Battery module, battery pack and energy storage system

Abstract

A battery module (600), a battery pack (1), and an energy storage system. The battery module (600) comprises a first protection unit (610), a first battery cell and a second battery cell; the first protection unit (610) comprises a first breaking device (613), a first detection unit (612) and a first controller (611); the first battery cell and the second battery cell are connected in series. The first breaking device (613) is connected in series between the first battery cell and the second battery cell. The first detection unit (612) is used for detecting first state information, the first state information being used for indicating the state of the battery module (600). When the first state information indicates that the battery module (600) is abnormal, the first controller (611) is used for controlling the first breaking device (613) to be cut off.

Description

Battery modules, battery packs and energy storage systems

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 8, 2023, with application number 202311683851.6, and priority to the Chinese patent application entitled “Battery Module, Battery Pack and Energy Storage System”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to battery modules, battery packs and energy storage systems. Background Art

[0003] Battery packs are widely used in energy storage systems and electric vehicles. As charged energy sources, battery packs can potentially experience safety failures during manufacturing, transportation, storage, installation, and operation. These safety failures fall into two main categories: manufacturing defects that lead to leakage or thermal runaway in the battery cells; and environmental abuse, such as overvoltage, overcurrent, or overtemperature, that ultimately pose safety risks to the battery pack. Therefore, system design requires specific battery pack protection. Summary of the Invention

[0004] The present application provides a battery module, a battery pack, and an energy storage system that can effectively reduce the risk of high voltage breakdown of battery cell insulation between battery cells.

[0005] In a first aspect, the present application provides a battery module, which includes a first protection unit, a first battery cell and a second battery cell; the first protection unit includes a first disconnecting device, a first detection unit and a first controller; the first battery cell and the second battery cell are connected in series; the first disconnecting device is connected in series between the first battery cell and the second battery cell; the first detection unit is used to detect first status information, and the first status information is used to indicate the status of the battery module; the first controller is used to control the first disconnecting device to disconnect when the first status information indicates that the battery module is abnormal.

[0006] Optionally, the first disconnecting device is an explosive fuse, a contactor, a relay or a semiconductor switch, etc., and this application does not impose any limitation on this.

[0007] In this solution, by setting a protection unit in the battery module and setting the disconnecting device in series between the battery cells, when an abnormality occurs in the battery cells in the battery module (such as overcurrent, overtemperature or leakage, etc.), the disconnecting device can be quickly disconnected, which can effectively reduce the risk of high voltage breakdown of the battery cell insulation between the battery cells in the battery module and realize the protection of the battery module.

[0008] In one possible implementation, the first cell and the second cell belong to a first cell group of the battery module; the battery module further includes a second cell group, and the second cell group includes a third cell and a fourth cell; the total voltage of the first cell group is less than or equal to the insulation withstand voltage of the first cell or the second cell, and the total voltage of the second cell group is less than or equal to the insulation withstand voltage of the third cell or the fourth cell; the first status information is used to indicate the status of the first cell group; the first controller is used to control the first disconnecting device to disconnect when the first status information indicates that the first cell group is abnormal; the battery module further includes a second protection unit; the second protection unit includes a second disconnecting device, a second detection unit and a second controller; the second disconnecting device is connected in series between the third cell and the fourth cell; the second detection unit is used to detect second status information; the second status information is used to indicate the status of the second cell group; the second controller is used to control the second disconnecting device to disconnect when the second status information indicates that the second cell group is abnormal.

[0009] In this solution, multiple protection units can be set up in the battery module, and different protection units protect different groups of cells. In addition, the total voltage of the cell group is not greater than the insulation withstand voltage of the cells within the group. This grouping design ensures that the voltage applied to the cells by the external pathway formed by leakage, etc. within the group is not greater than the insulation voltage of the cells, that is, the voltage applied to the cells by the external pathway can be reduced. In addition, this grouping design can also comprehensively and promptly detect abnormalities. That is, no matter which cell in the battery module has an abnormality, there is a corresponding protection unit that can detect it and take protective measures, thereby effectively reducing the risk of cell breakdown.

[0010] In another possible implementation, the first cell belongs to a first cell group, and the second cell belongs to a second cell group; the battery module further includes a third cell group, and the third cell group includes a fifth cell; the total voltage of the first cell group is less than or equal to the insulation withstand voltage of the first cell, the total voltage of the second cell group is less than or equal to the insulation withstand voltage of the second cell, and the total voltage of the third cell group is less than or equal to the insulation withstand voltage of the fifth cell; the first status information is used to indicate the status of the first cell group; the first controller is used to control the first disconnecting device to disconnect when the first status information indicates that the first cell group is abnormal; the battery module further includes a third protection unit, and the third protection unit includes a third disconnecting device, a third detection unit and a third controller; the third disconnecting device is connected in series between the second cell and the fifth cell; the third detection unit is used to detect third status information; the third status information is used to indicate the status of the second cell group; the third controller is used to control the third disconnecting device to disconnect when the third status information indicates that the second cell group is abnormal.

[0011] In this solution, protection units can be placed between cell groups. Similarly, this grouping design ensures that the voltage applied to the cells within the group due to leakage, etc., resulting in an external path, is no greater than the insulation voltage of the cells. This reduces the voltage applied to the cells by this external path. Furthermore, this grouping design allows for comprehensive and timely detection of anomalies. That is, no matter which cell in the battery module experiences an anomaly, a corresponding protection unit can detect it and take protective measures, effectively reducing the risk of cell breakdown.

[0012] In one possible implementation, the first detection unit includes a current detection unit, which is used to detect the current between the first battery cell and the second battery cell; the first controller is used to control the first disconnecting device to disconnect when the current is different from the current at the positive or negative pole of the battery module; or, the first controller is used to control the first disconnecting device to disconnect when the current is greater than a first threshold value.

[0013] In this solution, when an abnormal current (such as overcurrent) occurs between the battery cells, the disconnecting device can be quickly disconnected to protect the battery module. For example, when an external path is formed between the battery cells in the battery module due to leakage, the external path forms an additional current loop with the battery cell in the battery module (referred to as battery cell A for short). The current flowing through the battery cell A includes the superposition of the current of the additional current loop and the current in the main circuit of the battery module (which is also the current at the positive or negative pole of the above-mentioned battery module). Therefore, by comparing the difference between the current flowing through the battery cell A and the current in the main circuit of the battery module or judging whether the current flowing through the battery cell A is greater than a preset threshold, it can be judged whether the current is abnormal, so that protective measures can be taken in time to protect the battery module.

[0014] In one possible implementation, the first detection unit includes a temperature detection unit, which is used to detect the temperature of the first battery cell or the second battery cell; the first controller is used to control the first disconnecting device to disconnect when the temperature of the first battery cell or the second battery cell is greater than a second threshold value.

[0015] In this solution, when a temperature abnormality (such as overheating) occurs between the battery cells, the disconnecting device can be quickly disconnected to protect the battery module. For example, the temperature of the battery cell is related to the current flowing through the battery cell. The greater the current flowing through the battery cell, the higher the temperature of the battery cell. Therefore, the current flowing through the battery cell A includes the superposition of the current of the additional current loop and the current in the main circuit of the battery module, that is, the current flowing through the battery cell A increases, and the temperature of the battery cell A also increases. Therefore, by judging whether the temperature of the battery cell A is greater than the preset threshold, it can be determined whether the temperature is abnormal, so that protective measures can be taken in time to protect the battery module.

[0016] In one possible implementation, the first detection unit includes a leakage detection circuit, which is connected to the ground wire of the battery module and is used to detect the current flowing through the ground wire; the first controller is used to control the first disconnecting device to disconnect when the current flowing through the ground wire is greater than a third threshold.

