Battery pack with electrolyte discharge function and energy storage system

Abstract

The embodiment of the utility model provides a battery pack with an electrolyte discharging function and an energy storage system comprising the battery pack, and relates to the technical field of energy storage, the battery pack comprises a plurality of battery cells and a base, the base is provided with a supporting surface for supporting the plurality of battery cells, the plurality of battery cells are arranged on the supporting surface, the base is provided with a first flow guide groove concaved from the supporting face, the base is provided with a through hole, one end of the through hole is communicated with the first flow guide groove, and the through hole is used for discharging liquid in the first flow guide groove. According to the technical scheme, after the electrolyte in the battery cell leaks, the accumulation amount of the electrolyte at the bottom of the battery cell can be reduced, and the possibility that the electrolyte corrodes and dissolves an insulating film of the battery cell is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and in particular to a battery pack and energy storage system with an electrolyte discharge function. Background Art

[0002] With the emergence of a global energy crisis, the electrochemical energy storage industry has flourished. In the field of electrochemical energy storage, batteries (e.g., lithium-ion batteries) may leak electrolyte inside the battery cell from the pressure relief valve or shell of the battery cell due to poor workmanship or abnormal use, and the leaked electrolyte will accumulate at the bottom of the battery cell.

[0003] The electrolyte is an ionic conductor that is both conductive and corrosive. The leaked electrolyte accumulates at the bottom of the battery cell, which can easily corrode and dissolve the insulating film wrapped around the outside of the battery cell, causing the battery cell to overlap with the battery pack casing, making the insulation between the battery cell and the battery pack casing fail, and increasing the risk of the battery pack short circuit and fire. Utility Model Content

[0004] The present application provides a battery pack with an electrolyte discharge function, and an energy storage system including the battery pack. When the electrolyte inside the battery cell leaks out, the accumulation of electrolyte at the bottom of the battery cell can be reduced, thereby reducing the possibility of electrolyte corrosion and dissolution of the battery cell insulation film.

[0005] In order to achieve the above purpose, this application adopts the following technical solutions:

[0006] In a first aspect of the present application, a battery pack is provided, which includes a plurality of battery cells and a base, the base having a supporting surface for supporting the plurality of battery cells, the plurality of battery cells being arranged on the supporting surface, the base being provided with a first guide groove recessed from the supporting surface, the base being provided with a through hole, one end of the through hole being connected to the first guide groove, and the through hole being used for discharging liquid in the first guide groove.

[0007] The battery cell is placed on the support surface of the base, and the support surface of the base can support the battery cell. The first guide groove is recessed downward from the support surface, that is, the first guide groove is lower than the bottom of the battery cell. When the electrolyte in the battery cell leaks out, at least part of the leaked electrolyte will flow into the first guide groove, reducing the amount of electrolyte accumulation at the bottom of the battery cell. After the electrolyte flowing into the first guide groove accumulates to a certain extent, it will be discharged through the through hole set in the first guide groove. The electrolyte in the first guide groove will not continue to accumulate, that is, the liquid level of the electrolyte in the first guide groove will not continue to rise, so that the electrolyte in the first guide groove will not overflow to the bottom of the battery cell, reducing the possibility of the electrolyte corroding and dissolving the insulating film of the battery cell, reducing the risk of short circuit and fire of the battery pack, and improving the safety of the battery pack.

[0008] In an optional embodiment, the first guide groove is inclined toward the bottom surface of the base, and the first guide groove has a first end and a second end along the inclined direction, the first end is closer to the bottom surface than the second end, and the first end is closer to the through hole than the second end.

[0009] The first guide groove is inclined toward the bottom surface of the base, which can drain the liquid (electrolyte) in the first guide groove. In the inclined part of the first guide groove, the lower end is closer to the through hole, that is, the inclined part of the first guide groove can guide the electrolyte to the through hole, so that the electrolyte in the first guide groove can be discharged from the through hole faster, reducing the amount of electrolyte accumulated on the base and reducing the risk of battery pack explosion.

[0010] In an optional embodiment, a first guide groove is arranged around a plurality of battery cells, the plurality of battery cells include a first row of battery cells and a second row of battery cells, the first row of battery cells and the second row of battery cells respectively include a plurality of battery cells arranged along a first direction, the base is provided with a second guide groove recessed from the supporting surface, the second guide groove is located between the first row of battery cells and the second row of battery cells, the second guide groove extends along the first direction, and both ends of the second guide groove are connected to the first guide groove.

[0011] The first guide groove surrounds multiple battery cells, so that the electrolyte at the bottom of the battery cell can overflow into the surrounding first guide groove after accumulating a certain amount. The battery cells in the battery pack can be distributed in multiple rows (including the first row of battery cells and the second row of battery cells), and a second guide groove is arranged between the first row of battery cells and the second row of battery cells. When a battery cell in the first row of battery cells or the second row of battery cells leaks, the electrolyte will flow out of the battery cell and flow into the first guide groove or the second guide groove, that is, no matter which direction the electrolyte flows out of the battery cell, it can flow into the groove (the first guide groove or the second guide groove). For example, when the electrolyte in a battery cell in the first row of battery cells flows down from the side of the battery cell close to the second row of battery cells, the electrolyte will flow into the second guide groove; when the electrolyte flows down from the side of the battery cell away from the second row of battery cells, the electrolyte will flow into the first guide groove. In this way, the possibility of leaked electrolyte accumulating at the bottom of the battery cell can be reduced, so that more electrolyte can flow into the first guide groove or the second guide groove.

[0012] In an optional embodiment, the second guide groove is inclined toward the bottom surface of the base, and the second guide groove has a third end and a fourth end along the inclined direction, the third end is closer to the bottom surface than the fourth end, and the third end is closer to the through hole than the fourth end.

[0013] The electrolyte in the second flow guide groove will be combined with the electrolyte in the first flow guide groove under the action of gravity, and then discharged from the through hole. The possibility of electrolyte accumulation in the second flow guide groove is reduced, so that the electrolyte in the second flow guide groove and the first flow guide groove can be discharged smoothly, reducing the risk of battery pack explosion.

