TWI702771B - Energy storage system with two different battery modules - Google Patents

Abstract

An energy storage system includes a first battery module and a second battery module. The first battery module includes a first casing, a plurality of first battery cells disposed in the first casing, and a plurality of first conductive sheets disposed at two ends of the first battery cells so that the first battery cells are connected in series or in parallel. The second battery module includes a second casing, a plurality of second battery cells disposed in the second casing, and a plurality of second conductive sheets disposed at two ends of the second battery cells so that the second battery cells are connected in series or in parallel. Moreover, the length or width of the current paths of the first conductive sheets is different from the length or width of the current paths of the second conductive sheets.

Description

Energy storage system with two different battery modules

The invention relates to an energy storage system, in particular to an energy storage system with two different battery modules.

Figure 1 shows a perspective view of a conventional servo energy storage cabinet. As shown in FIG. 1, the conventional servo energy storage cabinet 100 includes a housing 110 and a plurality of battery modules 120. The battery modules 120 are disposed in the housing 110 and are electrically connected to each other. With the increasing demand for high power in the system, the battery modules 120 carried by the battery system of the servo energy storage cabinet 100 are also increasing. Therefore, the impedance uniformity design requirements of the battery modules 120 are increasingly strict. In order to overcome the aforementioned problems, traditionally, power components are added to adjust the overall impedance of the battery module 120.

Figure 2 shows an exploded view of a conventional battery module. As shown in FIG. 2, the battery module 120 includes a plurality of cylindrical battery cells 121, at least one cell holder 123 and a plurality of conductive sheets 124. The brackets 123 define a plurality of battery accommodating spaces for placing and fixing the battery cells 121, and the battery cells 121 are respectively stacked in the longitudinal direction x and the width direction z of the brackets 123. The conductive sheets 124 are respectively disposed on two ends of the battery cell 121 to connect the battery cells 121 in parallel or in series to form a plurality of battery cell arrays. The conductive sheets 124 are welded on each battery cell 121 by welding to achieve series and parallel Linked functions. The battery module 120 further includes a circuit board 126. The circuit board 126 may be a BMS control board. The at least one bracket 123 further defines an accommodating space for accommodating the circuit board 126. The conductive sheets 124 of the final positive electrode or negative electrode located at both ends of the battery module 120 are fastened to the circuit board 126 by screws 125, and the circuit board 126 is also fastened to the bracket 123 by screws 125. The circuit board 126 is provided with a plurality of electrical connectors.

Figure 3 shows a top view of a conventional conductive sheet. As shown in FIG. 3, in order to be able to electrically weld the conductive sheets 124 to the battery cells 120 more smoothly, a slot 140 is formed on the conductive sheet 124 corresponding to the electrode of the battery cell 120. The slot 140 separates the two electric welding points 142, so that the current can bypass the slot 140 and travel a longer distance, thereby increasing the temperature of the electric welding point 142. Such a design can enhance the fixing effect of electric welding and prevent the conductive sheet 120 from moving or shaking.

Figure 4 shows a schematic circuit diagram of a conventional servo energy storage cabinet. As shown in FIG. 4, the battery modules 120 of the servo energy storage cabinet 100 are connected in parallel with each other. When the overall impedances of the battery modules 120 are not the same, the current will flow to the battery module 120 with a low impedance, and the single battery module 120 may be damaged due to excessive current. Traditionally, the battery module 120 also includes a power element 127 which can be installed on the circuit board 126 to adjust the overall impedance of the battery module 120, so that the overall impedance of the battery modules 120 of the servo energy storage cabinet 100 can be mutually To match.

The traditional use of adding power elements 127 to adjust the overall impedance of the battery module 120, because it is a single point of local heating, that is, only the power element 127 heats up, so the required auxiliary heat dissipation components are very large. Often, the temperature rise of the power element 127 is too high, causing safety problems. Therefore, how to adjust the overall impedance of the battery module 120 while taking into account the heat dissipation problem, and simplifying the manufacturing process and reducing the cost without adding power elements 127, are issues worthy of discussion at present.

The purpose of one embodiment of the present invention is to provide an energy storage system in which the conductive sheets of the two different battery modules have different structures, so that the overall impedance of the two different battery modules are matched with each other.

According to an embodiment of the present invention, an energy storage system includes a first battery module and a second battery module. The first battery module includes: a first shell; a plurality of first battery cells are arranged in the first shell; and a plurality of first conductive sheets are arranged on both ends of the first battery cells and used to The first battery cells are connected in series or in parallel. The second battery module includes: a second shell; a plurality of second battery cells are arranged in the second shell; and a plurality of second conductive sheets are arranged on both ends of the second battery cells and used to These second battery cells are connected in series or in parallel. Moreover, the length or width of the current paths of the first conductive sheets is different from the length or width of the current paths of the second conductive sheets.