[0017] In this solution, when a battery module leaks, the disconnect device can be quickly disconnected to protect the battery module. For example, if the aforementioned external path forms an additional current loop, and if a ground wire is connected to this current loop, the current flowing through the ground wire will also increase. That is, the current in the current loop flows to the ground wire with a lower potential, causing leakage. Therefore, determining whether the current in the ground wire is greater than a preset threshold can determine whether there is a leakage anomaly, allowing timely protective measures to be taken to protect the battery module.

[0018] In one possible implementation, the first detection unit and the first controller are powered by one or more cells in the battery module. In this solution, the protection unit can be powered by the cells in the battery module, ensuring continuous power to the protection unit. This allows for effective battery module anomaly detection and protection even when the battery system is disconnected due to storage or transportation.

[0019] In a second aspect, the present application provides a battery pack (PACK), which includes a battery module as described in any one of the first aspects above and a first battery management unit; the first battery management unit is used to collect status information of the battery pack.

[0020] Optionally, the status information of the battery pack may include parameters such as main current, temperature or leakage current in the battery pack.

[0021] Optionally, the first battery management unit may be a battery management unit (BMU). For example, the BMU may include a module battery management system (mBMS) and corresponding sampling control modules, communication modules, power supply modules, switch bridge arm drive control circuits, etc., for implementing status detection and control of battery modules in the battery pack.

[0022] In one possible implementation, the battery pack further includes a first auxiliary power supply, and the first detection unit and the first controller in the battery module are powered by the first auxiliary power supply. In this solution, the auxiliary power supply is used to power the protection unit in the battery module, thereby reducing the impact of power supply from the battery module on the battery module.

[0023] In a third aspect, the present application provides an energy storage system, comprising the battery pack described in the second aspect and a second battery management unit; the second battery management unit is connected to the first battery management unit and to the first controller included in the battery module; the second battery management unit is configured to receive status information of the battery pack collected by the first battery management unit; the second battery management unit is further configured to notify the first controller to control the first disconnecting device to disconnect when the status information indicates that the battery pack is abnormal.

[0024] Optionally, the second battery management unit may be a battery control unit (BCU). For example, the BCU may be connected to the BMU in the battery pack via a control bus, interacting with the battery pack in real time to achieve real-time, unified monitoring of the battery pack, thereby enabling flexible control of the energy storage system and strong applicability.

[0025] In one possible implementation, the energy storage system further includes a second auxiliary power supply, and the first detection unit and the first controller are powered by the second auxiliary power supply. In this solution, the auxiliary power supply is used to power the protection unit in the battery module, thereby reducing the impact of power supply from the battery module on the battery module.

[0026] In a fourth aspect, the present application provides a vehicle comprising a battery module as described in any one of the first aspects above.

[0027] The beneficial effects of the second to fourth aspects mentioned above can be found in the relevant introduction of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figures 1 to 3 are schematic structural diagrams of existing battery packs;

[0029] Figures 4 and 5 are schematic structural diagrams of a battery pack provided in an embodiment of the present application;

[0030] 5A, 5B and 5C are schematic structural diagrams of an energy storage system provided in an embodiment of the present application;

[0031] 6 to 9 , 10A and 10B are schematic structural diagrams of a battery module provided in an embodiment of the present application;

[0032] FIG11 is a schematic diagram showing the connection between a battery module and a BMS provided in an embodiment of the present application;

[0033] FIG12 is a schematic diagram showing an additional current loop generated in a battery module provided by an embodiment of the present application;

[0034] FIG13 is a schematic diagram showing an additional current loop generated between battery packs according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] In the embodiment of the present application, "multiple" refers to two or more. In the embodiment of the present application, "and / or" is used to describe the association relationship of associated objects, indicating three relationships that can exist independently. For example, A and / or B can be expressed as follows: A exists alone, B exists alone, or A and B exist at the same time. The description methods such as "at least one of a1, a2, ... and an" adopted in the embodiment of the present application include the situation where any one of a1, a2, ... and an exists alone, and also include any combination of any multiple of a1, a2, ... and an, each of which can exist alone; for example, the description method of "at least one of a, b and c" includes the situation where a is alone, b is alone, c is alone, a and b combination, a and c combination, b and c combination, or abc combination.

[0036] In this application, the terms "first", "second", etc. are used to distinguish between identical or similar items with substantially the same effects and functions. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor is there a limit on the quantity and execution order. It should also be understood that although the following description uses the terms first, second, etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another. The connections described in the embodiments of the present application refer to electrical connections.

[0037] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the various embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0038] The following is an illustrative description of the embodiments of the present application with reference to the accompanying drawings.

[0039] The battery pack may include multiple battery cells. The multiple battery cells may be connected in series. For example, see Figure 1, which exemplifies a schematic diagram of a battery pack. Figure 1 takes a battery pack including three battery cells as an example. It can be seen that each battery cell includes a positive electrode (+) and a negative electrode (-). Battery cell 1, battery cell 2, and battery cell 3 are connected in series in sequence. BAT- represents the negative electrode of the battery pack, and BAT+ represents the positive electrode of the battery pack. It will be understood that what is shown in Figure 1 is only an example and does not constitute a limitation to the embodiments of the present application.

[0040] Battery packs are widely used, but they may pose safety risks during manufacturing, transportation, storage, installation, and operation. Therefore, battery packs need to be protected. In one existing protection solution, as shown in Figure 2, for example, a fuse is placed at the negative electrode of the battery pack (as shown in Figure 2(a)), at the positive electrode of the battery pack (as shown in Figure 2(b)), or between the battery cells in a series-connected battery pack (as shown in Figure 2(c)). In other words, the fuses are all located outside the battery pack. In the event of a main power overcurrent or short circuit in the battery pack, causing a large current to flow through the fuse, the fuse automatically blows, thereby interrupting the large current and avoiding the risk of thermal runaway or fire. However, this solution cannot prevent the risk of thermal runaway or fire caused by high voltage outside the battery pack, internal leakage caused by electrolyte leakage in the battery cells themselves, or leakage between multiple battery packs. Because this leakage does not cause a large current to flow through the fuse, the fuse will not blow, resulting in a protection blind spot.

[0041] In another existing protection solution, a disconnect device is added to the outside of the battery pack. The disconnect device is controlled by the Battery Management System (BMS), as shown in Figure 3. When the BMS detects a fault such as overvoltage, overcurrent or overtemperature outside the battery pack, it controls the disconnect device to disconnect to disconnect the battery pack's external energy channel. Cut off the external fault source or energy source to ensure the safety of the battery pack. However, this solution cannot provide protection for the battery pack in scenarios where high voltage breaks down the insulation of the battery cells in the battery pack, or in scenarios where the BMS is not working, such as warehousing or transportation.

[0042] Exemplarily, the above-mentioned high voltage breakdown of the battery cell insulation means that: the voltage applied to the battery cell exceeds the maximum voltage upper limit that the battery cell can withstand. In this case, the electrolyte inside the battery cell will be broken down, and a current path will be formed through the electrolyte, that is, the battery cell insulation is broken down. The maximum voltage upper limit that the battery cell can withstand can be called the insulation withstand voltage of the battery cell. The insulation withstand voltage can be, for example, the insulation withstand voltage of the positive and negative poles and the outer shell of the battery cell. In order to facilitate understanding of the scenario of high voltage breakdown of the battery cell insulation, the following exemplary introduction is combined with Figures 4 and 5.

[0043] For example, see Figure 4 , which illustrates the case where a high voltage breakdown of the cell insulation occurs due to the formation of an external cell path between the cells within a battery pack. As shown in Figure 4 , assume that an external cell path is created between cells 1 and 3 in the battery pack due to condensation, electrolyte leakage in the cells, coolant (such as the coolant used to heat or dissipate heat in a car), or damage to the cell insulation layer. The current in this external cell path forms a loop through the positive electrode of cell 1 and the negative electrodes of cells 2 and 3 within the battery pack. This external cell path is equivalent to short-circuiting cells 1 and 3, and cell 2 is connected in series between cells 1 and 3, resulting in an increase in the voltage applied to cells 1 and 3. If this applied voltage exceeds the insulation withstand voltage of cells 1 and 3, it will break down the insulation protection of cells 1 and 3, exposing cells 1 and 3 to the risk of thermal runaway or even fire. The BMS mainly detects abnormalities outside the battery pack and cannot detect insulation breakdown between battery cells inside the battery pack in time. Therefore, it cannot cut off the energy channel in time, and thus cannot effectively protect the battery pack.

