Energy storage battery system

Abstract

The invention provides an energy storage battery system which comprises a plurality of battery cells, heating films and hollow cooling partition plates are sequentially and alternately arranged between every two adjacent battery cells, the cooling partition plates are hollow, an air duct inlet and an air duct outlet are formed in the two ends of each cooling partition plate respectively, and a hollow blowing plate is arranged on one side of each battery cell. One side of the blowing plate is connected with air blowing equipment, and the blowing plate is provided with an output air port communicated with the air duct inlet; a plurality of hollowed-out holes changing in a gradient mode are formed in the surface of the cooling partition plate, and the hole diameters and the number of the hollowed-out holes are gradually increased in the direction from the air duct inlet to the air duct outlet. The uniform air cooling temperature control process can be achieved, the cooling capacity is improved through the arranged hollowed-out holes, meanwhile, multiple voltage grades are achieved, and the charging and discharging processes under different requirements are met.

Description

Technical Field

[0001] The present invention belongs to the technical field of power and energy storage batteries, and in particular relates to an energy storage battery system. Background Art

[0002] The existing battery system temperature control methods mainly include air cooling and liquid cooling. Air cooling has a series of obvious advantages over liquid cooling, such as low cost, no leakage risk, and lightweight. Therefore, it is suitable for electric vehicles and energy storage systems. However, the main disadvantage of the air cooling system is that the specific heat of air is low, and it is immediately heated after flowing into the battery pack, resulting in a significant temperature difference between the front and rear ends of the air duct, which is not conducive to the life and performance of the battery system.

[0003] In addition, battery systems are used in a variety of scenarios and require a wide voltage range, from several volts to hundreds of volts. Common charging and discharging equipment includes: low-voltage starting power supplies and portable electronic devices, medium-voltage light electric vehicles and household appliances; high-voltage large electric vehicles, charging piles and other special equipment. In some cases, the voltage of the battery cell changes greatly during the charging and discharging process, causing incompatibility problems. Traditional battery systems require expensive electromagnetic induction transformer components to achieve wide voltage matching, and the transformer components suffer from severe energy loss under high-power conditions.

[0004] In summary, the battery system in the prior art has problems such as short service life, poor temperature control effect, high cost and serious energy loss. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an energy storage battery system to solve the problems raised in the above background technology.

[0006] In a first aspect, an embodiment of the present invention provides the following technical solution: an energy storage battery system, comprising a plurality of groups of battery cells, wherein heating films and cooling baffles are alternately arranged between two adjacent groups of battery cells, wherein the cooling baffles are hollow and air duct inlets and air duct outlets are respectively arranged at both ends of the cooling baffles, wherein a hollow blowing plate is arranged on one side of the battery cell, a blasting device is connected to one side of the blowing plate, and an output air outlet connected to the air duct inlet is arranged on the blowing plate; The surface of the cooling baffle is provided with a plurality of hollow holes with a gradient change, and the diameter and number of the hollow holes increase gradually along the direction from the air duct inlet to the air duct outlet.

[0007] Compared with the prior art, the beneficial effects of the present application are as follows: the present invention forces the air flow in the cooling partition through the blowing equipment to achieve uniform heat dissipation of the battery cells, and at the same time cooperates with the heating film to realize the heating process of the battery cells, thereby realizing an efficient and low-cost air-cooled temperature control process for the battery cells, and a number of gradient-distributed hollow holes are provided on the cooling partition. At the hollow holes, the battery cells are in direct contact with the cold air, resulting in significant heat exchange. At the position where there are no hollow holes, the battery cells and the cold air are separated by the outer wall of the cooling partition, and the heat exchange is hindered to keep the air low. Near the entrance of the air duct, the air temperature is low and the heat exchange capacity is high. A small number of hollow holes with a small aperture are provided. Along the direction of air flow, the cold air is gradually heated and the heat exchange capacity decreases. Therefore, more hollow holes are provided at the outlet of the air duct and their apertures are increased to improve the cooling capacity and ensure the temperature uniformity of the battery cells.

