Energy storage system

Abstract

The present application relates to the technical field of energy storage, in particular to an energy storage system. The energy storage system of some embodiments comprises: a main circuit (10) for storing and / or providing electrical energy, the main circuit (10) comprising a plurality of battery cells (101) in groups; and a state-of-charge sensitive unit (20) connected in series with the main circuit (10), wherein a sensitivity of a voltage of the state-of-charge sensitive unit (20) to a state of charge is higher than a sensitivity of a voltage of the battery cells (101) to a state of charge, or an electrical energy capacity of the battery cells (101) is less than the electrical energy capacity of the state-of-charge sensitive unit (20); and the battery cells (101) and the state-of-charge sensitive unit (20) are separated into groups. Based on the solution of the embodiments of the present application, the design of the state-of-charge sensitive unit is not necessarily limited by the battery cells, and is capable of satisfying the requirement of assessing the state of charge of a battery cell of a main circuit of an energy storage system, while also having high selectivity and high scalability.

Description

Energy storage system

[0001] Cross-reference to related applications

[0002] This application is based on the Chinese Patent Application No. 2024107811792 entitled "Energy storage system" filed on June 17, 2024, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of energy storage, and particularly relates to an energy storage system. BACKGROUND

[0004] Due to the technical advantages of green, clean, peak shaving, flexibility, high efficiency and the like, the energy storage system has been rapidly developed and has become one of the important development directions of future energy development. The energy storage system contains multiple battery monomers. In the application process of the energy storage system, the state of charge of the energy storage system is evaluated by the state of charge of the energy storage system, so that the state of charge of the energy storage system can be understood, which is helpful to improve the stability and safety of the operation of the energy storage system. However, the current energy storage system needs to be further improved.

[0005] SUMMARY

[0006] Therefore, it is necessary to provide an energy storage system.

[0007] In a first aspect, the present application provides an energy storage system. The energy storage system comprises:

[0008] a main loop for storing and / or providing electric energy, the main loop comprising a plurality of battery monomers in a group; and

[0009] a charge sensitive unit connected in series with the main loop, the charge sensitive unit having a higher sensitivity of voltage to state of charge than the battery monomers; or, the electric energy capacity of the battery monomers is less than the electric energy capacity of the charge sensitive unit.

[0010] The battery monomers and the charge sensitive unit are separated into groups.

[0011] Based on the energy storage system provided in this embodiment, on the basis of the main loop with a plurality of battery monomers in groups, a charge sensitive unit is further included in series with the main loop, and the charge sensitive unit is separated from the battery monomers in groups, and the sensitivity of the voltage of the charge sensitive unit to the state of charge is higher than the sensitivity of the voltage of the battery monomers to the state of charge, or the electric energy capacity of the battery monomers is less than the electric energy capacity of the charge sensitive unit. In the case where the electric energy capacity of the battery monomers is less than the electric energy capacity of the charge sensitive unit, the sensitivity of the charge sensitive unit to the state of charge will also be higher than that of the battery monomers to a certain extent, so that the state of charge of the battery monomers of the energy storage system can be evaluated based on the state of charge of the charge sensitive unit, and since the charge sensitive unit is separated from the battery monomers in groups, the design of the charge sensitive unit is not limited by the battery monomers, which can meet the demand of evaluating the state of charge of the battery monomers of the main loop of the energy storage system, and has high selectivity and high scalability.

[0012] In some embodiments, the energy storage system includes at least one main loop, a single main loop corresponds to a battery cluster, and a single battery cluster is provided with a charge sensitive unit.

[0013] Based on this embodiment, a single main loop of the energy storage system corresponds to a battery cluster, and a charge sensitive unit is provided for each battery cluster, so that the state of charge of the battery monomers in each battery cluster can be evaluated based on the state of charge of the charge sensitive unit, and since the charge sensitive unit is separated from the main loop, it is not limited by the battery monomers in the battery cluster, and has wide selectivity and high scalability.

[0014] In some embodiments, the battery cluster includes a single cabinet, and the charge sensitive unit is arranged in the cabinet.

[0015] Based on this embodiment, the battery cluster of the energy storage system includes a cabinet, and the charge sensitive unit is arranged in the cabinet, so that the charge sensitive unit can be arranged without considering other spatial positions outside the cabinet, the space occupation is small, the space resources can be saved to a certain extent, and in the case where the battery cluster is arranged in the energy storage container, since each battery cluster in the energy storage container is in a parallel relationship, by arranging a charge sensitive unit for each battery cluster and arranging the charge sensitive unit in the cabinet of the battery cluster, the arrangement requirement of the energy storage container can be met, and the integration of the energy storage system is improved.

[0016] In some embodiments, the main loop includes at least one battery box, and a charge sensitive unit is arranged in each battery box.

[0017] Based on the embodiment, the main circuit of the energy storage system comprises the battery box, and the charge sensitive unit is correspondingly arranged in each battery box, so that the charge sensitive unit can be arranged in each battery box without considering the arrangement of other space positions outside the battery box, the space occupation is small, the space resources can be saved to a certain extent, and each battery box is correspondingly provided with the charge sensitive unit, the single battery box can be controlled, the estimation of the state of charge is more favorable, and the convenience of the control of the energy storage system is improved.

[0018] In some embodiments, the energy storage system further comprises a control unit for electrically controlling the main circuit, and the control unit comprises a first chamber, and the charge sensitive unit is arranged in the first chamber.

[0019] Based on the embodiment, the first chamber is arranged in the control unit for electrically controlling the main circuit, and the charge sensitive unit is arranged in the first chamber, so that the arrangement of other space positions outside the control unit is not considered, the space occupation is small, the space resources can be saved to a certain extent, the charge sensitive unit can be isolated from other electrical components in the control unit, and the safety of the energy storage system is improved.

[0020] In some embodiments, the control unit comprises a main control box, a high-voltage box, a busbar cabinet or a low-voltage box.

[0021] Based on the embodiment, any one of the main control box, the high-voltage box, the busbar cabinet or the low-voltage box can be used as the control unit, the first chamber is arranged in the control unit to accommodate the charge sensitive unit, and the main control box, the high-voltage box, the busbar cabinet or the low-voltage box all have independent spaces, so that the charge sensitive unit and the battery monomer can be distinguished, the safety is effectively improved, the first chamber is further arranged in the main control box, the high-voltage box, the busbar cabinet or the low-voltage box to accommodate the charge sensitive unit, and the charge sensitive unit and other components of the control unit can be distinguished, so as to further improve the safety.

[0022] In some embodiments, a plurality of charge sensitive units are arranged in the first chamber, and the plurality of charge sensitive units are respectively connected in series with different main circuits.

[0023] Based on the embodiment, a plurality of charge sensitive units connected in series with different main circuits can be arranged in the first chamber, that is, a plurality of charge sensitive units connected in series with different main circuits can be arranged in the same first chamber, the space resources can be effectively saved, and the maintenance efficiency can be improved.

[0024] In some embodiments, the energy storage system further comprises a first fixing member, the plurality of battery monomers are fixed by the first fixing member, and the charge sensitive unit is arranged outside the first fixing member.

[0025] Based on this embodiment, the plurality of battery monomers of the energy storage system are fixed by the first fixing member, and the charge sensitive unit is arranged outside the first fixing member, so that the charge sensitive unit can be effectively separated from the battery monomers in the fixing structure, which can not only improve the stability of the battery monomers and reduce the influence of the movement of the battery monomers on the performance and safety of the energy storage system, but also effectively realize the separated arrangement of the battery monomers and the charge sensitive unit to further improve the safety.

[0026] In some embodiments, the energy storage system further comprises a second fixing member, and the charge sensitive unit is fixed by the second fixing member.

[0027] Based on this embodiment, the charge sensitive unit is fixed by the second fixing member, so that the stability of the charge sensitive unit can be improved, the influence of the movement of the charge sensitive unit on the performance and safety of the energy storage system can be reduced, and the safety can be further improved.

[0028] In some embodiments, the first fixing member comprises a box body, a fixing frame or a binding band, and / or the second fixing member comprises a box body, a fixing frame or a binding band.

[0029] Based on this embodiment, the first fixing member and the second fixing member can be implemented by using different forms of fixing members such as box bodies, fixing frames or binding bands, which has strong selectivity and can help improve the practicality and expandability of the energy storage system.

[0030] In some embodiments, the first fixing member comprises a first box body, and the second fixing member comprises a second box body, and the first box body and the second box body are arranged to form a box body of a sealed battery box.

[0031] Based on this embodiment, the first fixing member for fixing the battery monomers comprises a first box body, the second fixing member for fixing the charge sensitive unit comprises a second box body, and the first box body and the second box body are arranged to form a box body of a sealed battery box, which has strong structural stability, improves the fixing performance of the battery monomers and the charge sensitive unit, and reduces the influence of the safety problems of the battery monomers or the charge sensitive unit on the safety of the energy storage system, further improving the safety of the energy storage system.

[0032] In some embodiments, the second box body is provided with an electrical assembly, and the charge sensitive unit is arranged inside the second box body.