In one embodiment, the impedance of the first battery cells of each of the first battery modules does not match the impedance of the second battery cells of each of the second battery modules, and each of the first battery modules The impedance of a battery module matches the impedance of each second battery module.

In one embodiment, an energy storage system includes a first battery module and a second battery module group. The first battery module includes: a first shell; a plurality of first battery cells are arranged in the first shell; and a plurality of first conductive sheets are arranged on both ends of the first battery cells and used to The first battery cells are connected in series or in parallel. The second battery module includes: a second shell; a plurality of second battery cells are arranged in the second shell; and a plurality of second conductive sheets are arranged on both ends of the second battery cells and used to These second battery cells are connected in series or in parallel. Moreover, each of the first conductive sheets includes a first slot, each of the second conductive sheets includes a second slot, and the shape of the second slot is different from the shape of the first slot, thereby Make the width or length of the current path between the second slot and the edge of the surface of each second conductive sheet different from that of the current path between the first slot and the edge of the surface of the first conductive sheet Width or length.

In one embodiment, the impedance of the second battery cells of each of the second battery modules is smaller than the impedance of the first battery cells of each of the first battery modules, and the second slot and The width of the current path between the edges of the surface of the second conductive sheet is smaller than the width of the current path between the first slot and the edges of the surface of the first conductive sheet, so that the width of each of the first battery modules The impedance matches the impedance of each second battery module.

In one embodiment, each of the first conductive sheet and each of the second conductive sheet includes a plurality of electrode ends and a plurality of connecting channel parts, and each of the connecting channel parts is connected to two adjacent ones of the electric Between the pole ends, and the first slot is located at each electrode end of each first conductive sheet, and the second slot is located at each electrode end of each second conductive sheet.

In one embodiment, the second slot includes a curved slot, and the curved slot has an opening unit. Preferably, at least two of the electrode ends of the electrode ends of each second conductive sheet have two of the openings in the shape of the curved grooves facing each other in opposite directions.

In one embodiment, the second slot further includes a strip slot, and the first slot is another strip slot. In one embodiment, the shape of the curved slot is a semicircle or a C-shape. In one embodiment, each of the second conductive sheets further includes a plurality of channel slots, and each channel slot is located in each of the connecting channel portions.

In one embodiment, the current path of each second conductive sheet is greater than the linear distance of each connecting channel portion of each second conductive sheet, and the current path of each second conductive sheet is greater than each A current path of the first conductive sheet.

According to an embodiment of the present invention, in the energy storage system, the length or width of the current path of the first conductive sheets of the first battery module is different from the current of the second conductive sheets of the second battery module The length or width of the path. In another embodiment, the shape of the second slot is different from the shape of the first slot, so that the width or length of the current path between the second slot and the edge of the surface of the second conductive sheet is different from The width or length of the current path between the first slot and the edge of the surface of the first conductive sheet. With this design, the structure of the conductive sheet can be different, so that the overall impedance of the first battery module and the second battery module can be matched with each other, without increasing the arrangement of power components and without increasing additional costs. In one embodiment, the second conductive sheets with higher impedance are evenly distributed and less heat is concentrated in the local area, causing the local temperature to be too high. Moreover, the second conductive sheets directly contact the battery cells , Can transfer the overall heat into these battery cells Disperse in one step.

100‧‧‧Servo Energy Storage Cabinet

110‧‧‧Shell

120‧‧‧Battery Module

121‧‧‧Battery cell

123‧‧‧bracket

124‧‧‧Conductive sheet

125‧‧‧Be screwed

126‧‧‧Circuit board

127‧‧‧Power Components

140‧‧‧Slotting

142‧‧‧soldering point

200‧‧‧Energy Storage System

210‧‧‧Shell

220a‧‧‧First battery module

220b‧‧‧Second battery module

221‧‧‧These battery cells

224a‧‧‧First conductive sheet

224b‧‧‧Second conductive sheet

228‧‧‧Shell

241a‧‧‧Slotting

241b‧‧‧Slotting

243‧‧‧Two welding points

245‧‧‧electrode end

246‧‧‧Connecting channel part

411‧‧‧Strip slotting

412‧‧‧Curve slotting

461‧‧‧Channel Slotting

Figure 1 shows a perspective view of a conventional servo energy storage cabinet.

