Battery body active self-balancing energy storage system

Abstract

The invention relates to a battery body active self-balancing energy storage system which comprises an energy storage battery unit. The energy storage battery unit comprises a plurality of battery subunits distributed along a first direction, and each battery subunit comprises at least one battery module; a plurality of single batteries distributed along a second direction are arranged in the battery modules, and the plurality of single batteries in any battery module are correspondingly and electrically connected with the plurality of single batteries in the adjacent battery module; the electrolyte cavities in any two adjacent single batteries are communicated with each other, so that the electrolyte in any single battery can circulate into the adjacent single battery. According to the energy storage system, the active self-equalization of the battery body is realized through the series-parallel structural design of the single batteries, so that the problems of inconsistency of the batteries, low charging and discharging electric quantity, low energy conversion efficiency, short service life and the like in the energy storage system are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage batteries, and particularly to an active self-balancing energy storage system for a battery body. Background Art

[0002] Electrochemical energy storage stores electrical energy as chemical energy through the reversible chemical reaction of batteries and then converts the chemical energy back into electrical energy when needed. This conversion process mainly depends on the characteristics of electrode materials and electrolytes and is an important part of modern energy systems, widely used in power systems, transportation, communication base stations, data centers and other fields.

[0003] Since the voltage and capacity of single cells are limited, single cells need to be connected in series and parallel to meet the requirements of the application scenario for the voltage and installed capacity of the energy storage system. Especially for large-scale energy storage systems with high voltage and large capacity, in order to prevent problems such as uneven current, premature decline of system capacity, and shortened lifespan, higher requirements are put forward for the consistency of batteries. However, the materials involved in battery manufacturing cannot be completely identical in themselves. In addition, they are also affected by the fluctuations of equipment, process parameter control, and environmental temperature and humidity during the manufacturing process. Therefore, in theory, the battery bodies cannot be completely identical when leaving the factory, and even some batteries may have potential manufacturing defects, such as micro-short circuits, poor welding, etc. These problems will gradually deteriorate as the battery usage time increases, widening the inconsistency between single cells, resulting in large differences in the internal resistance, voltage, capacity, charge and discharge characteristics, and single cell temperature of the batteries, increasing the difficulty of thermal management and energy management of the entire energy storage system, and further having an adverse impact on the charge and discharge amount, energy utilization efficiency, and lifespan of the entire energy storage system.

[0004] For the management of energy storage systems aiming at battery inconsistency, currently, mainly two technologies, passive equalization or active equalization, are adopted. Passive equalization is a technology that achieves the consistency of the voltage and charge of individual cells within a battery pack by dissipating excess energy through resistor discharge. When the battery management system (BMS) detects that the voltage of a certain individual cell is higher than that of other cells (exceeding the set threshold), equalization is initiated. The electrical energy of the high-voltage individual cell is released in the form of heat through a shunt resistor connected in parallel, reducing its voltage to be the same as that of other cells. This technology converts the excess electrical energy into heat and releases it, resulting in energy waste and reduced system efficiency. At the same time, the equalization current is small and the speed is slow, making it difficult to meet the equalization requirements of large-capacity and high-efficiency energy storage systems. Active equalization is a technology that achieves the balance of the voltage and charge of individual cells within a battery pack through energy transfer. The BMS monitors the state of individual cells in real time and transfers the energy of high-voltage individual cells to low-voltage individual cells or redistributes the energy through intermediate energy storage elements (such as capacitors, inductors, transformers). This technology has a relatively large equalization current and high speed, and can significantly improve the energy utilization efficiency and cycle life of the battery pack. However, for large-capacity individual batteries, the equalization ability is limited. In addition, an additional DC-DC circuit and control chip need to be configured to monitor in real time and dynamically adjust the equalization strategy, increasing the complexity of the BMS and the difficulty of algorithm development, as well as the cost. In summary, whether it is passive equalization or active equalization technology, an external device is required to achieve it, the equalization ability and effect are limited, and at the same time, the difficulty and cost of system management are increased. Summary of the Invention

