Energy storage system

Abstract

An energy storage system relates to the technical field of energy storage. The energy storage system comprises a plurality of battery cell groups, each battery cell group comprises a power supply switching circuit, a control module and a plurality of battery cells arranged along a set direction, a film type pressure sensor is arranged between two adjacent battery cells, the power supply switching circuit comprises a plurality of switch tubes (triodes and / or insulated gate field effect transistors), a first end of each switch tube is connected with the control module, and a second end of each switch tube is connected with the control module. The second end is connected with each film type pressure sensor; when a switching tube between the control module and a target film type pressure sensor in the battery cell group is closed, acquiring a pressure signal detected by the target film type pressure sensor; and determining an expansion force detection result of the battery cell corresponding to the target film type pressure sensor according to the pressure signal. Therefore, the energy storage system uses the thin film type pressure sensor with thinner thickness and smaller occupied space to detect the expansion force between the battery cells, so that the overall space utilization rate of the energy storage system can be effectively improved, and the overall battery capacity of the energy storage system is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to an energy storage system. Background Art

[0002] With the rapid development of electrochemical energy storage technology, electrochemical energy storage products such as lithium-ion batteries are becoming increasingly widely used in the field of new energy storage. During the charge and discharge cycles of energy storage products, the expansion force of the battery cells gradually increases. This is not only directly related to the degradation of the energy storage product's capacity, but may even lead to safety issues such as failure of the energy storage system's frame structure. Therefore, accurate and real-time monitoring of the battery cell expansion force is crucial to ensuring the safety and reliability of electrochemical energy storage products.

[0003] Currently, the expansion force of the battery cells of energy storage products is mainly detected by two types of sensors: the first is a load-type pressure sensor, which can accurately measure the maximum expansion force of the battery cell plane. However, it cannot reflect the distribution of the expansion force across the entire surface of the battery cell. In addition, because the load-type pressure sensor is large and requires use with a fixture, it takes up too much space in the energy storage product, which is not conducive to the integration and compact design of the energy storage product. The second type is a fiber optic pressure sensor, which measures the expansion force by pre-embedding optical fibers in the battery cell. However, the pre-embedded optical fiber method increases the complexity and cost of production and is also not conducive to the integration of energy storage products. Utility Model Content

[0004] In view of the above problems, the present invention provides an energy storage system, which can effectively improve the overall space utilization of the energy storage system and thereby improve the overall battery capacity of the energy storage system.

[0005] The embodiment of the present utility model discloses the following technical solutions:

[0006] The present application discloses an energy storage system, comprising a plurality of battery cell groups; each of the battery cell groups comprises a plurality of battery cells arranged along a set direction, and a thin film pressure sensor is provided between two adjacent battery cells.

[0007] Optionally, the thickness of the thin film pressure sensor ranges from 0.1 mm to 0.5 mm.

[0008] Optionally, the signal output ends of each of the thin film pressure sensors are connected in series via a flexible circuit board.

[0009] Optionally, the battery cell group further includes a power switching circuit, and the power switching circuit is connected to each of the thin film pressure sensors;

[0010] The power switching circuit is used to supply power to any one of the thin film pressure sensors.

[0011] Optionally, the power switching circuit includes a plurality of switching tubes; each of the switching tubes is connected to a unique corresponding thin film pressure sensor.

[0012] Optionally, the switching tube is a triode and / or an insulated gate field effect tube.

[0013] Optionally, the battery cell group further includes a signal processing circuit, and the signal processing circuit is connected to the total signal output end;

[0014] The signal processing circuit is used to convert the analog pressure signal detected by the thin film pressure sensor into a digital pressure signal.

[0015] Optionally, the signal processing circuit includes an analog-to-digital converter and multiple analog multiplexers; the input ends of the multiple analog multiplexers are connected to the total signal output end, and the output ends of the multiple analog multiplexers are connected to the input end of the analog-to-digital converter.

[0016] Optionally, the thin film pressure sensor is fixed between two adjacent battery cells via a fixing member.