[0008] Preferably, a tab is fixed on the battery cell.

[0009] Preferably, the air duct outlet is located on a side of the cooling baffle close to the pole ear.

[0010] Preferably, the heating film and the cooling baffle are attached to the outer wall of the battery core.

[0011] Preferably, the battery cells are respectively provided with a first switch group and a second switch group, the first switch group includes a plurality of first switches arranged corresponding to the battery cells, the second switch group includes a plurality of second switches arranged corresponding to the battery cells, and a series circuit and a parallel circuit are arranged between the battery cells.

[0012] Preferably, the first switch is arranged in the parallel circuit, and the second switch is arranged between the series circuit and the parallel circuit, and the second switch is used for switching the series circuit and the parallel circuit to realize multi-level voltage switching.

[0013] Preferably, the cooling baffle is provided with alternately arranged flow channel walls, the length of the flow channel walls is smaller than the length of the cooling baffle, and the height of the flow channel walls is equal to the height of the inner cavity of the cooling baffle.

[0014] Preferably, a plurality of support columns are provided on both sides of the flow channel wall.

[0015] Preferably, the flow channel wall and the support column are both arranged obliquely, and the flow channel wall and the support column are both made of elastic material.

[0016] Preferably, the first switch is a single-pole single-throw switch, and the second switch is a single-pole double-throw switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A three-dimensional diagram of the energy storage battery system provided in the first embodiment of the present invention; Figure 2 A three-dimensional diagram of the energy storage battery system provided in Embodiment 1 of the present invention from another perspective; Figure 3 This is a structural diagram of a blowing plate provided in Embodiment 1 of the present invention; Figure 4 is a structural diagram of a second switch group provided in Embodiment 1 of the present invention; Figure 5 This is a structural diagram of a cooling baffle provided in Embodiment 1 of the present invention; Figure 6 A structural diagram of a cooling baffle from another perspective provided in Embodiment 1 of the present invention; Figure 7 A circuit connection diagram of a battery cell provided in Embodiment 1 of the present invention; Figure 8 This is a diagram of the internal structure of the cooling baffle provided in the first embodiment of the present invention; Fig. 9 A three-dimensional diagram of the energy storage battery system provided in the second embodiment of the present invention; Fig.10 This is a three-dimensional diagram of the cooling baffle provided in the second embodiment of the present invention.

[0019] Description of reference numerals:

[0020] The embodiments of the present invention will be further described below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0022] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0024] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0025] Embodiment 1 like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the first embodiment of the present invention provides an energy storage battery system, including a plurality of groups of battery cells 15, heating films 7 and cooling baffles 6 are alternately arranged between two adjacent groups of battery cells 15, the cooling baffles 6 are hollow and air duct inlet 10 and air duct outlet 11 are respectively arranged at both ends of the cooling baffles 6, a hollow blowing plate 4 is arranged on one side of the battery cell 15, a blast device 3 is connected to one side of the blowing plate 4, and an output air outlet 8 connected to the air duct inlet 10 is arranged on the blowing plate 4; Specifically, for each group of battery cells 15, it is composed of several battery cells 15 combined together. Each group of battery cells 15 represents the physical and positional relationship of the battery cells 15 within the group. The battery cells 15 can be lithium-ion, sodium-ion or other ion batteries. In this embodiment, they are in a square structure. In the battery system of the present invention, several groups of battery cells 15 are arranged in sequence, and a heating film 7 and a cooling partition 6 are alternately provided between adjacent two groups of battery cells 15 in sequence. And a heating film 7 is provided on the outside of the outermost group of battery cells 15. The several groups of battery cells 15 are sequentially numbered as (1), (2), (3), (4), …, (A - 1), (A). The outsides of the battery cells 15 in group (1) and group (A) are both heating films 7. There is a cooling partition 6 between group (1) and group (2) of battery cells 15, a heating film 7 between group (2) and group (3) of battery cells 15, a cooling partition 6 between group (3) and group (4) of battery cells 15, and so on. There is a cooling partition 6 between group (A - 1) and group (A) of battery cells 15. Therefore, it can be known that both sides of each group of battery cells 15 are in contact with the heating film 7 and the cooling partition 6 respectively; Specifically, during the process of thermal management, if heating is required, the heating film 7 can be used to heat the battery cells 15 on both sides. If cooling is required, the air blower device 3 can be used to blow cold air into the blowing plate 4. The cold air in the blowing plate 4 will enter the cooling partition 6 through the air outlet 8 and the air duct inlet 10, and then cool the battery cells on both sides of the cooling partition 6. The heating film 7 between each group of battery cells 15 converts electrical energy into heat energy to increase the temperature of the battery cells 15 when necessary. Each heating film 7 is independent and can be turned on and off separately. The temperatures of different regions can be detected by multiple temperature sensors arranged in the battery system. During the process of thermal management, if the temperature sensor detects that the local temperature is too low or too high, the heating film 7 in that region is turned on or off to promote the temperature uniformity of the battery system. And the blowing plate 4 is installed on one or more surfaces of the battery system. The cold air in the blowing plate 4 is pushed to flow through each cooling partition 6, so as to uniformly dissipate heat from the battery cells 15. The air blower device 3 can be an axial flow fan or a side blowing fan.