[0005] The present invention provides an energy storage system with active self-equalization of the battery body, which realizes the active self-equalization of the battery body through the design of the series-parallel structure of individual cells, so as to solve problems such as battery inconsistency, low charge and discharge capacity, low energy conversion efficiency, and short life in the energy storage system.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An energy storage system with active self-equalization of the battery body, comprising an energy storage battery unit; The above-mentioned energy storage battery unit includes a plurality of battery subunits distributed along a first direction, and the above-mentioned battery subunits include at least one battery module; A plurality of individual cells are arranged in the above-mentioned battery module along a second direction, and the plurality of above-mentioned individual cells in any one of the above-mentioned battery modules are electrically connected to the plurality of above-mentioned individual cells in the adjacent above-mentioned battery module; And the electrolyte chambers in any two adjacent above-mentioned individual cells are connected to each other, so that the electrolyte in any one of the above-mentioned individual cells can flow into the adjacent above-mentioned individual cell.

[0007] Preferably, it further includes a charge and discharge device and a current detection and analysis unit; A plurality of the single cells in any of the above battery modules and a plurality of the single cells in the adjacent battery modules are correspondingly electrically connected with a plurality of first connection rows. A plurality of single cells in two battery modules located at two connection ends of the energy storage battery unit are correspondingly connected with a plurality of second connection rows, and a module bus bar is connected to the plurality of second connection rows; The above charging and discharging device is electrically connected to the two above module bus bars respectively to charge and discharge the above energy storage battery unit; The above current detection and analysis unit is used to collect the current values flowing through the above first connection row and the above second connection row in the above energy storage battery unit and perform analysis.

[0008] Preferably, the above current detection and analysis unit includes a current detection device, a current detection signal transmission wire harness, and a current display screen; The above current detection device is installed on the above first connection row and the above second connection row and is used to detect and collect the current values flowing through the above first connection row and the above second connection row; The above current detection device is connected to the above current display screen through the above current detection signal transmission wire harness and is used to transmit the current value signals collected at the positions of each connection row to the above current display screen; The above current display screen is used to centrally display the current values collected at the positions of each connection row and compare the current values with the set threshold range therein to analyze whether a single cell fails.

[0009] Preferably, the analysis process of the above current display screen is as follows: When the above energy storage battery unit is charged, the direction of the current flowing through the above energy storage battery unit is from the positive terminal to the negative terminal. When a certain current value collected by the above current display screen is greater than the threshold range, along the current direction, it is determined that a short circuit occurs inside the above single cell upstream of the corresponding connection row and needs to be repaired; when a certain current value collected by the above current display screen is less than the threshold range, along the current direction, it is determined that the internal resistance of the above single cell upstream of the corresponding connection row increases due to attenuation and needs to be repaired; Or, when the above current display screen energy storage battery unit discharges, the direction of the current flowing through the above current display screen energy storage battery unit is from the negative terminal to the positive terminal. When a certain current value collected by the above current display screen is less than the threshold range, along the current direction, it is determined that a short circuit occurs inside the above single cell upstream of the corresponding connection row and needs to be repaired; when a certain current value collected by the above current display screen is greater than the threshold range, along the current direction, it is determined that the internal resistance of the above single cell upstream of the corresponding connection row increases due to attenuation and needs to be repaired.

[0010] Preferably, the above-mentioned single cell includes a housing and a positive electrode group, a negative electrode group, a positive electrode bus bar, a negative electrode bus bar, and a cell group protective film disposed within the housing; The multiple positive electrode plates within the above-mentioned positive electrode group and the multiple negative electrode plates within the above-mentioned negative electrode group are arranged in an alternating manner along the thickness direction of the single cell, and a separator is provided between two adjacent positive electrode plates and negative electrode plates; The tabs of the multiple positive electrode plates are all electrically connected to the positive electrode bus bar, and the tabs of the multiple negative electrode plates are all connected to the negative electrode bus bar; The above-mentioned cell group protective film is coated on the outer sides of the above-mentioned positive electrode group and the above-mentioned negative electrode group.

[0011] Preferably, the tabs of the above-mentioned positive electrode plate and the above-mentioned negative electrode plate are respectively located at both ends of the single cell, and are respectively electrically connected to the positive electrode bus bar and the negative electrode bus bar through their respective tabs.