[0033] Based on the embodiment, by arranging the charge sensitive unit inside the second box body provided with the electrical components, the box body structure has strong stability, which not only improves the fixing performance of the battery monomer and the charge sensitive unit, but also does not need to consider the arrangement of other space positions outside the control unit, has small space occupation, and can save space resources to a certain extent. The arrangement of the box body structure reduces the safety influence of the safety problem of the electrical components or the charge sensitive unit on the energy storage system, and further improves the safety of the energy storage system.

[0034] In some embodiments, the electrical components include a signal acquisition unit, the signal acquisition unit is used to acquire an electrical signal, and the control unit of the energy storage system controls corresponding based on the electrical signal.

[0035] Based on the embodiment, the electrical components in the second box body include the signal acquisition unit for acquiring the electrical signal, so that the control unit for controlling the energy storage system can control corresponding based on the electrical signal, the electrical control of the energy storage system can be separated from the battery monomer, and the safety of the energy storage system can be further improved.

[0036] In some embodiments, the signal acquisition unit includes a thermal runaway associated signal acquisition unit, the thermal runaway associated signal acquisition unit acquires a thermal runaway associated signal, and the control unit controls thermal runaway based on the thermal runaway associated signal.

[0037] Based on the embodiment, the signal acquisition unit in the second box body includes the thermal runaway associated signal acquisition unit, so that the acquisition of the thermal runaway associated signal can be realized, and the thermal runaway control is performed accordingly, which is helpful to realize the monitoring of the thermal runaway, and the safety of the energy storage system can be further improved.

[0038] In some embodiments, the thermal runaway associated signal includes a flame signal and / or a vacuum degree signal and / or a temperature signal.

[0039] Based on the embodiment, one or more of different types of thermal runaway associated signals such as the flame signal, the vacuum degree signal, and the temperature signal can be used to realize the monitoring of the thermal runaway, which is helpful to further improve the safety of the energy storage system.

[0040] In some embodiments, a plurality of battery monomers are arranged in the first box body, a large surface of the plurality of battery monomers is arranged along a first direction, and the second box body is located at at least one end of both ends of the first box body along the first direction.

[0041] Based on the embodiment, when the plurality of batteries are arranged in the first box body, the large faces of the plurality of battery cells are arranged along the first direction, and the second box body is arranged at at least one end of the first box body along the first direction. Since the area of the large face of the battery cell is large, the battery cell is greatly affected by the expansion force. By arranging the second box body at at least one end of the first box body along the first direction, and since the charge sensitive unit is arranged separately from the battery cell, a certain expansion space can be reserved for the large face of the battery cell, the safety influence caused by the insufficient expansion space of the battery cell is reduced, and the safety of the energy storage system is improved.

[0042] In some embodiments, the first fixing member includes a first frame, and the second fixing member includes a second frame, and the first frame and the second frame are arranged separately or integrally.

[0043] Based on the embodiment, the first fixing member and the second fixing member are both realized by frames, the fixing of the battery cell and the charge sensitive unit is realized by the frame structure, the safety factor is high, and by arranging the first frame and the second frame separately or integrally, different personalized requirements for the arrangement positions of the first frame and the second frame can be met.

[0044] In some embodiments, the first box body includes a box main body, the plurality of battery cells are arranged in the box main body, a spacing portion is arranged on one side of the battery cell close to a front panel of the box main body, and the charge sensitive unit is arranged between the front panel and the spacing portion.

[0045] In the embodiment, by arranging the box main body in the first box body and arranging the plurality of battery cells in the box main body, the safety placement of the battery cell can be realized. At the same time, by arranging the spacing portion on one side of the battery cell close to the front panel of the box main body and arranging the charge sensitive unit between the front panel and the spacing portion, the requirement for compact structure can be met, the battery cell and the charge sensitive unit can be spaced apart, and the safety requirement of the energy storage system can be met.

[0046] In some embodiments, the adjacent battery cells are arranged at intervals to form a flow passage extending along the first direction, and a flow acceleration device is arranged at the front panel to accelerate the flow of the fluid in the flow passage.

[0047] Based on the embodiment, by arranging the adjacent battery cells at intervals to form a flow passage extending along the first direction, the fluid can flow through the flow passage, the cooling of the battery cell can be realized to improve the safety. At the same time, by arranging the flow acceleration device at the front panel to accelerate the flow of the fluid in the flow passage, the flow of the fluid in the flow passage can be accelerated, the cooling rate of the battery cell can be improved, the cooling effect of the battery cell can be further strengthened, and the safety can be further improved.

[0048] In some embodiments, the energy storage system comprises a plurality of charge-sensitive unit groups, each charge-sensitive unit group comprises at least one charge-sensitive unit, and the energy storage system comprises a plurality of charge-sensitive unit groups connected in series with the main circuit.

[0049] Based on this embodiment, by grouping the charge-sensitive units and connecting a plurality of charge-sensitive unit groups in series with the main circuit, the redundancy of the charge-sensitive unit groups is achieved, so that even in the case of an abnormality in one of the charge-sensitive unit groups, the state of charge of the battery cells can be monitored by the other charge-sensitive unit groups with redundancy, which has strong scalability and helps to improve the stability and safety of the energy storage system.

[0050] In some embodiments, the energy storage system comprises a plurality of charge-sensitive unit groups, each charge-sensitive unit group comprises at least one charge-sensitive unit, and the energy storage system comprises a plurality of charge-sensitive unit groups connected in series with the main circuit.

[0051] Based on this embodiment, by grouping the charge-sensitive units and connecting a plurality of charge-sensitive unit groups in series with the main circuit, the redundancy of the charge-sensitive unit groups is achieved, so that even in the case of an abnormality in one of the charge-sensitive unit groups, the state of charge of the battery cells can be monitored by the other charge-sensitive unit groups with redundancy, which has strong scalability and helps to improve the stability and safety of the energy storage system.

[0052] In some embodiments, the energy storage system comprises a plurality of charge-sensitive unit groups, the main circuit comprises a plurality of battery cell assemblies connected in series, each battery cell assembly comprises a plurality of battery cells connected in series and / or parallel, and the electric energy capacity of the battery cell assembly is equal to or less than the electric energy capacity of the charge-sensitive unit group.

[0053] Based on this embodiment, by connecting a plurality of battery cells in series and / or parallel to form a single battery cell assembly and connecting a plurality of battery cell assemblies in series in the main circuit, battery cell assemblies with different electric energy capacities can be achieved to meet different electric energy capacity requirements, while the electric energy capacity of the battery cell assembly is less than or equal to the electric energy capacity of the charge-sensitive unit group, reducing the possibility of the electric energy capacity of the charge-sensitive unit group causing a shortcoming in the electric energy of the energy storage system, and further improving the reliability of the energy storage system.

[0054] In some embodiments, the size of the battery cell is the same as or different from the size of the charge-sensitive unit.

[0055] Based on this embodiment, the size of the battery cell can be the same as or different from the size of the charge-sensitive unit, which can meet different individual needs and improve the scalability and applicability of the energy storage system.

[0056] In some embodiments, the open-circuit voltage curve of the charge-sensitive unit is a linear curve with a slope greater than a preset threshold.

[0057] Based on the above embodiment, by selecting the charge-sensitive unit with the open-circuit voltage curve being a linear curve with a slope greater than a preset threshold, the charge-sensitive unit has higher charge sensitivity, and the accuracy of the state of charge of the battery cell evaluated based on the state of charge of the battery cell can be improved.

[0058] In some embodiments, the battery cell includes a lithium iron phosphate battery cell.

[0059] Based on the above embodiment, the battery cell includes a lithium iron phosphate battery cell, and the lithium iron phosphate battery has low cost, high safety, long service life, and wide operating temperature range, thereby effectively reducing the cost of the energy storage system and improving the safety and service life of the energy storage system.

[0060] In some embodiments, the charge-sensitive unit includes a lithium iron phosphate battery cell, a non-lithium iron phosphate battery cell, a supercapacitor energy storage unit, a flywheel energy storage unit, or a gas compression energy storage unit.

[0061] Based on the above embodiment, the charge-sensitive unit can include a lithium iron phosphate battery cell, a non-lithium iron phosphate battery cell, a supercapacitor energy storage unit, a flywheel energy storage unit, or a gas compression energy storage unit, thereby making the type of the charge-sensitive electric energy not limited, the selectivity of the charge-sensitive unit strong, and the scalability and applicability of the energy storage system further improved.

[0062] In some embodiments, the non-lithium iron phosphate battery cell includes a sodium battery cell, a hard carbon battery cell, a ternary battery cell, or a lithium manganese iron phosphate battery cell.

[0063] Based on the above embodiment, the non-lithium iron phosphate battery cell can include a sodium battery cell, a hard carbon battery cell, a ternary battery cell, or a lithium manganese iron phosphate battery cell, thereby the charge-sensitive unit can be implemented by any possible non-lithium iron phosphate battery cell, the selectivity of the charge-sensitive unit strong, and the scalability and applicability of the energy storage system improved.

[0064] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0065] Various other advantages and benefits will become apparent to those of ordinary skill in the art, upon reading the following detailed description of the preferred embodiment. The detailed description is made with reference to the accompanying drawings.

