Distributed energy storage lithium ion battery pack and energy storage system

Abstract

The invention belongs to the technical field of lithium ion batteries, and mainly relates to a distributed energy storage lithium ion battery pack which comprises at least two battery monomers, and each battery monomer is composed of a polymer lithium ion battery. Each battery monomer is provided with a heat dissipation module, a protection module and a battery management module; the heat dissipation module is responsible for cooling a charge-discharge battery, the protection module is powered off when the voltage is abnormal, and the battery management module controls power connection according to an instruction and transmits electric quantity data; the battery pack control module drives the battery pack to output electric energy according to an electric quantity and demand matching strategy under the discharging instruction; under the charging instruction, the battery pack control module formulates a priority strategy according to the electric quantity, and preferentially charges the single battery with the lowest electric quantity; therefore, the running state of each single battery is sensed in real time and independently managed; in addition, the invention further designs an energy storage system, and the risk that the battery pack is out of control is further reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium-ion batteries, and in particular relates to a distributed energy storage lithium-ion battery pack and an energy storage system. Background Art

[0002] At present, electric vehicles and other devices that need energy storage usually integrate multiple battery cells in a battery cabinet to meet greater power requirements to achieve overall charging and discharging functions. This design significantly increases the capacity of the energy storage device by combining multiple battery cells.

[0003] However, the existing technology has some obvious defects. First, in the existing lithium-ion battery pack, multiple battery cells are connected in series or in parallel through a busbar. Although this method can achieve high-capacity energy storage to a certain extent, it lacks the ability to independently manage and control each battery cell. During the charging and discharging process, due to the imbalance of power between the single cells, some battery cells are easily overcharged or over-discharged, thereby shortening the life of the entire battery pack. In addition, since the existing technology cannot monitor and independently control the battery cells in real time, the state differences between the single cells cannot be handled in time. During the charging and discharging process, the battery cells may experience abnormal changes in voltage or temperature, but the lack of an effective protection mechanism may cause safety problems such as overheating and short circuits.

[0004] Based on this, it is urgent to distribute the lithium-ion battery packs in the energy storage system to solve the above technical defects. Summary of the invention

[0005] One of the purposes of the present invention is to provide a distributed lithium-ion battery pack to address the technical defect of the prior art that lithium-ion battery cells cannot be monitored and independently controlled in real time.

[0006] In order to achieve the above technical objectives, this application implements the following technical solutions:

[0007] A distributed energy storage lithium-ion battery pack, comprising a battery cabinet and at least two battery cells arranged in the battery cabinet, wherein the battery cabinet is provided with an input end and an output end, wherein the input end inputs electric energy provided from the outside and distributes it to the battery cells according to a battery pack control module arranged in the battery cabinet, and the output end outputs the electric energy of the battery cells selected by the battery pack control module;

[0008] The battery cell is composed of a plurality of polymer lithium-ion batteries of the same model. Each battery cell is connected with a heat dissipation module, a protection module and a battery management module. The heat dissipation module is used to dissipate heat from the battery cell during the charging and discharging process. The protection module performs power-off protection for the battery cell with abnormal voltage changes during the charging and discharging process. The battery management module drives the power supply to access the battery cell through the instruction of the battery pack control module and transmits the power data of the battery cell to the battery pack control module.

[0009] After receiving the discharge command, the battery pack control module generates an energy distribution strategy based on the power of each battery cell in the battery cabinet and the discharge demand, and drives the battery cell to output power;

[0010] After receiving the charging instruction, the battery pack control module generates a charging priority strategy according to the power of each battery cell in the battery cabinet, and preferentially charges the battery cell with the smallest power among the battery cells in the battery cabinet.

[0011] The above technical solution produces the following technical effects:

[0012] In the technical solution proposed in this application, each battery cell is connected to an independent heat dissipation module, a protection module and a battery management module. The heat dissipation module dissipates the heat of the battery cells in the process of charging and discharging in real time to ensure that the battery operates within a safe temperature range and effectively extend the battery life. The protection module can monitor the abnormal voltage changes of the battery cells in real time during the charging and discharging process, and quickly disconnect the power supply when an abnormality is detected to avoid battery damage caused by overvoltage, undervoltage and other problems. The battery management module BMU can monitor the power, temperature and other parameters of the single battery, and transmit the data to the battery pack control module to ensure that the operating status of each single battery is sensed in real time and managed independently.