[0017] Optionally, the fixing element is an ultra-thin gel.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The utility model discloses an energy storage system comprising a plurality of battery cell groups; each battery cell group comprises a plurality of battery cells arranged along a predetermined direction, and a thin-film pressure sensor is disposed between two adjacent battery cells. Thus, the energy storage system provided herein utilizes thinner, less space-consuming thin-film pressure sensors to detect the expansion force between the battery cells, effectively improving the overall space utilization of the energy storage system and thereby increasing the overall battery capacity of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 A schematic diagram of an energy storage system provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of another energy storage system provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of a third energy storage system provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of a signal acquisition strategy for an energy storage system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] As described above, the expansion force of the battery cells of energy storage products is currently detected mainly through two types of sensors: the first is a load-type pressure sensor, which can accurately measure the maximum expansion force of the battery cell plane. However, it cannot reflect the distribution of the expansion force across the entire surface of the battery cell. In addition, because the load-type pressure sensor is large and requires use with a fixture, it will occupy too much space in the energy storage product, which is not conducive to the integration and compact design of the energy storage product. The second type is a fiber optic pressure sensor, which measures the expansion force by pre-embedding optical fibers in the battery cell. However, the pre-embedded optical fiber method increases the complexity and cost of production and is also not conducive to the integration of energy storage products.

[0026] In view of this, the present utility model discloses an energy storage system, which includes a plurality of battery cell groups; each battery cell group includes a plurality of battery cells arranged along a set direction, and a thin film pressure sensor is provided between two adjacent battery cells. Therefore, the energy storage system provided by the present application uses a thin film pressure sensor with a thinner thickness and smaller space occupation to detect the expansion force between the battery cells, which can effectively improve the overall space utilization of the energy storage system, and thus improve the overall battery capacity of the energy storage system. In addition, since the thin film pressure sensor is relatively small in size, the required materials and production process are also relatively simplified, which helps to reduce production costs. At the same time, due to the reduction in the overall size of the energy storage system, the installation and maintenance costs are also reduced accordingly.

[0027] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0028] See also Figure 1 , which is a schematic diagram of an energy storage system provided in an embodiment of the present application. The energy storage system 10 includes several battery cell groups ( Figure 1In the example, the energy storage system 10 includes a battery cell group); each battery cell group includes a plurality of battery cells 101 arranged along a set direction ( Figure 1 In the example, a cell group includes three cells 101 ; a thin film pressure sensor 102 is provided between two adjacent cells 101 .

[0029] It should be noted that the above-mentioned several battery cell groups can exist in the energy storage system independently or in the form of a combination. For example, two or more battery cell groups are combined to form a battery pack PACK or a battery cluster RACK, and exist in the energy storage system in the form of a battery pack PACK or a battery cluster RACK.

[0030] It should also be noted that the above-mentioned “set direction” can be a straight direction, a curved direction, or other feasible battery cell arrangement directions, and this embodiment does not specifically limit this.

[0031] Traditional energy storage systems using load-type pressure sensors are typically over 10cm thick, while the thin-film pressure sensors used in this application are typically 0.1mm to 0.5mm thick, only 0.1% to 0.5% of the thickness of the thin-film pressure sensors used in this application. Therefore, the energy storage system provided in this application uses thinner, less space-consuming thin-film pressure sensors to detect the expansion force between battery cells, effectively improving the overall space utilization of the energy storage system and, in turn, increasing the overall battery capacity of the energy storage system.

[0032] See also Figure 2 , which is a schematic diagram of another energy storage system provided by an embodiment of the present application. The energy storage system includes several battery cell groups, each of which includes a control module and several battery cells arranged along a set direction, and a thin film pressure sensor is provided between two adjacent battery cells.

[0033] Specifically, battery cells are the basic units of energy storage systems, responsible for storing electrical energy. During the charging and discharging process, battery cells may expand due to internal chemical reactions or external factors.

[0034] A thin-film pressure sensor is a miniaturized, high-precision pressure-measuring device that uses thin-film material as a sensing element. It features small size, light weight, and fast response. In the energy storage system disclosed in this application, each thin-film pressure sensor is fixed between two adjacent battery cells via a fixture (such as an ultrathin gel). When a battery cell expands due to internal chemical reactions or external factors, the pressure between the cells changes. This change is sensed by the thin-film pressure sensor and converted into an electrical signal (i.e., a pressure signal) that is output to the control module.

[0035] The control module first obtains pressure signals detected by multiple thin-film pressure sensors. Then, based on the pressure signals, it determines the expansion force detection results of the battery cells corresponding to the pressure signals. The expansion force detection results may include the expansion degree and expansion speed, etc.

