Energy storage system

Abstract

An energy storage system includes a battery module and a temperature difference adjustment structure. The temperature difference adjustment structure is disposed on the battery module and includes a first plate and a second plate. The second plate includes a first side and an opposite second side, the first side being connected to the first plate, and the second side being closer to the battery module relative to the first side.

Description

Technical Field

[0001] This invention relates to an energy storage system. Prior Technology

[0002] Currently, battery modules used in energy storage systems and automobiles do not charge and discharge individual lithium batteries, but rather employ a series connection structure of multiple lithium batteries. However, using a series connection structure can lead to uneven temperature distribution within the battery module. If the temperature difference between the lithium batteries remains too large over a long period, it will negatively impact battery life. Summary of the Invention

[0003] The present invention relates to an energy storage system, which includes a temperature difference adjustment structure for adjusting the temperature difference between different zones of a battery module.

[0004] According to one aspect of the present invention, an energy storage system is provided, including a battery module and a temperature difference adjustment structure. The temperature difference adjustment structure is disposed on the battery module and includes a first plate and a second plate. The second plate includes a first side and an opposing second side, the first side being connected to the first plate, and the second side being closer to the battery module relative to the first side.

[0005] To provide a better understanding of the above and other aspects of the present invention, specific embodiments are described below in conjunction with the accompanying drawings: Simple Explanation of the Diagram

[0006] Figure 1 illustrates a schematic diagram of an energy storage system according to an embodiment of the present invention. Figures 2A to 2E illustrate schematic diagrams of a temperature difference adjustment structure according to an embodiment of the present invention. Figures 3A to 3D respectively illustrate schematic diagrams of temperature difference adjustment structures according to different embodiments of the present invention. Figures 4A to 4E respectively illustrate schematic diagrams of temperature difference adjustment structures according to different embodiments of the present invention. Figures 5A to 5B respectively illustrate schematic diagrams of temperature difference adjustment structures according to different embodiments of the present invention. Implementation

[0007] Please refer to Figure 1, which illustrates a schematic diagram of an energy storage system 1 according to an embodiment of the present invention. The energy storage system 1 may include a battery module 100, a temperature differential adjustment structure 130, a first heat sink 141, a second heat sink 142, a first fan 151, and a second fan 152. The temperature differential adjustment structure 130 includes a first plate 131 and a second plate 132. The temperature differential adjustment structure 130 includes heat dissipation holes, which may be disposed on the first plate 131, the second plate 132, or both the first plate 131 and the second plate 132. The number of heat dissipation holes can be adjusted according to requirements.

[0008] A temperature difference adjustment structure 130 is disposed on a battery module 100 to regulate the temperature difference between different areas of the battery module 100. The battery module 100 can be a structure of multiple battery cells 120 connected in series and parallel, which can increase the voltage, battery capacity, and internal resistance of the battery module 100, thereby extending the power supply time. However, when connecting battery cells 120 in series and parallel, attention must be paid to the consistency of the battery module 100. For example, when the battery cells 120 are in a series structure, uneven temperature distribution may occur in the battery module 100. If the battery module 100 is subjected to excessive temperature differences for a long period, its lifespan will be affected. The battery cells 120 can be, for example, lithium batteries.

[0009] In particular, the cuboid battery module 100 is prone to significant temperature differences in at least three zones. Referring to Figure 1, the battery module 100 includes a housing 110 and multiple battery cells 120 located inside the housing 110. The housing 110 includes at least three zones: a front zone 111, a middle zone 112, and a rear zone 113. Inconsistent temperatures of the battery cells 120 within each zone can affect the charging and discharging efficiency and lifespan of the battery module 100. Therefore, controlling the temperature of the battery module 100 requires not only maintaining the temperature of the battery cells 120 themselves within the standard range, but also maintaining the temperature difference between the battery cells 120 within each zone within a predetermined range to ensure the consistency of the battery module 100.

[0010] Referring to Figure 1, the first fan 151 is located at the front end of the housing 110, and the second fan 152 is located at the rear end of the housing 110. The first fan 151 and the second fan 152 are used to guide a cooling airflow 123 through the upper surface 110a of the housing 110, for example, guiding the cooling airflow from the rear end to the front end of the housing 110 to remove excess heat dissipated from the upper surface 110a. The first fan 151 is, for example, an exhaust fan, and the second fan 152 is, for example, a draft fan.

