Battery management system and energy storage system

Abstract

The utility model discloses a battery management system and an energy storage system, and belongs to the technical field of power electronics. The utility model provides a battery management system, which comprises a plurality of battery cell groups, each battery cell group comprises at least one battery cell, each battery cell comprises a sampling module and a wireless communication module, the sampling module is configured to collect battery cell information of the battery cells, and the wireless communication module is configured with a first near-field antenna; a plurality of first communication nodes, each first communication node is arranged corresponding to each cell group, the first communication node is configured with a second near-field antenna, and the second near-field antenna is used for establishing wireless communication connection with each first near-field antenna in the corresponding cell group; and the second communication node is in wireless communication connection with each first communication node. Wireless communication connection is adopted between the battery cell group and the first communication node, and between the first communication node and the second communication node, so that wireless transmission of battery cell data is realized, and the problem of communication wire harness failure is reduced.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and in particular relates to a battery management system and an energy storage system. Background Art

[0002] Currently, the mainstream communication methods for energy storage products on the market are mostly achieved through wired methods. In actual use, the number of wiring harnesses will increase with the number of battery cells. Therefore, the quality of the wiring harness will affect the reliability of the energy storage system. Any short circuit, connection, or disconnection in the wiring harness may cause the energy storage system to fail. The mainstream wireless energy storage systems on the market only install wireless modules outside the battery pack for wireless communication. Inside the battery pack, the communication harness of each battery cell must still be connected to a sampling board for signal acquisition and transmission. This does not solve the reliability issues caused by the communication harness. Utility Model Content

[0003] This application aims to solve at least one of the technical problems existing in the prior art. To this end, this application proposes a battery management system and energy storage system, in which wireless communication connections are used between the battery cell group and the first communication node, and between the first communication node and the second communication node, to achieve wireless transmission of battery cell data and reduce the problem of communication harness failure.

[0004] In a first aspect, the present application provides a battery management system, comprising:

[0005] A plurality of battery cell groups, each battery cell group including at least one battery cell, each battery cell including a sampling module and a wireless communication module, the sampling module being configured to collect battery cell information of the battery cell, and the wireless communication module being configured with a first near-field antenna;

[0006] A plurality of first communication nodes, each first communication node being provided corresponding to each battery cell group, the first communication node being configured with a second near-field antenna, the second near-field antenna being used to establish a wireless communication connection with each first near-field antenna in the corresponding battery cell group;

[0007] The second communication node is wirelessly connected to each first communication node.

[0008] According to the battery management system of the present application, the wireless communication module transmits the battery cell information to the corresponding first communication node through the near-field antenna. After each first communication node receives the information of each battery cell in the corresponding battery cell group, it wirelessly transmits the battery cell information to the second communication node. The second communication node collects all battery cell information. Wireless communication connections are used between the battery cell group and the first communication node, and between the first communication node and the second communication node to realize wireless transmission of battery cell data and reduce the problem of communication harness failure.

[0009] According to one embodiment of the present application, the battery cell group includes a plurality of battery cells, the second near-field antenna extends along the battery cell arrangement direction, and the second near-field antenna is arranged close to each first near-field antenna.

[0010] According to one embodiment of the present application, a plurality of battery cells are arranged in an array, a first communication node and the battery cell array are arranged along the row direction of the battery cell array, and the second near-field antenna includes a first part that is partially overlapped with each row of battery cells in a facing direction, a second part connected between two adjacent first parts, and a third part connected to the first part and the first communication node, and each first part, each second part, each third part and the first communication node are connected end to end.

[0011] According to one embodiment of the present application, a plurality of battery cells are arranged in an array, a first communication node and the battery cell array are arranged along the row direction of the battery cell array, and the second near-field antenna includes a plurality of fourth parts and a fifth part connected between the fourth parts and the first communication node, and the fourth parts are arranged to partially overlap with the corresponding battery cells arranged along the row direction in the facing direction.

[0012] According to one embodiment of the present application, the battery cell further includes:

[0013] The battery cell body has a positive electrode column and a negative electrode column, and the sampling module is connected to the positive electrode column and the negative electrode column respectively;

[0014] The controller and storage unit are arranged on the battery cell body, and the controller is connected to the storage unit, the sampling module and the wireless communication module respectively.

[0015] According to one embodiment of the present application, the first communication node and the second communication node adopt near field communication.