[0014] In an optional embodiment, the first guide groove includes two first parts distributed in a first direction and two second parts distributed in a second direction, the first direction is perpendicular to the second direction, the two first parts both extend along the second direction, the two second parts both extend along the first direction, the two ends of each second part are respectively connected with the two first parts, one of the first parts is closer to the bottom surface of the base than the other first part, each second part is inclined from the first part closer to the bottom surface to the other first part, and one end of the through hole is connected with the first part closer to the bottom surface.

[0015] The first part and the second part are interconnected so that the electrolyte in the first part and the second part can circulate with each other, which facilitates the discharge of the electrolyte in the first guide groove from the through hole. In addition, the first guide groove arranged in the above-mentioned design is more compatible with the shape of the battery pack base, which is convenient for production and processing. The distance between the two first parts and the bottom surface is different, that is, the two first parts have a height difference. The two second parts connected between the two first parts are tilted downward. The electrolyte in the first part with a higher height and the electrolyte in the two second parts will be collected in the first part with a lower height (the first part closer to the bottom surface) under the action of gravity. One end of the through hole is connected to the first part with a lower height, so that the electrolyte collected in the first part with a lower height is discharged from the through hole, which reduces the possibility of electrolyte accumulation in the first guide groove and reduces the risk of explosion of the battery pack.

[0016] In an optional embodiment, the battery pack also includes a valve body and a sensor, the valve body is arranged in the through hole and is used to open or block the through hole, the sensor is arranged on the base and is used to detect liquid, and the valve body is used to open or block the through hole according to the detection result of the sensor.

[0017] A valve body is provided in the through hole to control the discharge time of the electrolyte. For example, when the electrolyte accumulates to a certain extent, the valve body can be opened to make the through hole conductive and the electrolyte discharged from the through hole. After the electrolyte is discharged, the valve body can be closed to seal the through hole, so that the discharged electrolyte will not return to the battery cell in the form of steam, reducing the possibility of electrolyte steam backflow, reducing the electrolyte steam accumulated around the battery cell, and reducing the risk of battery pack explosion.

[0018] In an optional embodiment, the sensor is used to detect the liquid level of the liquid accumulated above the valve body, the valve body is used to open the through hole when the liquid level is greater than or equal to a preset value, and the valve body is used to block the through hole when the liquid level is less than the preset value.

[0019] When the sensor detects that the electrolyte above the valve body has accumulated to a certain extent (the liquid level of the electrolyte is greater than or equal to the preset value), the valve body opens to make the through hole conductive, and the electrolyte in the first guide groove can be discharged through the through hole, thereby reducing the possibility of electrolyte accumulation in the first guide groove. When the amount of electrolyte accumulated above the valve body is small, the liquid level of the electrolyte cannot reach the preset value, and the valve body blocks the through hole, thereby reducing the possibility of electrolyte vapor backflow.

[0020] In an optional embodiment, the battery pack further includes a controller, and the sensor and the valve body are electrically connected to the controller. The sensor is used to send a signal to the controller, and the controller is used to control the valve body to conduct or block the through hole according to the received signal.

[0021] The sensor will send a signal to the controller. After receiving the signal, the controller will determine whether the valve body needs to be opened based on the signal, thereby controlling the conduction or blocking of the through hole.

[0022] In an optional embodiment, the sensor includes a first probe and a second probe located above the valve body, both of which extend into the through hole through the first guide groove, and the valve body is used to open the through hole when both of the first probe and the second probe are in contact with liquid.

[0023] The first probe and the second probe both pass through the first guide groove and extend into the through hole. The first probe and the second probe are close to the valve body. When the electrolyte above the valve body accumulates to a certain extent, it will contact the first probe and the second probe in turn (there is a height difference between the first probe and the second probe), or contact the first probe and the second probe at the same time (there is no height difference between the first probe and the second probe). Due to the conductivity of the liquid, when the first probe and the second probe are both in contact with the electrolyte, the first probe and the second probe (two-stage probe) are connected, and the sensor will output a dry contact signal. After the controller receives the above signal, it controls the valve body to open, so that the through hole is connected, allowing the electrolyte to be discharged, and the electrolyte is actively and timely discharged from the through hole, reducing the amount of electrolyte accumulated above the valve body. When the first probe and the second probe are not in contact with the electrolyte at the same time, the first probe and the second probe are insulated by air and will not transmit a signal to open the valve body to the controller. The valve body is closed and the through hole is blocked.

[0024] In an optional embodiment, the battery pack further includes a liquid collecting box, which is disposed below the base, and a receiving cavity is formed inside the liquid collecting box, one end of the through hole is connected to the first guide groove, and the other end of the through hole is connected to the receiving cavity.

[0025] When the electrolyte on the base flows into the first guide groove, the electrolyte in the first guide groove will be discharged through the through hole. In order to collect the electrolyte, the present application sets a liquid collecting box, and the electrolyte discharged from the through hole can enter the receiving cavity of the liquid collecting box, so that the electrolyte will not be discharged at will, so as to facilitate unified treatment later. The liquid collecting box provides a temporary placement space for the discharged electrolyte.

[0026] In an optional embodiment, a liquid absorbing member is provided in the accommodating chamber, and the liquid absorbing member is used to absorb the liquid flowing into the accommodating chamber.

[0027] The liquid absorbing member can absorb the discharged electrolyte, so that the electrolyte will not shake randomly in the receiving chamber, which is conducive to the storage of the electrolyte. In addition, it can also reduce the possibility of evaporation of the electrolyte in the receiving chamber, reduce the electrolyte vapor in the receiving chamber, and reduce the risk of electrolyte vapor explosion.

[0028] In an optional embodiment, the liquid collecting box is connected to the bottom wall of the base, the through hole passes through the bottom wall of the base, the top wall of the liquid collecting box is provided with a liquid receiving port connected to the accommodating cavity, and the through hole is located above the liquid receiving port.