[0011] In this embodiment, without the temperature difference adjustment structure 130, and simply using the airflow 123 generated by the first fan 151 and the second fan 152 to reduce the temperature of the battery module 100, the temperature difference of the battery cells 120 in each zone is still relatively high. For example, the measured casing temperature of the front zone 111 and the middle zone 112 is approximately 56.5°C, and the measured casing temperature of the rear zone 113 is approximately 48.4°C. The temperature difference between the two is approximately 8.1°C. This is because the battery cells 120 in the rear zone 113 are closer to the second fan 152, and the airflow 123 generated by the second fan 152, which has a higher cooling efficiency, directly dissipates heat from the battery cells 120 in the rear zone 113. However, the battery cells 120 in the front zone 111 and the middle zone 112 are farther away from the second fan 152, so the airflow 123 generated by the second fan 152, which has a higher cooling efficiency, cannot directly dissipate heat from the battery cells 120 in the front zone 111 and the middle zone 112. Therefore, in order to avoid the housing temperature of the rear zone 113 being significantly lower than that of the front zone 111 and the middle zone 112, this embodiment sets the temperature difference adjustment structure 130 close to the second fan 152 (i.e., the air inlet) to reduce the temperature difference of the battery cells 120 in each zone.

[0012] Please refer to Figures 1 and 2A. The temperature difference adjustment structure 130 includes a first plate 131 and a second plate 132, which are disposed on an upper surface 110a of the housing 110. The first plate 131 includes a plurality of heat dissipation holes 131c. The second plate 132 includes a first side 132a and an opposite second side 132b. The first side 132a is connected to the first plate 131. The second plate 132 is inclined relative to the first plate 131, such that the second side 132b is closer to the battery module 100 relative to the first side 132a. The first plate 131 is generally parallel to the upper surface 110a of the housing 110, and the second plate 132 extends inclined toward the upper surface 110a of the housing 110.

[0013] Furthermore, a heat dissipation hole 131c is provided on the first plate 131. The heat dissipation hole 131c is, for example, a square, circular, rhomboid, trapezoidal, rectangular, triangular, hexagonal, or other polygonal opening. The heat dissipation hole 131c allows rising hot air to dissipate onto the first plate 131, and some hot air is blocked by the first plate 131 and kept below the first plate 131, thereby regulating the temperature difference of the battery module 100. In addition, a heat dissipation hole 132c is provided on the second plate 132, adjacent to the first side 132a (or the first plate 131) and away from the second side 132b (or the battery module 100).

[0014] In this embodiment, a higher number or density of heat dissipation holes 131c and 132c indicates a higher opening ratio of the first plate 131 and the second plate 132, which increases the volume of rising hot air that can escape, thereby reducing the temperature of the area covered by the first plate 131 and the second plate 132. Conversely, a lower number or density of heat dissipation holes 131c and 132c indicates a lower opening ratio of the first plate 131 and the second plate 132, which reduces the volume of rising hot air that can escape, thereby increasing the temperature of the area covered by the first plate 131 and the second plate 132. In one embodiment, the opening ratio of the first plate 131 and the second plate 132 is, for example, between 20% and 60%, such as 45%, but the present invention does not limit this.

[0015] Furthermore, the second plate 132 is tilted relative to the first plate 131 by a predetermined angle and a predetermined length, so that the second plate 132 can block the cooling airflow introduced by the second fan 152, thereby preventing excessive cold air from entering the area covered by the temperature-controlled first plate 131. In this embodiment, the tilt angle is, for example, between 10 degrees and 45 degrees, and the second plate 132 can be a flat surface, an arc surface, or a plate with a flow-guiding structure. As shown in Figure 2B, there is a distance D1 between the first plate 131 and the upper surface 110a of the housing 110, and there is an included angle A between the first plate 131 and the second plate 132, which is greater than or equal to 90 degrees and less than 180 degrees. For example, in Figure 3A, the included angle between the first plate 131 and the second plate 132 is, for example, 90 degrees.