[0016] According to one embodiment of the present application, the first communication node and the second communication node communicate wirelessly via Bluetooth, WiFi, or 433M.

[0017] According to one embodiment of the present application, the number of first communication nodes is greater than the number of second communication nodes, and each second communication node establishes communication connections with multiple first communication nodes.

[0018] According to one embodiment of the present application, the battery management system further includes a battery module management unit, and the second communication node is arranged in the battery module management unit.

[0019] In a second aspect, the present application provides an energy storage system, which includes: a battery system, an energy storage inverter and a controller. The battery system is configured with the aforementioned battery management system, the battery system is connected to the energy storage inverter, and the controller is connected to the battery management system and the energy storage inverter respectively.

[0020] According to the energy storage system of the present application, the wireless communication module in the battery management system transmits the battery cell information to the corresponding first communication node through the near-field antenna. After each first communication node receives the information of each battery cell in the corresponding battery cell group, it wirelessly transmits the battery cell information to the second communication node. The second communication node collects all battery cell information. Wireless communication connections are used between the battery cell group and the first communication node, and between the first communication node and the second communication node to realize wireless transmission of battery cell data and reduce the problem of communication harness failure.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 This is one of the structural block diagrams of the battery management system provided in the embodiment of the present application;

[0024] Figure 2 This is one of the structural diagrams of the battery cell provided in the embodiment of the present application;

[0025] Figure 3 This is one of the schematic diagrams of the second near-field antenna and battery cell positions provided in an embodiment of the present application;

[0026] Figure 4 This is the second schematic diagram of the position of the second near-field antenna and the battery cell provided in an embodiment of the present application;

[0027] Figure 5 This is one of the structural block diagrams of the battery management system provided in the embodiment of the present application;

[0028] Figure 6 This is the second structural schematic diagram of the battery cell provided in the embodiment of the present application.

[0029] Reference numerals:

[0030] Battery cell group 100, battery cell 110, sampling module 111, wireless communication module 112, first near-field antenna 113, battery cell body 114, controller 115, storage unit 116, first communication node 200, second near-field antenna 210, first part 211, second part 212, third part 213, fourth part 214, fifth part 215, third near-field antenna 220, second communication node 300, fourth near-field antenna 310, battery pack 400. DETAILED DESCRIPTION

[0031] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0032] In the following description, a "circuit" refers to a conductive loop consisting of at least one element or subcircuit connected electrically or electromagnetically. When an element or circuit is said to be "coupled to" or "connected to" another element, or when an element / circuit is said to be "coupled to" or "connected between" two nodes, it can be directly coupled or connected to the other element or there can be intervening elements. The connection between the elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there are no intervening elements between the two elements.

[0033] In the description, the terms "first," "second," etc. are used to distinguish similar objects, not to describe a particular order or precedence. It should be understood that the numerical descriptors used in this manner are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of a class and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0034] In addition, descriptions with reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0035] Currently, the mainstream communication method for energy storage products on the market is mostly achieved through wired methods. In actual use, the number of wiring harnesses will increase with the number of battery cells. Therefore, the quality of the wiring harness will affect the reliability of the energy storage system. Any short circuit, connection, or disconnection in the wiring harness may cause the energy storage system to fail. The wireless energy storage system in related technologies only installs a wireless module outside the battery pack for wireless communication. Inside the battery pack, the communication harness of each battery cell must still be connected to a sampling board for signal acquisition and transmission. This cannot solve the reliability issues caused by the communication harness.

[0036] Reference Figure 1 , Figure 1 The structural block diagram of the battery management system provided by an embodiment of the present application is shown. One embodiment of the present application proposes a battery management system, comprising: a plurality of battery cell groups 100, a plurality of first communication nodes 200 and a second communication node 300. The battery cell group 100 includes at least one battery cell 110, and the battery cell 110 includes a sampling module 111 and a wireless communication module 112. The sampling module 111 is configured to collect battery cell information of the battery cell 110, and the wireless communication module 112 is configured with a first near-field antenna 113; each first communication node 200 is arranged corresponding to each battery cell group 100, and the first communication node 200 is configured with a second near-field antenna 210, and the second near-field antenna 210 is used to establish a wireless communication connection with each first near-field antenna 113 in the corresponding battery cell group 100; the second communication node 300 is wirelessly connected with each first communication node 200.