[0029] The liquid collecting box is arranged below the base, and the through hole is located above the liquid receiving port. The electrolyte is discharged from the through hole and enters the accommodating cavity through the liquid receiving port below under the action of gravity, so that the electrolyte is stored in the liquid collecting box. Each battery pack is equipped with a liquid collecting box, which enables a single battery pack to have the function of collecting electrolyte, so that the electrolyte inside the battery pack can be discharged into a space specially used for storage.

[0030] In an optional embodiment, the battery pack further includes a conduit, the liquid collecting box is located below the base, a liquid receiving port connected to the accommodating cavity is provided on the liquid collecting box, one end of the conduit is connected to the through hole, and the other end of the conduit is connected to the liquid receiving port.

[0031] After the battery pack is installed, each battery pack may be equipped with a liquid collecting box, and the leaked electrolyte in each battery pack will flow into the conduit through the through hole. The liquid collecting box is located below the base, and the electrolyte in the conduit will be discharged into the liquid collecting box under the action of gravity. Alternatively, one of the multiple battery packs may have a liquid collecting box, and the bases of the other battery packs may also be connected to conduits, and the multiple conduits are all connected to the liquid collecting box, so that the leaked electrolyte in the multiple battery packs can be discharged into one liquid collecting box.

[0032] In an optional embodiment, a coolant flow channel is provided in the base, the coolant flow channel avoids the through hole, and a liquid inlet and a liquid outlet are provided on the base, and both the liquid inlet and the liquid outlet are connected to the coolant flow channel.

[0033] The base of the battery pack can be a liquid cooling base. The coolant enters the base from the liquid inlet and then flows in the coolant flow channel to cool the base, thereby cooling the battery cell and the battery pack. When the coolant has finished cooling, it will be discharged from the liquid outlet, and after being cooled externally, it will enter the coolant flow channel again through the liquid inlet to achieve a liquid cooling cycle.

[0034] In a second aspect of the present application, an energy storage system is provided. The energy storage system includes a frame and a plurality of the above-mentioned battery packs, wherein the plurality of battery packs are arranged on the frame.

[0035] The battery pack of the energy storage system can be installed on the frame of the energy storage system to achieve the placement of the battery pack. The energy storage system provided in this application includes the above-mentioned battery pack, so the energy storage system provided in this application and the battery pack of the above-mentioned technical solution can solve the same technical problems and have the same technical effects, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the overall structure of an energy storage system provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the overall structure of a battery pack provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the arrangement of the battery cells of the battery pack provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of the structure of a base of a battery pack provided in an embodiment of the present application;

[0040] Figure 5 A schematic structural diagram of the second part of the first guide groove provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the structure of the second guide groove of the battery pack provided in an embodiment of the present application;

[0042] Figure 7 A schematic diagram of the structure of a sensor for a battery pack provided in an embodiment of the present application;

[0043] Figure 8 A schematic diagram of the structure of a valve body of a battery pack provided in an embodiment of the present application;

[0044] Fig. 9 A schematic diagram of the overall structure of another energy storage system provided in an embodiment of the present application;

[0045] Fig.10 A schematic structural diagram of another base of a battery pack provided in an embodiment of the present application.

[0046] Reference numerals:

[0047] 100-energy storage system; 110-frame; 120-battery pack; 1-battery cell; 11-first row of battery cells; 12-second row of battery cells; 2-base; 21-support surface; 211-first plane; 212-second plane; 22-first guide groove; 221-first part; 222-second part; 223-first end; 224-second end; 23-through hole; 24-second guide groove; 241-third end; 242-fourth end; 25-cooling liquid flow channel; 3-upper cover; 4-valve body; 5-sensor; 51-first probe; 52-second probe; 6-liquid collecting box; 61-accommodating chamber; 62-liquid suction piece; 63-liquid receiving port; 7-catheter. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0049] In the present application, unless otherwise clearly specified and limited, the directions or positional relationships indicated by the terms "upper" and "lower" may be defined, including but not limited to, the directions relative to the schematic placement of the components in the drawings, wherein these directional terms may be relative concepts, which are used for relative description and clarification, and may change accordingly according to the changes in the placement of the components in the drawings, and shall not be understood as limitations on the present application.

[0050] In this application, the terms "first", "second", etc. are used only for descriptive purposes to distinguish one element from another, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. Moreover, in this application, unless otherwise expressly specified and limited, the meaning of "plurality" is two or more.

[0051] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" 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, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances. In addition, when describing pipelines or channels, the words "connected" and "connected" used in this application have the meaning of conduction. The specific meaning needs to be understood in conjunction with the context.

[0052] In addition, in this application, the words "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0053] In the drawings of the embodiments of the present application, solid structures such as components and assemblies are represented by guide lines; hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with arrows.

[0054] The present application embodiment provides an energy storage system 100, referring to Figure 1 , Figure 1 The structure of the energy storage system 100 is shown by way of example. The energy storage system 100 may be an energy storage cabinet, an energy storage box, etc. The exemplary energy storage system 100 includes a frame 110, which is used to house and store the internal structure of the energy storage system 100. A protective structure may be provided outside the frame 110 (not shown in the drawings, for example, cabinet panels and box panels, etc.).

[0055] In order to achieve energy storage, the energy storage system 100 further includes a plurality of battery packs 120 (e.g., lithium-ion battery packs), which are mounted on the frame 110. The plurality of battery packs 120 may be distributed as “multiple clusters” on the frame 110, each “cluster” including a plurality of battery packs 120 in a vertical column, for example, the plurality of battery packs 120 included in the dotted box indicated by the arrow C1 is one of the “clusters”.

[0056] In addition, the energy storage system 100 may also include a power distribution module, a control module, a cooling module, etc., which is not specifically limited in this application.