[0026] As Figure 5 、 Figure 6 shown, a number of gradient-changing hollow holes 12 are provided on the surface of the cooling partition 6. Along the direction from the air duct inlet 10 to the air duct outlet 11, the aperture and the number of the hollow holes 12 increase; Specifically, along the direction from the air duct inlet 10 to the air duct outlet 11, the hollow holes 12 can be divided into several groups. The closer to the air duct outlet 11, the more the number of each group of hollow holes 12 and the larger the aperture. The closer to the air duct inlet 10, the fewer the number of each group of hollow holes 12 and the smaller the aperture; Moreover, the cooling baffle 6 is made of plastic material and is hollow inside. The low thermal conductivity of the plastic prevents the cold air from being heated prematurely at the air duct inlet 10, ensuring that the cold air can penetrate deeply into the battery system to achieve uniform heat exchange. At the hollow holes 12, the battery cells 15 are in direct contact with the cold air, resulting in significant heat exchange. At the position where there are no hollow holes 12, the battery cells 15 and the cold air are separated by the plastic outer wall, and the heat exchange is hindered, thereby maintaining the low temperature of the air. Near the air duct inlet 10, the air temperature is low and the heat exchange capacity is high. A small number of hollow holes 12 with a small aperture are set. Along the direction of air flow, the cold air is gradually heated and the heat exchange capacity decreases. Therefore, more hollow holes 12 are set at the air duct outlet 11 and their apertures are increased to improve the cooling capacity and ensure the temperature uniformity of the battery cells. The shapes of the hollow holes 12 can be round, square, and irregular.

[0027] In this embodiment, a tab 2 is fixed to the battery cell 15 .

[0028] In this embodiment, the air duct outlet 11 is located on a side of the cooling baffle 6 close to the pole ear 2; Specifically, by setting the position of the air duct outlet 11 at a side close to the pole ear 2, the airflow output by the air duct outlet 11 directly blows the high-heat-generating pole ear 2 and the connecting parts, achieving the effect of efficient heat dissipation and rapid temperature reduction.

[0029] In this embodiment, the heating film 7 and the cooling baffle 6 are attached to the outer wall of the battery cell 15; Specifically, the heating film 7 and the cooling baffle 6 are both in close contact with the outer wall of each group of battery cells 15 , and the shapes of the heating film 7 and the cooling baffle 6 are adapted to the shape of the outer wall of the battery cells 15 , and can be a flat shape or a curved shape.