[0066] Fig. 1 is a schematic diagram of a partial structure of an energy storage system according to some embodiments of the present application;

[0067] Fig. 2 is a schematic diagram of a partial structure of an energy storage system according to some other embodiments of the present application;

[0068] Fig. 3 is a schematic diagram of a partial structure of an energy storage system according to some other embodiments of the present application;

[0069] Fig. 4 is a schematic diagram of a partial structure of an energy storage system according to some other embodiments of the present application;

[0070] Fig. 5 is a schematic diagram of a partial structure of an energy storage system according to some other embodiments of the present application;

[0071] Fig. 6 is a schematic diagram of a partial structure of an energy storage system according to some other embodiments of the present application;

[0072] Fig. 7 is a schematic diagram of the relationship between a fixing member of a battery cell and a state-of-charge sensitive unit according to some embodiments of the present application;

[0073] Fig. 8 is a schematic diagram of the relationship between a fixing member of a battery cell and a state-of-charge sensitive unit according to some other embodiments of the present application;

[0074] Fig. 9 is a schematic diagram of the relationship between a fixing member of a battery cell and a state-of-charge sensitive unit according to some other embodiments of the present application;

[0075] Fig. 10 is a schematic diagram of a partial structure of a first box according to some embodiments of the present application.

[0076] Reference signs: 1000, energy storage system; 10, main circuit; 101, battery cell; 20, state-of-charge sensitive unit; 100, battery cluster; 30, control unit; 301, first cavity; 400, first fixing member; 40, first box; 50, second box; 601, box body; 602, front panel; 603, spacing part; 6011, through hole. DETAILED DESCRIPTION

[0077] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0078] The embodiments of the present application will be described in detail below with reference to the drawings. The following examples are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, but cannot be used to limit the protection scope of the present application.

[0079] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the present specification and claims and the aforementioned description of the drawings, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0080] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0081] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0082] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0083] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0084] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "connection" and the like should be understood in a broad sense, for example, it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be internal communication of two elements or mutual interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0085] In the description of the embodiments of the present application, the directions or positional relationships indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0086] At present, with the development of energy storage technology, the performance evaluation of the energy storage system, such as the evaluation of the state of charge of the battery in the energy storage system, plays an important role in maintaining and improving the safety and stability of the energy storage system. Taking the evaluation of the state of charge of the battery in the energy storage system as an example, usually the voltage and other parameters of the battery or battery cell of the energy storage system are directly detected, and the state of charge is evaluated in combination with the obtained voltage and other parameters. However, for the battery or battery cell in the energy storage system, the sensitivity of the voltage of the battery cell to the state of charge is not high, which easily leads to low accuracy of the obtained state of charge, and thus affects the stability and safety of the energy storage system. Based on this consideration, in order to improve the accuracy of the obtained state of charge, a battery cell with higher sensitivity to the state of charge can be selected, but this will increase the cost of the energy storage system.

[0087] It is found through research that the state of charge of the energy storage system can be accurately evaluated by setting a charge-sensitive unit on the energy storage system, and the sensitivity of the voltage of the charge-sensitive unit to the state of charge is higher than the sensitivity of the voltage of the battery cell of the main circuit in the energy storage system to the state of charge, or the energy capacity of the charge-sensitive unit is greater than the energy capacity of the battery cell of the main circuit in the energy storage system. At the same time, the charge-sensitive unit and the main circuit of the energy storage system are connected in series, so that the current flowing through the charge-sensitive unit and the main circuit is the same, and thus the state of charge of the battery cell of the main circuit in the energy storage system can be evaluated in combination with the state of charge of the charge-sensitive unit. At the same time, the battery cell and the charge-sensitive unit are separated into groups, so that the design of the charge-sensitive unit is not limited by the battery cell, thereby meeting the demand of evaluating the state of charge of the battery cell of the main circuit of the energy storage system and having high selectivity. In addition, the battery cell and the charge-sensitive unit are separated into groups, so that the safety requirement of the charge-sensitive unit can be different from that of the battery cell, and no additional safety protection measures are needed. At the same time, the separate arrangement makes it possible to replace the charge-sensitive unit alone when it fails, which is convenient for maintenance.

[0088] The energy storage system provided by the embodiments of the present application can improve the accuracy of the state of charge estimation of the battery cells in the main circuit of the energy storage system, improve the safety, and have high selectivity.

[0089] Referring to FIG. 1, the energy storage system 1000 in some embodiments of the present application includes:

[0090] a main circuit 10 for storing and / or providing electric energy, the main circuit 10 including a plurality of battery cells 101 grouped together; and

[0091] a charge-sensitive unit 20 connected in series with the main circuit 10, the voltage of the charge-sensitive unit 20 being more sensitive to the state of charge than the voltage of the battery cells 101, or the electric energy capacity of the battery cells 101 being smaller than the electric energy capacity of the charge-sensitive unit 20.

[0092] In the embodiments of the present application, the battery cells 101 and the charge-sensitive unit 20 are separated into groups.

[0093] A battery cell is the smallest unit that constitutes a battery or a battery module and is a place where electric energy and chemical energy are converted. The main circuit of an energy storage system is a circuit of the energy storage system for power supply, mainly used for electric energy transmission and distribution, etc. The main circuit includes a plurality of battery cells grouped together, and the grouping manner of the plurality of battery cells is not limited. The battery cell includes but is not limited to a cell monomer, and can also be a module or other electric energy carrier, which is not limited in the present application.

[0094] The state of charge (SOC) is also called battery state of charge or remaining capacity, which is the ratio of the remaining dischargeable capacity to the capacity of the fully charged state, and is usually expressed in percentage.

[0095] The voltage sensitivity to the state of charge refers to the sensitivity of the voltage to the change of the state of charge. In general, if the voltage changes when the state of charge changes, the voltage sensitivity to the state of charge is high. If the voltage changes only when the change of the state of charge reaches a certain degree, the voltage sensitivity to the state of charge is low. In the embodiments of the present application, the voltage sensitivity of the charge-sensitive unit 20 to the state of charge is not limited as long as it is higher than the voltage sensitivity of the battery cells 101 to the state of charge.

[0096] The electric energy capacity represents the capacity of the electric energy that can be stored. The electric energy capacity of the battery cell 101 is not limited to be less than the electric energy capacity of the charge sensitive unit 20, as long as it is less than the electric energy capacity of the charge sensitive unit 20. In some embodiments, the difference between the electric energy capacity of the charge sensitive unit 20 and the electric energy capacity of the battery cell 101 can be greater than or equal to a preset capacity threshold, so that the electric energy capacity of the charge sensitive unit 20 and the electric energy capacity of the battery cell 101 are different, so that in the case of a change in the state of charge, the voltage of the charge sensitive unit 20 and the voltage of the battery cell 101 can be distinguished, but it is not necessarily limited to this. In the case where the electric energy capacity of the battery cell 101 is less than the electric energy capacity of the charge sensitive unit 20, the electric energy types of the battery cell 101 and the charge sensitive unit 20 can be set to be the same, for example, both are lithium iron phosphate batteries, etc., but not limited to this.

[0097] In some embodiments, taking the battery cell as a lithium iron phosphate battery and the charge sensitive unit as a sodium ion battery as an example, since the open circuit voltage curve of the sodium ion battery generally has no platform region and is a linear open circuit voltage curve, while the open circuit voltage curve of the lithium iron phosphate battery has a platform region, the open circuit voltage curve of the sodium ion battery is different from that of the lithium iron phosphate battery, that is, the sodium ion battery has higher sensitivity than the lithium iron phosphate battery, so under the same charging / discharging conditions, since the open circuit voltage curve of the lithium iron phosphate battery has no platform region, the state of charge of the sodium ion battery can be determined based on the open circuit voltage curve of the sodium ion battery, and the state of charge of the lithium iron phosphate battery can be analyzed, that is, in the case where the open circuit voltage curve of the lithium iron phosphate battery has a platform region, the accuracy of the state of charge evaluation of the lithium iron phosphate battery can also be improved.

[0098] In other embodiments, taking the battery cell and the charge sensitive unit as lithium iron phosphate batteries as an example, although the open circuit voltage curve of the lithium iron phosphate battery has a platform region, the electric energy capacity of the charge sensitive unit is greater than that of the battery cell, so when the battery cell is charged to the platform region, the charge sensitive unit is still in the non-platform region at the corresponding time, that is, the voltage changes when the state of charge changes, so the state of charge of the battery cell can also be analyzed based on the state of charge of the charge sensitive unit, and the accuracy of the state of charge evaluation of the battery cell can be improved.

[0099] The separation of the battery cell 101 and the charge sensitive unit 20 into groups means that the battery cell 101 and the charge sensitive unit 20 are not grouped, that is, the battery cell 101 and the charge sensitive unit 20 are separately arranged, and there is a certain distance or space between the battery cell 101 and the charge sensitive unit 20, and the position of the charge sensitive unit 20 relative to the battery cell of the main circuit 10 can be independently set.