[0044] For another example, refer to Figure 5, which takes the example of a high voltage breakdown of the cell insulation caused by the formation of an external cell path between two battery packs connected in series. As shown in Figure 5, similarly, it is assumed that due to condensation, leakage of electrolyte in the cell, coolant (such as coolant used to heat or dissipate heat in the battery in a car), or damage to the insulation layer of the cell, an external cell path is generated between cell 1 in battery pack 1 and cell 5 in battery pack 2. The current in this external cell path forms a loop through the positive electrode of cell 1, cells 2 and 3 in battery pack 1, cell 4 in battery pack 2, and the negative electrode of cell 5. This external cell path is equivalent to short-circuiting cell 1 and cell 5, and cells 2, 3, and 4 are connected in series between cell 1 and cell 5, resulting in an increase in the voltage applied to cell 1 and cell 5. If the applied voltage exceeds the insulation withstand voltage of cells 1 and 5, it will break down the insulation protection of cells 1 and 5, causing thermal runaway or even fire in cells 1 and 5. Similarly, the BMS mainly detects abnormalities outside the battery pack and cannot promptly detect insulation breakdown between cells in different battery packs. Therefore, it cannot promptly cut off the energy channel and thus cannot effectively protect the battery pack.

[0045] Based on the above introduction, in order to better protect the battery pack, the embodiments of the present application provide a battery module, battery pack, and energy storage system. This can effectively reduce the risk of high voltage breakdown between battery cells and protect the battery module, battery pack, or energy storage system. In another possible implementation, effective protection can also be provided in scenarios such as warehousing or transportation where the BMS is not working and cannot provide protection for the battery module, battery pack, or energy storage system.

[0046] Exemplarily, the energy storage system provided in the embodiment of the present application involves a multi-layer structure. The first layer is called an energy storage system or a battery energy storage system, the second layer is called a battery pack (PACK), and the third layer is called a battery module or an energy storage module. Among them, the energy storage system may include one or more battery packs, and the battery pack may include one or more battery modules. In another possible implementation, an intermediate layer may be included between the energy storage system and the battery pack, and the intermediate layer may be, for example, an energy storage unit cluster or a battery cluster. Exemplarily, the energy storage system may include one or more battery clusters. The battery cluster may include multiple battery packs. It can be understood that different names for the same layer structure have the same meaning in the embodiment of the present application, and are all used to refer to this specific layer structure, and the embodiment of the present application does not distinguish between them. In addition, the energy storage system layering described here is only an example and does not constitute a limitation on the embodiment of the present application. In specific implementations, other layering methods may also be adopted, and the embodiment of the present application does not limit this.

[0047] The following first describes, by way of example, the energy storage system provided in an embodiment of the present application. For example, see FIG. 5A , which illustrates a schematic structural diagram of a possible energy storage system. As shown in FIG. 5A , the energy storage system may include multiple battery packs connected in series ( FIG. 5A uses n as an example, where n is an integer greater than 1). Each battery pack may include a battery module 600 and a first battery management unit 601.

[0048] The energy storage system further includes a second battery management unit 602. The second battery management unit 602 is connected to the first battery management unit 601 in each battery pack.

[0049] In one possible implementation, the energy storage system may further include a direct current (DC) / alternating current (AC) converter, namely a DC / AC converter 603. The DC / AC converter 603 may be connected to the series-connected battery pack via a DC bus. The DC / AC converter 603 may convert DC power into AC power and exchange energy with the AC grid.

[0050] For example, the detailed introduction of the battery module 600 can be seen in the following related descriptions of FIG. 6 to FIG. 10B , which will not be described in detail here.

[0051] For example, taking battery pack 1 in an energy storage system as an example, the first battery management unit 601 in battery pack 1 can be used to collect status information of battery pack 1. The status information of battery pack 1 can include parameters such as the main current in the battery pack 1 (e.g., the current at the positive or negative electrode of the battery pack 1), temperature, or leakage current.

[0052] In one implementation, the first battery management unit 601 may be, for example, a battery management unit (BMU). For example, the BMU may include a module battery management system (mBMS) and corresponding sampling control modules, communication modules, power supply modules, switch bridge arm drive control circuits, etc., to implement status detection in the battery pack.

[0053] For example, the second battery management unit 602 can be connected to the first battery management unit 601 in the battery pack via a control bus. The second battery management unit 602 can exchange information with the first battery management unit 601 in each battery pack in real time to achieve real-time and unified monitoring of each battery pack, thereby achieving flexible control of the energy storage system with strong applicability. For example, the first battery management unit 601 can send the collected battery pack status information to the second battery management unit 602. The second battery management unit 602 can be used to take corresponding protective measures when the status information indicates that the battery pack is abnormal. For specific implementation, please refer to the exemplary introduction of Figure 11 below, which will not be described in detail here.

[0054] Exemplarily, the second battery management unit 602 may be a battery control unit (BCU).

[0055] For example, the multiple first battery management units 601 and second battery management units 602 may be collectively referred to as the BMS of the energy storage system. It is understood that, in specific implementations, the BMS in the energy storage system may also be implemented in other ways, not limited to the implementation described in the embodiments of this application.

[0056] In one possible implementation, for example, as shown in FIG5B , the energy storage system may further include a DC / DC converter 604. The multiple battery packs connected in series may be coupled to a DC bus via the DC / DC converter 604. The DC / DC converter 604 may flexibly control the energy of the multiple battery packs connected in series and has strong applicability. For example, the DC / DC converter 604 may be a bidirectional DC / DC converter, and the circuit topology of the bidirectional DC / DC converter 604 may be an isolated circuit topology or a non-isolated circuit topology. The circuit topology of the bidirectional DC / DC converter may be a boost circuit, a flying capacitor boost circuit, a flying capacitor multilevel circuit, a positive and negative symmetrical three-level boost circuit, a four-switch buck-boost circuit, etc. The specific circuit topology may be determined according to the actual application scenario requirements, and this application does not impose any restrictions on this.

[0057] For example, as shown in FIG5B , the second battery management unit 602 can be integrated into the DC / DC converter 604 to simplify the system structure of the energy storage system. Furthermore, since the multiple battery packs connected in series are typically installed in close proximity to the DC / DC converter 604, integrating the second battery management unit 602 into the DC / DC converter 604 facilitates control bus connection. Alternatively, in another possible implementation, the second battery management unit 602 and the DC / DC converter 604 can be independently configured. This embodiment of the present application is not limited thereto.

[0058] By way of example, in another possible implementation, the multiple battery packs connected in series may form a battery cluster, as shown in FIG5C . A cluster control box 605 may be configured for the battery cluster to provide unified control of the battery cluster. Cluster control box 605 may include components such as cluster-level fuses, cluster-level insulation impedance detection, and cluster-level switches to implement cluster-level management and protection. As shown in FIG5C , the battery cluster may be coupled to the DC bus via cluster control box 605. By way of example, the second battery management unit 602 may be integrated into the cluster control box 605 (as shown in FIG5C ), or may be independently configured, and this is not a limitation in the present embodiment.

[0059] It will be understood that the structure of the energy storage system shown in FIG. 5A to FIG. 5C is merely an example. In a specific implementation, it may be any energy storage structure including the battery module or battery pack provided in the embodiment of the present application. The embodiment of the present application does not limit the structure of the specific energy storage system.