[0016] In addition, the temperature difference adjustment structure 130 may further include a support member 133, and there may be one or more of them. The support member 133 is disposed between the first plate 131 and the battery module 100 (the upper surface 110a of the housing 110). The first plate 131 is separated from the battery module 100 (the upper surface 110a of the housing 110) by a distance through the support member 133 (it will not contact the battery module 100), thereby regulating the temperature difference of the battery module 100. Please refer to Figures 2B and 2C, which respectively show side views of the temperature difference adjustment structure 130 according to two embodiments of the present invention. The support member 133 is, for example, a fixing post. The fixing post has a height (for example, between 5 mm and 40 mm) and a screw hole (not shown in the figure). The screw hole is used for a fastener (for example, a screw) to pass through the through hole (not shown in the figure) of the first plate 131 and be fixed in the screw hole.

[0017] Please refer to Figures 2B and 2C. In Figure 2B, the height X2 of the support member 133 is approximately equal to the height X1 of the first side 132a of the second plate 132 relative to the second side 132b, such that the second side 132b of the second plate 132 contacts or approaches the upper surface 110a of the housing 110, for example. The height X2 of the support member 133 may be the same as the distance D1 between the first plate 131 and the upper surface 110a of the housing 110. The height X2 of the support member 133 is related to the velocity of the rising hot air H. When the height X2 of the support member 133 is low, the rising hot air H has a shorter distance to dissipate heat, which hinders the velocity of the hot air H to dissipate into the air; conversely, when the height X2 of the support member 133 is high, the rising hot air H has a longer distance to dissipate heat, and the velocity of the hot air H to dissipate into the air is relatively faster. Therefore, by controlling the height X2 of the support member 133, the amount of heat energy contained in a unit volume within the control range can be increased or decreased, thereby controlling the temperature of the area covered by the first plate member 131.

[0018] Additionally, the support member 133 can be a magnetic support member, such as a magnet or a column containing ferromagnetic material. The first plate 131 can be fixed to the support member 133 by magnetic attraction, without the need for fasteners. On the other hand, in Figure 2C, when the height X2 of the support member 133 is greater than the height X1 of the first side 132a of the second plate 132 relative to the second side 132b, the second side 132b of the second plate 132 has a notch C1 relative to the upper surface 110a of the housing 110, so that the second side 132b of the second plate 132 and the upper surface 110a of the housing 110 are not completely closed. Therefore, the area covered by the second plate 132 can be partially vented by the notch C1 of the second side 132b of the second plate 132 to reduce the temperature of the area covered by the first plate 131. There is a gap D2 between the second side 132b of the second plate and the upper surface 110a of the housing 110.

[0019] In Figures 2D and 2E, the temperature difference adjustment structure 130 further includes a third plate 136, which is connected to the second side 132b of the second plate 132, and the third plate 136 is attached to the battery module 100 (the upper surface 110a of the housing 110). The third plate 136 can be more securely attached to the battery module 100. The third plate 136 can be horizontally designed with the first plate 131 and attached to the upper side of the battery module 100, or it can be vertically designed with the first plate 131 and attached to the side 110b of the battery module 100.

[0020] Referring to Figure 1, in addition to the temperature difference adjustment structure 130, the energy storage system 1 may further include a first heat sink 141 and a second heat sink 142 respectively disposed on the upper surface 110a of the housing 110. The first heat sink 141 and the second heat sink 142 are, for example, metal heat dissipation fins of the same or different areas. By controlling the number and height of the heat dissipation fins, the heat dissipation efficiency of the heat dissipation fins can be changed. At the same time, the first heat sink 141 and the second heat sink 142 can be guided by the first fan 151 and the second fan 152 to move the cooling airflow 123 from the rear end to the front end of the housing 110 to remove excess heat energy from the first heat sink 141 and the second heat sink 142, thereby reducing the temperature of the battery cell 120 in the front area 111 or the middle area 112.