[0100] The charge sensitive unit, in the embodiments of the present application, refers to a unit whose voltage sensitivity to state of charge is higher than that of the battery monomer 101, and the specific form is not limited, for example, it can be a sodium ion battery as described above, in the case where the battery monomer and the charge sensitive unit are both lithium iron phosphate batteries, a lithium iron phosphate battery with an electric energy capacity greater than that of the battery monomer, but not limited to this, for example, it can also be other non-lithium iron phosphate system battery monomers, supercapacitor energy storage units, flywheel energy storage units or gas compression energy storage units, etc., as long as the voltage sensitivity to state of charge of the charge sensitive unit 20 is higher than that of the battery monomer 101.

[0101] Based on the energy storage system provided in the embodiments, on the basis of the main loop with a plurality of battery monomers in groups, a charge sensitive unit is further included in series with the main loop, and the charge sensitive unit is separated from the battery monomers into groups, and the voltage sensitivity to state of charge of the charge sensitive unit is higher than that of the battery monomer, or the electric energy capacity of the battery monomer is less than that of the charge sensitive unit, in the case where the electric energy capacity of the battery monomer is less than that of the charge sensitive unit, the sensitivity to state of charge of the charge sensitive unit will also be higher than that of the battery monomer to a certain extent, so that the state of charge of the battery monomers of the energy storage system can be evaluated based on the state of charge of the charge sensitive unit, and since the charge sensitive unit is separated from the battery monomers into groups, the design of the charge sensitive unit is not limited by the battery monomers, which can meet the demand of evaluating the state of charge of the battery monomers of the main loop of the energy storage system, and has high selectivity and high scalability.

[0102] In the case where the voltage and / or state of charge of the battery monomers is evaluated based on the voltage and / or state of charge of the charge sensitive unit, the specific evaluation method is not limited, and the embodiments of the present application do not make specific limitations.

[0103] In some embodiments, the energy storage system includes at least one main loop, a single main loop corresponds to a battery cluster, and a single battery cluster is provided with a charge sensitive unit.

[0104] The battery cluster refers to a battery combination connected by batteries in series, parallel or mixed connection. For example, the battery cluster in the present application can be formed by a plurality of batteries in series or parallel. For another example, the battery cluster in the present application can be formed by a plurality of batteries first in parallel and then in series. The battery refers to a single physical module including one or more battery monomers to provide higher voltage and capacity. For example, the battery can be a battery module or a battery pack.

[0105] A single main loop corresponds to a battery cluster, that is, each battery cluster is arranged in a main loop to supply electric energy respectively. A single battery cluster corresponds to an arrangement of a charge-sensitive unit, that is, each main loop in which the battery cluster is arranged has a charge-sensitive unit in series, or a single battery cluster has a charge-sensitive unit in series respectively.

[0106] Referring to FIG. 2, taking one main loop as an example, one main loop 10 corresponds to one battery cluster 100, and the battery cluster 100 includes a plurality of battery monomers 101. One or more battery monomers 101 can form a battery in series, parallel, or a combination of series and parallel (not shown in the figure), and the plurality of batteries can form a battery module in series, parallel, or a combination of series and parallel. The specific series and parallel relationship is not shown in the figure. A single battery cluster 100 corresponds to an arrangement of a charge-sensitive unit 20, which is exemplarily illustrated by one charge-sensitive unit in FIG. 2.

[0107] Based on this embodiment, a single main loop of the energy storage system corresponds to a battery cluster, and a charge-sensitive unit is arranged for a single battery cluster, so that each main loop of the energy storage system corresponds to a battery cluster, and each battery cluster corresponds to an arrangement of a charge-sensitive unit. Therefore, for each battery cluster, the state of charge of the battery monomers in the battery cluster can be evaluated based on the state of charge of the charge-sensitive unit, and the charge-sensitive unit is arranged separately from the main loop, so it is not limited by the battery monomers in the battery cluster, and has a wide selection and high scalability.

[0108] In some embodiments, the battery cluster corresponds to an electric cabinet or a battery box, which are described below respectively.

[0109] In some embodiments, the battery cluster includes a single electric cabinet, and the charge-sensitive unit is arranged in the electric cabinet.

[0110] The electric cabinet is a unit arranged for the convenience of placing, repairing, and maintaining the battery, and can be used to accommodate and protect the battery cluster. The charge-sensitive unit arranged in the electric cabinet is not limited, as long as it is not grouped with the battery cluster.

[0111] Based on this embodiment, the battery cluster of the energy storage system includes an electric cabinet, and the charge-sensitive unit is arranged in the electric cabinet, so that the charge-sensitive unit can be arranged without considering other space positions outside the electric cabinet, the space occupation is small, and the space resources can be saved to a certain extent. Moreover, in the case that the battery cluster is arranged in the energy storage container, since each battery cluster in the energy storage container is in a parallel relationship, by arranging a charge-sensitive unit for each battery cluster and arranging the charge-sensitive unit in the electric cabinet of the battery cluster, the arrangement requirement of the energy storage container can be met, and the integration of the energy storage system is improved.

[0112] In some embodiments, the main circuit includes at least one battery box, and a single battery box is correspondingly provided with a state-of-charge sensitive unit.

[0113] The battery box is a device for accommodating a battery, and the battery refers to a single physical module including one or more battery monomers to provide higher voltage and capacity. The state-of-charge sensitive unit is not limited in the manner of being arranged in the battery box, as long as it is not grouped with the battery cluster.

[0114] Based on this embodiment, the main circuit of the energy storage system includes the battery box, and the state-of-charge sensitive unit is correspondingly arranged in each battery box, so that the state-of-charge sensitive unit can be arranged in each battery box without considering the arrangement of other space positions outside the battery box, the space occupation is small, the space resources can be saved to a certain extent, and moreover, each battery box is correspondingly provided with the state-of-charge sensitive unit, the single battery box can be controlled, which is more conducive to the estimation of the state-of-charge and is also conducive to improving the convenience of the control of the energy storage system.

[0115] In some embodiments, referring to FIG. 3, the energy storage system 1000 further includes a control unit 30 for electrically controlling the main circuit 10, and the control unit 30 includes a first chamber 301 in which the state-of-charge sensitive unit 20 is arranged.

[0116] The control unit 30 is a unit capable of electrically controlling the main circuit, and the type and manner of the electrical control of the main circuit by the control unit 30 are not limited. Some possible electrical controls of the main circuit can include, but are not limited to, one or more of the following: controlling the turn-on and turn-off of the main circuit, controlling the charging power of the charging of the main circuit, controlling the discharging power of the discharging of the main circuit to the outside, detecting the fault of the main circuit and giving an alarm prompt and / or fault clearing treatment in the case of possible or actual fault, and the like.

[0117] The chamber is a structure with an internal hollow and capable of being isolated from the outside. In the embodiments of the present application, the chamber arranged in the control unit is referred to as the first chamber. The specific type of the first chamber 301 is not limited, as long as the chamber space can be used to place the state-of-charge sensitive unit 20.

[0118] The first chamber in some embodiments can include an isolation chamber, which refers to a chamber capable of achieving isolation, so as to effectively isolate the state-of-charge sensitive unit from the outside of the first chamber 301, thereby further improving the safety. The arrangement position of the state-of-charge sensitive unit 20 in the first chamber 301 is not limited, as long as the state-of-charge sensitive unit 20 is arranged in the first chamber 301.

[0119] Based on the embodiment, by setting the first chamber in the control unit for electrically controlling the main circuit, and setting the charge-sensitive unit in the first chamber, the space occupation is small without considering the setting of other spatial positions outside the control unit, the space resources can be saved to a certain extent, the charge-sensitive unit can be isolated from other electrical components in the control unit, and the safety of the energy storage system is improved.

[0120] The specific type of the control unit is not limited, and in some embodiments, the control unit can include a master control box, a high-voltage box, a busbar cabinet, or a low-voltage box.

[0121] The master control box can be a device capable of controlling the battery, which is realized by a box structure, and the type and form of the master control box are not limited. The high-voltage box is a control unit capable of classifying battery energy and can distribute high-voltage to the battery energy, and the specific type and form of the high-voltage box are not limited. The busbar cabinet can realize the busbar connection of multiple main circuits, and the currents of the multiple main circuits can be output to the rear-end equipment through the disconnector after being connected by the busbar cabinet, and the specific type and form of the busbar cabinet are not limited. The low-voltage box is mainly used to place low-voltage devices such as MBMU (Master Battery Management Unit), SBMU (Slave Battery Management Unit), EMS (Energy Management System), thermal management system, etc., and the specific type and form of the low-voltage box are not limited.

[0122] Based on the embodiment, any one of the master control box, the high-voltage box, the busbar cabinet, or the low-voltage box can be used as the control unit, and the first chamber is arranged in the control unit to accommodate the charge-sensitive unit, and the master control box, the high-voltage box, the busbar cabinet, or the low-voltage box all have independent spaces, so that the charge-sensitive unit and the battery monomer can be distinguished, the safety is effectively improved, and by further arranging the first chamber in the master control box, the high-voltage box, the busbar cabinet, or the low-voltage box to accommodate the charge-sensitive unit, the charge-sensitive unit and other components of the control unit can be distinguished to further improve the safety.

[0123] In some embodiments, the first chamber is provided with a plurality of charge-sensitive units, and the plurality of charge-sensitive units are connected in series with different main circuits.