[0060] In a possible implementation, please refer to FIG6 , which shows a schematic structural diagram of a battery module provided in an embodiment of the present application.

[0061] The battery module 600 shown in Figure 6 may include a first protection unit 610 and a plurality of battery cells 620 (six battery cells 620 are shown as an example in Figure 6). The first protection unit 610 may include a first controller 611, a first detection unit 612 and a first disconnecting device 613. It can be seen that the plurality of battery cells 620 and the first disconnecting device 613 are connected in series. For example, the first disconnecting device 613 is connected in series between battery cell 3 and battery cell 4. It is understandable that the first disconnecting device 613 can be connected in series between any two adjacent battery cells in the plurality of battery cells 620. For example, it can be connected in series between battery cell 2 and battery cell 3, or it can be connected in series between battery cell 5 and battery cell 6, etc., which are not listed here one by one.

[0062] For example, since the six battery cells 620 are connected in series, the first disconnecting device 613 can be said to be connected in series between any two battery cells 1 to 6. For example, the first disconnecting device 613 is connected in series between battery cells 1 and 6. Alternatively, the first disconnecting device 613 is connected in series between battery cells 1 and 5. Alternatively, the first disconnecting device 613 is connected in series between battery cells 2 and 6. Alternatively, the first disconnecting device 613 is connected in series between battery cells 2 and 5, and so on.

[0063] For the convenience of the following description, the path connecting the plurality of battery cells 620 and the first disconnecting device 613 in series is referred to as a first series path. For example, the first series path can be connected through a power line.

[0064] Exemplarily, the above-mentioned first disconnecting device can be, for example, an explosive fuse, a contactor, a relay or a semiconductor switch, etc., and the embodiments of the present application do not limit this. Exemplarily, the semiconductor switch can include, for example, an insulated gate bipolar transistor (IGBT) or a metal-oxide semiconductor field effect transistor (MOSFET), etc. When the disconnecting device adopts a switch, the switch can be disconnected under the control of a control signal, thereby disconnecting the current path between the battery cells. When the disconnecting device adopts an explosive fuse, the explosive fuse can be disconnected under the control of a control signal, thereby disconnecting the current path between the battery cells. It should be understood that any device that can be disconnected according to a control signal can be used as a controllable disconnecting device in the embodiments of the present application, and the controllable disconnecting device can be flexibly selected according to actual needs. The embodiments of the present application do not limit the specific implementation of the disconnecting device.

[0065] The first controller 611 is connected to the first detection unit 612 and the first disconnecting device 613. The first detection unit 612 can be used to detect abnormalities in the first series path and feedback the detection results to the first controller 611. If an abnormality occurs in the first series path, the first controller 611 can control the first disconnecting device 613 to disconnect, thereby severing the first series path and protecting the battery module 600. For example, the first detection unit 612 can be used to detect first status information. This first status information indicates the status of the first series path. Specifically, this first status information may include, for example, the current flowing through the battery cells in the first series path, the temperature of the battery cells, or the leakage current of the first series path, although this embodiment of the present application is not limited thereto. The first detection unit 612 or the first controller 611 can use this first status information to determine that an abnormality exists in the battery module 600. For a detailed analysis, please refer to the following description and will not be elaborated here.

[0066] In a possible implementation, the first detection unit 612 may include, for example, one or more of a first current detection unit 6121, a first temperature detection unit 6122, and a first leakage detection unit 6123. FIG6 shows the example of including these three items.

[0067] The above-mentioned first current detection unit 6121 can be used to detect the current of the above-mentioned first series path. For example, as shown in Figure 6, the first current detection unit 6121 is connected to the first series path through a signal line, and the current in the first series path is fed back to the first current detection unit 6121 through the connected signal line. It can be understood that the position where the first current detection unit 6121 is connected to the first series path through the signal line in Figure 6 is only an example and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the first current detection unit 6121 can be connected to any position on the first series path through a signal line. For example, the first current detection unit 6121 can be any circuit or sensor that can realize current detection, and the embodiments of the present application do not limit this.

[0068] The above-mentioned first temperature detection unit 6122 can be used to detect the temperature of the above-mentioned first series path. For example, as shown in Figure 6, the first temperature detection unit 6122 is connected to the battery cell 2 in the first series path through a signal line, and the temperature of the battery cell 2 (which can be used to represent the temperature of the first series path) is fed back to the first temperature detection unit 6122 through the connected signal line. It can be understood that the battery cell connected to the first temperature detection unit 6122 through the signal line in Figure 6 is only an example and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the first temperature detection unit 6122 can be connected to any battery cell on the first series path through a signal line. For example, the first temperature detection unit 6122 can be any circuit or sensor that can realize temperature detection, etc., and the embodiments of the present application do not limit this.

[0069] The first leakage detection unit 6123 can be used to detect leakage in the first series path. For example, as shown in FIG6 , the first leakage detection unit 6123 is connected to the ground wire (see ground 1 in FIG6 ) in the first series path via a signal line, and the current on the ground wire is fed back to the first leakage detection unit 6123 via the connected signal line. It is understandable that the connection position of the ground wire in FIG6 is only an example and does not constitute a limitation on the embodiments of the present application. For example, the first leakage detection unit 6123 can be any circuit or sensor that can realize battery leakage detection, and the embodiments of the present application are not limited to this.

[0070] In another possible implementation, the first detection unit 612 may further include other detection units, such as a voltage detection unit. For example, the voltage detection unit may be used to detect the voltage between any two points in the first series path. The above description of the first detection unit 612 is merely an example. In a specific implementation, the first detection unit 612 may include more or fewer detection units, and this embodiment of the application does not impose any limitation on this.

[0071] In one possible implementation, as shown in FIG7 , for example, the first protection unit 610 may further include an auxiliary power supply unit 614. The auxiliary power supply unit 614 may be used to connect an auxiliary power source or battery to the first protection unit 610 to supply power to the first controller 611 and the first detection unit 612. For example, as shown in FIG7 , the auxiliary power supply unit 614 is connected to the first controller 611, and the power signal is first input to the first controller 611, and then input to the first detection unit 612 via the first controller 611. Alternatively, for example, the auxiliary power supply unit 614 may be directly connected to the first detection unit 612 without passing through the first controller 611 to supply power to the first detection unit 612. The embodiment of the present application does not impose any restrictions on this connection method. For example, the auxiliary power supply unit 614 may be, for example, a power supply circuit that can implement functions such as voltage stabilization, current stabilization, or power conversion, and the embodiment of the present application does not impose any restrictions on the specific structure of the auxiliary power supply unit 614.

[0072] Exemplarily, the auxiliary power supply connected to the first protection unit 610 may be, for example, an auxiliary power supply in the battery pack to which the battery module 600 belongs. For example, assuming that the battery module 600 is the battery module 600 in the battery pack 1 shown in FIG. 5A , then the auxiliary power supply may be the auxiliary power supply in the battery pack 1. Alternatively, exemplarily, the auxiliary power supply may be, for example, an auxiliary power supply in the energy storage system to which the battery module 600 belongs, and the auxiliary power supply may power the BMS in the energy storage system. For example, assuming that the battery module 600 is any one of the battery modules 600 in the energy storage system shown in FIG. 5A , then the auxiliary power supply may be the auxiliary power supply in the energy storage system. And the auxiliary power supply may be used to power the first battery management unit 601 and / or the second battery management unit 602 in the energy storage system.

[0073] For example, the battery connected to the first protection unit 610 may be one or more battery cells in the battery module 600 .

[0074] For example, as shown in FIG7 , the auxiliary power supply can be connected to the auxiliary power supply unit 614 via a diode D1. The battery can be connected to the auxiliary power supply unit 614 via a diode D2. The cathode of the diode D1 and the cathode of the diode D2 are connected together. The auxiliary power supply can be connected via the anode of the diode D1. The battery can be connected via the anode of the diode D2.