[0037] The battery pack 100 may include a single battery cell 110 or multiple battery cells 110 connected in series or in parallel. A first communication node 200 is provided in a one-to-one correspondence with each battery pack 100. A battery pack 100 and a first communication node 200 form a battery pack 400. The battery pack 400 is provided with a housing, and the first communication node 200 and the corresponding battery pack 100 are encapsulated within the housing of the battery pack 400.

[0038] In actual applications, a battery pack 400 usually includes multiple battery cells 110. The number of battery cells 110 in different battery packs 400 may be different. The first communication node 200 can simultaneously collect information transmitted by the wireless communication module 112 of each battery cell 110 in the battery pack 400. The specific number of battery cells 110 is not limited here and can be selected according to the application scenario.

[0039] Reference Figure 2 , Figure 2The structure of the battery cell 110 provided in an embodiment of the present application is shown. The battery cell 110 may include a battery cell body 114 and a sampling module 111 and a wireless communication module 112 arranged on the battery cell body 114. The battery cell body 114 has a positive pole and a negative pole, and the sampling module 111 is connected to the positive pole and the negative pole respectively. The sampling module 111 is mainly used to collect battery cell information of each battery cell, and the battery cell information includes but is not limited to the voltage, current, temperature and remaining capacity of the battery cell. The sampling module 111 may include a shell and a PCB (Printed Circuit Board) arranged inside the shell. The sampling module 111 and the wireless communication module 112 may be arranged on the same PCB, or they may be arranged on different PCBs respectively. Among them, when the sampling module 111 and the wireless communication module 112 are arranged on different PCBs, they can be connected through a board-to-board connector.

[0040] The wireless communication module 112 is electrically connected to the sampling module 111 and is mainly used to receive the cell information collected by the sampling module 111 and transmit the cell information to the corresponding first communication node 200 to achieve wireless transmission of the cell information within the battery pack 400 .

[0041] Near-field antennas use the principle of electromagnetic induction to transmit information over a relatively short range by inducing current. They are suitable for short-distance communications, where communication devices are typically close together. Near-field antennas can automatically transmit data between each other, eliminating the need for manual configuration and resulting in faster connection speeds.

[0042] After receiving the cell information collected by the sampling module 111 , the wireless communication module 112 uses the first near-field antenna 113 to wirelessly communicate with the second near-field antenna 210 in the first communication node 200 to transmit the cell information to the first communication node 200 .

[0043] The battery management system is equipped with a management layer device that can intelligently manage the battery pack 400. Its main function is to manage the power, charging status, temperature and health status of the battery pack 400, prevent the battery pack 400 from over-discharge and overcharge, thereby extending the life of the battery pack 400, and support fault diagnosis and data analysis of the battery pack 400.

[0044] The second communication node 300 can be set in the management layer device of the battery management system. The second communication node 300 can be an independent CMU (Cell Monitor Unit) or the controller 115 in the battery management system, which is not limited here. The second communication node 300 receives the battery cell information transmitted by the first communication node 200 via wireless communication, thereby enabling data transmission between each battery pack 400 and the upper-level control device.

[0045] According to the battery management system of the present application, the wireless communication module 112 transmits the battery cell information to the corresponding first communication node 200 through the near-field antenna. After each first communication node 200 receives the information of each battery cell 110 in the corresponding battery cell group 100, it wirelessly transmits the battery cell information to the second communication node 300. The second communication node 300 collects all battery cell information. Wireless communication connections are used between the battery cell group 100 and the first communication node 200, and between the first communication node 200 and the second communication node 300 to realize wireless transmission of battery cell information and reduce the problem of communication harness failure.

[0046] In some embodiments, the battery cell group 100 includes a plurality of battery cells 110 , the second near-field antenna 210 extends along an arrangement direction of the battery cells 110 , and the second near-field antenna 210 is arranged close to each of the first near-field antennas 113 .

[0047] The battery cell group 100 includes multiple battery cells 110, each of which includes a corresponding wireless communication module 112, which is equipped with a first near-field antenna 113. The second near-field antenna 210 in the first communication node 200 extends along the arrangement direction of the battery cells 110 in its corresponding battery cell group 100 and is arranged close to each first near-field antenna 113 to receive battery cell information transmitted by the wireless communication module 112 on each corresponding battery cell 110, thereby enabling a communication node to receive battery cell information of all battery cells 110 in its corresponding battery cell group 100.