[0057] The battery pack 120 is provided with a battery cell 1. Due to poor workmanship or abnormal use of the battery cell 1, the electrolyte inside the battery cell 1 may be exposed from the pressure relief valve or the shell of the battery cell 1, and the leaked electrolyte will accumulate at the bottom of the battery cell 1. The electrolyte is an ion conductor, which is conductive and corrosive. The leaked electrolyte accumulates at the bottom of the battery cell 1, which is easy to corrode and dissolve the insulating film wrapped around the outside of the battery cell 1, causing the battery cell 1 to overlap with the outer shell of the battery pack 120, making the insulation between the battery cell 1 and the outer shell of the battery pack 120 invalid, and increasing the risk of short circuit and fire of the battery pack 120.

[0058] In order to solve the above problems, the present application embodiment further provides a battery pack 120, referring to Figure 2 and Figure 3 , Figure 2 The external structure of the battery pack 120 is shown as an example. Figure 3The internal structure of the battery pack 120 is shown as an example. The exemplary battery pack 120 includes a plurality of battery cells 1, a base 2 and an upper cover 3. The plurality of battery cells 1 are arranged on the base 2, and the base 2 can support the battery cells 1. The upper cover 3 is arranged outside the plurality of battery cells 1 to protect the battery cells 1 and other structures inside the battery pack 120. The upper cover 3 can be fixedly connected to the base 2.

[0059] The base 2 may be in the shape of a tray or a plate, and the present application does not impose any specific restrictions on the shape of the base 2.

[0060] In one example, referring to Figure 4 , Figure 4 The structure of the base 2 is shown as an example. The base 2 has a support surface 21 for supporting a plurality of battery cells 1. That is, the battery cells 1 are placed on the support surface 21 of the base 2. The base 2 is provided with a first guide groove 22 recessed from the support surface 21 (which can be combined with reference to Figure 3 That is, the first guide groove 22 is recessed downward from the support surface 21, and the first guide groove 22 is lower than the bottom of the battery cell 1. When the electrolyte in the battery cell 1 leaks out, at least part of the leaked electrolyte will flow into the first guide groove 22, thereby reducing the accumulation of electrolyte at the bottom of the battery cell 1.

[0061] Reference Figure 4 The base 2 is provided with a through hole 23, one end of which is connected to the first guide groove 22, and the through hole 23 is used to discharge the liquid flowing into the first guide groove 22. For example, a port at one end of the through hole 23 is arranged in the first guide groove 22, or in other words, a port at one end of the through hole 23 is formed on the wall surface of the base 2 that surrounds the first guide groove 22, so that the electrolyte can be discharged from the through hole 23 when it flows to the through hole 23.

[0062] After the electrolyte flowing into the first guide groove 22 accumulates to a certain extent, it will be discharged through the through hole 23 arranged in the first guide groove 22, so that the electrolyte in the first guide groove 22 will not continue to accumulate, and the liquid level of the electrolyte in the first guide groove 22 will not continue to rise. In this way, the electrolyte in the first guide groove 22 will not overflow, and the electrolyte will not flow back to the bottom of the battery cell 1, thereby reducing the possibility of the electrolyte corroding and dissolving the insulating film of the battery cell 1, reducing the risk of short circuit and fire of the battery pack 120, and improving the safety of the battery pack 120.

[0063] In order to allow the liquid in the first guide groove 22 to flow quickly to the through hole 23, the first guide groove 22 is inclined toward the bottom surface of the base 2, that is, when the base 2 is placed flat, the first guide groove 22 is inclined downward to play a role in drainage. The downward inclination mentioned in the present application can be understood as the bottom of the first guide groove 22 being inclined, or the first guide groove 22 becoming deeper and deeper in the inclined direction.

[0064] Among them, the first flow guiding groove 22 has a first end 223 and a second end 224 along the inclined direction. The first end 223 is closer to the bottom surface of the base 2 than the second end 224, that is, the first section 223 is lower. The first end 223 (the end with a lower height) is closer to the through hole 23 than the second end 224 (the end with a higher height), so that the first flow guiding groove 22 can guide the electrolyte towards the through hole 23, and the electrolyte in the first flow guiding groove 22 can be discharged from the through hole 23 faster, reducing the amount of electrolyte accumulated on the base 2 and reducing the risk of explosion of the battery pack 120.

[0065] In this application, "up" and "down" are referenced based on the direction of gravity when the battery pack 120 is placed flat. For example, the battery cell 1 is arranged above the base 2, the base 2 is located below the battery cell 1, and the inclined part of the first flow guiding groove 22 inclines "downward" towards the bottom surface of the base 2.

[0066] The shape of the first flow guiding groove 22 can be various. For example, the first flow guiding groove 22 can be a "U"-shaped groove, a straight groove, a serpentine groove, a "mouth"-shaped groove, a "day"-shaped groove, a "eye"-shaped groove, etc. In addition, the first flow guiding groove 22 can be an overall inclined groove, or a certain part or multiple parts can be inclined.

[0067] Take Figure 4 the shown base 2 as an example. The first flow guiding groove 22 can surround multiple battery cells 1. For example, the first flow guiding groove 22 can be a "mouth"-shaped groove and is arranged on the periphery of all the battery cells 1, so that after a certain amount of electrolyte accumulates at the bottom of the battery cell 1, it overflows into the surrounding first flow guiding groove 22.

[0068] Among them, with reference to Figure 4 , the first flow guiding groove 22 can include two first parts 221 distributed in the first direction and two second parts 222 distributed in the second direction. The first direction and the second direction are perpendicular, and the first direction and the second direction can both be parallel to the supporting surface. Both of the two first parts 221 extend along the second direction, both of the two second parts 222 extend along the first direction, one end of each second part 222 is connected to one of the first parts 221, and the other end of each second part 222 is connected to the other first part 221. That is, the two ends of the second part 222 are respectively connected to the two first parts 221, and all the battery cells 1 in the battery pack are located in the area surrounded by the two first parts 221 and the two second parts 222.