[0021] In this embodiment, after setting the temperature difference adjustment structure 130 and the first heat sink 141 and the second heat sink 142, the measured shell temperature of the front area 111 and the middle area 112 is approximately 53.7°C (a decrease of approximately 2.8°C), and the measured shell temperature of the rear area 113 is approximately 50.8°C (an increase of approximately 2.4°C). The temperature difference between the two is approximately 2.9°C, which is within a predetermined temperature difference range to maintain the consistency of the battery module 100. Referring to Figure 1, the battery module 100 has a first battery cell (e.g., battery cell 120) and a second battery cell (e.g., another battery cell 120). The vertical projection of the first plate 131 onto the battery module 100 overlaps with the first battery cell, and the vertical projections of the first and second heat sinks 141 and 142 onto the battery module 100 overlap with the second battery cell, respectively.

[0022] Please refer to Figures 3A to 3D, which respectively illustrate schematic diagrams of the temperature difference adjustment structure 130 according to different embodiments of the present invention. In Figure 3A, in addition to the first plate 131 and the second plate 132, the support member of the temperature difference adjustment structure 130 includes a front baffle 134, which is connected to the front side 131a of the first plate 131 and extends perpendicularly to the first plate 131 to form an L-shaped structure. In Figure 3B, the support member of the temperature difference adjustment structure 130 includes a front baffle 134 and two side baffles 135. The front baffle 134 is connected to the two side baffles 135 and is completely sealed, but the two side baffles 135 are not connected to the second plate 132 and retain a notch C2. In Figure 3C, the front baffle 134 is connected to the two side baffles 135 and is completely sealed without retaining the notch C2. In the 3D diagram, two side baffles 135 are connected to the opposite sides of the first plate 131 and the second plate 132 and extend perpendicularly relative to the first plate 131 to form a cap-shaped (U-shaped) structure. The structures of the above four embodiments can increase the temperature of the battery cell 120 in the area covered by the first plate 131 and keep the temperature difference of the battery module 100 within a predetermined temperature difference range to maintain the consistency of the battery module 100.

[0023] Please refer to Figures 4A to 4E, which respectively illustrate schematic diagrams of the temperature difference adjustment structure 130 according to different embodiments of the present invention. In Figure 4A, the second plate 132 is an arc-shaped plate extending from the first plate 131 and having an arc-shaped surface, with the arc-shaped surface bent downwards to have an upper inflection point. In Figure 4B, the second plate 132 is an arc-shaped plate extending from the first plate 131 and having an arc-shaped surface, with the arc-shaped surface bent upwards to have a lower inflection point. In Figure 4C, in addition to the first plate 131 and the second plate 132, the temperature difference adjustment structure 130 also includes one or more semi-cylindrical structures 137 disposed on the second plate 132. The surface of each semi-cylindrical structure 137 forms a semi-cylindrical shape or other possible deformation, and the surfaces of each semi-cylindrical structure 137 may be connected or separated by a gap. In Figure 4D, in addition to the first plate 131 and the second plate 132, the temperature difference adjustment structure 130 also includes one or more triangular prism structures 138 disposed on the second plate 132. The surface of each triangular prism structure 138 forms a triangular prism shape or other possible deformation, and the surfaces of each triangular prism structure 138 may be connected or separated by a gap. In Figure 4E, in addition to the first plate 131 and the second plate 132, the temperature difference adjustment structure 130 also includes one or more fin structures 139 disposed on the second plate 132. Each fin structure 139 is rectangular or other possible deformation, and adjacent fins are separated by a gap. The structures of the above five embodiments can increase wind resistance or form a stable airflow, so that the temperature difference of the battery module 100 is within a predetermined temperature difference range, thereby maintaining the consistency of the battery module 100.