[0012] Preferably, the positive electrode bus bar is connected to a positive terminal, the negative electrode bus bar is connected to a negative terminal, and the positive terminal and the negative terminal are diagonally arranged on the single cell.

[0013] Preferably, the above-mentioned battery module includes a mounting case, and a plurality of mounting cavities are provided within the mounting case, and the plurality of above-mentioned single cells are correspondingly mounted within the mounting cavities, and there is a partition wall between any two adjacent mounting cavities, and a communication hole is provided on the partition wall so that the electrolyte cavities within two adjacent above-mentioned single cells are communicated to form a flow channel for the electrolyte.

[0014] Preferably, there is one above-mentioned battery module within the above-mentioned battery sub-unit, and a current detection device is provided on the first connection row between two adjacent corresponding above-mentioned single cells along the first direction; Or, there are multiple above-mentioned battery modules within the above-mentioned battery sub-unit, and two adjacent corresponding above-mentioned single cells within the above-mentioned battery sub-unit are connected through a third connection row along the first direction.

[0015] Preferably, for two adjacent corresponding above-mentioned single cells arranged along the first direction, the positive terminal or the negative terminal of one of the above-mentioned single cells is respectively arranged close to the positive terminal or the negative terminal of the other above-mentioned single cell; and the positive terminal and the negative terminal on the same above-mentioned single cell are diagonally arranged, and the arrangement positions of the positive terminal and the negative terminal on two adjacent above-mentioned single cells are opposite. Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The single cells within the battery module achieve self-balancing through the flowing shared electrolyte, maintaining the voltage consistency of each single cell within the module, thereby ensuring the charge and discharge efficiency and service life of the entire energy storage battery unit.

[0016] 2. Through real-time current detection and analysis, the inconsistency trend of single cells or modules can be judged, and maintenance can be carried out in a timely manner. For severely lagging or faulty single cells or modules that no longer have the value of continued use, they can be replaced through operation and maintenance in a timely manner to prevent the performance deterioration of the energy storage system. Description of the Drawings

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 System overall schematic of the embodiment in the present invention Figure 1 ; Figure 2 System overall schematic of the embodiment in the present invention Figure 2 ; Figure 3 System overall schematic of the embodiment in the present invention Figure 3 ; Figure 4 Single cell schematic of the embodiment in the present invention Figure 1 , where the positive terminal is located at the upper left and the negative terminal is located at the lower right; Figure 5 Of the embodiment in the present invention Figure 4 Schematic diagram of the internal current direction of the single cell; Figure 6 Single cell schematic of the embodiment in the present invention Figure 1 , where the positive terminal is located at the lower left and the negative terminal is located at the upper right; Figure 7 Single cell schematic of the embodiment in the present invention Figure 2 .

[0019] Description of the Reference Numerals: 100, energy storage battery unit; 1, battery subunit; 2, battery module; 3, single cell; 31, positive electrode group; 32, negative electrode group; 33, positive busbar; 34, negative busbar; 35, electrode group protective film; 36, positive terminal; 37, negative terminal; 38, separator; 4, mounting shell; 41, partition wall; 42, flow channel; 5, first connection row; 6, second connection row; 7, third connection row; 8, module busbar; 200, charge and discharge equipment; 201, cable; 300. Current detection and analysis unit; 301. Current detection device; 302. Current detection signal transmission harness; 303. Current display screen. Detailed implementation manner