[0013] Based on this, the technical solution of the present application solves the problem in traditional technology that the differences in battery cell states cannot be perceived and processed in real time by independently managing each battery cell, avoiding the performance degradation of single cells caused by overcharging or over-discharging, and significantly improving the overall life of the battery pack.

[0014] As a further improvement to a distributed energy storage lithium-ion battery pack of the present invention, the charging priority strategy is that the battery pack control module outputs the battery cell with the smallest power according to the battery power information of the battery cells that are not in the discharge process;

[0015] When the power difference between other battery cells and the battery cell with the lowest power is less than the first threshold, the battery pack control module drives the battery management module to simultaneously charge the battery cells whose power difference with the battery cell with the lowest power is less than the first threshold.

[0016] As a further improvement to the distributed energy storage lithium-ion battery pack of the present invention, the first threshold is 0.01-0.05.

[0017] As a further improvement to a distributed energy storage lithium-ion battery pack of the present invention, when the difference between the battery power of a battery cell in at least two battery cells that are simultaneously charged and discharged and the average battery power of at least two battery cells that are simultaneously charged and discharged exceeds a second threshold, the battery pack control module drives the battery cell that meets the above situation to stop charging.

[0018] As a further improvement of a distributed energy storage lithium-ion battery pack of the present invention, the power distribution strategy is that the battery pack control module sorts the battery power of battery cells that are not charging and prioritizes them from high to low according to the battery power, and discharges at least one battery cell with a high priority that meets the discharge requirements.

[0019] As a further improvement to the distributed energy storage lithium-ion battery pack of the present invention, each battery cell is fixedly connected to a battery temperature sensor, and the battery temperature sensor transmits the temperature information of the battery to the heat dissipation module.

[0020] As a further improvement of a distributed energy storage lithium-ion battery pack of the present invention, each battery cell is fixedly connected to a voltage sensor. The voltage sensor transmits the voltage signal of the battery cell to the battery management module through a digital-to-analog converter. The battery management module calculates the battery power of the battery cell through the coulomb counting method based on the received voltage signal of the battery cell.

[0021] As a further improvement of a distributed energy storage lithium-ion battery pack of the present invention, the battery pack control module is provided with at least one communication interface, the communication interface is connected to the control terminal via the CAN bus protocol or the RS485 protocol, and the control terminal is used to input charging instructions or discharging instructions to the battery pack control module.

[0022] As a further improvement to the distributed energy storage lithium-ion battery pack of the present invention, heat dissipation plates are arranged on both sides of the battery cabinet, and heat dissipation through holes are arranged on the heat dissipation plates.

[0023] The second technical purpose of the present application is to design an energy storage system to solve the problem that the existing energy storage system cannot effectively monitor and manage the battery pack in real time in view of the technical defects in the existing technology.

[0024] In order to achieve the above technical purpose, this application implements the following technical solutions:

[0025] An energy storage system, comprising at least two of any one of the above-mentioned distributed energy storage lithium-ion battery packs and a control terminal communicatively connected to a battery pack control module in the distributed energy storage lithium-ion battery pack;

[0026] The control terminal outputs a discharge instruction to a battery pack control module of one or more distributed energy storage lithium-ion battery packs that meet the power demand of the user end;

[0027] When the total power of all distributed energy storage lithium-ion battery groups in the energy storage system is less than a third threshold, the battery group control module of the distributed energy storage lithium-ion battery group with the smallest power among all the distributed energy storage lithium-ion battery groups outputs a charging instruction.

[0028] The above technical solution produces the following technical effects:

[0029] The energy storage system can intelligently allocate and schedule the charging and discharging status of each distributed energy storage lithium-ion battery pack according to the power demand of the user end, thereby realizing efficient management of the entire energy storage system. The control terminal can promptly respond to changes in the power demand of the user end and optimize the operating efficiency of the energy storage system by monitoring the power status of each battery pack in real time. When the overall power of all distributed energy storage lithium-ion battery packs in the energy storage system is less than the third threshold, the control terminal will automatically issue a charging instruction to the battery pack with the smallest power to ensure that the energy storage system always maintains the best working state and avoids affecting the power demand of the user end due to insufficient power. In addition, by setting up multiple battery packs, the energy storage system has good scalability and flexibility, and can adapt to scenarios of different scales and different power demands. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention;

[0032] Figure 2 It is a side view of the structure of Example 1 of the present invention;

[0033] Figure 3 This is a working flow chart of the energy storage system in Examples 4-5 of the present invention.