[0069] When the battery cell 1 leaks liquid, the electrolyte will flow into the first part 221 or the second part 222 of the first flow guiding groove 22. In order to guide the electrolyte to the through hole 23, with reference to Figure 5 , Figure 5The inclined portion of the first guide groove 22 is shown as an example. The two first portions 221 may have a height difference, wherein one first portion 221 is closer to the bottom surface of the base 2 than the other first portion 221, and one end of the through hole 23 is connected to the first portion 221 closer to the bottom surface of the base 2 (the first portion 221 with a lower height) (see FIG. Figure 4 Each second portion 222 is inclined from the first portion 221 with a higher height toward the first portion 221 with a lower height, that is, the two second portions 222 connected between the two first portions 221 are arranged to be inclined downward, and the second portion 222 is inclined toward the bottom surface of the base 2 in the direction from the first portion 221 with a higher height to the first portion 221 with a lower height.

[0070] The two first portions 221 have a height difference, which can be understood as one first portion 221 opening deeper downward than the other first portion 221. Figure 5 For example, the first portion 221 with a lower height refers to the first portion with a deeper groove depth (eg Figure 5 The first portion 221 on the left side of the figure is located at the first portion 221 on the left side, and the first portion 221 with a higher height refers to the first portion with a shallower groove depth (for example Figure 5 The first part 221 on the right side of the drawing).

[0071] The two second parts 222 are arranged at an angle so that the electrolyte in the first part 221 with a higher height and the electrolyte in the two second parts 222 are collected in the first part 221 with a lower height under the action of gravity and discharged from the through hole 23, thereby reducing the possibility of electrolyte accumulation in the first guide groove 22 and reducing the risk of combustion and explosion of the battery pack 120.

[0072] In other examples, the first portion 221 may also be configured as an inclined groove. For example, the first portion 221 closer to the bottom surface of the base 2 may be a "V"-shaped groove that slopes downward from both sides to the center, and the through hole 23 is disposed at the lowest position in the above-mentioned "V"-shaped groove.

[0073] In other examples, the through hole 23 is disposed at the junction of the first portion 221 with a lower height (closer to the bottom surface of the base 2) and one of the second portions 222. In this example, the first portion 221 with a lower height can be tilted (tilted downward), that is, one end of the first portion 221 where the through hole 23 is disposed is closer to the bottom surface of the base 2 than the other end, so that the liquid in the first portion 221 can be guided to the through hole 23.

[0074] Regarding the arrangement of battery cell 1, refer back to Figure 3, multiple battery cells 1 can be arranged in multiple rows on the base 2. When the battery cell 1 located in the middle area of ​​the battery pack 120 leaks, the electrolyte will accumulate between the multiple battery cells 1. In the example where the first guide groove 22 surrounds the multiple battery cells 1, it is difficult for the electrolyte to flow from the support surface 21 to the first guide groove 22. In order to allow more leaked electrolyte to be discharged smoothly, the base 2 can also be provided with a second guide groove 24 recessed from the support surface 21, referring to Figure 3 and Figure 4 The second guide groove 24 is arranged between the plurality of battery cells 1 to allow the electrolyte to flow in. The second guide groove 24 may be a straight groove, a serpentine groove, or the like.

[0075] In one example, referring to Figure 3 and Figure 4 The plurality of battery cells 1 include a first row of battery cells 11 and a second row of battery cells 12, the first row of battery cells 11 and the second row of battery cells 12 respectively include a plurality of battery cells 1 distributed along a first direction, and there is a gap between the first row of battery cells 11 and the second row of battery cells 12. For example, the support surface 21 may include a first plane 211 and a second plane 212, the first plane 211 is used to support the first row of battery cells 11, and the second plane 212 is used to support the second row of battery cells 12. The second guide groove 24 is located between the first row of battery cells 11 and the second row of battery cells 12, that is, between the first plane 211 and the second plane 212. The second guide groove 24 extends along the first direction and both ends are connected to the first guide groove 22. In the example where the first guide groove 22 includes a first portion 221 and a second portion 222, the two ends of the second guide groove 24 in the first direction are respectively connected to the two first portions 221.

[0076] In other examples, the multiple battery cells 1 may also include a third row, a fourth row, etc., that is, the multiple battery cells 1 are distributed in multiple rows, each row includes multiple battery cells 1 arranged along the first direction, there is a gap between two adjacent rows, and a second guide groove 24 extending along the first direction is provided between two adjacent rows.

[0077] Taking the battery pack 120 in which the multiple battery cells 1 are distributed as the first row of battery cells 11 and the second row of battery cells 12 as an example, when a battery cell 1 in the first row of battery cells 11 or the second row of battery cells 12 leaks, the electrolyte will flow out of the battery cell 1 and flow into the first guide groove 22 or the second guide groove 24. That is, no matter which direction the electrolyte flows out from the battery cell, it can flow into the first guide groove 22 or the second guide groove 24.

[0078] For example, when the electrolyte in a cell 1 in the first row of cells 11 flows down from the side of the cell 1 close to the second row of cells 12, the electrolyte will flow into the second guide groove 24. When the electrolyte flows down from the side of the cell 1 away from the second row of cells 12, the electrolyte will flow into the first guide groove 22 (the second part 222). In addition, the electrolyte in the cell 1 at the end of the first row of cells 11 may flow into the first part 221. In this way, the possibility of the leaked electrolyte accumulating at the bottom of the cell 1 can be reduced, so that more electrolyte can flow into the first guide groove 22 or the second guide groove 24, and finally discharged from the through hole 23.

[0079] In the example where the two first portions 221 have a height difference, the second guide groove 24 connected between the two first portions 221 is tilted downward. Figure 6 , Figure 6 The second guide groove 24 is exemplarily shown as being inclined, and the second guide groove 24 is inclined toward the bottom surface of the base 2. The second guide groove 24 has a third end 241 and a fourth end 242 along the inclined direction, and the third end 241 is closer to the bottom surface of the base 2 than the fourth end 242, and the third end 241 is closer to the through hole 23 than the fourth end 242. The electrolyte in the second guide groove 24 will be collected with the electrolyte in the first guide groove 22 under the action of gravity, and then discharged from the through hole 23, so that the electrolyte in the second guide groove 24 and the first guide groove 22 can be discharged smoothly, reducing the possibility of electrolyte accumulation in the second guide groove 24.