[0036] Depend on Figure 2 It can be seen that the signal output terminal of each thin-film pressure sensor for outputting the pressure signal can be connected in series through a flexible circuit board (FRC) to obtain a total signal output terminal. As a result, the pressure signals output by all thin-film pressure sensors are transmitted through the same FRC, that is, the control module only needs to receive the pressure signals detected by all thin-film pressure sensors through one total signal output terminal. This design simplifies the wiring of the energy storage system, ensuring the convenient transmission and processing of pressure signals while also reducing maintenance difficulty and improving the reliability of the energy storage system.

[0037] Specifically, FRC was chosen as the connection medium because, as a special type of circuit board, it is flexible, insulating, and thin. These characteristics enable FRC to adapt to various complex environments and shapes, making it particularly suitable for integration into compact spaces such as energy storage systems (e.g., lithium batteries).

[0038] See also Figure 3 , which is a schematic diagram of the third energy storage system provided in the embodiment of the present application. Figure 3 It can be seen that the battery cell group included in the energy storage system includes, in addition to the above-mentioned control module, battery cells and thin-film pressure sensor, a power switching circuit and a signal processing circuit.

[0039] A first terminal of the power switching circuit is connected to the control module, and a second terminal of the power switching circuit is connected to each thin-film pressure sensor. The power switching circuit's primary function is to allow the control module to selectively supply power to any one of the multiple thin-film pressure sensors. This allows the targeted thin-film pressure sensor to receive power and begin detecting pressure signals.

[0040] It should be noted that the reasons why the power switching circuit selectively provides power to any one of the multiple thin-film pressure sensors are mainly as follows:

[0041] First, if all thin-film pressure sensors are powered simultaneously, even if some are not required during the current measurement phase, they will still consume power. Selective power supply can avoid this unnecessary energy consumption and improve the energy efficiency of the energy storage system.

[0042] Second, thin-film pressure sensors may generate electromagnetic interference during operation, which may affect the measurement accuracy of other thin-film pressure sensors. By selectively powering, it is possible to ensure that only one thin-film pressure sensor is operating at a time, reducing mutual interference between thin-film pressure sensors.

[0043] Third, in some application scenarios, it may be necessary to measure pressure at different locations according to a certain strategy or sequence. By selectively powering, it is possible to ensure that the corresponding thin-film pressure sensors are activated according to the predetermined sequence or strategy.

[0044] See also Figure 4 This figure is a schematic diagram of a signal acquisition strategy for an energy storage system provided in an embodiment of the present application. In some specific implementations, the power switching circuit may include multiple switching transistors S1-SN. The switching transistors may be transistors and / or insulated gate field-effect transistors. The first end of each switching transistor is connected to a control module, and the second end of each switching transistor is connected to a unique thin-film pressure sensor.

[0045] To achieve selective power supply, the control module first determines which thin-film pressure sensor requires power. It then sends a control signal to the corresponding switch, closing it and providing power to the sensor. Simultaneously, the control module ensures that all other switches except that one are off, ensuring that only that one thin-film pressure sensor receives power.

[0046] The first terminal of the signal processing circuit is connected to the control module, and the second terminal of the signal processing circuit is connected to the main signal output terminal. The main function of the power switching circuit is to convert the analog pressure signal detected by the target thin-film pressure sensor into a digital pressure signal to facilitate subsequent data processing and analysis by the control module.

[0047] Specifically, the signal processing circuit first receives an analog pressure signal from the thin-film pressure sensor. This analog pressure signal reflects the pressure changes caused by the expansion of the battery cell. Next, the signal processing circuit converts the analog pressure signal into a digital pressure signal, which is a digital signal corresponding to the analog pressure signal. This conversion process typically includes steps such as amplification, filtering, sampling, and quantization. Amplification and filtering remove noise and interference from the signal, improving signal quality; sampling and quantization convert the continuous analog signal into a discrete digital signal for subsequent processing. The control module then receives the digital pressure signal sent by the signal processing circuit and, based on the digital pressure signal, determines the expansion force detection result of the battery cell corresponding to the digital pressure signal.

