insulation layer, a measurement layer, and an isolation layer; the insulating layer is disposed between two adjacent cells of the multi-cell battery; the measurement layer is disposed on at least a portion of a side of the insulating layer that is close to the cell, one measurement layer corresponds to one of the cells, and the measurement layer is used to measure the negative electrode potential of the cell; The charging circuit for a multi-cell battery, wherein the isolation layer is disposed between the measurement layer and the cell, and the isolation layer is used to insulate the measurement layer from the cell.

2. 2. The multi-cell battery charging circuit of claim 1, wherein the second preset current is less than the first preset current.

3. 2. The charging circuit for a multi-cell battery according to claim 1, wherein the control circuit is used to control the multi-cell battery to remain in a stationary state until the minimum negative electrode potential becomes equal to or greater than the safe potential when the minimum negative electrode potential is less than the safe potential.

4. 2. The charging circuit for a multi-cell battery according to claim 1, wherein the control circuit is used to control the multi-cell battery to remain in a discharged state until the minimum negative electrode potential becomes equal to or greater than the safe potential when the minimum negative electrode potential is less than the safe potential.

5. 2. The charging circuit for a multi-cell battery according to claim 1, wherein the at least one insulation measurement structure is used to obtain the negative electrode potential of each of the cells in real time, or to obtain the negative electrode potential based on a preset period after the multi-cell battery is charged at the first preset current for a preset time.

6. 2. The charging circuit of claim 1, wherein the control circuit is further configured to obtain a voltage between the positive and negative terminals of the multi-cell battery, and determine whether the multi-cell battery is fully charged based on the voltage between the positive and negative terminals of the multi-cell battery; and stop charging the multi-cell battery if the multi-cell battery is fully charged.

7. A multi-cell battery including a plurality of cells, an insulation measurement structure, and a housing, The plurality of cells are connected in parallel or in series, The insulation measurement structure is installed between two adjacent cells, and the insulation measurement structure is used to isolate the adjacent cells; the housing is used to cover the plurality of cells and the insulation measurement structure; the insulation measurement structure includes an insulation layer, a measurement layer, and an isolation layer; the insulating layer is disposed between two adjacent cells of the multi-cell battery; the measurement layer is disposed on at least a portion of a side of the insulating layer that is close to the cell, one measurement layer corresponds to one of the cells, and the measurement layer is used to measure the negative electrode potential of the cell; The isolation layer is disposed between the measurement layer and the cell, and the isolation layer is used to insulate the measurement layer from the cell.

8. The cell includes a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab penetrating the housing and being exposed to the outside of the housing; 8. The multi-cell battery of claim 7, wherein a reference tab is provided on the measurement layer, and the negative electrode potential is the potential difference between the negative electrode tab and the reference tab.

9. the multi-cell battery further includes a control assembly; the control assembly is connected to the positive tab, the negative tab, and the reference tab; 10. The multi-cell battery of claim 8, wherein the control assembly collects a potential difference between the negative tab and the reference tab as a negative electrode potential of each of the cells of the multi-cell battery, and is used to control the state of charge of the multi-cell battery.

10. 8. The multi-cell battery of claim 7, wherein when two adjacent cells are connected in parallel, the surface area of ​​a side of the insulating layer closest to the cell matches the surface area of ​​a side of the cell.

11. 8. The multi-cell battery of claim 7, wherein when two adjacent cells are connected in series, the insulating layer and the housing are packaged to form a plurality of unit-cell accommodating spaces, and the unit-cell accommodating spaces are used to accommodate a single cell.

12. An electronic device comprising the multi-cell battery of any one of claims 7 to 11, a processor, and a memory, the memory is used to store executable instructions for the processor; 1. The electronic device of claim 1, wherein the processor is configured to: obtain the negative electrode potential from at least one insulation measurement structure of the multi-cell battery; determine a minimum negative electrode potential from the negative electrode potential of the cell; control the multi-cell battery to charge at a first preset current if the minimum negative electrode potential is equal to or greater than a safety potential; and control the multi-cell battery to operate at a second preset current if the minimum negative electrode potential is less than the safety potential.

Images