[0080] The fourth end 242 is connected to the first portion 221 with a higher height, and the third end 241 is connected to the first portion 221 with a lower height. The electrolyte in the first portion 221 with a higher height and the electrolyte in the second guide groove 24 will be collected in the first portion 221 with a lower height under the action of gravity, and then discharged from the through hole 23, reducing the possibility of electrolyte accumulation in the second guide groove 24, so that the electrolyte in the second guide groove 24 and the first guide groove 22 can be discharged smoothly.

[0081] In other examples, the first guide groove 22 and the second guide groove 24 may not be provided with an inclined portion.

[0082] The through hole 23 may be disposed at any suitable position, for example, Figure 6 The through hole 23 can be arranged at a position where one end of the second guide groove 24 is connected to the first guide groove 22. In addition, one or more through holes 23 can be arranged, and the present application does not make any specific restrictions on this.

[0083] In order to control the discharge of the through hole 23, in one embodiment provided in the present application, refer to Figure 7 The battery pack 120 further includes a valve body 4, Figure 7 The position of the valve body 4 is shown as an example, and the valve body 4 is arranged in the through hole 23 and is used to conduct or block the through hole 23. The valve body 4 may include a valve seat (not numbered in the drawings) and a valve core (not numbered in the drawings), a liquid passage (not numbered in the drawings) is formed inside the valve seat, the valve seat is fixedly connected to the wall surface surrounding the through hole 23, and the valve core is arranged in the liquid passage of the valve seat and is used to open or close the liquid passage of the valve seat.

[0084] By providing the valve body 4, the discharge time of the electrolyte can be controlled. For example, when the electrolyte accumulates to a certain extent, the valve body 4 can be opened to make the through hole 23 conductive, and the electrolyte is discharged from the through hole 23. After the electrolyte is discharged, the valve body 4 can be closed to block the through hole 23, so that the discharged electrolyte will not return to the battery cell 1 in the form of steam, reducing the possibility of electrolyte steam backflow, reducing the electrolyte steam accumulated around the battery cell 1, and reducing the risk of explosion of the battery pack 120.

[0085] Further, see Figure 7 The battery pack 120 may also include a sensor 5 and a controller (not shown in the drawings), the sensor 5 is disposed on the base 2 (directly fixedly connected to the base 2, or indirectly connected to the base 2 through other structures), and the sensor 5 and the valve body 4 are both electrically connected to the controller. The controller may be a battery management unit (BMU), or a battery management system (BMS) including multiple battery management units.

[0086] The sensor 5 is used to detect the liquid and send a signal to the controller, and the controller is used to control the valve body 4 to open or block the through hole 23 according to the received signal.

[0087] For example, the sensor 5 may be a liquid level sensor, the sensor 5 is used to detect the liquid level of the liquid accumulated above the valve body 4, the sensor 5 is used to send a signal to the controller (a signal to open the valve body 4) when the liquid level reaches a preset value, and the controller is used to control the valve body 4 to conduct the through hole 23 upon receiving the above signal. That is, when the sensor 5 detects that the electrolyte above the valve body 4 has accumulated to a certain extent (the liquid level of the electrolyte is greater than or equal to the preset value), it will send a signal to the controller to open the valve body 4, and after receiving the signal, the controller controls the valve body 4 to open, and the opened valve body 4 makes the through hole 23 conductive, and the electrolyte in the first guide groove 22 can be discharged through the through hole 23, thereby reducing the possibility of the electrolyte accumulating in the first guide groove 22.

[0088] In addition, the controller is used to control the valve body 4 to block the through hole 23 when the liquid level is less than a preset value. That is, when there is less electrolyte above the valve body 4 and the electrolyte level cannot reach the preset value, the controller cannot receive a signal to open the valve body 4. At this time, the controller controls the valve body 4 to block the through hole 23, so that the through hole 23 cannot be conducted, and external substances (for example, the vapor of the discharged electrolyte) will not enter between the base 2 and the upper cover 3 through the through hole 23, thereby reducing the possibility of electrolyte vapor accumulating around the battery cell 1.

[0089] In one example, the sensor 5 can monitor the liquid level of the electrolyte in real time and feed back a signal to the controller. When the controller determines that the signal is a signal to open the valve body 4, the valve body 4 is controlled to conduct the through hole 23 to discharge the electrolyte; when the controller determines that the signal is not a signal to open the valve body 4, the valve body 4 is controlled to block the through hole 23. In another example, the sensor 5 can also feed back a signal to the controller only when the liquid level of the electrolyte reaches a preset value. When the controller receives the signal, the valve body 4 is controlled to conduct the through hole 23.

[0090] In order to facilitate the detection of the electrolyte above the valve body 4, refer to Figure 8 , Figure 8 The position of the sensor 5 is shown as an example, and the sensor 5 can be arranged directly above the valve body 4. The sensor 5 can be completely or partially located in the first guide groove 22 (for example, a contact sensor), and the sensor 5 can also be completely located outside the first guide groove 22 (for example, a non-contact sensor).

[0091] In addition, the sensor 5 can be any detection device capable of detecting electrolyte, for example, Figure 7 The sensor 5 may include a first probe 51 and a second probe 52 located above the valve body 4, and the first probe 51 and the second probe 52 both extend into the first guide groove 22. The sensor 5 is used to send a signal to the controller when the first probe 51 and the second probe 52 both contact the liquid.

[0092] That is, when the electrolyte above the valve body 4 accumulates to a certain level, it will contact the first probe 51 and the second probe 52 at the same time. Since the liquid is conductive, when the first probe 51 and the second probe 52 are both in contact with the electrolyte, the first probe 51 and the second probe 52 (two-stage probes) are turned on, and the sensor 5 will output a dry contact signal. After the controller receives the above signal, it controls the valve body 4 to open, so that the through hole 23 is turned on. At this time, the through hole 23 allows the electrolyte to be discharged.

[0093] When the first probe 51 and the second probe 52 are not in contact with the electrolyte at the same time, the first probe 51 and the second probe 52 are insulated by air and will not transmit a signal to open the valve body 4 to the controller. The controller controls the valve body 4 to close, so that the valve body 4 blocks the through hole 23 .