[0048] Reference Figure 3 , Figure 3 Figure 2 shows the positional relationship between the second near-field antenna 210 and the battery cell 110 provided in an embodiment of the present application. In some embodiments, the plurality of battery cells 110 are arranged in an array, the first communication node 200 and the battery cell array are arranged along the row direction of the battery cell array, and the second near-field antenna 210 includes a first portion 211 that partially overlaps with each row of battery cells 110 in the facing direction, a second portion 212 connected between two adjacent first portions 211, and a third portion 213 connected between the first portion 211 and the first communication node 200. Each first portion 211, each second portion 212, each third portion 213 and the first communication node 200 are connected end to end.

[0049] The number of battery cells 110 in each row may be the same or different, as long as the first near-field antennas 113 in the battery cells 110 in each row are arranged on the same horizontal line.

[0050] The first communication node 200 can be located on the left side of the cell array, or the first communication node 200 can be located on the right side of the cell array. The second near-field antenna 210 is extended from the first end of the first communication node 200 along the column direction of the cell array. The first portion 211 of the second near-field antenna 210 is located in a relatively close space directly above the first near-field antenna 113 of each cell 110 in the cell array to receive cell information transmitted by each first near-field antenna 113.

[0051] For example, a battery pack 400 includes 40 battery cells 110, and the battery cells 110 are numbered 1 to 40. Each 10 battery cells 110 are arranged in a row, with the battery cells 110 numbered 1 to 10 arranged in the first row, the battery cells 110 numbered 11 to 20 arranged in the second row, the battery cells 110 numbered 21 to 30 arranged in the third row, and the battery cells 110 numbered 31 to 40 arranged in the fourth row.

[0052] The first portion 211 of the second near-field antenna 210 is arranged along the row direction of the battery cell array, and the first portion 211 of the second near-field antenna 210 is partially overlapped with the first near-field antenna 113 in each row of battery cells in the battery cell array in the facing direction to collect battery cell information in each battery cell.

[0053] The second portion 212 of the second near-field antenna 210 is arranged along the column direction of the battery cell array to connect the first portion 211 arranged between battery cell No. 10 110 and battery cell No. 110 , the first portion 211 arranged between battery cell No. 20 110 and battery cell No. 30 110 , and the first portion 211 arranged between battery cell No. 21 110 and battery cell No. 31 110 .

[0054] The third portion 213 of the second near-field antenna 210 can be extended from the first end of the first communication node 200 and connected to the first portion 211 arranged in the first row of battery cells 110. The third portion 213 of the second near-field antenna 210 can also be extended from the second end of the first communication node 200 and connected to the first portion 211 arranged in the fourth row of battery cells 110. The second near-field antenna 210 is arranged in a serpentine pattern in the battery cell array and ultimately returns to the first communication node 200 to form a ring connection, thereby enabling the transmission of battery cell information from each battery cell 110 to the first communication node 200.

[0055] Reference Figure 4 , Figure 4The figure shows the positional relationship between the second near-field antenna 210 and the battery cell 110 provided in an embodiment of the present application. In some embodiments, multiple battery cells 110 are arranged in an array, the first communication node 200 and the battery cell array are arranged along the row direction of the battery cell array, and the second near-field antenna 210 includes multiple fourth portions 214 and fifth portions 215 connected between the fourth portions 214 and the first communication nodes 200. The fourth portions 214 are arranged to partially overlap with the corresponding battery cells 110 arranged along the row direction in the facing direction.

[0056] The plurality of fifth portions 215 of the second near-field antenna 210 are drawn out from the first communication node 200 and extend to be parallel to each row array and connected to the first end of each fourth portion 214 .

[0057] As an example, a battery pack 400 includes 40 battery cells 110 , and the battery cells 110 are numbered 1 to 40 . The first fourth portion 214 of the second near-field antenna 210 is arranged partially overlapping with the first near-field antenna 113 of battery cells 110 in the facing direction, the second fourth portion 214 of the second near-field antenna 210 is arranged partially overlapping with the first near-field antenna 113 of battery cells 110 in the facing direction, the third fourth portion 214 of the second near-field antenna 210 is arranged partially overlapping with the first near-field antenna 113 of battery cells 110 in the facing direction, the fourth fourth portion 214 of the second near-field antenna 210 is arranged partially overlapping with the first near-field antenna 113 of battery cells 110 in the facing direction, the first end of each fourth portion 214 is connected to the first end of the fifth portion 215, the first end of the fifth portion 215 is connected to the first communication node 200, and the second end of each fourth portion 214 of the second near-field antenna 210 is suspended to form a single-ended connection.