[0034] in:

[0035] 1-Battery cabinet;

[0036] 11- input terminal;

[0037] 12- output terminal;

[0038] 13-Battery pack control module;

[0039] 131 - Communication interface;

[0040] 14- heat sink;

[0041] 141 - heat dissipation through hole;

[0042] 2-Battery monomer;

[0043] 21-Polymer lithium-ion battery;

[0044] 22- heat dissipation module;

[0045] 23- protection module;

[0046] 24-Battery management module;

[0047] 3- Control terminal. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0049] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the claims. Any technical personnel in this field may make several possible changes and modifications without departing from the concept of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

[0051] The present invention is further described in detail below in conjunction with specific embodiments, but the embodiments of the present invention are not limited thereto.

[0052] Example 1

[0053] like Figure 1-2As shown, in order to solve the technical defects of the existing energy storage lithium-ion battery pack, the present application designs a distributed energy storage lithium-ion battery pack, including a battery cabinet 1 and at least two battery cells 2 arranged in the battery cabinet 1, the battery cabinet 1 is provided with an input end 11 and an output end 12, the input end 11 inputs externally provided electric energy and distributes it to the battery cell 2 according to the battery pack control module 13, and the output end 12 outputs the electric energy of the battery cell 2 selected by the battery pack control module 13;

[0054] Among them, the input terminal 11 and the output terminal 12 of the battery cabinet 1 are used to receive externally provided electrical energy and release internal electrical energy, and during the charging and discharging process, the electrical energy charge and discharge amount is distributed to different battery cells 2 according to the battery pack control module 13. In the prior art, multiple battery cells 2 are usually directly connected in series or in parallel to form a fixed battery pack structure, and it is not possible to flexibly control a single battery cell 2. Instead, the electrical energy is directly delivered to each battery cell connected in series or in parallel. The unified charging or discharging method may cause some battery cells 2 to be overcharged or over-discharged, thereby reducing the overall life of the energy storage system. However, the present application realizes the flexible allocation of each battery cell 2 during the charging and discharging process through the independent design of the input terminal 11 and the output terminal 12, combined with the dynamic management of the battery pack control module 13, thereby avoiding waste of resources. Moreover, the input terminal 11 can preferentially distribute external electrical energy to the battery cell 2 with the lowest power, and the output terminal 12 can dynamically select a suitable battery cell 2 to provide energy according to the load demand, thereby improving the overall efficiency of charging and discharging.

[0055] Furthermore, the battery cell 2 is composed of multiple polymer lithium-ion batteries 21 of the same model, and each battery cell 2 is connected to a heat dissipation module 22, a protection module 23 and a battery management module 24. The heat dissipation module 22 is used to dissipate heat for the battery cell 2 that is in the process of charging and discharging. The protection module 23 performs power-off protection for the battery cell 2 whose voltage changes abnormally during the charging and discharging process. The battery management module 24 drives the power supply to access the battery cell 2 through the instructions of the battery pack control module 13 and transmits the power data of the battery cell 2 to the battery pack control module 13.

[0056] Among them, the heat dissipation module 22 connected to each battery cell 2 can dissipate the heat of the battery cell 2 during the charging and discharging process, the protection module 23 detects voltage abnormalities in the battery cell 2 and performs power-off protection when necessary; the battery management module 24 monitors the status data of the battery cell 2 such as power, voltage, and temperature in real time. It only needs to add corresponding sensors and perform independent charging and discharging operations through the control module.

[0057] However, the traditional battery pack does not have a separate heat dissipation module 22 to dissipate heat for each battery pack separately, but adopts a collective heat dissipation technical solution, which may cause local overheating during charging and discharging, thereby affecting the performance and safety of the battery. In addition, in the prior art, safety protection is usually achieved only through overvoltage or undervoltage protection of the entire battery pack, and it is impossible to protect a single battery cell 2, which poses a safety hazard. It is more noteworthy that the monitoring of battery cells 2 in traditional technology is usually limited to the total voltage of the battery pack, and it is impossible to independently monitor and manage the power, voltage and temperature of the cell.

[0058] The present application ensures that each battery cell 2 can maintain a safe temperature range during high-load operation such as rapid charging and discharging by introducing a heat dissipation module 22, thereby avoiding performance degradation or thermal runaway caused by overheating. The protection module 23 can independently monitor voltage anomalies and power-off protection for each battery cell 2, thereby greatly improving the overall safety of the system. In addition, the battery management module 24 can transmit the power, voltage and temperature data of each cell in real time, and perform charging and discharging tasks for the cell, solving the problem of insufficient cell management capabilities in traditional technologies.