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0023] An embodiment of the present invention provides a battery body active self-balancing energy storage system, as Figures 1 - 3As shown, it includes an energy storage battery unit 100, where the energy storage battery unit 100 includes a plurality of battery sub-units 1 distributed along a first direction. The plurality of battery sub-units 1 are electrically connected. The battery sub-unit 1 includes a battery module 2, and the battery module 2 is provided with a plurality of single cells 3 distributed along a second direction. The single cell 3 is the smallest unit. In this embodiment, the electrolyte cavities in any two adjacent single cells 3 are connected to each other, that is, the electrolyte in the electrolyte cavity of any single cell 3 can flow into the adjacent single cell 3 and into the more outer single cells 3, and the electrolyte in the adjacent single cell 3 can also flow into its adjacent electrolyte cavity. Thus, the electrolyte cavities in all the single cells 3 in the entire battery module 2 are sequentially connected, and all the electrolyte cavities are connected to form an equalization cavity, and the sharing of the electrolyte is realized in the equalization cavity. Specifically, during charge and discharge, the ions with positive and negative charges participating in the reaction migrate in the shared electrolyte: during charging, the charges of the single cells with higher voltage will be automatically transferred to the single cells with lower voltage through ion migration to achieve voltage clamping; during discharging, the single cells with lower voltage will also accept the charges provided by the single cells with higher voltage through ion migration to achieve voltage increase or a slower rate of decline, thereby realizing the self-equalization of the single cell 3, improving the voltage consistency of all the single cells 3 in the module, achieving the active self-equalization of the single cell 3 body in each energy storage module, and moreover, the overall concentration balance will be automatically achieved with the shared electrolyte in circulation, further maintaining the consistency of the chemical potential, solving the cask effect on the series battery cluster caused by the lag of one or more single cells 3, and ensuring the normal use of the energy storage module. The first direction and the second direction are as Figure 1 shown, the first direction is as Figure 1 the horizontal direction in Figure 1 and the second direction is as

[0024] Moreover, further, the connection relationship of the single cells 3 between multiple battery sub-units 1 is as follows: multiple single cells 3 within any battery module 2 are electrically connected to the corresponding multiple single cells 3 within the adjacent battery module 2. Combining with the equalization cavity formed by multiple single cells 3 within a single battery module 2, a connection relationship of strong series and weak parallel is formed between adjacent battery modules 2. For the convenience of understanding, all the single cells 3 within the entire energy storage battery unit can be regarded as a combination of multiple rows of single cells 3 (distributed along the first direction) and multiple columns of single cells 3 (multiple battery modules 2 distributed along the second direction). Each row of single cells 3 can be regarded as a series circuit, and multiple rows of batteries are regarded as multiple series circuits. Therefore, multiple battery modules 2 can be regarded as series circuits. And combining with the fact that multiple single cells 3 within a single battery module 2 are connected to form an equalization cavity, then the multiple single cells 3 within the battery module 2 are in parallel. So, a connection of strong series and weak parallel is formed between the battery modules 2. Along the direction of the current, when a faulty single cell 3 within a certain battery module 2 causes an increase or decrease in the current, due to the strong series electrical connection method, the current flowing through the connection row to the corresponding next normal battery will also increase or decrease. As the charge and discharge proceed, its voltage will correspondingly enter a high-voltage or low-voltage state first. Also, because the electrolyte is shared between the single cells to form a weak parallel structure, when it is in a high-voltage state, ion migration automatically transfers to adjacent or more outer low-voltage single cells to achieve current shunting and voltage clamping. When it is in a low-voltage state, it will also receive charges provided by adjacent or more outer high-voltage single cells through ion migration to achieve current convergence and voltage boost. Therefore, through the parallel structure, the charge and discharge of the corresponding next module's normal battery are not affected, further improving the consistency of the entire energy storage system unit and ensuring that the charge and discharge are not affected.

[0025] Furthermore, as Figures 1 - 3 shown, the energy storage system further includes a charge and discharge device 200 and a current detection and analysis unit 300. The charge and discharge device 200 is electrically connected to the energy storage battery unit 100 to charge and discharge the energy storage battery unit 100, and the current detection and analysis unit 300 is used to detect the current inside the energy storage battery unit 100 and further analyze to determine the inconsistency trend of the single cells 3 and perform maintenance in a timely manner.