[0024] Please refer to Figures 5A to 5B, which respectively illustrate schematic diagrams of the temperature difference adjustment structure 130 according to different embodiments of the present invention. In Figure 5A, in addition to the first plate 131 and the second plate 132, the temperature difference adjustment structure 130 also includes a fourth plate 131' and at least one support member 133'. The vertical projection of the fourth plate 131' toward the battery module 100 overlaps with the first plate 131. The fourth plate 131' may be a plate added to the first plate 131. The fourth plate 131' covers the first plate 131 and is separated from the first plate 131 by a distance (e.g., 5mm to 20mm) by the support member 133'. In this embodiment, in addition to providing heat dissipation holes 131c in the first layer to allow rising hot air to dissipate onto the first plate 131, the fourth plate 131' located in the second layer is, for example, a plate without heat dissipation holes (see Figure 5A) or a plate with heat dissipation holes 131c' (see Figure 5B). Therefore, in Figure 5A, the rising hot air passing through the first plate 131 is blocked by the fourth plate 131' and maintained between the first plate 131 and the fourth plate 131'. Alternatively, in Figure 5B, some of the rising hot air passing through the first plate 131 escapes through the heat dissipation hole 131c' of the fourth plate 131', and some of the hot air is blocked by the fourth plate 131' and maintained between the first plate 131 and the fourth plate 131'. The structures of the above two embodiments can increase the temperature of the battery cell 120 in the area covered by the first plate 131 and keep the temperature difference of the battery module 100 within a predetermined temperature difference range, so as to maintain the consistency of the battery module 100.

[0025] The energy storage system and its temperature difference adjustment structure described in the above embodiments of the present invention are used to regulate the temperature differences between different zones of the battery module, which can prevent the battery life from being affected by excessively large temperature differences between lithium batteries over a long period of time. In particular, rectangular battery modules are prone to significant temperature differences in at least three zones. By effectively controlling the battery temperature in different zones and reducing the temperature differences between them, the charging and discharging efficiency, lifespan, reliability, and maintenance costs of the battery module can be improved.

[0026] In summary, although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0027] 1: Energy Storage System 100: Battery Module 130: Temperature difference adjustment structure 131: First Slab 131a: Anterior side 132: Second plate 132a: First side 132b: Second side 133: Support component 133': Support component 135: Side panel 134: Front windshield 131c, 132c, 131c': Heat dissipation holes 136: Third plate 131': Fourth plate 110: Shell 110a: Upper surface 110b: Side view 111: Front Area 112: Central District 113: Rear Area 120: Battery cell 123: Airflow 137: Semi-cylindrical structure 138: Triangular prism structure 139: Fin Structure 141: First Radiator 142: Second radiator 151: First Fan 152: Second Fan H: Hot air D1, D2: Spacing X1, X2: Height C1, C2: Gap

Claims

1. An energy storage system, comprising: One battery module; And a temperature difference adjustment structure, which is disposed on an air inlet side of the battery module, the temperature difference adjustment structure includes: a first plate, which is disposed on an upper surface of the battery module and has a gap between the first plate and the battery module; And a second plate, the second plate including a first side and an opposite second side, the first side being connected to the first plate, the second side being closer to the battery module relative to the first side, wherein the second plate is inclined relative to the first plate.

2. The energy storage system as described in claim 1, wherein the temperature difference adjustment structure includes a heat dissipation hole.

3. The energy storage system as described in claim 1, wherein the temperature difference adjustment structure further includes a support member connected to the first plate and disposed between the first plate and the battery module.

4. The energy storage system as described in claim 3, wherein the height of the support member is greater than or equal to the height of the first side of the second plate relative to the second side.

5. The energy storage system as claimed in claim 1, wherein the first plate and the second plate have an included angle that is greater than or equal to 90 degrees and less than 180 degrees.

6. The energy storage system as claimed in claim 1, wherein the temperature difference adjustment structure further includes a third plate connected to the second side and attached to the battery module.

7. The energy storage system as claimed in claim 1, wherein the energy storage system further includes a first fan and a second fan, the battery module includes a housing located between the first fan and the second fan, wherein the first plate and the second plate are disposed on an upper surface of the housing and the second plate extends from the first side toward the upper surface.

8. The energy storage system as claimed in claim 1, wherein the second plate has a flat surface, an arc surface, or a plate with a flow guiding structure.

9. The energy storage system as claimed in claim 1, wherein the energy storage system further includes a heat sink, the battery module has a first battery cell and a second battery cell, the vertical projection of the first plate toward the battery module overlaps with the first battery cell, and the vertical projection of the heat sink toward the battery module overlaps with the second battery cell.

10. The energy storage system as described in claim 1, wherein the temperature difference adjustment structure further comprises: A fourth plate, the vertical projection of the fourth plate toward the battery module overlaps with the first plate, and the fourth plate is separated from the first plate by a distance.

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