[0075] For example, in a specific implementation, if the battery pack or energy storage system to which the battery module 600 belongs is in working state, the auxiliary power supply can be used to power the first protection unit 610. If the battery pack or energy storage system to which the battery module 600 belongs is in a dormant state, the battery can be used to power the first protection unit 610. For example, the voltage at the anode of the auxiliary power input diode D1 can be set to be higher than the voltage at the anode of the battery input diode D2. Under this design, if the first battery management unit 601 is in working state and the voltage at the anode of the auxiliary power input diode D1 is higher than the voltage at the anode of the battery input diode D2, the auxiliary power supply will give priority to powering the first protection unit 610. If the first battery management unit 601 is in a dormant state, the voltage at the anode of the auxiliary power input diode D1 is very low or even zero, and the first protection unit 610 is powered by the connected battery.

[0076] Alternatively, in another possible implementation, if the auxiliary power supply is an auxiliary power supply in the energy storage system to which the battery module 600 belongs, a switch can be provided between the auxiliary power supply unit 614 and the interface for connecting the auxiliary power supply and the interface for connecting the battery. In this design, if the energy storage system is in operation (i.e., the BMS in the energy storage system is also in operation), the BMS can control the switch to close and connect the auxiliary power supply unit 614 and the interface for connecting the auxiliary power supply, so that the auxiliary power supply can supply power to the first protection unit 610. If the BMS is in a dormant state, before going into dormancy, the BMS can control the switch to close and connect the auxiliary power supply unit 614 and the interface for connecting the battery, so that the connected battery can supply power to the first protection unit 610. For example, in one possible implementation, based on the above description, the first protection unit 610 can determine whether the BMS is in operation or in a dormant state based on the object being powered. Specifically, if the first protection unit 610 detects a power signal from the interface for connecting the auxiliary power supply, it can determine whether the BMS is in operation. If the first protection unit 610 detects that the power signal comes from the interface to which the battery is connected, it can be known that the BMS is in the sleep state.

[0077] In the above solution, if the battery pack or energy storage system to which battery module 600 belongs is operating, the auxiliary power supply supplies power to the protection unit in the battery pack, thereby reducing the impact of power supply from the battery module on the battery module. If the battery pack or energy storage system to which battery module 600 belongs is dormant, the battery module can supply power to the first protection unit 610, ensuring that battery module anomalies can be detected and protected even when the battery pack or energy storage system to which battery module 600 belongs is dormant. In addition, reusing the power of the battery module to power the first protection unit 610 also saves costs.

[0078] In another possible implementation, the first protection unit 610 may be powered by other additional auxiliary power supplies, for example, which is not limited in this embodiment of the present application.

[0079] In one possible implementation, as shown in FIG8 , for example, the battery module 600 may further include a second protection unit 640 and one or more battery cells 620 ( FIG8 , taking three battery cells 620 , battery cells 7 to 9 , as an example). The second protection unit 640 may include a second controller 641 , a second detection unit 642 , and a second disconnecting device 643 . It can be seen that the multiple battery cells 620 and the second disconnecting device 643 are connected in series. For example, the second disconnecting device 643 is connected in series between battery cell 6 and battery cell 7. It is understandable that the second disconnecting device 643 can be connected in series between any two adjacent battery cells from battery cell 4 to battery cell 9. For example, it can be connected in series between battery cell 7 and battery cell 8, and so on, which are not listed here one by one.

[0080] For example, since the battery cells 620 in the battery module 600 are connected in series, the second disconnecting device 643 can be said to be connected in series between any two battery cells from battery cells 4 to 9. For example, the second disconnecting device 643 can be connected in series between battery cells 4 and 9. Alternatively, the second disconnecting device 643 can be connected in series between battery cells 1 and 8. Alternatively, the second disconnecting device 643 can be connected in series between battery cells 5 and 9. Alternatively, the second disconnecting device 643 can be connected in series between battery cells 5 and 8, and so on.

[0081] For the convenience of the following description, the path connecting the battery cells 4 to 9 and the second disconnecting device 643 in series is referred to as a second series path.

[0082] The second controller 641 is connected to the second detection unit 642 and the second disconnecting device 643. The second detection unit 642 can be used to detect anomalies in the second series path and feedback the detection results to the second controller 641. If an abnormality occurs in the second series path, the second controller 641 can control the second disconnecting device 643 to disconnect, thereby severing the second series path and protecting the battery module 600. For example, the second detection unit 642 can be used to detect second status information. This second status information is used to indicate the status of the second series path. Specifically, this second status information may include, for example, the current flowing through the battery cells in the second series path, the temperature of the battery cells, or the leakage current of the second series path, etc., which is not limited in this embodiment of the present application. The second detection unit 642 or the second controller 641 can use this second status information to determine whether an abnormality exists in the second series path. This analysis process is similar to the analysis process for determining whether an abnormality exists in the first series path.

[0083] In a possible implementation, the second detection unit 642 may include, for example, one or more of a second current detection unit 6421, a second temperature detection unit 6422, and a second leakage detection unit 6423. FIG8 shows the example of including these three items.

[0084] The above-mentioned second current detection unit 6421 can be used to detect the current of the above-mentioned second series path. For example, as shown in Figure 8, the second current detection unit 6421 is connected to the second series path through a signal line, and the current in the second series path is fed back to the second current detection unit 6421 through the connected signal line. It can be understood that the position where the second current detection unit 6421 is connected to the second series path through the signal line in Figure 8 is only an example and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the second current detection unit 6421 can be connected to any position on the second series path through a signal line. For example, the second current detection unit 6421 can be any circuit or sensor that can realize current detection, and the embodiments of the present application do not limit this.

[0085] The above-mentioned second temperature detection unit 6422 can be used to detect the temperature of the above-mentioned second series path. For example, as shown in Figure 8, the second temperature detection unit 6422 is connected to the battery cell 6 in the second series path through a signal line, and the temperature of the battery cell 6 (which can be used to represent the temperature of the second series path) is fed back to the second temperature detection unit 6422 through the connected signal line. It can be understood that the battery cell connected by the second temperature detection unit 6422 through the signal line in Figure 8 is only an example and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the second temperature detection unit 6422 can be connected to any battery cell on the second series path through a signal line. For example, the second temperature detection unit 6422 can be any circuit or sensor that can realize temperature detection, etc., and the embodiments of the present application do not limit this.

[0086] The above-mentioned second leakage detection unit 6423 can be used to detect the leakage of the above-mentioned second series path. For example, as shown in Figure 8, the second leakage detection unit 6423 is connected to the ground wire (see ground 2) in the second series path through a signal line, and the current on the ground wire is fed back to the second leakage detection unit 6423 through the connected signal line. It can be understood that the connection position of the ground wire in Figure 8 is only an example and does not constitute a limitation on the embodiments of the present application. For example, the second leakage detection unit 6423 can be any circuit or sensor that can realize battery leakage detection, and the embodiments of the present application are not limited to this. For example, the ground 2 can be connected to the above-mentioned ground 1, or it can be separated.

[0087] In another possible implementation, the second detection unit 642 may further include other detection units, such as a voltage detection unit. For example, the voltage detection unit may be used to detect the voltage between any two points in the second series path. The above description of the second detection unit 642 is merely an example. In a specific implementation, the second detection unit 642 may include more or fewer detection units, and this embodiment of the application does not limit this.

[0088] In one possible implementation, as shown in FIG8 , the second protection unit 640 may further include an auxiliary power supply unit 644. The auxiliary power supply unit 644 may be used to connect an auxiliary power supply or a battery to the second protection unit 640 to power the second controller 641 and the second detection unit 642. For specific implementation, reference may be made to the aforementioned introduction to the auxiliary power supply unit 614, which will not be described in detail here. In addition, the auxiliary power supply may be connected to the auxiliary power supply unit 644 via a diode D3. The battery may be connected to the auxiliary power supply unit 644 via a diode D4. For specific implementation, reference may be made to the aforementioned introduction to the diode D1 and the diode D2, which will not be described in detail here.