[0059] Furthermore, after receiving the discharge instruction, the battery pack control module 13 generates an energy distribution strategy according to the power of each battery cell 2 in the battery cabinet 1 and the discharge demand, and drives the battery cell 2 to output power;

[0060] After receiving the charging instruction, the battery control module 13 generates a charging priority strategy according to the power of each battery cell 2 in the battery cabinet 1 , and preferentially charges the battery cell 2 with the smallest power among the battery cells 2 in the battery cabinet 1 .

[0061] Among them, the introduction of the battery pack control module 13, after it receives the discharge instruction, the battery pack control module 13 matches the power of each battery cell 2 with the discharge demand, dynamically generates an energy distribution strategy, and drives the battery cell 2 to output. After it receives the charging instruction, it generates a charging priority strategy according to the power of the battery cell 2, and gives priority to charging the cell with the lowest power. In contrast, when the traditional battery pack is discharging, all battery cells 2 participate in the power supply together, and the battery cell 2 with a lower power will reach the discharge limit first, thereby affecting the output capacity of the entire battery pack. During the charging process, the existing technology cannot dynamically allocate charging power, resulting in the battery cell 2 with a lower power cannot be charged first, thereby extending the overall charging time, and cannot be flexibly adjusted according to the status of the battery cell 2.

[0062] Based on this, the battery pack control module 13 of the present application can give priority to using battery cells 2 with sufficient power for discharge according to the discharge demand and the power status of the battery cells 2, avoiding the over-discharge problem of battery cells 2 with low power. And through the charging priority strategy, the battery cells 2 with the lowest power can be charged first, thereby shortening the charging time and improving the charging efficiency. In addition, the battery pack control module 13 can dynamically adjust the strategy according to the real-time changes in the status of the battery cells 2, improving the adaptability and efficiency of the system.

[0063] Example 2

[0064] like Figure 1-2 As shown, what is different from Example 1 is that in order to further improve the effective management of the battery pack control module 13 during the charging process of the battery cells 2 in the distributed energy storage lithium-ion battery pack of the present application, further, the charging priority strategy is that the battery pack control module 13 outputs the battery cell 2 with the smallest battery power according to the battery power information of the battery cells 2 that are not in the discharge process; when the power difference between the power of other battery cells 2 and the power of the battery cell 2 with the lowest battery power is less than a first threshold value, the battery pack control module 13 drives the battery management module 24 to simultaneously charge the battery cells 2 whose power difference with the battery cell 2 with the lowest battery power is less than the first threshold value.

[0065] Thus, the battery pack control module 13 can ensure that during the charging process, there will be no uneven charging problem between the battery cells 2 due to excessive power differences. This strategy effectively avoids the performance difference caused by uneven charging between the battery cells 2 and prolongs the service life of the battery pack. In addition, by setting the first threshold, the battery pack control module 13 can flexibly adjust the charging strategy to adapt to different usage scenarios and battery states, ensuring that the battery pack can maintain optimal performance under various conditions.

[0066] Furthermore, the first threshold is 0.01-0.05. In the specific implementation process, the first threshold is set to 0.05, i.e. 5%, and the power distribution of the battery cell 2 in the battery pack is as follows:

[0067] First row: battery cell 2A (85% SOC), battery cell 2B (80% SOC), battery cell 2C (78% SOC).

[0068] Second row: battery cell 2D (50% SOC), battery cell 2E (48% SOC).

[0069] Third row: battery cell 2F (20% SOC), battery cell 2G (18% SOC).

[0070] The charging instruction received by the battery pack control module 13 is: the external input power is 50W. Through the initial monitoring of the battery management module 24 connected to each battery cell 2, it is learned that the SOC of the detected battery cell 2F and the battery cell 2G are 20% and 18% respectively, and the remaining batteries are all above the first threshold range of 5%. The charging priority logic is output as follows: battery G>battery F>battery D. However, considering that the difference in SOC between battery cell 2G and battery cell 2F is less than the first threshold ±5%, these two battery cells 2 are charged at the same time.

[0071] Furthermore, after 10 minutes, the SOC of battery cells 2G and 2F both increase by 30%. At this time, it is detected again that the SOC of battery cells 2D and 2E is below the 5% range, and the priority is adjusted to charge battery cells 2G, 2F, 2D, and 2E simultaneously.