[0094] In one example, the first probe 51 and the second probe 52 may have a height difference, for example, the bottom end of the first probe 51 is lower than the bottom end of the second probe 52. That is, the electrolyte will first contact the first probe 51 and then contact the second probe 52. When the electrolyte contacts the first probe 51 first, the sensor 5 will not send a signal to open the valve body 4 to the controller. When the electrolyte contacts the first probe 51 and the second probe 52 at the same time, the sensor 5 will send a signal to open the valve body 4 to the controller.

[0095] In another example, there is no height difference between the first probe 51 and the second probe 52, for example, the bottom end of the first probe 51 is flush with the bottom end of the second probe 52. That is, when the electrolyte above the valve body 4 accumulates to a certain extent, the electrolyte will contact the first probe 51 and the second probe 52 at the same time.

[0096] In one example, the first probe 51 and the second probe 52 may only extend into the first flow guide groove 22, but not into the through hole 23. Figure 8 The first probe 51 and the second probe 52 can both pass through the first guide groove 22 and extend into the through hole 23, so that the first probe 51 and the second probe 52 are closer to the valve body 4. When a small amount of electrolyte accumulates above the valve body 4, the first probe 51 and the second probe 52 will be contacted at the same time, so that the controller opens the valve body 4 and connects the through hole 23. The electrolyte can be actively and timely discharged from the through hole 23, reducing the accumulation of electrolyte above the valve body 4.

[0097] In other examples, the sensor 5 may also be a hydraulic sensor, an infrared sensor, an ultrasonic sensor, a capacitive sensor, and the like.

[0098] In order to collect the discharged electrolyte for later unified treatment, refer to Figure 8 The battery pack 120 may further include a liquid collecting box 6, which may be a hollow box with a receiving chamber 61 formed inside thereof, and the receiving chamber 61 is used to receive the electrolyte. The liquid collecting box 6 is disposed below the base 2, and one end of the through hole 23 is connected to the first guide groove 22, and the other end of the through hole 23 is connected to the receiving chamber 61. When the electrolyte on the base 2 flows into the first guide groove 22 or the second guide groove 24, the electrolyte in the first guide groove 22 and the second guide groove 24 will be discharged through the through hole 23, and the electrolyte discharged from the through hole 23 can be collected in the receiving chamber 61 of the liquid collecting box 6, so that the electrolyte will not be discharged at will.

[0099] The electrolyte flows into the liquid collecting box 6 under the action of gravity. That is, the liquid collecting box 6 can be arranged below the base 2, and its specific arrangement position can be determined according to needs.

[0100] In one example, referring to Figure 8The liquid collecting box 6 is connected to the bottom wall of the base 2, for example, the liquid collecting box 6 is detachably connected to the bottom wall of the base 2, so as to facilitate the replacement of the liquid collecting box 6. The through hole 23 passes through the bottom wall of the base 2, for example, the through hole 23 passes through the base 2 in the vertical direction, and the top wall of the liquid collecting box 6 is provided with a liquid receiving port 63 communicating with the accommodating cavity 61, and the through hole 23 is located above the liquid receiving port 63. After the electrolyte is discharged from the through hole 23, it enters the accommodating cavity 61 through the liquid receiving port 63 below under the action of gravity, so that the electrolyte is stored in the liquid collecting box 6.

[0101] Based on the above-mentioned setting method of the liquid collecting box 6, each battery pack 120 in the energy storage system 100 can include a liquid collecting box 6, so that a single battery pack 120 has the function of collecting electrolyte, and the electrolyte inside the battery pack 120 can be discharged into a space specifically used for storage (accommodation chamber 61).

[0102] In another example, referring to Fig. 9 , Fig. 9 The structure of another battery pack 120 is shown as an example. The battery pack 120 of the example may further include a conduit 7. The liquid collecting box 6 is located below the base 2. The liquid collecting box 6 is provided with a liquid receiving port 63 connected to the accommodating cavity 61 (the liquid receiving port 63 may be provided at the top of the liquid collecting box 6, Fig. 9 One end of the conduit 7 is connected to the through hole 23 (the through hole 23 can pass through the bottom wall of the base 2, Fig. 9 The other end of the conduit 7 is connected to the liquid receiving port 63.

[0103] Based on the above arrangement of the liquid collecting box 6, after the battery pack 120 is installed on the frame 110 of the energy storage system 100, refer to Fig. 9 , one of the battery packs 120 may include both the conduit 7 and the liquid collecting box 6 , and the remaining battery packs 120 may only have the conduit 7 connected to the base 2 without the liquid collecting box 6 , and the multiple conduits 7 are connected to one liquid collecting box 6 .

[0104] For example, only one battery pack 120 in a "cluster" includes a conduit 7 and a liquid collecting box 6, and the liquid collecting box 6 is located below all bases 2 in a "cluster" (for example, the liquid collecting box 6 is located at the bottom of the frame 110). The remaining battery packs 120 in a "cluster" have only bases 2 connected to conduits 7, and all conduits 7 in a "cluster" are connected to the liquid collecting box 6, and the electrolyte in all battery packs 120 in a "cluster" is discharged into the only liquid collecting box 6 in the "cluster".

[0105] There are many ways to connect the catheter 7. In one example, refer to Fig. 9As shown in the dotted box indicated by the arrow C2, the ducts 7 of two upper and lower adjacent battery packs 120 in a "cluster" are connected to each other. For example, the duct 7 of the upper battery pack 120 is connected to the duct 7 of the lower battery pack 120, and the duct 7 of the battery pack 120 with the lowest height is connected to the liquid receiving port 63 of the liquid collecting box 6.

[0106] In another example, referring to Fig. 9 As shown in the dotted box indicated by the arrow C3 , the conduit 7 of each battery pack 120 in a “cluster” is directly connected to the liquid receiving port 63 of the liquid collecting box 6 . In this example, a plurality of liquid receiving ports 63 may be provided.