[0124] The connection mode of the plurality of charge-sensitive units with different main circuits is not limited, for example, one main circuit is connected with one charge-sensitive unit, as shown in FIG. 4. Alternatively, one main circuit is connected with one or more than two charge-sensitive units, as shown in FIG. 5, which is exemplarily illustrated by taking one of the main circuits connected with two charge-sensitive units 20 as an example.

[0125] Alternatively, one main circuit is connected in series with one or more than one group of charge sensitive units, and each group of charge sensitive units includes two or more charge sensitive units arranged in parallel, and the like, as shown in FIG. 6. FIG. 6 shows an example in which one main circuit is connected in series with one group of charge sensitive units, which includes two charge sensitive units 20 connected in series, but the application is not limited thereto.

[0126] Based on this embodiment, multiple charge sensitive units connected in series with different main circuits can be arranged in the first chamber, that is, multiple charge sensitive units connected in series with different main circuits can be arranged in the same first chamber, which can effectively save space resources and facilitate the maintenance of multiple charge sensitive units, thereby improving the maintenance efficiency.

[0127] In some embodiments, the energy storage system further includes a first fixing member, and the multiple battery monomers are fixed by the first fixing member, and the charge sensitive unit is arranged outside the first fixing member.

[0128] The fixing member refers to a component for fixing structural components or components, which can keep the fixed structural components or components stable and immobile. In the embodiments of the application, the fixing member for fixing the battery monomers is referred to as the first fixing member. The multiple battery monomers can be fixed by the first fixing member. The charge sensitive unit arranged outside the first fixing member means that the objects fixed by the first fixing member do not include the charge sensitive unit.

[0129] The number of the first fixing members included in the energy storage system is not limited. For example, one first fixing member can be provided for the battery monomers of one main circuit, that is, one first fixing member can fix all the battery monomers of the corresponding main circuit. Alternatively, two or more first fixing members can be provided for the battery monomers of one main circuit, and the two or more first fixing members can collectively fix all the battery monomers of the corresponding main circuit, wherein each first fixing member can fix part of the battery monomers of the corresponding main circuit. Alternatively, one first fixing member can be provided for the battery monomers of two or more main circuits, that is, one first fixing member can fix the battery monomers of two or more main circuits.

[0130] Taking the example of fixing multiple battery monomers by one first fixing member, some possible schematic diagrams are shown in FIG. 7. As shown in FIG. 7, one first fixing member 400 can fix multiple battery monomers 101. In the case of grouping the multiple battery monomers 101, one first fixing member 400 can fix the grouped multiple battery monomers 101. The charge sensitive unit 20 is arranged outside the first fixing member 400, that is, the first fixing member 400 is not used for fixing the charge sensitive unit.

[0131] Based on the embodiment, the plurality of battery monomers of the energy storage system are fixed by the first fixing member, and the charge sensitive unit is arranged outside the first fixing member, so that the charge sensitive unit is effectively separated from the battery monomers on the fixing structure, which can not only improve the stability of the battery monomers and reduce the influence of the movement of the battery monomers on the performance and safety of the energy storage system, but also effectively realize the separated arrangement of the battery monomers and the charge sensitive unit to further improve the safety.

[0132] In some embodiments, the energy storage system further comprises a second fixing member, and the charge sensitive unit is fixed by the second fixing member.

[0133] In the embodiments of the present application, the fixing member for fixing the charge sensitive unit is referred to as the second fixing member. The plurality of battery monomers can be fixed by the second fixing member, so that the charge sensitive unit remains stable and immobile.

[0134] Based on the embodiment, the charge sensitive unit is fixed by the second fixing member, so that the stability of the charge sensitive unit can be improved, the influence of the movement of the charge sensitive unit on the performance and safety of the energy storage system can be reduced, and the safety can be further improved.

[0135] The specific types of the first fixing member and the second fixing member are not limited. In some embodiments, the first fixing member can include but is not limited to a box, a fixed frame or a bandage, and the second fixing member can include but is not limited to a box, a fixed frame or a bandage.

[0136] The box is a container that can be used to store, protect and transport objects, which is usually a closed cuboid or rectangular cuboid. In some cases, it can be opened to access the inside of the box and / or put objects into the inside of the box and / or inspect the objects in the inside of the box if necessary. The box is usually made of a strong material such as metal, wood or plastic to protect the objects in the box, such as equipment, machinery or electronic components, etc. It can also reduce the impact on the environment outside the box in the case of damage to the objects in the box. For example, in the case of leakage of battery monomers or charge sensitive units in the box, the possibility of pollution of the environment outside the box can be reduced.

[0137] The fixed frame is a kind of frame structure, which can usually be fixedly arranged at a specified position. In the embodiments of the present application, the battery monomers or the charge sensitive unit can be fixed in the fixed frame to realize the fixation of the battery monomers or the charge sensitive unit.

[0138] The bandage refers to a device that can bind the object to be fixed, which is usually in the form of a band. When fixing the object, the bandage is tied on the surface of the object to be fixed to realize the fixation of the object. Taking the first fixing member including the bandage as an example, the bandage can be tied on the surface of one or more battery monomers to realize the fixation of the one or more battery monomers.

[0139] Based on this embodiment, the first fixing member and the second fixing member can be implemented in different forms such as a box, a fixed frame, or a bandage, which has strong selectivity and can help improve the practicality and scalability of the energy storage system.

[0140] The types of the first fixing member and the second fixing member can be the same or different. For example, the first fixing member and the second fixing member can both be a box, the first fixing member and the second fixing member can both be a fixed frame, and the first fixing member and the second fixing member can both be a bandage. For another example, the first fixing member can be a box, and the second fixing member can be a fixed frame or a bandage, or the first fixing member can be a fixed frame, and the second fixing member can be a box or a bandage, or the first fixing member can be a bandage, and the second fixing member can be a box or a fixed frame. It can be understood that in the case of still other types of fixing members, the first fixing member and the second fixing member can also be set as the same type of fixing member or different types of fixing members.

[0141] Taking the case that the fixing member includes a box and the first fixing member and the second fixing member both include a box as an example, in some embodiments, the first fixing member includes a first box, and the second fixing member includes a second box, and the first box and the second box are arranged to form the box of the sealed battery box.

[0142] The box of the battery box is a box for the battery box for accommodating the battery pack, and the battery pack in the battery box can be protected by the box of the battery box.

[0143] The first fixing member includes a first box, and the first box is arranged to form the box of the sealed battery box, so that the battery monomer can be fixed by the box of the sealed battery box, and the battery monomer can be protected at the same time. The arrangement position and manner of the battery monomer in the box of the battery box are not limited.

[0144] The second fixing member includes a second box, and the second box is arranged to form the box of the sealed battery box, so that the charge-sensitive unit can be fixed by the box of the sealed battery box, and the charge-sensitive unit can be protected at the same time. The arrangement position and manner of the charge-sensitive unit in the box of the battery box are not limited.

[0145] The arrangement position of the first box and the second box is not limited, and the first box and the second box can be arranged adjacently or separately, and in some possible embodiments, the second box can also be arranged inside the first box.

[0146] Based on this embodiment, the first fixing member for fixing the battery monomer includes a first box body, the second fixing member for fixing the charge sensitive unit includes a second box body, and the first box body and the second box body are both arranged as a box body of a sealed battery box, the box body has strong structural stability, which not only improves the fixing performance of the battery monomer and the charge sensitive unit, but also reduces the safety influence of the battery monomer or the charge sensitive unit on the energy storage system, and further improves the safety of the energy storage system.

[0147] In some embodiments, the second box body is internally provided with an electrical component, and the charge sensitive unit is arranged inside the second box body.

[0148] The component type of the electrical component is not limited, which can be an electrical component for realizing various functions, including but not limited to a BMS (Battery Management System), a control board, a high-voltage box, etc. The arrangement position of the electrical component in the second box body is not limited. In some embodiments, the arrangement position of the electrical component in the second box body and the arrangement position of the charge sensitive unit inside the second box body can be variously set.

[0149] Based on this embodiment, by arranging the charge sensitive unit inside the second box body provided with the electrical component, the box body has strong structural stability, which not only improves the fixing performance of the battery monomer and the charge sensitive unit, but also reduces the safety influence of the electrical component or the charge sensitive unit on the energy storage system, and further improves the safety of the energy storage system.

[0150] In some embodiments, the electrical component includes a signal acquisition unit, the signal acquisition unit is used for acquiring an electrical signal, and a control unit of the energy storage system performs corresponding control based on the electrical signal.

[0151] The signal acquisition unit is a unit for acquiring an electrical signal, and the type of the electrical signal to be acquired is not limited, including but not limited to a voltage signal, a current signal, etc., which can be set according to actual technical scenes.

[0152] Based on this embodiment, the electrical component in the second box body includes a signal acquisition unit for acquiring an electrical signal, so that a control unit for controlling the energy storage system can perform corresponding control based on the electrical signal, the electrical control of the energy storage system can be separated from the battery monomer, and the safety of the energy storage system can be further improved.

[0153] In some embodiments, the signal acquisition unit comprises a thermal runaway associated signal acquisition unit, the electrical signal comprises a thermal runaway associated signal, the thermal runaway associated signal acquisition unit acquires the thermal runaway associated signal, and the control unit controls thermal runaway based on the thermal runaway associated signal.