[0089] In one possible implementation, for example, see FIG9 . The battery module 600 may further include more battery cells 620 connected in series, and more protection units (such as the third protection unit 650 , the fourth protection unit 660 , and the fifth protection unit 670 exemplarily shown in FIG9 ). For the introduction of the third protection unit 650 and the fifth protection unit 670 , reference may be made to the description of the first protection unit 610 . For the introduction of the fourth protection unit 660 , reference may be made to the description of the second protection unit 640 , and no further details are given here.

[0090] For example, it can be seen in Figures 8 and 9 above that multiple protection units can be set in the battery module, and different protection units protect different groups of cells. This is equivalent to grouping (or partitioning) the multiple cells 620 in the battery module for protection, and the cells 620 included in different groups may overlap or not overlap. For example, the grouping can be based on the voltage between the positive and negative poles of the cell 620, the voltage at both ends of the series path (such as the first series path or the second series path mentioned above), and the insulation withstand voltage of the cell 620. Specifically, the voltage at both ends of the series path cannot be greater than the insulation withstand voltage of the cell 620. If the voltage at both ends of the series circuit is greater than the insulation withstand voltage of the cell 620, then, when an external cell path is generated between the cells at both ends of the series circuit (for example, see the external cell path shown in Figure 4 or Figure 5), the maximum voltage applied to the cells at both ends is the voltage at both ends of the series circuit. Because the voltage across the series circuit is greater than the insulation withstand voltage of the battery cell 620, the insulation of the battery cells at both ends may be broken down, resulting in the risk of thermal runaway or even fire (see the relevant descriptions of Figures 4 or 5 for examples). For ease of understanding, the following uses the first series path as an example.

[0091] For example, in the first series path described above, assume that the voltage of cell 620 is a volt (V) and the insulation withstand voltage of cell 620 is b volts. Then, when calculating the number of cells in each cell group, the number of cells in the group can be calculated by dividing b by a, i.e., b / a. Assuming b / a = 6, 6 cells or cells connected in series can be grouped together, as shown in the first series path. Alternatively, the number of cells in a cell group can be greater than 1 and less than 6. The voltage across the first series path is the voltage of cells 1 to 6 connected in series. The voltage across the first series path is 6a volts. This 6a is not greater than the insulation withstand voltage b of cell 620. Therefore, an external cell path is created between cells 1 and 6, and the maximum voltage applied to cells 1 and 6 is 6a. Since the insulation withstand voltage b is not exceeded, there will be no cell insulation breakdown. If b / a = 5, the voltage 6a volts across the first series path is greater than the insulation withstand voltage b (b = 5a). In this case, if an external path is generated between the battery cell 1 and the battery cell 6, the maximum voltage applied to the battery cell 1 and the battery cell 6 is 6a. If it exceeds the insulation withstand voltage b, the battery cell insulation will be broken down.

[0092] In another possible implementation, please refer to Figures 10A and 10B, which exemplify two possible implementation methods of battery cell grouping. For example, as shown in Figure 10A, the protection unit is arranged between the battery cell groups. For example, four battery cell groups are exemplarily shown in Figure 10A. Among them, the first protection unit 610 is arranged between the first battery cell grouping and the second battery cell grouping, that is, the first disconnecting device 613 included in the first protection unit 610 is connected in series between the first battery cell grouping and the second battery cell grouping. The second protection unit 640 is arranged between the second battery cell grouping and the third battery cell grouping, that is, the second disconnecting device 643 included in the second protection unit 640 is connected in series between the second battery cell grouping and the third battery cell grouping. The setting positions of the remaining protection units are similar and will not be repeated.

[0093] For example, as shown in Figure 10B , the protection units are arranged within the cell groups. For example, Figure 10B illustrates three cell groups. The first protection unit 610 is arranged within the first cell group, meaning that the first disconnecting device 613 included in the first protection unit 610 is connected in series between the cells in the first cell group. The second protection unit 640 is arranged within the second cell group, meaning that the second disconnecting device 643 included in the second protection unit 640 is connected in series between the cells in the second cell group. The placement of the remaining protection units is similar and will not be further described.

[0094] For example, in Figures 10A and 10B , the first detection unit 612 in the first protection unit 610 can be used to detect status information of the first cell grouping; the first controller 611 is used to control the first disconnecting device 613 to disconnect if the status information indicates that the first cell grouping is abnormal. The second detection unit 642 in the second protection unit 640 can be used to detect status information of the second cell grouping; the second controller 641 is used to control the second disconnecting device 643 to disconnect if the status information indicates that the second cell grouping is abnormal.

[0095] It is understood that the above grouping is only an example and does not constitute a limitation on the embodiments of the present application. In addition, the number of cells included in each cell group can be determined based on the voltage of the cell and the insulation withstand voltage of the cell, and the embodiments of the present application do not impose any limitation on this.

[0096] In summary, the above-mentioned cell grouping protection solution ensures that even if a shell path forms between two cells within a group, the maximum voltage applied to the cells will not exceed the cell insulation withstand voltage, thereby reducing the risk of cell insulation breakdown and effectively protecting the battery. Furthermore, grouping allows for comprehensive and timely detection of abnormalities and the implementation of protective measures.

[0097] In one possible implementation, the controller included in the protection unit in the battery module 600 can also be connected to the second battery management unit 602 in the energy storage system. For example, see Figure 11 , which illustrates the connection between the first controller 611 of the first protection unit 610 in the battery module 600 and the second battery management unit 602. Furthermore, the first battery management unit 601 shown in Figure 11 is the first battery management unit in the battery pack to which the battery module 600 belongs. The first battery management unit 601 can collect status information of the battery pack to which the battery module 600 belongs. For example, this status information may include information such as the current, temperature, or leakage status of the battery pack.

[0098] For example, in a specific implementation, the above-mentioned first battery management unit 601 can send the collected status information of the battery pack to the second battery management unit 602. The second battery management unit 602 can notify the first controller 611 to control the first disconnecting device 613 to disconnect when the status information indicates that the battery pack is abnormal. For example, the abnormal situation of the battery pack may include one or more of the following: the main current in the battery pack detected by the first battery management unit 601 (such as the current at the positive or negative pole of the battery pack, etc.) is greater than a preset current threshold; the temperature in the battery pack detected by the first battery management unit 601 is greater than a preset temperature threshold; the leakage current in the battery pack detected by the first battery management unit 601 is greater than a preset leakage current threshold, etc. The embodiment of the present application does not limit the abnormal situation of the battery pack.

[0099] For example, when the first battery management unit 601 and the second battery management unit 602 are in normal operation, the first protection unit 610 can operate or stop operating. If the first protection unit 610 is also operating, it can detect status information in the first series path (or first cell group), as described in detail in FIG12 below. If the detected status information indicates an abnormality, the first controller 611 will also control the first disconnecting device 613 to disconnect.

[0100] Exemplarily, if the first battery management unit 601 and the second battery management unit 602 are in a dormant state. For example, when the energy storage system is in storage or transportation, in order to reduce the consumption of the remaining power of the battery in the energy storage system by the first battery management unit 601 and the second battery management unit 602, the first battery management unit 601 and the second battery management unit 602 are generally in a dormant state. The first battery management unit 601 and the second battery management unit 602 can no longer detect the status information in the battery module 600. In this case, the first protection unit 610 can normally detect the status information in the first series path (or the first battery cell grouping). If the detected status information indicates an abnormality, the first controller 611 can control the first disconnecting device 613 to disconnect.