[0107] In another example, a plurality of conduits 7 in a “cluster” are connected to a common manifold, which is connected to the liquid receiving port 63 .

[0108] In order to discharge the electrolyte from the liquid collecting box 6, a liquid discharge structure may be provided on the liquid collecting box 6. When the electrolyte needs to be discharged, the electrolyte in the liquid collecting box 6 may be discharged from the liquid discharge structure. Alternatively, the liquid collecting box 6 is removed from the battery pack 120 or the energy storage system 100, and the electrolyte inside is poured out from the liquid receiving port 63.

[0109] In addition, refer to Figure 8 and Fig. 9 A liquid absorbing member 62 may also be provided in the accommodating chamber 61, and the liquid absorbing member 62 is used to absorb the liquid flowing into the accommodating chamber 61. The electrolyte will not shake randomly in the accommodating chamber 61, which is conducive to the storage of the electrolyte. In addition, the possibility of evaporation of the electrolyte in the accommodating chamber 61 can be reduced, the electrolyte vapor in the accommodating chamber 61 is reduced, and the risk of explosion of the electrolyte vapor is reduced.

[0110] In other examples, in order to cool the battery pack 120, refer to Fig.10 , Fig.10 Another structure of the base 2 is shown as an example. A cooling liquid flow channel 25 is provided in the base 2, that is, the base 2 of the battery pack 120 can be a liquid cooling base. The cooling liquid flow channel 25 can be a serpentine flow channel, or can include a plurality of interconnected flow channels, and the cooling liquid flow channel 25 avoids the through hole 23.

[0111] In order to realize the circulation of the coolant, the base 2 is provided with a liquid inlet (not shown in the drawings) and a liquid outlet (not shown in the drawings), both of which are connected to the coolant flow channel 25. The coolant enters the base 2 from the liquid inlet, and then flows in the coolant flow channel 25, which has a cooling effect on the base 2, thereby realizing the cooling of the battery cell 1 and the battery pack 120. When the coolant is cooled, it will be discharged from the liquid outlet, and after being cooled externally, it will enter the coolant flow channel 25 through the liquid inlet.

[0112] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery pack with electrolyte discharge function, characterized in that: include: Multiple cells; A base, wherein the base has a supporting surface for supporting the plurality of battery cells, the plurality of battery cells are arranged on the supporting surface, the base is provided with a first guide groove recessed from the supporting surface, the base is provided with a through hole, one end of the through hole is connected to the first guide groove, and the through hole is used for discharging liquid in the first guide groove.

2. The battery pack according to claim 1, characterized in that: The first guide groove is inclined toward the bottom surface of the base, and has a first end and a second end along the inclined direction. The first end is closer to the bottom surface than the second end, and the first end is closer to the through hole than the second end.

3. The battery pack according to claim 1 or 2, characterized in that: The first guide groove is arranged around the plurality of battery cells, the plurality of battery cells include a first row of battery cells and a second row of battery cells, the first row of battery cells and the second row of battery cells respectively include a plurality of the battery cells arranged along a first direction, The base is provided with a second guide groove recessed from the support surface, the second guide groove is located between the first row of battery cells and the second row of battery cells, the second guide groove extends along the first direction, and both ends of the second guide groove are connected to the first guide groove.

4. The battery pack according to claim 3, characterized in that: The second guide groove is inclined toward the bottom surface of the base, and has a third end and a fourth end along the inclined direction. The third end is closer to the bottom surface than the fourth end, and the third end is closer to the through hole than the fourth end.

5. The battery pack according to claim 3, characterized in that: The first guide groove includes two first parts distributed in the first direction and two second parts distributed in the second direction, the first direction is perpendicular to the second direction, the two first parts extend along the second direction, the two second parts extend along the first direction, the two ends of each second part are respectively connected with the two first parts, one of the first parts is closer to the bottom surface of the base than the other first part, each second part is inclined from the first part closer to the bottom surface to the other first part, and one end of the through hole is connected with the first part closer to the bottom surface.

6. The battery pack according to claim 1 or 2, characterized in that: The battery pack also includes a valve body and a sensor. The valve body is arranged in the through hole and is used to open or block the through hole. The sensor is arranged on the base and is used to detect the liquid. The valve body is used to open or block the through hole according to the detection result of the sensor.

7. The battery pack according to claim 6, characterized in that: The sensor is used to detect the liquid level of the liquid accumulated above the valve body; The valve body is used to open the through hole when the liquid level of the liquid is greater than or equal to a preset value, and the valve body is used to block the through hole when the liquid level of the liquid is less than the preset value.

8. The battery pack according to claim 6, characterized in that: The battery pack also includes a controller, and the sensor and the valve body are both electrically connected to the controller. The sensor is used to send a signal to the controller, and the controller is used to control the valve body to open or block the through hole according to the received signal.

9. The battery pack according to claim 6, characterized in that: The sensor includes a first probe and a second probe located above the valve body, the first probe and the second probe both pass through the first guide groove and extend into the through hole, and the valve body is used to open the through hole when the first probe and the second probe both contact the liquid.

10. The battery pack according to claim 1 or 2, characterized in that: The battery pack further includes a liquid collecting box, which is arranged below the base. A receiving cavity is formed inside the liquid collecting box. One end of the through hole is connected to the first guide groove, and the other end of the through hole is connected to the receiving cavity.

11. The battery pack according to claim 10, characterized in that: A liquid absorbing member is arranged in the accommodating cavity, and the liquid absorbing member is used for absorbing the liquid flowing into the accommodating cavity.

12. The battery pack according to claim 10, characterized in that: The battery pack also includes a conduit, the liquid collecting box is located below the base, the liquid collecting box is provided with a liquid receiving port connected to the accommodating cavity, one end of the conduit is connected to the through hole, and the other end of the conduit is connected to the liquid receiving port.

13. An energy storage system, characterized in that: It comprises a frame and a plurality of battery packs as claimed in any one of claims 1 to 12, wherein the plurality of battery packs are arranged on the frame.

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