[0072] Furthermore, when the difference between the battery power of a battery cell 2 in at least two battery cells 2 that are simultaneously charged and discharged and the average value of the battery power of at least two battery cells 2 that are simultaneously charged and discharged exceeds a second threshold, the battery pack control module 13 drives the battery cells 2 that meet the above conditions to stop charging. In the specific implementation process, when the difference between the battery power of a battery cell 2 and the average power exceeds the second threshold, it indicates that the charging speed of the battery cell 2 is too fast or too slow, which may cause unstable battery performance or damage. The battery pack control module 13 protects the battery cell 2 by stopping charging to ensure the overall stability and safety of the battery pack. The setting of the second threshold depends on the specific performance parameters of the battery cell 2 and the use environment, and is usually between 10% and 20%.

[0073] For example, if the second threshold is set to 15%, when the difference between the power of the battery cell 2 and the average power exceeds 15%, the battery pack control module 13 will immediately stop the charging process of the battery cell 2 until the difference between the power of the battery cell 2 and the average power falls back to a safe range. In this way, the battery pack control module 13 can effectively avoid charging imbalance between the battery cells 2, extend the service life of the battery pack, and ensure that the battery pack can maintain optimal performance under various working conditions.

[0074] The other details that are the same as those in Example 1 are not described in detail in this example.

[0075] Example 3

[0076] like Figure 1-2As shown, what is different from Example 1 is that: in order to further improve the control of each battery cell 2 by the battery pack control module 13 in the distributed energy storage battery pack of the present application during the discharge process, further, the power distribution strategy is that the battery pack control module 13 sorts the battery power of the battery cells 2 that are not in the charging process and prioritizes them from high to low according to the battery power, and discharges at least one battery cell 2 with a high priority that meets the discharge requirements.

[0077] Therefore, the battery pack control module 13 can ensure that during the discharge process, the battery cells 2 with higher power are used first, thereby extending the discharge time of the entire battery pack, and ensuring that no battery cell 2 is over-consumed while meeting the power demand of the user end. This strategy not only improves the use efficiency of the battery pack, but also reduces the wear of the battery cells 2 and extends the service life of the battery pack by reasonably allocating the discharge load. In addition, the battery pack control module 13 monitors the power status of each battery cell 2 in real time during the discharge process, and dynamically adjusts the discharge strategy according to the discharge demand to ensure that the battery pack can maintain optimal performance under various working conditions.

[0078] Other details that are the same as those in Example 1 are not described in detail in this example.

[0079] Example 4

[0080] like Figure 1-3 As shown, the difference from Example 1 is that: in order to further improve the performance of the distributed energy storage lithium-ion battery pack of the present application, further, each battery cell 2 is fixedly connected to a battery temperature sensor, and the battery temperature sensor transmits the battery temperature information to the heat dissipation module 22. Thus,

[0081] The heat dissipation module 22 can adjust the heat dissipation strategy in real time according to the battery temperature information to ensure that the temperature of the battery cell 2 under different working conditions is maintained within a safe range. The introduction of the battery temperature sensor enables the heat dissipation module 22 to accurately monitor the temperature changes of the battery cell 2 and respond promptly to abnormal increases in battery temperature, thereby effectively avoiding battery performance degradation or damage due to overheating. In addition, the data from the battery temperature sensor can also be used in the battery management system as an important parameter for evaluating the battery health status, further improving the overall performance and safety of the battery pack. In this way, the battery pack control module 13 can more accurately manage the charging and discharging process of the battery cell 2, ensuring the stability and reliability of the battery pack under various working environments.

[0082] Specifically, each battery cell 2 is fixedly connected to a voltage sensor, which transmits the voltage signal of the battery cell 2 to the battery management module 24 through a digital-to-analog converter. The battery management module 24 calculates the battery power of the battery cell 2 through the coulomb metering method based on the voltage signal of the battery cell 2 received. Therefore, the introduction of the voltage sensor enables the battery management module 24 to monitor the voltage state of each battery cell 2 in real time and accurately calculate the power of the battery cell 2 through the coulomb metering method. This ability of real-time monitoring and accurate calculation is crucial for the efficient management and maintenance of the battery pack. The battery management module 24 can timely detect the abnormal state of the battery cell 2, such as overcharge or over-discharge, based on the data provided by the voltage sensor, so as to take corresponding protective measures to avoid damage to the battery cell 2. In addition, the data of the voltage sensor can also be used to evaluate the health status of the battery, providing an important basis for the maintenance and life prediction of the battery pack. In this way, the battery pack control module 13 can more accurately manage the charging and discharging process of the battery cell 2 to ensure the stability and reliability of the battery pack under various working environments.