[0030] like Figure 7 As shown, in this embodiment, the battery cells 15 are respectively provided with a first switch group 5 and a second switch group 9, the first switch group 5 includes a plurality of first switches 16 corresponding to the battery cells 15, the second switch group 9 includes a plurality of second switches 17 corresponding to the battery cells 15, and a series circuit and a parallel circuit are connected between the battery cells 15; Specifically, in the present embodiment, a plurality of battery cells 15 connected in series are recorded as a battery cell group 1, each battery cell group 1 represents the electrical connection relationship of the battery cells 15 in the group, and the battery cells 15 in each battery cell group 1 are connected in series in sequence, so the first switch group 5 and the second switch group 9 are arranged above the battery cell group 1, the first switch 16 is arranged corresponding to each battery cell group 1, the second switch 17 is also arranged corresponding to each battery cell group 1, and the series circuit and the parallel circuit are arranged between two adjacent battery cell groups 1.

[0031] The first switch 16 is arranged in the parallel circuit, and the second switch 17 is arranged between the series circuit and the parallel circuit, and the second switch 17 is used to switch the series circuit and the parallel circuit to realize multi-level voltage switching; Specifically, the first switch group 5 and the second switch group 9 are arranged on the surface where the pole ear of the battery cell 15 is located. In the connection circuit of each battery cell 15 in the battery system, all the battery cells 15 in each battery cell group 1 are connected in series in sequence to form a complete battery cell group 1. For each battery cell group 1, each battery cell group 1 is connected in series in sequence from beginning to end to form a series circuit. The two ends of each battery cell group 1 are connected in parallel in sequence to form a parallel circuit. The number of first switches 16 and second switches 17 is the number of battery cell groups 1 minus one, and the first switch 16 is arranged in the parallel circuit of the battery cell group 1. For the parallel circuit and the series circuit of the battery cell group 1, there is an intersection, which is the connection position of the second switch 17. Therefore, through the second switch The switch 17 can freely choose to connect the battery cell group 1 to a parallel circuit or a series circuit. Therefore, it can be known that when the second switch 17 is switched to the series circuit, the two adjacent battery cell groups 1 are connected in series, and when the second switch 17 is switched to the parallel circuit, the two adjacent battery cell groups 1 are connected in parallel. At the same time, it should be noted that the corresponding first switch 16 needs to be disconnected when switching to the series circuit, and the corresponding first switch 16 needs to be closed when switching to the parallel circuit. The series-parallel relationship of the battery cell group 1 is actually the series-parallel relationship between the battery cells 15. Therefore, when the second switch 17 is switched to the series circuit, the two adjacent battery cell groups 1 are connected in series, and when the second switch 17 is switched to the parallel circuit, the two adjacent battery cell groups 1 are connected in parallel; It should be noted that the present invention changes the rated voltage of the entire battery system by dynamically adjusting the connection mode between the battery cell groups 1, and specifically realizes that the rated voltage is not less than three gears. In actual situations, a larger voltage range can be covered and quickly switched to match the rated voltages of various charging and discharging devices, or switched during the charging and discharging process to compensate for the voltage fluctuations of the single battery cells; Specifically, the positive pole of each battery cell group 1 is connected to the first switch 16, and the negative pole is connected to the second switch 17. The order and position of the switches can be changed, and highly integrated analog switches such as MOSFET, relays, chips and other control elements are used to achieve the same effect. When the first switch 16 corresponding to a battery cell group 1 is closed, its second switch 17 is simultaneously switched to the corresponding parallel circuit, which can realize the parallel connection between the battery cell group 1 and an adjacent battery cell group 1. When the first switch 16 corresponding to a battery cell group 1 is disconnected, its second switch 17 is simultaneously switched to the corresponding series circuit, which can realize the series connection between the battery cell group 1 and an adjacent battery cell group 1.