[0026] Specifically, a plurality of single cells in any one battery module 2 and a plurality of single cells in an adjacent battery module 2 are correspondingly electrically connected with a plurality of first connection buses 5. The first connection buses 5 connect the battery modules 2 in series and conduct electricity. A plurality of single cells in two battery modules 2 located at two connection ends of the energy storage battery unit 100 are correspondingly connected with a plurality of second connection buses 6. A plurality of module busbars 8 are connected to the plurality of second connection buses 6. The module busbars 8 conduct the energy storage battery unit 100 and an external electrical appliance. Specifically, the charging and discharging device 200 is respectively connected to the two module busbars 8 through cables 201 to charge and discharge the energy storage battery unit 100, so that the energy storage battery unit 100 is conducted, and there is current on the first connection buses 5 and the second connection buses 6. The charging and discharging device 200 may be one of a PCS, a DC-DC, or a hybrid inverter. Of course, it may also be other charging and discharging devices 200. Here, only examples are given and no specific limitations are made. It should be noted that when the charging and discharging device 200 charges the energy storage battery unit 100, the direction of the current flowing through the energy storage battery unit 100 is from the positive terminal 36 to the negative terminal 37. When the energy storage battery unit 100 discharges, the direction of the current flowing through the energy storage unit is from the negative terminal 37 to the positive terminal 36.

[0027] Among them, the current detection and analysis unit 300 includes a current detection device 301, a current detection signal transmission harness 302, and a current display screen 303. The current detection device 301 is installed on the first connection bus 5 and the second connection bus 6 between two adjacent battery modules 2 in different battery sub-units 1. Each current detection device 301 is connected to the current display screen 303 through the current detection signal transmission harness 302, so as to transmit the current value signal collected at each connection bus point to the current display screen 303. The current display screen 303 is used to centrally display the current values collected at each connection bus point, and then compare the current values with the set threshold range therein to further analyze the results. The current detection device 301 may be a current sensor.

[0028] Specifically, the current detection and analysis unit 300 sets the stable current value as I, where the stable current value I is set by the designer according to the energy storage battery unit 100 and the single battery 3 itself. Taking 20% higher or lower than the set value I as the threshold range. Since the current detection device 301 can measure the current on the first connection row 5 and the second connection row 6 of the energy storage battery unit 100 during both charging and discharging, there are two cases here: when the charging and discharging device 200 charges the energy storage battery unit 100, or when the energy storage battery unit 100 discharges; it should be noted that when the charging and discharging device 200 charges the energy storage battery unit 100, the direction of the current flowing through the energy storage battery unit 100 is from the positive terminal 36 to the negative terminal 37, and the current collected by the current detection device 301 is positive, that is, I collected is positive, and the corresponding threshold range is set as 0.8I - 1.2I. When the energy storage battery unit 100 discharges, the direction of the current flowing through the energy storage battery unit 100 is from the negative terminal 37 to the positive terminal 36, and the current collected by the current detection device 301 is negative, that is, I collected is negative, and the corresponding threshold range is set as -1.2I - -0.8I. The specific judgment situations are as follows: 1. When the charging and discharging device 200 charges the energy storage battery unit 100, the direction of the current flowing through the energy storage battery unit 100 is from the positive terminal 36 to the negative terminal 37, and the current detection device 301 collects the current. When the collected current value I collected is not within the threshold range, the current detection and analysis unit 300 gives an alarm; specifically, when the current value I collected is greater than the maximum value 1.2I within the threshold range, it is considered that the single battery 3 upstream of the corresponding connection row (the first connection row or the second connection row) has an internal short circuit resulting in a decrease in internal resistance, and further repair is required; when the current value I collected is less than the minimum value 0.8I within the threshold range, it is considered that the single battery 3 upstream of the corresponding connection row (the first connection row or the second connection row) has a defect or attenuation resulting in an increase in internal resistance, and further repair or replacement is required.

[0029] 2. When the energy storage battery unit 100 discharges, the direction of the current flowing through the energy storage battery unit 100 is from the negative terminal 37 to the positive terminal 36. When the collected current value I collected is not within the threshold range, the current detection and analysis unit 300 gives an alarm. Specifically, when the current value I collected is less than the minimum value -1.2I within the threshold range, it is considered that the single battery 3 upstream of the corresponding connection row (the first connection row or the second connection row) has an internal short circuit resulting in a decrease in internal resistance, and further repair is required; when the current value I collected is greater than the minimum value -0.8I within the threshold range, it is considered that the single battery 3 upstream of the corresponding connection row (the first connection row or the second connection row) has a defect or attenuation resulting in an increase in internal resistance, and further repair or replacement is required.