[0058] Reference Figure 5 , Figure 5 The structure of the battery cell 110 provided in an embodiment of the present application is shown. In some embodiments, the battery cell 110 further includes: a battery cell body 114, a controller 115 and a storage unit 116 disposed on the battery cell body 114. The controller 115 is connected to the storage unit 116, the sampling module 111 and the wireless communication module 112 respectively.

[0059] Controller 115 has computing capabilities and can store comparison programs, threshold data, and other information. Controller 115 is connected to sampling module 111 and can obtain data collected by sampling module 111 and other data, and perform comparison operations and other processing on the data. Furthermore, controller 115 is also connected to storage unit 116 and wireless communication module 112 to control their respective operating states.

[0060] The storage unit 116 can be used to store the cell information collected by the sampling module 111. When no near-field antenna or other communication module is provided, the storage unit 116 can also temporarily store the information collected by the collection unit and read the stored information when the cell information is needed.

[0061] Providing the controller 115 and the storage unit 116 in the sampling module 111 can realize functions such as calculation and temporary storage, and can make the sampling module 111 better adapt to complex environments in actual applications.

[0062] As an example, a voltage threshold of a single battery cell 110 is set in the controller 115, and the sampling module 111 transmits the collected actual voltage value of the battery cell 110 to the controller 115. The controller 115 can compare the actual voltage value with the voltage threshold and transmit the comparison result to the host computer through the wireless communication module 112.

[0063] Reference Figure 6 , Figure 6 FIG. 1 is a block diagram of a battery management system according to an embodiment of the present application. In some embodiments, the first communication node 200 and the second communication node 300 use near field communication.

[0064] Wireless transmission of cell information can be achieved between the first communication node 200 and the second communication node 300 through a near-field antenna.

[0065] As an example, the first communication node 200 is configured with a third near-field antenna 220, and the second communication node 300 is configured with a fourth near-field antenna 310. The fourth near-field antenna 310 is arranged to partially overlap with each third near-field antenna 220 in the facing direction. The third near-field antenna 220 can convert battery cell information into high-frequency current. When the current flows in the third near-field antenna 220, a magnetic field is generated around the third near-field antenna 220. When the magnetic field generated around the third near-field antenna 220 encounters the fourth near-field antenna 310, an induced current is generated, and the induced current can realize the transmission of the battery cell signal.

[0066] The fourth near-field antenna 310 and each third near-field antenna 220 are partially overlapped in the facing direction, so that the transmission efficiency of the cell information can be maximized and distortion of the cell information can be avoided.

[0067] It should be noted that the fourth near-field antenna 310 only needs to be arranged close to the third near-field antenna 220 so that the fourth near-field antenna 310 can sense the electromagnetic field generated by the third near-field antenna 220. The relative position of the fourth near-field antenna 310 and the third near-field antenna 220 is not specifically limited here and can be selected according to the actual scenario.

[0068] In some embodiments, the first communication node 200 and the second communication node 300 communicate wirelessly via Bluetooth, WiFi, or 433M.

[0069] Bluetooth is used to achieve wireless communication between the first communication node 200 and the second communication node 300, which has low power consumption and extends the service life of the device battery; WiFi is used to achieve wireless communication between the first communication node 200 and the second communication node 300, which can achieve a higher transmission rate and a larger transmission capacity; 433M is used to achieve wireless communication between the first communication node 200 and the second communication node 300, which can achieve long-distance transmission and can adapt to more complex environmental conditions.

[0070] In some embodiments, the number of first communication nodes 200 is greater than the number of second communication nodes 300 , and each second communication node 300 establishes communication connections with multiple first communication nodes 200 .

[0071] Each first communication node 200 wirelessly communicates with a cell group 100 to receive cell information from the cell group 100. Each second communication node 300 establishes communication connections with multiple first communication nodes 200, allowing one second communication node 300 to collect cell information from multiple cell groups 100, thereby reducing the number of second communication nodes 300 and lowering the cost of data collection.

[0072] In some embodiments, the battery management system further includes a battery module management unit, and the second communication node 300 is disposed in the battery module management unit.