Figure 2 shows an exploded view of a conventional battery module.

Figure 3 shows a top view of a conventional conductive sheet.

Figure 4 shows a schematic circuit diagram of a conventional servo energy storage cabinet.

Fig. 5 shows a perspective view of an energy storage system according to an embodiment of the invention.

FIG. 6 shows a side view of a battery module according to an embodiment of the invention.

FIG. 7 shows a top view of the first conductive sheet according to an embodiment of the invention.

FIG. 8 shows a top view of a second conductive sheet according to an embodiment of the invention.

Fig. 5 shows a perspective view of an energy storage system according to an embodiment of the invention. As shown in FIG. 5, according to an embodiment of the present invention, the energy storage system 200 includes a module housing 210, a first battery module 220a, and a second battery module 220b. In this embodiment, the energy storage system 200 may be a servo energy storage cabinet. The first battery module 220a and the second battery module 220b are disposed in the module housing 210, and are electrically connected in parallel with each other.

FIG. 6 shows a side view of a battery module according to an embodiment of the invention. As shown in Figure 6, the second battery The module 220b includes a casing 228, a plurality of cylindrical battery cells 221, and a plurality of second conductive sheets 224b. The casing 228 is used for accommodating the battery cores 221. In one embodiment, the battery cores 221 may be supported by a bracket (not shown) to be accommodated in the casing 228. The second conductive sheets 224b are respectively placed on both ends of the battery cells 221 to form a plurality of battery arrays in parallel with the battery cells 221, and to connect the battery arrays in series to form a second battery module 220b.

In one embodiment, a fixing groove is formed on the bracket, and the battery case 228 is fixed by the bracket groove structure. The conductive sheets 224a and 224b (please refer to Figures 7 and 8) for spot welding during production can be placed on the bracket. The bracket may have positioning pins passing through the positioning holes of the conductive sheets 224a and 224b for positioning, and then the spot welding process is performed.

The structure of the first battery module 220a is similar to the structure of the second battery module 220b. Therefore, the same components use the same symbols. The following describes at least one difference between the two. The first battery module 220a includes a first conductive sheet 224a, and the current path structure of the first conductive sheet 224a is different from the current path structure of the second conductive sheet 224b. According to the aforementioned characteristics, the overall impedance value of the battery module can be adjusted, while the heat dissipation problem is considered, and the manufacturing process can be simplified and the cost can be reduced without adding power components. The differences between the two conductive sheets will be described in more detail below.

FIG. 7 shows a top view of the first conductive sheet according to an embodiment of the invention. As shown in FIG. 7, the first conductive sheet 224 a includes a plurality of electrode end portions 245 and a plurality of connection channel portions 246. The connecting channel part 246 is connected between two adjacent electrode ends 245. Each electrode end 245 includes a slot 241 a and two electric welding points 243. The slot 241a and the edge of the surface of the first conductive sheet 224a form at least one current path, and The slot 241a is located between the two electric welding points 243 and separates the two electric welding points 243, so that the current of the electric welding can bypass the slot 241a. In this embodiment, the slot 241a is elongated, and in one embodiment It is an I-shape, so that the width wa of the current path between the slot 241a and the edge of the surface of the first conductive sheet 224a can be as large as possible, so that the impedance can be reduced and the working current i can easily pass. In one embodiment, the maximum width wa is greater than the width W of the connecting channel portion 246. Preferably, the width wa of most areas is greater than the width W of the connecting channel portion 246.

FIG. 8 shows a top view of a second conductive sheet according to an embodiment of the invention. As shown in FIG. 8, the second conductive sheet 224b includes a plurality of electrode end portions 245 and a plurality of connection channel portions 246. The connecting channel part 246 is connected between two adjacent electrode ends 245. Each electrode end 245 includes a slot 241b and two electric welding points 243. The slot 241b and the edge of the surface of the second conductive sheet 224b form at least one current path, and the slot 241b is located between the two electric welding points 243 and separates the two electric welding points 243, so that the current can bypass the slot 241b. In this embodiment, the width wb of the current path between the slot 241b and the edge of the surface of the second conductive sheet 224b can be made smaller, so that the impedance of the battery module 220b when discharging is increased. In one embodiment, the width wb of the current path between the slot 241b and the edge of the surface of the second conductive sheet 224b is smaller than the width wa of the current path between the slot 241a and the edge of the surface of the first conductive sheet 224a. In one embodiment, the width wb of most areas is smaller than the width W of the connecting channel portion 246. Preferably, the maximum width wb is smaller than the width W of the connecting channel part 246.