[0030] It should be noted here that the threshold range is set to 20% above and below the set value because once a single battery 3 fails, the current in the connecting row corresponding to the adjacent single battery 3 will increase or decrease correspondingly. However, this is not due to the failure but due to the self-balancing within the single battery 3. Therefore, the threshold range is set slightly larger to make the analysis results more accurate.

[0031] In summary, based on the self-balancing of the energy storage battery unit 100, through real-time current detection and analysis, the inconsistency trend of the single battery 3 or the battery module can be judged, and maintenance can be carried out in a timely manner. For severely lagging or faulty single batteries 3 or modules that no longer have the value of continued use, they can be replaced in a timely manner through operation and maintenance to prevent the performance deterioration of the energy storage system. Moreover, no external device is used in the whole system, and no complex BMS control and algorithm development are required, which not only reduces the cost, but also provides the balancing ability, improves the balancing effect, and is conducive to improving the energy utilization efficiency and service life of the whole energy storage system.

[0032] Specifically, for a single battery subunit 1, its interior can be composed of one battery module 2 or multiple battery modules 2; specifically, as Figure 1 and Figure 3 shown, for a battery subunit 1 composed of one battery module 2, current detection devices 301 are arranged on the first connecting row 5 between two adjacent single batteries 3 along the first direction; specifically, as Figure 2 shown, for an energy storage battery unit 100 composed of multiple battery modules 2, the single batteries 3 corresponding to two adjacent battery modules inside are connected through a third connecting row 7, and there is no current detection device 301 on it. The current detection devices 301 are arranged on the first connecting row 5 between two adjacent battery subunits 1 and the outer second connecting row 6. Therefore, when there is a problem with the current value on one of the first connecting rows 5, all the corresponding connected single batteries 3 in the battery subunit 1 upstream of the first connecting row 5 need to be repaired and maintained in a timely manner. For severely lagging or faulty single batteries 3 that no longer have the value of continued use, they can be replaced in a timely manner through operation and maintenance.

[0033] Specifically, as Figures 4 - 7As shown, the single cell 3 includes a housing and a positive electrode group 31, a negative electrode group 32, a positive electrode bus bar 33, a negative electrode bus bar 34, and a cell group protective film 35 disposed within the housing. The positive electrode group 31 includes a plurality of positive electrode plates, and the negative electrode group 32 includes a plurality of negative electrode plates. The plurality of positive electrode plates and the plurality of negative electrode plates are arranged to cross each other in the thickness direction of the single cell 3. A separator 38 is provided between two adjacent positive electrode plates and negative electrode plates to isolate the positive and negative electrodes, playing a crucial role in isolation and preventing short circuits inside the battery. The cell group protective film 35 covers the outside of the positive electrode group 31 and the negative electrode group 32 to protect the electrode plates during the process of installing the cell group into the battery housing. Both the positive electrode plate and the negative electrode plate have electrode tabs. The positive electrode plate and the negative electrode plate are electrically connected to the positive electrode bus bar 33 and the negative electrode bus bar 34 through their respective electrode tabs. Positive terminal 36 and negative terminal 37 are correspondingly provided on the positive electrode bus bar 33 and the negative electrode bus bar 34, and are externally electrically connected through the negative terminal 37 and the positive terminal 36.

[0034] At the same time, the positive electrode tab corresponding to the positive electrode plate and the negative electrode tab corresponding to the negative electrode plate are respectively located at both ends of the single cell 3, so that the positive electrode bus bar 33 and the negative electrode bus bar 34 are also correspondingly located at both ends of the single cell 3, in order to reduce the cost of the first connection row 5, the second connection row 6, and the third connection row 7.

[0035] Furthermore, the positive terminal 36 and the negative terminal 37 on the single cell 3 are arranged diagonally. Generally speaking, the positive terminal 36 and the negative terminal 37 of a storage battery (lithium battery, lead-acid battery, or other storage batteries) are both located on the same surface. When the single cell 3 is charged or discharged, the current inside the single cell 3 flows from the positive terminal 36 to the diagonal negative terminal 37 or from the negative terminal 37 to the diagonal positive terminal 36, which can ensure that the current path inside each single cell 3 is consistent.