[0154] The thermal runaway associated signal is a signal related to thermal runaway monitoring and control, and the specific signal type is not limited as long as it is related to thermal runaway monitoring and control.

[0155] The control device electrically connected to the signal acquisition unit can analyze whether there is a thermal runaway risk and whether a thermal runaway has occurred based on the thermal runaway associated signal after obtaining the acquired thermal runaway associated signal, so as to further control the processing, for example, in the case of a possible thermal runaway risk, reducing the possibility of thermal runaway by cooling and other processing, in the case of a thermal runaway, eliminating the mechanism of thermal runaway to reduce the further expansion of thermal runaway and control the risk level, but not limited thereto.

[0156] Based on the embodiment, the signal acquisition unit in the second box body comprises a thermal runaway associated signal acquisition unit, so that the acquisition of the thermal runaway associated signal can be realized, and the thermal runaway control based thereon helps to realize the monitoring of the thermal runaway, and the safety of the energy storage system can be further improved.

[0157] In some embodiments, the thermal runaway associated signal comprises a flame signal and / or a vacuum degree signal and / or a temperature signal.

[0158] The way of acquiring the flame signal is not limited, for example, the flame signal can be acquired by a flame detector, that is, the thermal runaway associated signal acquisition unit can comprise a flame detector, and the flame signal is acquired by the flame detector.

[0159] The way of acquiring the vacuum degree signal is not limited, for example, the vacuum degree signal can be acquired by a vacuum degree sensor, that is, the thermal runaway associated signal acquisition unit can comprise a vacuum degree sensor, and the vacuum degree signal is acquired by the vacuum degree sensor.

[0160] The thermal runaway associated signal acquisition unit can comprise a temperature sensor, and the temperature signal is acquired by the temperature sensor.

[0161] The control device electrically connected to the signal acquisition unit can analyze whether there is a thermal runaway risk and whether a thermal runaway has occurred based on the thermal runaway associated signal after obtaining the acquired thermal runaway associated signal, so as to further control the processing, for example:

[0162] If the flame signal is detected, it means that there is already a flame, and the risk of thermal runaway is high, so the processing of extinguishing the flame is needed;

[0163] If the detected vacuum degree is less than the preset vacuum degree threshold, it indicates that the vacuum degree is low, and there may be a condition for combustion, and the safety is low. If a flame signal is also detected, it indicates that the flame exists in an environment that continues to burn, and thus the vacuum degree can be reduced by extracting air to achieve a vacuum environment, to reduce the condition for generating a flame and / or the possibility of further combustion of the flame.

[0164] If the detected temperature signal is higher than the preset temperature threshold, it indicates that the risk of thermal runaway is high, and thus a cooling process can be performed.

[0165] Based on this embodiment, one or more of different types of thermal runaway associated signals such as a flame signal and / or a vacuum degree signal and / or a temperature signal can be used to monitor thermal runaway, which helps to further improve the safety of the energy storage system.

[0166] For example, the first fixing member includes a first box, and the second fixing member includes a second box. In some embodiments, a plurality of battery monomers are arranged in the first box, and the large faces of the plurality of battery monomers are arranged along a first direction. The second box is located at at least one of the two ends of the first box along the first direction.

[0167] The large face of the battery monomer refers to the surface with a larger area among the sides of the battery monomer. The first direction of the first box is not limited. For example, the first box is rectangular, and the first direction can be the length direction of the first box, or the width direction or the height direction of the first box, as long as the large faces of the plurality of battery monomers are arranged along the same direction.

[0168] The second box can be located at one of the two ends of the first box along the first direction, or a second box can be provided at each of the two ends of the first box along the first direction, which can be set according to actual needs. Among them, any one of the two ends of the first box along the first direction can be provided with only one second box, or more than two second boxes, which can be set according to actual needs.

[0169] Among them, the position of the second box at the end of the first box is not limited. In some embodiments, the second box can be located at the end of the box outside the first box. For example, as shown in FIG. 8, the second box 50 is provided at the end of the first direction of the first box 40 and is located outside the box of the first box 40. The charge sensitive unit 20 is arranged in the second box 50.

[0170] In some embodiments, the second box can be arranged at the end of the first box, for example, as shown in FIG. 9, the second box 50 is arranged at the end of the first box 40 in the first direction, and inside the first box 40, and the charge sensitive unit 20 is arranged in the second box 50.

[0171] According to the embodiments, when the plurality of batteries are arranged in the first box, the large faces of the plurality of battery cells are arranged in the first direction, and the second box is arranged at at least one end of the first box in the first direction. Since the large face of the battery cell has a large area, it is greatly affected by the expansion force. By arranging the second box at at least one end of the first box in the first direction, and since the charge sensitive unit is arranged separately from the battery cell, a certain expansion space can be reserved for the large face of the battery cell, reducing the impact on safety due to insufficient expansion space of the battery cell, and improving the safety of the energy storage system.

[0172] For example, the first fixing member includes the first box, and the second fixing member includes the second box. In the case where the first box and the second box are arranged separately, the arrangement positions of the first box and the second box can have a certain correlation or no certain correlation, as long as the main circuit of the battery cell in the first box is connected in series with the charge sensitive unit in the second box.

[0173] In some embodiments, the first box and the second box can be arranged adjacent to each other, for example, the first box and the second box have one box face opposite to each other, and the distance between the two opposite faces is within a certain distance range, so that the charge sensitive unit corresponding to the battery cell in the first box can be intuitively known, and the maintenance of the charge sensitive unit in the second box corresponding to the first box is facilitated, which helps to improve the maintenance efficiency. In the case where the first box and the second box are arranged adjacent to and opposite to each other, the integration of the energy storage system can also be improved on this basis.

[0174] In some embodiments, the first box and the second box can be arranged at a certain distance, and the distance is not limited, as long as the main circuit of the battery cell in the first box is connected in series with the charge sensitive unit in the second box, and in the case where there are a plurality of first boxes and second boxes, it can be determined or known which first box corresponds to which second box.

[0175] In some embodiments, the first box can be arranged in a battery box containing battery cells, and the second box can be arranged in a control unit or an electric cabinet such as a master control box, a high-voltage box, a busbar cabinet, or a low-voltage box, or the box structure of the control unit of the master control box, the high-voltage box, the busbar cabinet, or the low-voltage box, or the box structure of the electric cabinet can be used as the second box, but not limited thereto.

[0176] Taking the example that the fixing member includes a frame, and the first fixing member and the second fixing member each include a frame, in some embodiments, the first fixing member includes a first frame, and the second fixing member includes a second frame, and the first frame and the second frame are arranged separately or integrally.

[0177] The first fixing member includes a first frame, that is, the battery monomer is fixed by the frame, wherein the arrangement position and manner of the battery monomer in the first frame are not limited. The second fixing member includes a second frame, that is, the charge sensitive unit is fixed by the frame, wherein the arrangement position and manner of the charge sensitive unit in the second frame are not limited.

[0178] The first frame and the second frame are arranged separately, that is, the first frame and the second frame are different frame structures, so that the first frame and the second frame are arranged at different positions to separate the battery assembly and the charge sensitive unit. Based on actual needs, the first frame and the second frame can also be arranged adjacent to each other, as long as different frames are used to fix the battery monomer and the charge sensitive unit.

[0179] The first frame and the second frame are arranged integrally, that is, the same frame structure is used to fix the battery monomer and the charge sensitive unit, but different parts of the same frame structure are distinguished, one part of the frame structure is used to fix the battery monomer, and the other part is used to fix the charge sensitive unit, that is, the part of the frame structure used to fix the battery monomer and the part of the frame structure used to fix the charge sensitive unit are different, as long as the battery monomer and the charge sensitive unit can be arranged separately.

[0180] Based on the embodiment, the first fixing member and the second fixing member are implemented by frames, and the fixing of the battery monomer and the charge sensitive unit is implemented by the frame structure, which has a high safety factor. By arranging the first frame and the second frame separately or integrally, individualized requirements for the arrangement positions of the first frame and the second frame can be met.

[0181] In some embodiments, the first box body includes a plug-in box main body, a plurality of battery monomers are arranged in the plug-in box main body, a spacing part is arranged on one side of the battery monomer close to the front panel of the plug-in box main body, and the charge sensitive unit is arranged between the front panel and the spacing part.

[0182] The plug-in box is a frame structure member that can be used to mount and / or fix objects. In the embodiment of the application, the plug-in box is a frame structure member that can be used to mount and / or fix battery monomers. The main structure part of the frame structure member is referred to as a plug-in box main body in the embodiment of the application.

[0183] Referring to FIG. 10, the first box body includes a box main body 601, a plurality of battery monomers 101 are arranged in the box main body 601, a spacing part 603 is arranged on the side of the battery monomers 101 close to the front panel 602 of the box main body 601, and a charge sensitive unit (not shown in FIG. 10) is arranged between the front panel 602 and the spacing part 603.