[0048] In some specific implementations, the signal processing circuit may include an analog-to-digital converter (ADC) and multiple analog multiplexers (MUXs). The ADC is a device that converts a continuously changing analog signal into a discrete digital signal. The MUX is an electronic component used to select a signal from multiple analog input signals for output. Specifically, the input ends of the multiple analog multiplexers are connected to the total signal output end, the output ends of the multiple analog multiplexers are connected to the input end of the analog-to-digital converter, and the output end of the analog-to-digital converter is connected to the control module.

[0049] The analog multiplexer is used to obtain an analog pressure signal detected by a target thin-film pressure sensor. The analog pressure signal can be obtained by obtaining multiple first raw pressure signals detected by the target thin-film pressure sensor, where the first raw pressure signals are analog signals; averaging the multiple first raw pressure signals (or otherwise combining them) to obtain the analog pressure signal. The analog multiplexer then transmits the analog pressure signal to an analog-to-digital converter. The analog-to-digital converter then converts the analog pressure signal into a digital pressure signal.

[0050] In some specific implementations, after the control module determines the expansion force detection result of the battery cell corresponding to the digital pressure signal and recognizes that the expansion force detection result is greater than the expansion force threshold, the control module will determine that the battery cell may be in an unsafe or imminently dangerous state, and the control module will execute an alarm indication. Exemplary methods of alarm indication include but are not limited to one or more combinations of the following operations: the control module sends an alarm signal to the monitoring center or the operator's terminal device; the control module activates a local or remote sound and light alarm; the control module records the alarm event in a log for subsequent analysis; the control module initiates an emergency shutdown procedure, etc. Through this alarm mechanism, the energy storage system can issue an alarm in a timely manner when the battery cell expands or is about to be dangerous, reminding relevant personnel to take measures to avoid or reduce possible safety risks.

[0051] In summary, the present application discloses an energy storage system, which includes a plurality of battery cell groups; each battery cell group includes a plurality of battery cells arranged along a set direction, and a thin film pressure sensor is provided between two adjacent battery cells. Therefore, the energy storage system provided by the present application uses a thin film pressure sensor with a thinner thickness and smaller space occupation to detect the expansion force between the battery cells, which can effectively improve the overall space utilization of the energy storage system, thereby improving the overall battery capacity of the energy storage system. In addition, since the thin film pressure sensor is relatively small in size, the required materials and production process are also relatively simplified, which helps to reduce production costs. At the same time, due to the reduction in the overall size of the energy storage system, the installation and maintenance costs are also reduced accordingly.

[0052] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0053] The above description is only a preferred embodiment of the present application and does not constitute any formal limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the art can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. An energy storage system, characterized in that: The invention comprises a plurality of battery cell groups; each of the battery cell groups comprises a power switching circuit, a control module, and a plurality of battery cells arranged along a set direction, and a thin film pressure sensor is provided between two adjacent battery cells, the power switching circuit comprises a plurality of switching tubes, the switching tubes being triodes and / or insulated gate field effect tubes, the first end of each switching tube being connected to the control module, and the second end of each switching tube being connected to each thin film pressure sensor; The control module is configured to obtain a pressure signal detected by the target thin-film pressure sensor when a switch tube between the control module and the target thin-film pressure sensor in the battery cell group is closed; The control module is further configured to determine, based on the pressure signal, an expansion force detection result of the battery cell corresponding to the target thin-film pressure sensor.

2. The energy storage system according to claim 1, characterized in that The thickness of the thin film pressure sensor ranges from 0.1 mm to 0.5 mm.

3. The energy storage system according to claim 1, characterized in that The battery pack further includes a signal processing circuit, the signal processing circuit being connected to a total signal output terminal, the total signal output terminal being obtained by connecting the signal output terminals of each of the thin film pressure sensors in series via a flexible circuit board; The signal processing circuit is used to convert the analog pressure signal detected by the thin film pressure sensor into a digital pressure signal.

4. The energy storage system according to claim 3, characterized in that The signal processing circuit includes an analog-to-digital converter and a plurality of analog multiplexers; the input ends of the plurality of analog multiplexers are connected to the total signal output end, and the output ends of the plurality of analog multiplexers are connected to the input end of the analog-to-digital converter.

5. The energy storage system according to claim 1, characterized in that: The thin film pressure sensor is fixed between two adjacent battery cells via a fixing member.

6. The energy storage system according to claim 5, characterized in that: The fixing piece is an ultra-thin gel.

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