[0036] Specifically, the battery module 2 includes a mounting case 4. A plurality of partition walls 41 are arranged in the mounting case 4 along the second direction. The plurality of partition walls 41 divide the mounting case 4 into a plurality of mounting cavities. A plurality of single cells 3 are correspondingly installed in the mounting cavities. Communication holes are provided on the partition walls 41, which can make the electrolyte cavities in two adjacent single cells 3 communicate with each other to form a circulation channel 42 for the electrolyte. Of course, it should be noted that the partition wall 41 described here has a certain thickness, which can ensure the stable installation of the single cell 3 in the mounting cavity.

[0037] Specifically, since the two single cells 3 are connected by a connecting row to connect the positive terminal 36 of one single cell 3 to the negative terminal 37 of another single cell 3. Generally, the height between each battery module 2 is the same, and the positive terminal 36 and the negative terminal 37 of each single cell 3 are both located on its mounting surface. In order to make the length of the connecting row for connecting two single cells 3 between adjacent battery modules 2 shorter, so that the structure between the two battery modules 2 is more compact and the conduction path is shorter. In this embodiment, on the basis that the positive terminal 36 and the negative terminal 37 on each single cell 3 are diagonally arranged, for two single cells 3 distributed along the first direction and adjacent to each other, the two ends close to each other are respectively provided with a positive electrode and a negative electrode, and the setting positions of the positive terminal 36 and the negative terminal 37 on the two adjacent single cells 3 are opposite. As a result, for two adjacent single cells 3, the first connecting row 5 connecting the positive terminal 36 and the negative terminal 37 is horizontally arranged, with a short distance. For the convenience of understanding, the following is an example: For example, there are three battery modules 2 distributed along the first direction, and three single cells 3 are distributed along the second direction in each battery module 2. For the convenience of description, the three battery modules 2 are respectively the first battery module, the second battery module and the third battery module, and the three single cells 3 are respectively the first battery, the second battery and the third battery. The three first batteries in the first battery module, the second battery module and the third battery module correspond to each other, the three second batteries correspond to each other, and the three third batteries correspond to each other. Specifically, the connection of the first battery will be described. The positive terminal 36 and the negative terminal 37 of the first battery in the first battery module are respectively arranged at the upper left and the lower right, then the positive terminal 36 and the negative terminal 37 of the first battery in the second battery module are arranged at the lower left and the upper right, and the positive terminal 36 and the negative terminal 37 of the first battery in the third battery module are arranged at the upper left and the lower right. As a result, the connecting row connecting the positive terminal 36 and the negative terminal 37 between two adjacent first batteries, with respect to the mounting surface of the single cell 3, its projection is either horizontally located below the plane of the mounting surface or horizontally located above the plane of the mounting surface, and will not be inclined from the lower right to the upper right or from the upper right to the lower right. Thus, the connecting row connecting the positive terminal 36 and the negative terminal 37 on two adjacent and corresponding single cells 3 will not be inclined, and the horizontally arranged length will be shorter, which can make the conduction path between the corresponding two single cells 3 shorter and more compact. Further, the conduction path between two adjacent battery modules 2 is shorter and the structure is more compact. Moreover, the connecting row arranged in this way also makes the entire energy storage battery unit 100 more beautiful and the connection is orderly.

[0038] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention belong to the scope of protection required by the present invention.

Claims

1. An active self - balancing energy storage system for a battery body, characterized in that including an energy storage battery unit; The energy storage battery unit includes a plurality of battery subunits distributed along a first direction, and each battery subunit includes at least one battery module; A plurality of single cells are arranged in the battery module along a second direction, and the plurality of single cells in any one battery module are correspondingly electrically connected to the plurality of single cells in the adjacent battery module; Moreover, the electrolyte chambers in any two adjacent single cells are communicated with each other, so that the electrolyte in any one single cell can flow into the adjacent single cell.

2. The energy storage system according to claim 1, wherein It further includes a charge and discharge device and a current detection and analysis unit; A plurality of first connection buses are correspondingly electrically connected between the plurality of single cells in any one battery module and the plurality of single cells in the adjacent battery module. A plurality of second connection buses are correspondingly connected to the plurality of single cells in the two battery modules at the two connection ends of the energy storage battery unit, and a plurality of the second connection buses are all connected to a module busbar; The charge and discharge device is electrically connected to the two module busbars respectively to charge and discharge the energy storage battery unit; The current detection and analysis unit is used to collect and analyze the current values flowing through the first connection bus and the second connection bus in the energy storage battery unit.