The overall impedance of the battery module includes the impedance of the printed circuit board assembly (PCBA), the impedance of the battery cell, the impedance of the conductive sheet, the impedance of the cable, and the impedance of the terminal device. Since the energy storage system 200 requires a lot of battery cells 221, however The battery cells 221 may have different impedances due to different manufacturing processes of different suppliers. In order to make each impedance of the battery modules of the energy storage system 200 the same, in the prior art, the printed circuit board assembly is added Power components, such as mercury components, semiconductors, etc. But this will have additional costs such as high costs, additional circuits, heat generation, and so on. Moreover, when the heat generation is high, an additional heat dissipation module is required. In addition to increasing the cost, additional space for the heat dissipation module is also required.

On the contrary, according to the present invention, the length and width of the current path are changed by the second conductive sheet 224b of different shapes to adjust the impedance value of the conductive sheet 224b, thereby achieving the uniform impedance design of the battery modules 220a and 220b. More specifically, the structure of the slot 241b of the second conductive sheet 224b is changed to change the impedance. For example, when the impedance of the battery cells 221 of the first battery module 220a is 60mΩ; the impedance of the first conductive sheets 224a is 40mΩ; and the impedance of the battery cells 221 of the second battery module 220b is At 40mΩ, only by designing the slot shape of the second conductive sheet 224b, the impedance of the second conductive sheet 224b can be increased to 60mΩ, so that the resistance of the first battery module 220a and the second battery module 220b The overall impedance is 100mΩ. With this design, no additional components can be added, which can reduce manufacturing costs. In addition, since the overall impedance of the first battery module 220a and the second battery module 220b are both 100mΩ, when a short circuit occurs outside the energy storage system 200, the current will not be fully fed back to the battery cells with an impedance of 40mΩ 221, causing the second battery module 220b to withstand all the current, and is damaged due to excess capacity.

In addition, since the first conductive sheets 224a of the first battery module 220a and the second conductive sheets 224b of the second battery module 220b are evenly provided on the two ends of the battery cells 221, they generate more heat. Uniformity, no local heating and causing local overheating. In addition, these conductive The sheets 224b directly contact the battery cores 221, so when the conductive sheets 224b generate heat, they can also dissipate heat to the battery cores 221 without concentrating the heat locally.

As described above, according to an embodiment of the present invention, the length and width of the current travel path are changed by conductive sheets of different shapes to adjust the impedance value of the conductive sheet. The increased impedance is distributed to the conductive sheets, and the heat source is distributed to facilitate It is conducted to the battery cell 221 or the air to reduce the temperature, thereby achieving the uniform design of the battery module impedance, reducing the temperature of the battery module when the impedance increases, and improving the heat dissipation efficiency. There are but not limited to methods for adjusting the length and width of the current travel path on the conductive sheet.

Please refer to Figure 8 again. The slot 241b includes a curved slot 412. The width wb of the current path between the curved slot 412 and the edge of the surface of the second conductive sheet 224b is smaller than the width wa of the current path between the slot 241a and the edge of the surface of the first conductive sheet 224a. In one embodiment, the slot 241b further includes a strip slot 411, which is an I-shape in one embodiment. Preferably, the strip-shaped slot 411 is connected to the middle part of the curved slot 412. The strip groove 411 is located between the two electric welding points 243 and separates the two electric welding points 243, and the two electric welding points 243 are located in the area defined by the curved groove 412 and the strip groove 411.

In one embodiment, the shape of the curved slot 412 has an opening Oa, for example, it can be semicircular or C-shaped, and the curved slot 412 is spaced from the center of the electrode end 245 by a predetermined distance. In addition, in the electrode end portions 245, there are at least two electrode end portions 245 (for example, region S) in the shape of two curved grooves 412 opening portions Oa and Ob, respectively facing opposite directions. Such a design can make the length of the walking path of the current i longer. Preferably, the second conductive sheet 224b The current path of the current i is greater than the linear distance of the connecting channel portion 246 of the second conductive sheet 224b. In one embodiment, the current path of the current i of the second conductive sheet 224b is preferably greater than the current i of the first conductive sheet 224a的current path.

As above, as shown in Figure 7, according to the current density distribution, adjust the width of the first conductive sheet 224a of the current travel path so that the width of the conductive sheet at high current density is wider than the width of the conductive sheet at low current density. The impedance value of the first conductive sheet 224a is adjusted while avoiding excessive temperature rise and over-temperature to achieve the best design. In addition, as shown in FIG. 8, because the second conductive sheet 224b is provided with curved grooves, the length and width of the path that the current travels on the conductive sheet are changed to adjust the impedance value of the conductive sheet.