[0073] The battery module management unit (BMU) is primarily responsible for collecting and managing information such as the voltage, current, and temperature of individual battery cells and transmitting it to the upper-level management device. A second communication node 300 is located within the BMU to implement its information collection function, thus enabling wireless communication between the battery cell information and the management device.

[0074] One embodiment of the present application provides an energy storage system, which includes: a battery system, an energy storage converter and a controller. The battery system is configured with the aforementioned battery management system, the battery system is connected to the energy storage converter, and the controller is connected to the battery management system and the energy storage converter, respectively.

[0075] The battery cells 110 in the battery system use the aforementioned near-field antenna for wireless communication to achieve wireless transmission of battery cell information. Specific structures and principles can be found in the aforementioned embodiments and will not be described in detail here.

[0076] In some embodiments, the energy storage system also includes an Energy Management System (EMS) and a monitoring system. Both the EMS and the monitoring system are connected to a controller, which controls the EMS to dispatch energy. The monitoring system monitors the operation of each component of the energy storage system in real time and uploads the information to the controller.

[0077] According to the energy storage system of the present application, the wireless communication module 112 in the battery management system transmits the battery cell information to the corresponding first communication node 200 through the near-field antenna. After each first communication node 200 receives the information of each battery cell 110 in the corresponding battery cell group 100, it wirelessly transmits the battery cell information to the second communication node 300. The second communication node 300 collects all battery cell information. Wireless communication connections are used between the battery cell group 100 and the first communication node 200, and between the first communication node 200 and the second communication node 300 to realize wireless transmission of battery cell data and reduce the problem of communication harness failure.

[0078] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery management system, characterized in that: include: A plurality of battery cell groups, each battery cell group including at least one battery cell, each battery cell including a sampling module and a wireless communication module, the sampling module being configured to collect battery cell information of the battery cell, and the wireless communication module being configured with a first near-field antenna; a plurality of first communication nodes, each of which is provided corresponding to each of the battery cell groups, the first communication node being configured with a second near-field antenna, the second near-field antenna being used to establish a wireless communication connection with each of the first near-field antennas in the corresponding battery cell group; The second communication node is wirelessly connected to each of the first communication nodes.

2. The battery management system according to claim 1, characterized in that: The battery cell group includes a plurality of battery cells, the second near-field antenna extends along the battery cell arrangement direction, and the second near-field antenna is arranged close to each of the first near-field antennas.

3. The battery management system according to claim 2, characterized in that: The multiple battery cells are arranged in an array, the first communication node and the battery cell array are arranged along the row direction of the battery cell array, and the second near-field antenna includes a first part that is partially overlapped with each row of the battery cells in the opposite direction, a second part connected between two adjacent first parts, and a third part connected to the first part and the first communication node, and each first part, each second part, each third part and the first communication node are connected end to end.

4. The battery management system according to claim 2, characterized in that: The multiple battery cells are arranged in an array, the first communication node and the battery cell array are arranged along the row direction of the battery cell array, the second near-field antenna includes a plurality of fourth parts and a fifth part connected between the fourth parts and the first communication node, and the fourth parts are arranged to partially overlap with the corresponding battery cells arranged along the row direction in the facing direction.

5. The battery management system according to any one of claims 1 to 4, characterized in that: The battery cell further comprises: A battery cell body, wherein the battery cell body has a positive electrode column and a negative electrode column, and the sampling module is connected to the positive electrode column and the negative electrode column respectively; A controller and a storage unit are provided on the battery cell body, and the controller is connected to the storage unit, the sampling module and the wireless communication module respectively.

6. The battery management system according to any one of claims 1 to 4, characterized in that: The first communication node and the second communication node adopt near field communication.

7. The battery management system according to any one of claims 1 to 4, characterized in that: The first communication node and the second communication node communicate with each other wirelessly via Bluetooth, WiFi or 433M.

8. The battery management system according to any one of claims 1 to 4, characterized in that: The number of the first communication nodes is greater than the number of the second communication nodes, and each of the second communication nodes establishes communication connections with multiple first communication nodes.

9. The battery management system according to any one of claims 1 to 4, characterized in that: The battery management system further includes a battery module management unit, and the second communication node is arranged in the battery module management unit.

10. An energy storage system, characterized in that: It includes a battery system, an energy storage converter and a controller, wherein the battery system is configured with a battery management system according to any one of claims 1 to 9, the battery system is connected to the energy storage converter, and the controller is connected to the battery management system and the energy storage converter respectively.

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