[0101] In the above solution, when the first battery management unit 601 and the second battery management unit 602 (collectively referred to as the BMS) are operating, the BMS and / or the first protection unit 610 can detect the status information of the battery module 600. When the BMS is dormant, the first protection unit 610 can also detect the status information of the battery module 600, thereby achieving comprehensive and effective protection for the battery module 600.

[0102] The above mainly provides an exemplary introduction to the structures of the energy storage system, battery, and battery module, and the relationships therebetween, provided in the embodiments of the present application. The following describes the specific implementation of the battery protection method provided in the embodiments of the present application, combining the structures of the energy storage system, battery, and battery module, and the relationships therebetween. The first protection unit 610 described above is used as an example.

[0103] Exemplarily, in a specific implementation, if the above-mentioned first detection unit 612 includes a current detection unit (such as the above-mentioned first current detection unit 6121), then the current anomaly of the above-mentioned first series path can be detected by the first current detection unit 6121, or the current anomaly of the above-mentioned first battery cell group can be detected. For ease of understanding, for example, refer to Figure 12. In Figure 12, an external battery cell path is generated between the first battery cell (battery cell 1) and the second battery cell (battery cell 6) due to condensation, electrolyte leakage, coolant leakage or insulation damage. Due to the existence of the external battery cell path, an additional current loop is formed between battery cell 1, battery cell 2, battery cell 3, the first disconnecting device 613, battery cell 4, battery cell 5 and battery cell 6 (see the dotted line in Figure 12). As a result, the current in the first series path (or the first battery cell group) has changed.

[0104] For example, if the energy storage system to which battery module 600 belongs is in a powered-on state (i.e., battery module 600 and the energy storage system's BMS are in operation), and battery module 600 is supplying power to a load, current already exists in the first series path (or first cell grouping). If the external cell path described above appears between cell 1 and cell 2, forming the additional current loop described above, the current flowing through the first series path (or first cell grouping) will change. The first current detection unit 6121 can detect this current change. For example, the first current detection unit 6121 can compare the detected current in the first series path (or first cell grouping) with the current at BAT-, the current at BAT+, or the current between BAT- and BAT+. Because the connections are series, if no other current loops exist, the current in the first series path is the same as the current at BAT-, the current at BAT+, and the current between BAT- and BAT+. Therefore, if the comparison reveals a current difference, it indicates that the current in the first series path is abnormal. The first current detection unit 6121 may feed back the comparison result to the first controller 611. The first controller 611 may control the first disconnecting device 613 to be disconnected.

[0105] In another implementation, the current at BAT-, the current at BAT+, or the current between BAT- and BAT+ can be detected by the BMS in the energy storage system to which the battery module 600 belongs. The first current detection unit 6121 can detect the current of the first series path (or the first battery cell group). Then, the BMS and the first current detection unit 6121 respectively send the detected currents to the first controller 611. The first controller 611 compares the received currents and controls the first disconnecting device 613 to disconnect if a current anomaly occurs. In one possible implementation, for example, the first battery management unit 601 in the battery pack to which the battery module 600 belongs can detect the current at BAT-, the current at BAT+, or the current between BAT- and BAT+. Then, the detected current is sent to the second battery management unit 602. The second battery management unit 602 then sends the detected current to the first controller 611. It should be understood that the description herein of detecting the current at BAT-, the current at BAT+, or the current between BAT- and BAT+ is merely an example and does not constitute a limitation on the embodiments of the present application. For example, if the energy storage system to which the battery module 600 belongs is not powered on, the BMS is in a dormant state. Under normal circumstances, no current flows in the first series path (or first cell grouping). However, if the above-mentioned cell external path appears between cell 1 and cell 2, forming the above-mentioned additional current loop, current flows through the first series path. The above-mentioned first current detection unit 6121 can detect such current changes and feed back the detection results to the first controller 611. The first controller 611 can control the first disconnecting device 613 to disconnect. For example, the first current detection unit 6121 detects current and determines that the detected current is greater than zero. Then, the first current detection unit 6121 can feed back the detection result that the current is greater than zero to the first controller 611. The first controller 611 can control the first disconnecting device 613 to disconnect. Alternatively, for example, the first current detection unit 6121 detects the current and feeds the detected current back to the first controller 611. The first controller 611 determines that the detected current is greater than zero, and then controls the first disconnecting device 613 to disconnect.

[0106] In another possible implementation, regardless of whether the energy storage system to which the battery module 600 belongs is in a powered-on state, and regardless of whether the abnormality is determined by the first current detection unit 6121 or the first controller 611, a current threshold can be preset. If the current detected by the first current detection unit 6121 is greater than the current threshold, it indicates that the current is abnormal, and the first controller 611 can control the first disconnecting device 613 to disconnect.

[0107] Exemplarily, in a specific implementation, if the above-mentioned first detection unit includes a temperature detection unit (such as the above-mentioned first temperature detection unit 6122). Then, the temperature abnormality of the above-mentioned first series path (or the first battery cell group) can be detected by the temperature detection unit. For example, still in combination with the above-mentioned Figure 12 exemplarily described. Regardless of whether the BMS is in working state or in dormant state, if the above-mentioned battery cell external path appears between battery cell 1 and battery cell 6, the above-mentioned additional current loop is formed. The current flowing through the first series path (or the first battery cell group) increases compared to when the battery cell external path does not appear. The increase in current will cause the temperature of the battery cells in the first series path to rise. The first temperature detection unit 6122 can detect this temperature change. And feed back the detection result to the first controller 611. The first controller 611 can control the first disconnecting device 613 to disconnect.

[0108] For example, a temperature threshold can be preset. If the temperature detected by the first temperature detection unit 6122 is greater than the temperature threshold, the first controller 611 can control the first disconnecting device 613 to disconnect. For example, the first temperature detection unit 6122 detects a temperature and determines that the detected temperature is greater than the temperature threshold. Then, the first temperature detection unit 6122 can feed back the detection result that the temperature is greater than the temperature threshold to the first controller 611. The first controller 611 can control the first disconnecting device 613 to disconnect. Alternatively, for example, the first temperature detection unit 6122 detects a temperature and feeds back the detected temperature to the first controller 611. The first controller 611 determines that the detected temperature is greater than the temperature threshold and then controls the first disconnecting device 613 to disconnect.

[0109] Alternatively, in another possible implementation, a temperature change threshold can be preset. If the difference between the temperature before and after the change is greater than the preset temperature change threshold, the first controller 611 can control the first disconnecting device 613 to disconnect. The specific implementation is similar to the description of the temperature threshold in the previous section and will not be repeated here.

[0110] Exemplarily, in a specific implementation, if the first detection unit includes a leakage detection unit (e.g., the first leakage detection unit 6123), the temperature detection unit can be used to detect leakage in the first series path (or first battery cell grouping). If leakage occurs in the first series path (or first battery cell grouping), the current flowing through the ground wire will increase. The first leakage detection unit 6123 can detect this change in current and feed back the detection result to the first controller 611. The first controller 611 can control the first disconnecting device 613 to disconnect. Exemplarily, a leakage current threshold can be preset. If the leakage current detected by the first leakage detection unit 6123 is greater than the leakage current threshold, the first controller 611 can control the first disconnecting device 613 to disconnect. For example, the first leakage detection unit 6123 detects a leakage current and determines that the detected leakage current is greater than the leakage current threshold. The first leakage detection unit 6123 can then feed back the detection result that the leakage current is greater than the leakage current threshold to the first controller 611. The first controller 611 can control the first disconnecting device 613 to disconnect. Alternatively, for example, the first leakage detection unit 6123 detects a leakage current and feeds the leakage current back to the first controller 611. The first controller 611 determines that the detected leakage current is greater than the leakage current threshold and then controls the first disconnecting device 613 to disconnect.

[0111] It is understandable that the above description mainly takes the first protection unit 610 in the battery module 600 as an example. In a specific implementation, other protection units in the battery module 600 can also achieve corresponding functions, which will not be described in detail here.