In one embodiment, the second conductive sheets 224a may further include a plurality of channel slots 461, and each channel slot 461 is located in each of the connecting channel portions 246, thereby reducing the width W of the connecting channel portion 246 .

To sum up, according to an embodiment of the present invention, in the energy storage system 200, the structure of the current paths of the first conductive sheets 224a of the first battery module 220a is different from those of the second battery module 220b. The structure of the current path of the second conductive sheet 224b. Therefore, the length and width of the current path that can pass through the conductive sheet are designed so that the overall impedance of the first battery module 220a and the second battery module 220b can be matched with each other, without increasing the installation of power components. Need to increase additional costs. The second conductive sheets 224b with higher impedance are evenly distributed and will not cause heat to be concentrated in the local area, causing local temperature to be too high. Moreover, the second conductive sheets 224b directly contact the battery cells 221, which can keep the whole The heat of the battery is further dispersed through the battery cells 221.

220b‧‧‧Second battery module

221‧‧‧These battery cells

224b‧‧‧Second conductive sheet

228‧‧‧Shell

241b‧‧‧Slotting

411‧‧‧Strip slotting

412‧‧‧Curve slotting

Claims (11)

An energy storage system includes: a first battery module, including: a first housing; a plurality of first battery cells are arranged in the first housing; and a plurality of first conductive sheets are arranged on the first batteries The two ends of the core are used to connect the first battery cores in series or in parallel; and a second battery module including: a second casing; most of the second battery cores are arranged in the second casing; and A plurality of second conductive sheets are arranged at both ends of the second battery cells and used to connect the second battery cells in series or in parallel, wherein the length or width of the current path of the first conductive sheets is It is different from the length or width of the current paths of the second conductive sheets. The energy storage system according to claim 1, wherein the impedance of the first battery cells of each first battery module does not match the impedance of the second battery cells of each second battery module Impedance, and the impedance of each of the first battery modules matches the impedance of each of the second battery modules. An energy storage system includes: a first battery module, including: a first housing; a plurality of first battery cells are arranged in the first housing; and a plurality of first conductive sheets are arranged on the first batteries The two ends of the core are used to connect the first battery cores in series or in parallel; and a second battery module including: a second casing; most of the second battery cores are arranged in the second casing; and A plurality of second conductive sheets are arranged on both ends of the second battery cells and used to connect the second battery cells in series or in parallel, wherein each of the first conductive sheets includes a first slot, Moreover, each of the second conductive sheets includes a second slot, and the shape of the second slot is different from that of the first slot. The shape of the slot, so that the width or length of the current path between the second slot and the edge of the surface of each second conductive sheet is different from that of the first slot and each first conductive sheet The width or length of the current path between the edges of the surface. The energy storage system according to claim 3, wherein the impedance of the second battery cells of each second battery module is smaller than the impedance of the first battery cells of each first battery module, Moreover, the width of the current path between the second slot and the edge of the surface of the second conductive sheet is smaller than the width of the current path between the first slot and the edge of the surface of the first conductive sheet, so that each The impedance of the first battery module matches the impedance of each of the second battery modules. The energy storage system according to claim 4, wherein each of the first conductive sheet and each of the second conductive sheet includes a plurality of electrode ends and a plurality of connection channel portions, and each of the connection channel portions is connected to Between two adjacent electrode ends, the first slot is located at each electrode end of each first conductive sheet, and the second slot is located at each second conductive sheet. One end of the electrode. The energy storage system according to claim 5, wherein the second slot includes a curved slot, and the curved slot has an opening. The energy storage system according to claim 6, wherein each of the electrode ends of the second conductive sheet has at least two of the electrode ends and the openings in the shape of two curved grooves , Facing each other in opposite directions. The energy storage system according to claim 7, wherein the second slot further includes a strip slot, and The first slot is another strip slot. The energy storage system according to any one of claims 6 to 8, wherein the shape of the curved slot is a semicircle or a C-shape. The energy storage system according to any one of claims 6 to 8, wherein each of the second conductive sheets further includes a plurality of channel slots, and each of the channel slots is located in each of the connecting channel parts. The energy storage system according to any one of claims 6 to 8, wherein the current path of each second conductive sheet is greater than the linear distance of each connecting channel portion of each second conductive sheet, and each The current path of the second conductive sheet is larger than the current path of each first conductive sheet.

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