[0032] In the present invention, the number of cells 15 in a single cell group 1 is M, the number of cells in series between the cell groups 1 is N, and the number of cells in parallel is K. In the present embodiment, the cell group 1 is specifically a plurality of cells 15 connected in series, which is not necessarily Figure 1 In the arrangement mode, a number of cells can be arbitrarily selected to form a cell group 1, and the heating film 7 and the cooling baffle 6 are arranged on both sides of each group of cells 15. Here, each group of cells 15 and the cell group 15 have different meanings. Each group of cells 15 represents the physical and positional relationship between the cells 15, and the cell group 1 represents the electrical connection relationship between the cells 15. Assuming that there are 20 cell groups 1 in the present invention, each cell group 1 includes 4 cells 15, then M is 4, and assuming that all cell groups 1 are connected in series, then N is 20, K is 1, assuming that all cell groups 1 are connected in parallel, then N is 1, M is 20, and K, M, and N satisfy the following equations: Equation 1: Total number of cells 1 = M×K×N; Equation 2: Battery system rated voltage = (single cell rated voltage) × M × N; Equation 3: Battery system rated capacity = (single cell rated capacity) × K; Equation 4: The voltage level of the rated voltage of the battery system is the number of all combinations of K and N that satisfy Equation 1; In order to further illustrate the dynamic voltage level of the battery system of the present invention, the present invention sets several experimental examples, specifically including Experimental Examples 1 to 6, and sets the number of battery cell groups 1 to 20, M to 4, and battery cell 15 to be a ternary lithium soft-pack battery cell with a rated voltage of 3.7V and a rated capacity of 3Ah; In Experimental Example 1, K is set to 1 and N is set to 20, that is, 20 battery cell groups 1 are connected in series in sequence; In Experimental Example 2, K is set to 2 and N is set to 10, that is, 20 battery cell groups 1 are evenly divided into two large battery cell groups, each large battery cell group includes 10 battery cell groups 1, and the 10 battery cell groups 1 in each large battery cell group are sequentially connected in series, and then the two large battery cell groups are connected in parallel; In Experimental Example 3, K is set to 4 and N is set to 5, that is, 20 battery cell groups 1 are evenly divided into five battery cell groups, each battery cell group includes 4 battery cell groups 1, and the 4 battery cell groups 1 in each battery cell group are connected in parallel, and then the five battery cell groups are connected in series; In Experimental Example 4, K is set to 5 and N is set to 4, that is, 20 battery cell groups 1 are evenly divided into four battery cell groups, each battery cell group includes 5 battery cell groups 1, and the 5 battery cell groups 1 in each battery cell group are connected in parallel, and then the four battery cell groups are connected in series; In Experimental Example 5, K is set to 10 and N is set to 2, that is, 20 battery cell groups 1 are evenly divided into ten battery cell groups, each battery cell group includes two battery cell groups 1, and the two battery cell groups 1 in each battery cell group are connected in parallel, and then the ten battery cell groups are connected in series; In Experimental Example 6, K is set to 20 and N is set to 1, that is, 20 battery cell groups 1 are connected in parallel in sequence.

[0033] The voltage range corresponding to each experimental example is shown in Table 1: Table 1

[0034] According to the above Table 1, by dynamically adjusting the series-parallel relationship between the battery cell groups 1 through the first switch 16 and the second switch 17, the rated voltage of the battery system can be dynamically adjusted.

[0035] like Figure 8 As shown, in this embodiment, the cooling baffle 6 is provided with alternately arranged flow channel walls 14, the length of the flow channel wall 14 is less than the length of the cooling baffle 6, and the thickness of the flow channel wall 14 is equal to the height of the inner cavity of the cooling baffle 6; Specifically, by providing the flow channel wall 14, the inner cavity of the cooling baffle 6 can be divided into tortuous channels, thereby improving the heat exchange effect.

[0036] In this embodiment, a plurality of support columns 13 are disposed on both sides of the flow channel wall 14 .