[0112] In one possible implementation, the embodiment of the present application can also provide protection when abnormal conditions occur between battery packs connected in series. An example is given below with reference to FIG13 .

[0113] In Figure 13, two battery packs connected in series in a battery module are taken as an example. For example, Figure 13 assumes that the protection unit and the battery cell are encapsulated together in the battery pack. The number of battery cells connected in series and the number of protection units in the battery pack are only examples. In a specific implementation, more or fewer battery cells and protection units may be included. As shown in Figure 13, battery pack 1 includes protection unit 11, protection unit 12, and protection unit 13, as well as a plurality of battery cells connected in series. Similarly, battery pack 2 includes protection unit 21, protection unit 22, and protection unit 23, as well as a plurality of battery cells connected in series. The protection unit 11, protection unit 13, protection unit 21, and protection unit 23 can be exemplified by referring to the first protection unit 610 described above. The protection unit 12 and protection unit 22 can be exemplified by referring to the second protection unit 640 described above.

[0114] For example, in FIG13 above, it is assumed that the battery cell a in the battery pack 1 and the battery cell b in the battery pack 2 have an external cell path due to condensation, electrolyte leakage, coolant leakage or insulation damage. Due to the existence of the external cell path, an additional current loop is formed (see the dotted line in FIG13 ). The current in the path through the battery pack 1 and the battery pack 2 through which the current loop passes has changed. The protection unit 12, the protection unit 13, the protection unit 21 and the protection unit 22 in the path can detect the current anomaly in the path and disconnect their respective disconnecting devices based on the anomaly. The specific implementation of each protection unit can refer to the relevant introduction in FIG12 above and will not be repeated here.

[0115] In Figure 13, if the protection unit is not included in the path, then after the external cell path is generated, the maximum voltage applied to cell a and cell b may exceed the insulation withstand voltage of the two cells, causing the insulation of the two cells to break down, resulting in the risk of thermal runaway or even fire. Therefore, by providing the protection unit in the battery pack, the embodiment of the present application can reduce the risk of thermal runaway or even fire caused by the external cell path between battery packs, thereby ensuring the safety of the battery module.

[0116] In summary, the embodiments of the present application provide a protection unit in the battery module and connect the disconnecting device in series between the battery cells, so that when an abnormality occurs between the battery cells (such as overcurrent, overtemperature or leakage, etc.), the disconnecting device can be quickly disconnected to protect the battery module. In this solution, effective battery module protection can be provided for scenarios where high voltage breaks down the insulation of the battery cell, or for scenarios such as warehousing or transportation where the BMS system is not working and cannot provide protection for the battery module.

[0117] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0118] It will also be understood that the term “comprise” (also known as “includes,” “including,” “comprises,” and / or “comprising”) when used in this specification specifies the presence of stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0119] It should also be understood that references throughout this specification to "one embodiment," "an embodiment," or "one possible implementation" mean that specific features, structures, or characteristics associated with that embodiment or implementation are included in at least one embodiment of the present application. Therefore, the appearance of "in one embodiment," "in an embodiment," or "one possible implementation" throughout this specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery module, characterized in that: The battery module includes a first protection unit, a first battery cell and a second battery cell; the first protection unit includes a first disconnecting device, a first detection unit and a first controller; The first battery cell and the second battery cell are connected in series; The first disconnecting device is connected in series between the first battery cell and the second battery cell; The first detection unit is used to detect first status information, and the first status information is used to indicate the status of the battery module; The first controller is used to control the first disconnecting device to disconnect when the first status information indicates that the battery module is abnormal.

2. The battery module according to claim 1, characterized in that: The first battery cell and the second battery cell belong to a first battery cell group of the battery module; the battery module also includes a second battery cell group, and the second battery cell group includes a third battery cell and a fourth battery cell; the total voltage of the first battery cell group is less than or equal to the insulation withstand voltage of the first battery cell or the second battery cell, and the total voltage of the second battery cell group is less than or equal to the insulation withstand voltage of the third battery cell or the fourth battery cell; The first status information is used to indicate the status of the first battery cell group; The first controller is used to control the first disconnecting device to disconnect when the first status information indicates that the first battery cell grouping is abnormal; The battery module further includes a second protection unit; the second protection unit includes a second disconnecting device, a second detection unit and a second controller; The second disconnecting device is connected in series between the third battery cell and the fourth battery cell; The second detection unit is used to detect second state information; the second state information is used to indicate the state of the second battery cell group; The second controller is used for controlling the second disconnecting device to disconnect when the second status information indicates that the second battery cell grouping is abnormal.

3. The battery module according to claim 1, characterized in that: The first battery cell belongs to a first battery cell group, and the second battery cell belongs to a second battery cell group; the battery module further includes a third battery cell group, and the third battery cell group includes a fifth battery cell; the total voltage of the first battery cell group is less than or equal to the insulation withstand voltage of the first battery cell, the total voltage of the second battery cell group is less than or equal to the insulation withstand voltage of the second battery cell, and the total voltage of the third battery cell group is less than or equal to the insulation withstand voltage of the fifth battery cell; The first status information is used to indicate the status of the first battery cell group; The first controller is used to control the first disconnecting device to disconnect when the first status information indicates that the first battery cell grouping is abnormal; The battery module further includes a third protection unit, which includes a third disconnecting device, a third detection unit and a third controller; The third disconnecting device is connected in series between the second battery cell and the fifth battery cell; The third detection unit is used to detect third state information; the third state information is used to indicate the state of the second battery cell group; The third controller is used for controlling the third disconnecting device to disconnect when the third status information indicates that the second battery cell grouping is abnormal.

4. The battery module according to any one of claims 1 to 3, characterized in that: The first disconnecting device is an explosive fuse, a contactor, a relay or a semiconductor switch.

5. The battery module according to any one of claims 1 to 4, characterized in that: The first detection unit includes a current detection unit, and the current detection unit is used to detect the current between the first battery cell and the second battery cell; The first controller is used to control the first disconnecting device to disconnect when the current is different from the current at the positive electrode or the negative electrode of the battery module; or The first controller is used for controlling the first disconnecting device to disconnect when the current is greater than a first threshold.

6. The battery module according to any one of claims 1 to 5, characterized in that: The first detection unit includes a temperature detection unit, and the temperature detection unit is used to detect the temperature of the first battery cell or the second battery cell; The first controller is used for controlling the first disconnecting device to disconnect when the temperature of the first battery cell or the second battery cell is greater than a second threshold.

7. The battery module according to any one of claims 1 to 6, characterized in that: The first detection unit includes a leakage detection circuit, which is connected to the ground wire of the battery module and is used to detect the current flowing through the ground wire; The first controller is used for controlling the first disconnecting device to disconnect when the current flowing through the grounding line is greater than a third threshold.

8. The battery module according to any one of claims 1 to 7, characterized in that: The first detection unit and the first controller are powered by one or more battery cells in the battery module.

9. A battery pack, characterized in that: The battery pack comprises a battery module as described in any one of claims 1 to 7 and a first battery management unit; The first battery management unit is used to collect status information of the battery pack.

10. The battery pack according to claim 9, characterized in that: The battery pack also includes a first auxiliary power supply, and the first detection unit and the first controller in the battery module are powered by the first auxiliary power supply.

11. An energy storage system, characterized in that: The energy storage system comprises the battery pack as claimed in claim 9 and a second battery management unit; the second battery management unit is connected to the first battery management unit and to the first controller included in the battery module; The second battery management unit is used to receive the status information of the battery pack collected by the first battery management unit; The second battery management unit is further configured to notify the first controller to control the first disconnecting device to disconnect when the status information indicates that the battery pack is abnormal.

12. The energy storage system according to claim 11, characterized in that: The energy storage system further includes a second auxiliary power supply, and the first detection unit and the first controller are powered by the second auxiliary power supply.

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