3. The energy storage system according to claim 2, wherein The current detection and analysis unit includes a current detection device, a current detection signal transmission harness, and a current display screen; The current detection device is installed on the first connection bus and the second connection bus and is used to detect and collect the current values flowing through the first connection bus and the second connection bus; The current detection device is connected to the current display screen through the current detection signal transmission harness and is used to transmit the current value signals collected at the positions of each connection bus to the current display screen; The current display screen is used to centrally display the current values collected at the positions of each connection bus and compare them with the preset threshold range in it to analyze whether a single cell fails.

4. The energy storage system according to claim 3, characterized in that The analysis process of the current display screen is as follows: When the energy storage battery unit is charging, the direction of the current flowing through the energy storage battery unit is from the positive terminal to the negative terminal. When a certain current value collected by the current display screen is greater than the threshold range, then along the current direction, it is judged that a short circuit occurs inside the single cell upstream of the corresponding connection bus and needs to be repaired; when a certain current value collected by the energy storage battery unit is less than the threshold range, then along the current direction, it is judged that the internal resistance of the single cell upstream of the corresponding connection bus increases due to attenuation and needs to be repaired; Or, when the energy storage battery unit is discharging, the direction of the current flowing through the energy storage battery unit is from the negative terminal to the positive terminal. When a certain current value collected by the current display screen is less than the threshold range, then along the current direction, it is judged that a short circuit occurs inside the single cell upstream of the corresponding connection bus and needs to be repaired; when a certain current value collected by the current display screen is greater than the threshold range, then along the current direction, it is judged that the internal resistance of the single cell upstream of the corresponding connection bus increases due to attenuation and needs to be repaired.

5. The energy storage system according to claim 2, characterized in that, The single cell includes a housing and a positive electrode group, a negative electrode group, a positive electrode bus bar, a negative electrode bus bar, and a cell group protective film disposed within the housing; A plurality of positive electrode plates within the positive electrode group and a plurality of negative electrode plates within the negative electrode group are arranged in an interleaved manner along the thickness direction of the single cell, and a separator is disposed between two adjacent positive electrode plates and negative electrode plates; The tabs of the plurality of positive electrode plates are all electrically connected to the positive electrode bus bar, and the tabs of the plurality of negative electrode plates are all connected to the negative electrode bus bar; The cell group protective film is coated on the outer sides of the positive electrode group and the negative electrode group.

6. The energy storage system according to claim 5, wherein, The tabs of the positive electrode plate and the negative electrode plate are respectively located at two ends of the single cell, and are respectively electrically connected to the positive electrode bus bar and the negative electrode bus bar through their respective tabs.

7. The energy storage system according to claim 6, wherein The positive electrode bus bar is connected to a positive terminal, the negative electrode bus bar is connected to a negative terminal, and the positive terminal and the negative terminal are diagonally arranged on the single cell.

8. The energy storage system according to claim 5, wherein The battery module includes a mounting housing, and a plurality of mounting cavities are provided within the mounting housing, and a plurality of the single cells are correspondingly mounted within the mounting cavities, and there is a partition wall between any two adjacent mounting cavities, and a communication hole is provided on the partition wall so that the electrolyte cavities within two adjacent single cells are communicated to form a flow channel for the electrolyte.

9. The energy storage system according to claim 2, wherein One battery module within the battery sub-unit is provided, and a current detection device is provided on a first connection row between two adjacent corresponding single cells along a first direction; or, a plurality of battery modules are provided within the battery sub-unit, and two adjacent corresponding single cells within the battery sub-unit are connected through a third connection row along the first direction.

10. The energy storage system according to claim 9, wherein For two adjacent corresponding single cells arranged along the first direction, the positive terminal or the negative terminal of one of the single cells is respectively arranged close to the positive terminal or the negative terminal of the other single cell; and the positive terminal and the negative terminal on the same single cell are diagonally arranged, and the arrangement positions of the positive terminal and the negative terminal on two adjacent single cells are opposite.

Images