[0037] In this embodiment, the flow channel wall 14 and the support column 13 are both inclined, and the flow channel wall 14 and the support column 13 are both made of elastic material; Specifically, the inner cavity of the cooling baffle 6 is divided into a tortuous air duct by the flow channel wall 14, thereby increasing the air transmission path in the cooling baffle 6 and realizing sufficient heat exchange. The flow channel wall 14 in the air duct is inclined to the outer wall of the cooling baffle 6, and a large number of elastic support columns are also arranged inside the cooling baffle 6. The support columns 13 and the outer wall of the cooling baffle 6 are also inclined. The support columns 13, the flow channel wall 14 and the cooling baffle 6 are in a non-orthogonal inclined relationship. The non-orthogonal inclined relationship allows the flow channel wall 14 and the support columns 13 to be elastically compressed, thereby accommodating the expansion of the battery cell 15 during use and providing a constant pressure to the battery cell 15 to maintain the structural stability of the battery system. Preferably, the processing method of the cooling baffle 6 can be additive manufacturing of polymer materials.

[0038] In this embodiment, the first switch 16 is a single-pole single-throw switch, and the second switch 17 is a single-pole double-throw switch; Specifically, the single-pole double-throw switch can switch different circuits, so that the second switch 17 can switch between the series circuit and the parallel circuit.

[0039] Embodiment 2 like Fig. 9 , Fig.10 As shown, the second embodiment of the present invention provides an energy storage battery system, and the structure of the energy storage battery system provided by the second embodiment of the present invention is the same as that of the first embodiment, except that: The battery cell 15 in the second embodiment has a cylindrical structure, and the heating film 7 and the cooling partition 6 on both sides of the battery cell 15 fit the shape of each group of battery cells 15, and both have a wavy structure. The blowing plate 4 is arranged below the battery cell 15, and the pole ear 1 is arranged on the upper surface of the battery cell 15. The first switch group 5 and the second switch group 9 are arranged on the surface where the pole ear of the battery cell 15 is located, and the blowing device 3 is arranged on the side wall of the battery cell 15, and the outlet 8 is a hole-like structure, and the hollow hole 12 is a rectangular hole-like structure, which is distributed in a trapezoidal shape.

[0040] In the second embodiment, the heating film 7 and the cooling baffle 6 can be set. However, in the present embodiment, when the battery cell group 1 is actually confirmed, a number of battery cells 15 connected in series can be arbitrarily selected as the battery cell group 1. In the present embodiment, eight battery cells 15 connected in series in sequence are used as the battery cell group 1. When the battery cell 15 is connected in series in the same manner as in the embodiment, each group of battery cells 15 represents the physical and positional relationship of the battery cell 15, and the battery cell group 1 represents the electrical connection relationship of the battery cell 15. Therefore, M is set to 8, and as Figure 8 As shown in , the energy storage battery system provided in the second embodiment includes 144 2170 cylindrical sodium ion batteries, which are used for charging and discharging light vehicles. Since the voltage platform of the sodium ion battery varies greatly, ranging from 1.5 to 4V, the driving experience in the empty state and the fully charged state is very different, and it is necessary to adjust the voltage. Therefore, the following voltage adjustment range and corresponding state description are provided in the second embodiment, as shown in Table 2:

[0041] As can be seen from the above table, when charging the energy storage battery system provided in Example 2, the series-parallel mode is switched so that N is 18 and K is 1, that is, 18 battery cell groups 1 are connected in series in sequence to achieve high voltage and low current fast charging. When driving (the first 50% of the power, the single cell is 2.75 to 4V), N is 2 and K is 9, that is, the 18 battery cell groups 1 are divided into 2 large battery cell groups, each of which includes 9 battery cell groups 1. After the 9 battery cell groups 1 in each large battery cell group are connected in parallel, the two large battery cell groups are connected in series. The system voltage is 4 4 to 64V. When driving (the last 50% of the power, the single cell is 1.5 to 2.75V), N is 3 and K is 6, that is, 18 battery cell groups 1 are divided into 6 battery cell groups, each battery cell group includes 3 battery cell groups 1, and the 3 battery cell groups 1 in each battery cell group are connected in parallel and then the 6 battery cell groups are connected in series. The system voltage is 36 to 66V. Through the above voltage range adjustment strategy, the voltage range can be controlled within a reasonable range according to the charging and discharging status, thereby improving user experience, improving charging effect and extending battery life.