[0184] The spacing part arranged on the side of the battery monomers close to the front panel of the box main body can realize the spacing of the battery monomers and the front panel, and the form of the spacing part is not limited. In some embodiments, the spacing part can be a partition plate, so that the front panel and the battery monomers are spaced apart by the partition plate. The partition plate can be a plate structure, and the partition plate can also be an integrally formed structure. In some embodiments, the spacing part can have one or more through holes to improve the fluid flow between the battery monomers 101 and improve the heat dissipation effect. It can be understood that when the charge sensitive unit is arranged between the front panel 602 and the spacing part 603, the second box body can be arranged between the front panel 602 and the spacing part 603, and the charge sensitive unit is arranged in the second box body. It can be understood that the partition plate can also be arranged in other forms of structure, as long as the charge sensitive unit and the battery monomers 101 can be spaced apart.

[0185] In some embodiments, referring to FIG. 10, the box main body 601 can be a box main body with a plurality of through holes 6011, and the sizes of the plurality of through holes can be the same or different. By arranging the through holes, air and other fluids can enter between the battery monomers 101, so as to improve the fluid flow between the battery monomers 101 and improve the heat dissipation effect.

[0186] In this embodiment, by arranging the box main body in the first box body and arranging the plurality of battery monomers in the box main body, the safety of the battery monomers can be realized. At the same time, by arranging the spacing part on the side of the battery monomers close to the front panel of the box main body and arranging the charge sensitive unit between the front partition plate and the spacing part, the compact structure requirement can be met, and the battery monomers and the charge sensitive unit can be spaced apart, and the safety requirement of the energy storage system can be met.

[0187] In some embodiments, the adjacent battery monomers are arranged to form an overcurrent channel extending in the first direction, and an overcurrent accelerating device is arranged at the front panel to accelerate the fluid flow in the overcurrent channel.

[0188] The overcurrent channel refers to a channel through which air, liquid and other fluids can flow. By arranging the adjacent battery monomers to form an overcurrent channel extending in the first direction, the fluid can pass through the overcurrent channel, thereby taking away the heat generated in the working process of the battery monomers, realizing the cooling of the battery monomers, and improving the safety.

[0189] In some embodiments, the plurality of battery cells can be arranged along a first direction of the first box body, and a plurality of battery cell columns can be formed, each of which comprises a plurality of battery cells. For example, two battery cell columns can be formed, and a flow channel extending along the first direction can be formed between the two battery cell columns. For example, three or more battery cell columns can be formed, and a flow channel extending along the first direction can be formed between any two adjacent battery cell columns, i.e., two or more flow channels can be formed.

[0190] In some embodiments, the adjacent battery cells can be spaced apart along a second direction, thereby forming a flow channel extending along the second direction, wherein the second direction is perpendicular to the first direction. By further forming a flow channel along the second direction, the fluid can form a flow channel in the first direction and the second direction, and flow in the first direction and the second direction, thereby removing the heat generated during the operation of the battery cells from the plurality of sides of the battery cells, achieving cooling of the battery cells, and further improving safety.

[0191] In some embodiments, the battery cell column adjacent to the side panel of the first box body along the first direction can be spaced apart from the side panel by a certain distance, so that the fluid can also pass through the channel between the battery cell column and the side panel, further improving the cooling effect and further improving safety.

[0192] The flow acceleration device is a device capable of accelerating the flow speed of the fluid, and the specific type of the flow acceleration device is not limited, for example, it can include a fan. By using the flow acceleration device, the flow speed of the fluid in the flow channel can be accelerated, thereby accelerating the speed of the fluid in removing heat, and further improving safety.

[0193] Based on the above embodiment, by spacing apart the adjacent battery cells to form a flow channel extending along the first direction, the fluid can pass through the flow channel, thereby achieving cooling of the battery cells to improve safety, and by arranging the flow acceleration device at the front panel to accelerate the flow of the fluid in the flow channel, the fluid in the flow channel can be accelerated, thereby improving the cooling rate of the battery cells, further strengthening the cooling effect of the battery cells, and further improving safety.

[0194] In some embodiments, the energy storage system comprises a plurality of charge-sensitive unit groups, each charge-sensitive unit group comprising at least one charge-sensitive unit, and the energy storage system comprises a plurality of charge-sensitive unit groups connected in series with the main circuit.

[0195] The number of the charge-sensitive units in each charge-sensitive unit group can be the same or different. For example, in some embodiments, each charge-sensitive unit group includes only one charge-sensitive unit or a preset number of charge-sensitive units, and the preset number is an integer greater than or equal to 2. In some embodiments, the number of the charge-sensitive units in each charge-sensitive unit group is not completely the same, for example, some charge-sensitive unit groups include only one charge-sensitive unit, some charge-sensitive unit groups include more than two charge-sensitive units, or each charge-sensitive unit group includes more than two charge-sensitive units, but the number of the charge-sensitive units in each charge-sensitive unit group is not completely the same.

[0196] In the case where each charge-sensitive unit group includes the same number of charge-sensitive units, the types of the charge-sensitive units included in each charge-sensitive unit group can be the same or different, which is not specifically limited in the embodiments of the present application.

[0197] In the case where the number of the charge-sensitive units included in each charge-sensitive unit group is not completely the same, the types of the charge-sensitive units included in each charge-sensitive unit group can be the same or different, which is not specifically limited in the embodiments of the present application.

[0198] Based on this embodiment, by grouping the charge-sensitive units and arranging a plurality of charge-sensitive unit groups in series with the main circuit, the redundancy of the charge-sensitive unit groups is achieved, so that even in the case where one of the charge-sensitive unit groups is abnormal, the state of charge of the battery monomer can be monitored through the other charge-sensitive unit groups arranged redundantly, which has strong scalability and helps to improve the stability and safety of the energy storage system.

[0199] In some embodiments, the energy storage system includes a charge-sensitive unit group, and the charge-sensitive unit group includes more than two charge-sensitive units, and the charge-sensitive units in one charge-sensitive unit group are arranged in parallel.

[0200] Based on this embodiment, the charge-sensitive unit group can include more than two charge-sensitive units arranged in parallel. By arranging more than two charge-sensitive units in parallel, the electric energy capacity can be improved, and the upper limit of the current that can flow through the charge-sensitive unit group can be increased. Even if the electric energy capacity of a single charge-sensitive unit is lower than the electric energy capacity of the battery monomer or the current capacity that can flow through a single charge-sensitive unit is small, based on the parallel arrangement of more than two charge-sensitive units, the possibility of limiting the electric energy capacity and the current size of the charge-sensitive unit is avoided.

[0201] Based on this embodiment, by grouping the charge-sensitive units and arranging each charge-sensitive unit in a charge-sensitive unit group in parallel, even if the electrical energy capacity of a single charge-sensitive unit is lower than the electrical energy capacity of a battery cell, by arranging multiple charge-sensitive units in parallel to form a charge-sensitive unit group, the electrical energy capacity of the charge-sensitive unit group can be improved, and the current capacity that can flow through the charge-sensitive unit group can be increased, thereby eliminating the need for a high electrical energy capacity of the charge-sensitive unit, and having strong scalability and adaptability.

[0202] In some embodiments, the energy storage system includes a charge-sensitive unit group, and the main circuit includes a plurality of battery cell assemblies arranged in series, each battery cell assembly including a plurality of battery cells arranged in series and / or in parallel, and the electrical energy capacity of the battery cell assembly is equal to or less than the electrical energy capacity of the charge-sensitive unit group.

[0203] The battery cell assembly is an assembly including a plurality of battery cells, and the number of battery cells included in each battery cell assembly is not limited and can be the same or different. The series and parallel relationship of the plurality of battery cells in each battery cell assembly is not limited, for example, some battery cell assemblies include a plurality of battery cells arranged in series, some battery cell assemblies include a plurality of battery cells arranged in parallel, some battery cell assemblies include a plurality of battery cells arranged in series first and then in parallel, some battery cell assemblies include a plurality of battery cells arranged in parallel first and then in series, some battery cell assemblies include a plurality of battery cells arranged in series first, then in parallel, and then in series, and some battery cell assemblies include a plurality of battery cells arranged in parallel first, then in series, and then in parallel, but are not limited thereto.

[0204] By arranging the battery cells in series, the voltage of the battery cell assembly can be increased, and in the case of identical battery cells, the voltage of the battery cell assembly can be doubled. By arranging the battery cells in parallel, the electrical energy capacity of the battery cell assembly can be improved, and the upper limit of the current that can flow through the battery cell assembly can be increased.

[0205] Based on this embodiment, by arranging a plurality of battery cells in series and / or in parallel to form a single battery cell assembly, and arranging a plurality of battery cell assemblies in series in the main circuit, battery cell assemblies with different electrical energy capacities can be realized to meet different electrical energy capacity requirements, while the electrical energy capacity of the battery cell assembly is less than or equal to the electrical energy capacity of the charge-sensitive unit group, reducing the possibility that the electrical energy capacity of the charge-sensitive unit group causes a short board of the electrical energy of the energy storage system, and further improving the reliability of the energy storage system.

[0206] In some embodiments, the size of the battery cell is the same as or different from the size of the charge-sensitive unit.