[0083] Furthermore, the battery pack control module 13 is provided with at least one communication interface 131, which is connected to the control terminal 3 via the CAN bus protocol or the RS485 protocol, and the control terminal 3 is used to input a charging instruction or a discharging instruction to the battery pack control module 13.

[0084] The battery pack control module 13 can receive instructions from the control terminal 3 and perform corresponding charging and discharging operations according to the content of the instructions. The setting of the communication interface 131 enables the battery pack control module 13 to exchange data with external devices to achieve remote monitoring and management. Through the CAN bus protocol or RS485 protocol, the battery pack control module 13 can efficiently transmit battery status information to the control terminal 3, and at the same time receive instructions from the control terminal 3 to achieve precise control of the battery pack. This remote control capability is crucial for the operation of large-scale energy storage systems. It not only improves the convenience of operation, but also improves the intelligence level of the system. In addition, through the communication interface 131, the battery pack control module 13 can also interact with other system components to implement more complex energy management strategies and further improve the performance and efficiency of the energy storage system.

[0085] Furthermore, heat sinks 14 are provided on both sides of the battery cabinet 1, and heat dissipation holes 141 are provided on the heat sinks 14. As a result, the heat sink 14 can effectively dissipate the heat generated by the battery pack during the charging and discharging process, and keep the temperature of the battery pack within a safe range. The design of the heat dissipation holes 141 increases the heat dissipation area and further improves the heat dissipation efficiency. This heat dissipation design not only ensures the performance of the battery pack, but also extends the service life of the battery, while reducing the safety risks caused by overheating. In addition, the material and structural design of the heat sink 14 also take into account cost and durability, ensuring the long-term stable operation of the heat dissipation system.

[0086] Other details that are the same as those in Example 1 are not described in detail in this example.

[0087] Example 5

[0088] like Figure 1-3 As shown, the difference from Example 1 is that: in order to further improve the management of the distributed lithium-ion battery pack, further, the present application is also provided with a set of energy storage system, including at least 2 of any one of the above-mentioned distributed energy storage lithium-ion battery packs and a control terminal 3 that is communicatively connected to the battery pack control module 13 in the distributed energy storage lithium-ion battery pack;

[0089] The control terminal 3 outputs a discharge instruction to the battery pack control module 13 of one or more distributed energy storage lithium-ion battery packs that meet the power demand of the user end;

[0090] When the total power of all distributed energy storage lithium-ion battery groups in the energy storage system is less than the third threshold, the battery group control module 13 of the distributed energy storage lithium-ion battery group with the smallest power among all distributed energy storage lithium-ion battery groups outputs a charging instruction.

[0091] Specifically, the control terminal 3 of the above energy storage system can flexibly dispatch the charge and discharge status of each battery pack according to the actual power demand, and optimize the energy distribution of the entire energy storage system. When the power demand at the user end changes, the control terminal 3 can respond and adjust the discharge instruction in real time to ensure that the battery pack can provide the required power in time. At the same time, when the power in the energy storage system is lower than the set safety threshold (the third threshold), the control terminal 3 will automatically trigger the charging instruction, and give priority to charging the battery pack with the least power, so as to ensure the stable operation of the system and extend the service life of the battery pack.

[0092] In addition, the design of the energy storage system also takes into account the collaborative work between multiple battery packs, and realizes centralized management and optimized control of the entire energy storage system through the communication connection between the battery pack control modules 13. This centralized management strategy not only improves the response speed and efficiency of the energy storage system, but also enhances the reliability and flexibility of the system, providing strong technical support for large-scale energy storage applications.

[0093] Other details that are the same as those in Example 1 are not described in detail in this example.