[0042] In summary, the present invention forces the air flow in the cooling baffle 6 by the air blowing device to achieve uniform heat dissipation of the battery cell 15, and cooperates with the heating film 7 to achieve the heating process of the battery cell 15, thereby realizing a high-efficiency and low-cost air-cooling temperature control process for the battery cell 15. At the same time, the present invention can control the series-parallel connection mode of a plurality of battery cells 15 by controlling the on-off of the first switch 16 and the switching of the second switch 17, so that the battery system has multiple voltage levels to meet the charging and discharging under different voltage requirements, and a plurality of gradient-distributed hollow holes 12 are provided on the cooling baffle 6. At the hollow holes 12, the battery cells 15 are in direct contact with the cold air, resulting in significant heat exchange. At positions where there are no hollow holes 12, the battery cells 15 are separated from the cold air by the outer wall of the cooling partition 6, and the heat exchange is hindered, thereby maintaining the low temperature of the air. Near the air duct inlet 10, the air temperature is low and the heat exchange capacity is high. A small number of hollow holes 12 with a small aperture are set. Along the direction of air flow, the cold air is gradually heated and the heat exchange capacity decreases. Therefore, more hollow holes 12 are set at the air duct outlet 11 and their apertures are increased to improve the cooling capacity and ensure the temperature uniformity of the battery cells 15.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy storage battery system, comprising a plurality of groups of battery cells, wherein heating films and cooling baffles are alternately arranged between two adjacent groups of battery cells, wherein the cooling baffles are hollow and air duct inlet and air duct outlet are respectively arranged at both ends of the cooling baffles, wherein a hollow blowing plate is arranged on one side of the battery cell, a blasting device is connected to one side of the blowing plate, and an output air outlet connected to the air duct inlet is arranged on the blowing plate; The surface of the cooling baffle is provided with a plurality of hollow holes with a gradient change, and the diameter and number of the hollow holes increase gradually along the direction from the air duct inlet to the air duct outlet.

2. The energy storage battery system according to claim 1, characterized in that: A pole ear is fixed on the battery core.

3. The energy storage battery system according to claim 2, characterized in that: The air duct outlet is located on a side of the cooling baffle close to the pole ear.

4. The energy storage battery system according to claim 1, characterized in that: The heating film and the cooling baffle are attached to the outer wall of the battery core.

5. The energy storage battery system according to claim 1, characterized in that: The battery cells are respectively provided with a first switch group and a second switch group, the first switch group includes a plurality of first switches arranged corresponding to the battery cells, the second switch group includes a plurality of second switches arranged corresponding to the battery cells, and a series circuit and a parallel circuit are arranged between the battery cells.

6. The energy storage battery system according to claim 5, characterized in that: The first switch is arranged in the parallel circuit, the second switch is arranged between the series circuit and the parallel circuit, and the second switch is used for switching the series circuit and the parallel circuit to realize multi-level voltage switching.

7. The energy storage battery system according to claim 1, characterized in that: The cooling baffle is provided with alternately arranged flow channel walls, the length of the flow channel walls is smaller than the length of the cooling baffle, and the height of the flow channel walls is equal to the height of the inner cavity of the cooling baffle.

8. The energy storage battery system according to claim 7, characterized in that: A plurality of support columns are arranged on both sides of the flow channel wall.

9. The energy storage battery system according to claim 8, characterized in that: The flow channel wall and the support column are both arranged obliquely, and the flow channel wall and the support column are both made of elastic material.

10. The energy storage battery system according to claim 5, characterized in that: The first switch is a single-pole single-throw switch, and the second switch is a single-pole double-throw switch.

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