[0207] The size of the battery cell refers to the size of the appearance of the battery cell. For example, if the battery cell is in a rectangular structure, the size of the battery cell can include the length, width, and height of the battery cell. For example, if the battery cell is in a cylindrical structure, the size of the battery cell can include the diameter / radius and height of the battery cell. Similarly, the size of the charge-sensitive unit refers to the size of the appearance of the charge-sensitive unit. For example, if the charge-sensitive unit is in a rectangular structure, the size of the charge-sensitive unit can include the length, width, and height of the charge-sensitive unit. For example, if the charge-sensitive unit is in a cylindrical structure, the size of the charge-sensitive unit can include the diameter / radius and height of the charge-sensitive unit.

[0208] In the case where the main circuit includes a plurality of battery cell assemblies connected in series, the size of each battery cell in each battery cell assembly can be the same.

[0209] In the case where the charge-sensitive unit 20 is separated from the battery cell 101 into groups, the size of the charge-sensitive unit 20 can not be limited by the battery cell 101. A charge-sensitive unit with a size larger than, smaller than, or the same as the size of the battery cell 101 can be selected, and the selection is free.

[0210] Based on this embodiment, the size of the battery cell and the size of the charge-sensitive unit can be the same or different, which can meet different individual needs and improve the scalability and applicability of the energy storage system.

[0211] In some embodiments, the open-circuit voltage curve of the charge-sensitive unit is a linear curve with a slope greater than a preset threshold.

[0212] The threshold value of the preset threshold of the open-circuit voltage curve, i.e., the OCV (Open Circuit Voltage) curve, is not limited and can be set according to actual needs. The slope of the open-circuit voltage curve of the charge-sensitive unit is greater than the slope of the open-circuit voltage curve of the battery cell.

[0213] Based on this embodiment, by selecting a charge-sensitive unit with an open-circuit voltage curve that is a linear curve with a slope greater than a preset threshold, the charge-sensitive unit has high charge sensitivity. On this basis, the state of charge of the battery cell is evaluated, which can improve the accuracy of the state of charge of the battery cell obtained by evaluation.

[0214] The type of battery cell is not limited, and in some embodiments, the battery cell includes a lithium iron phosphate battery cell.

[0215] Based on this embodiment, the battery cell includes a lithium iron phosphate battery cell, which has low cost, high safety, long service life, and a wide operating temperature range, thereby effectively reducing the cost of the energy storage system and improving the safety and service life of the energy storage system.

[0216] The type of the charge-sensitive unit is not limited, and in some embodiments, the charge-sensitive unit includes a lithium iron phosphate system battery cell, a non-lithium iron phosphate system battery cell, a supercapacitor energy storage unit, a flywheel energy storage unit, or a gas compression energy storage unit.

[0217] Based on this embodiment, the charge-sensitive unit can include a lithium iron phosphate system battery cell, a non-lithium iron phosphate system battery cell, a supercapacitor energy storage unit, a flywheel energy storage unit, or a gas compression energy storage unit. Thus, the type of the charge-sensitive electric energy is not limited, the selectivity of the charge-sensitive unit is strong, and the scalability and applicability of the energy storage system can be improved.

[0218] In the case where the charge-sensitive unit includes a lithium iron phosphate system battery cell, the specific type is not limited, and in some embodiments, the non-lithium iron phosphate system battery cell includes a sodium battery cell, a hard carbon battery cell, a ternary battery cell, or a lithium manganese iron phosphate battery cell.

[0219] Based on this embodiment, the non-lithium iron phosphate system battery cell can include a sodium battery cell, a hard carbon battery cell, a ternary battery cell, or a lithium manganese iron phosphate battery cell, so that the charge-sensitive unit can be implemented by any possible non-lithium iron phosphate system battery cell, the selectivity of the charge-sensitive unit is strong, and the scalability and applicability of the energy storage system can be improved.

[0220] In combination with the above embodiments, it can be understood that the design of the charge-sensitive unit is not necessarily limited by the battery cell and can be embodied in multiple different aspects. For example, the size of the charge-sensitive unit can not necessarily be limited by the battery cell and can be larger or smaller than the battery cell, or can be the same. For another example, the service life requirement of the charge-sensitive unit can not necessarily be combined with the service life of the battery cell. If the service life of the charge-sensitive unit is shorter than the service life of the battery cell, the charge-sensitive unit can be conveniently replaced or maintained due to the separate arrangement. For another example, the expansion force of the charge-sensitive unit can not be considered too much, the expansion space can not be limited, and the heat dissipation performance is higher.

[0221] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An energy storage system, wherein, The energy storage system includes: A main circuit for storing and / or providing electrical energy, the main circuit comprising a group of multiple battery cells; and A charge-sensitive unit is connected in series with the main circuit. The voltage of the charge-sensitive unit is more sensitive to the state of charge than the voltage of the battery cell; or, the energy capacity of the battery cell is less than the energy capacity of the charge-sensitive unit. The battery cell and the charge-sensitive unit are grouped separately.

2. The energy storage system according to claim 1, wherein, The energy storage system includes at least one main circuit, each main circuit corresponds to one battery cluster, and each battery cluster is equipped with the charge-sensitive unit.

3. The energy storage system according to claim 2, wherein, The battery cluster includes a single cabinet, and the charge-sensitive unit is disposed within the cabinet.

4. The energy storage system according to any one of claims 1-3, wherein, The main circuit includes at least one battery box, and each battery box is equipped with a charge-sensitive unit.

5. The energy storage system according to any one of claims 1-4, wherein, The energy storage system also includes a control unit for electrically controlling the main circuit. The control unit includes a first chamber, and the charge-sensitive unit is disposed in the first chamber.

6. The energy storage system according to claim 5, wherein, The control unit includes a main control box, a high-voltage box, a combiner cabinet, or a low-voltage box.

7. The energy storage system according to any one of claims 5-6, wherein, The first chamber is provided with a plurality of charge-sensitive units, and the plurality of charge-sensitive units are connected in series with different main circuits.

8. The energy storage system according to any one of claims 1-7, wherein, The energy storage system also includes a first fixing member, through which multiple battery cells are fixed, and the charge sensing unit is disposed outside the first fixing member.

9. The energy storage system according to claim 8, wherein, The energy storage system also includes a second fixing component, through which the charge-sensitive unit is fixed.

10. The energy storage system according to claim 9, wherein, The first fastener includes a housing, a fixing frame, or a strap, and / or the second fastener includes a housing, a fixing frame, or a strap.

11. The energy storage system according to claim 9, wherein, The first fixing member includes a first housing, and the second fixing member includes a second housing, wherein the first housing and the second housing are configured to form a sealed battery box.

12. The energy storage system according to claim 11, wherein, The second enclosure contains electrical components, and the charge sensing unit is located inside the second enclosure. The electrical components include a signal acquisition unit that collects electrical signals, and the control unit of the energy storage system performs corresponding control based on the electrical signals.

13. The energy storage system according to claim 11, wherein, A plurality of battery cells are arranged in the first housing, with the large surfaces of the plurality of battery cells arranged along a first direction, and the second housing is located at at least one end of the first housing along the first direction.

14. The energy storage system according to claim 9, wherein, The first fastener includes a first frame, and the second fastener includes a second frame. The first frame and the second frame are either separately configured or integrated.

15. The energy storage system according to any one of claims 11 to 13, wherein, The first housing includes a housing body, and a plurality of battery cells are disposed within the housing body. A spacer is provided on the side of the battery cells near the front panel of the housing body, and the charge sensing unit is disposed between the front panel and the spacer.

16. The energy storage system according to claim 15, wherein, The adjacent battery cells are spaced apart to form a flow channel extending along a first direction, and a flow acceleration device is provided at the front panel to accelerate the flow of fluid in the flow channel.

17. The energy storage system according to any one of claims 1 to 16, wherein, The energy storage system includes a charge-sensitive unit group, each charge-sensitive unit group including at least one charge-sensitive unit, and the energy storage system includes multiple charge-sensitive unit groups connected in series with the main circuit.

18. The energy storage system according to any one of claims 1 to 17, wherein, The energy storage system includes a charge-sensitive unit group, which includes two or more charge-sensitive units, and the charge-sensitive units in a charge-sensitive unit group are arranged in parallel.

19. The energy storage system according to claim 17 or 18, wherein, The main circuit includes multiple battery cell assemblies connected in series. Each battery cell assembly includes multiple battery cells connected in series and / or in parallel. The energy capacity of the battery cell assembly is equal to or less than the energy capacity of the charge-sensitive unit group.

20. The energy storage system according to any one of claims 1 to 19, wherein, The size of the battery cell may be the same as or different from the size of the charge-sensitive unit.

21. The energy storage system according to any one of claims 1 to 20, wherein: The open-circuit voltage curve of the charge-sensitive unit is a linear curve with a slope greater than a preset threshold.

22. The energy storage system according to any one of claims 1 to 21, wherein, The battery cells include lithium iron phosphate battery cells.

23. The energy storage system according to any one of claims 1 to 22, wherein, The charge-sensitive unit includes a lithium iron phosphate battery cell, a non-lithium iron phosphate battery cell, a supercapacitor energy storage unit, a flywheel energy storage unit, or a gas compression energy storage unit.

24. The energy storage system according to claim 23, wherein, The non-lithium iron phosphate battery cells include: sodium battery cells, hard carbon battery cells, ternary battery cells, or lithium manganese iron phosphate battery cells.

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