[0094] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A distributed energy storage lithium-ion battery pack, comprising a battery cabinet (1) and at least two battery cells (2) arranged in the battery cabinet (1), characterized in that: The battery cabinet (1) is provided with an input end (11) and an output end (12), the input end (11) inputs externally provided electric energy and distributes it to the battery cells (2) according to a battery pack control module (13) (13) provided in the battery cabinet (1), and the output end (12) outputs the electric energy of the battery cells (2) selected by the battery pack control module (13); The battery cells (2) are composed of a plurality of polymer lithium-ion batteries (21) of the same model. Each of the battery cells (2) is connected to a heat dissipation module (22), a protection module (23) and a battery management module (24). The heat dissipation module (22) is used to dissipate heat for the battery cells (2) during the charging and discharging process. The protection module (23) performs power-off protection for the battery cells (2) whose voltage changes abnormally during the charging and discharging process. The battery management module (24) drives the power supply to access the battery cells (2) through the instructions of the battery pack control module (13) and transmits the power data of the battery cells (2) to the battery pack control module (13). After receiving the discharge instruction, the battery pack control module (13) generates an electric energy distribution strategy by matching the electric quantity of each battery cell (2) in the battery cabinet (1) with the discharge demand quantity and drives the battery cell (2) to output electric energy; After receiving a charging instruction, the battery pack control module (13) generates a charging priority strategy according to the power levels of the battery cells (2) in the battery cabinet (1), and preferentially charges the battery cell (2) with the smallest power level among the battery cells (2) in the battery cabinet (1).

2. A distributed energy storage lithium-ion battery pack according to claim 1, characterized in that: The charging priority strategy is that the battery pack control module (13) outputs the battery cell (2) with the smallest power according to the battery power information of the battery cells (2) that are not in the discharge process; When the difference between the power levels of the other battery cells (2) and the power level of the battery cell (2) with the lowest power level is less than a first threshold, the battery pack control module (13) drives the battery management module (24) to simultaneously charge the battery cells (2) whose power levels differ from the power level of the battery cell (2) with the lowest power level being less than the first threshold.

3. A distributed energy storage lithium-ion battery pack according to claim 2, characterized in that: The first threshold is 0.01-0.

05.

4. A distributed energy storage lithium-ion battery pack according to claim 2, characterized in that: When the difference between the battery power of the battery cell (2) in at least two of the battery cells (2) that are simultaneously charged and discharged and the average value of the battery power of the at least two of the battery cells (2) that are simultaneously charged and discharged exceeds a second threshold, the battery pack control module (13) drives the battery cell (2) that meets the above condition to stop charging.

5. A distributed energy storage lithium-ion battery pack according to claim 1, characterized in that: The electric energy distribution strategy is that the battery pack control module (13) sorts the battery power of the battery cells (2) that are not being charged and prioritizes them from high to low according to the battery power, and discharges at least one battery cell (2) with a high priority that meets the discharge requirement.

6. A distributed energy storage lithium-ion battery pack according to claim 1, characterized in that: Each of the battery cells (2) is fixedly connected to a battery temperature sensor, and the battery temperature sensor transmits temperature information of the battery to the heat dissipation module (22).

7. A distributed energy storage lithium-ion battery pack according to claim 1, characterized in that: Each of the battery cells (2) is fixedly connected to a voltage sensor, the voltage sensor transmits the voltage signal of the battery cell (2) to the battery management module (24) through a digital-to-analog converter, and the battery management module (24) calculates the battery power of the battery cell (2) through the coulomb counting method based on the received voltage signal of the battery cell (2).

8. A distributed energy storage lithium-ion battery pack according to claim 1, characterized in that: The battery pack control module (13) is provided with at least one communication interface (131), the communication interface (131) being connected to a control terminal (3) via a CAN bus protocol or an RS485 protocol, and the control terminal (3) being used to input a charging instruction or a discharging instruction to the battery pack control module (13).

9. A distributed energy storage lithium-ion battery pack according to claim 1, characterized in that: Heat dissipation plates (14) are provided on both sides of the battery cabinet (1), and heat dissipation through holes (141) are provided on the heat dissipation plates (14).

10. An energy storage system, characterized in that: Comprising at least two distributed energy storage lithium-ion battery packs as claimed in any one of claims 1 to 9 and a control terminal (3) communicatively connected to a battery pack control module (13) in the distributed energy storage lithium-ion battery pack; The control terminal (3) outputs a discharge instruction to a battery pack control module (13) of one or more distributed energy storage lithium-ion battery packs that meet the power demand of the user end; When the total power of all the distributed energy storage lithium-ion battery groups in the energy storage system is less than a third threshold, the battery group control module (13) of the distributed energy storage lithium-ion battery group with the smallest power among all the distributed energy storage lithium-ion battery groups outputs a charging instruction.

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