KR102877728B1 - Battery module and battery pack having the same - Google Patents

Abstract

A battery module is provided, comprising: a cell stack formed by stacking a plurality of battery cells; a module housing accommodating the cell stack therein; and a cooling unit having a cooling plate that cools the module housing and has a flow path space formed therein through which a coolant flows, and a thermoelectric element installed on an outer surface of the cooling plate; wherein the cooling plate includes a base portion and a protrusion portion that protrudes from the base portion toward the cell stack to form a sunken space, and the thermoelectric element is installed in the sunken space of the protrusion portion.

Description

Battery module and battery pack having the same {BATTERY MODULE AND BATTERY PACK HAVING THE SAME}

The present invention relates to a battery module having a plurality of battery cells composed of secondary batteries and a battery pack having the same.

Unlike primary batteries, secondary batteries can be recharged and discharged, making them suitable for a wide range of applications, including digital cameras, mobile phones, laptops, hybrid vehicles, and electric vehicles. Examples of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, and lithium secondary batteries.

Among these secondary batteries, extensive research is being conducted on lithium secondary batteries, which boast high energy density and discharge voltage. Recently, lithium secondary batteries have been manufactured and used in flexible pouch-type battery cells or rigid square or cylindrical can-type battery cells. Multiple battery cells are electrically connected to form a battery module.

Meanwhile, prolonged use of a battery module generates heat within the battery cells, and the internal temperature rises rapidly, especially during charging. This rise in battery cell temperature shortens the battery module's lifespan, reduces its efficiency, and, in the worst case, can even lead to fire or explosion.

To address these issues, a structure has been developed that dissipates heat from the battery module by allowing heat exchange between the module housing and the refrigerant. Specifically, conventional battery modules feature a cooling element connected to the module housing with a flow path, and the refrigerant flowing through the flow path cools the module housing and the battery cells contained within.

When cooling a battery module using conventional technology, the refrigerant flowing through the inlet flows through the flow path, exchanging heat with the module housing and increasing its temperature. This creates a difference in the refrigerant temperature between the area adjacent to the inlet and the area adjacent to the outlet.

Accordingly, the temperature of the battery cell (or part of the battery cell) located in the area where the coolant flows in the direction of discharge toward the outlet becomes higher than that of the battery cell (or part of the battery cell) located in the area where the coolant flowing in through the inlet flows. Therefore, the heat dissipation effect of the battery cell (or part of the battery cell) corresponding to the area adjacent to the outlet is reduced, resulting in a temperature difference depending on the location of the battery cell within the battery module.

The temperature deviation of these battery cells poses a problem that causes a decline in the overall quality and lifespan of the battery module.

The present invention, in one aspect, aims to provide a battery module capable of reducing temperature deviation and heat dissipation unevenness of a cell stack (battery cell) and a battery pack including the same.

In addition, the present invention aims, as one aspect, at providing a battery module and a battery pack including the same that facilitate heat dissipation in a region where the temperature of a cell stack (battery cell) and/or a coolant is high.

And, as one aspect, the present invention aims to provide a battery module capable of increasing heat dissipation and cooling efficiency through a thermoelectric element and a battery pack including the same.

In addition, the present invention aims, as one aspect, to provide a battery module capable of easily installing a thermoelectric element using the existing shape of a cooling plate, and a battery pack including the same.

And, as one aspect, the present invention aims to provide a battery module that can stably be used even when the external temperature is low, and a battery pack having the same.

As an aspect for achieving at least some of the above objects, the present invention provides a battery module including: a cell stack formed by stacking a plurality of battery cells; a module housing accommodating the cell stack therein; and a cooling unit having a cooling plate that cools the module housing and has a flow path space formed therein through which a coolant flows, and a thermoelectric element installed on an outer surface of the cooling plate; wherein the cooling plate includes a base portion and a protrusion portion that protrudes from the base portion toward the cell stack to form a sunken space, and the thermoelectric element is installed in the sunken space of the protrusion portion.

The above protrusion may have a structure that supports the module housing and may be in thermal contact with the module housing.

Additionally, the thermoelectric element may be installed asymmetrically on the outer surface of the base portion.

And, the protrusion includes a plurality of protrusions spaced apart from each other on the base, and the thermoelectric element can be installed on at least a part of the protrusion. At this time, the protrusion can have a cross-section perpendicular to the direction in which it protrudes from the base part having a circular or square shape. The thermoelectric element can be installed more on the outer surface of the base part corresponding to an area where the refrigerant flows out of the flow path space than on the outer surface of the base part corresponding to an area where the refrigerant flows into the flow path space.

In addition, the protrusion includes a partition wall portion having a shape extending along the flow direction of the refrigerant to form a sunken space by protruding from the base portion toward the cell stack and guide the flow of the refrigerant, and the thermoelectric element may be installed in at least a portion of the sunken space of the partition wall portion. The thermoelectric element may be installed in an area of the sunken space of the partition wall portion where the refrigerant flows outward from the flow path space.

And, the thermoelectric element forms a temperature difference between the first and second parts that face each other according to the power supply, and a first heat transfer member may be positioned between at least one of the first and second parts and the protrusion.

Additionally, the cooling plate may have a wire installation groove formed in the protrusion or an area adjacent to the protrusion for installing a wire that supplies power to the thermoelectric element.

And, the cooling plate may include a first body having the base portion and the protrusion portion formed therein, and a second body coupled to the first body to form the flow path space therebetween.

In another aspect, the present invention provides a battery pack comprising: a cell stack formed by stacking a plurality of battery cells; a pack housing accommodating the cell stack therein; and a pack cooling unit installed in the pack housing to cool the cell stack, wherein the pack cooling unit includes a cooling plate having a flow path space formed therein through which a coolant flows, and a thermoelectric element installed on an outer surface of the cooling plate, wherein the cooling plate includes a base portion and a protrusion portion that protrudes from the base portion toward the cell stack to form a sunken space, and the thermoelectric element is installed in the sunken space of the protrusion portion.

The above cell stack is mounted on the pack housing via a heat transfer member, and the pack cooling unit can be located at the lower portion of the pack housing.

In addition, a battery pack according to one aspect of the present invention further includes a module housing that accommodates the cell stack therein, and the pack cooling unit can be located between the module housing and the pack housing.

At this time, a first heat transfer member is positioned between the thermoelectric element and the protrusion, a second heat transfer member is positioned between the outer surface of the base portion and the pack housing, and the thickness of the second heat transfer member may have a value greater than the thickness of the first heat transfer member. In addition, the first heat transfer member and the second heat transfer member may be connected to each other.

A battery pack according to one aspect of the present invention further includes a control unit that controls the operation of the thermoelectric element, wherein the thermoelectric element is connected to a low voltage line to receive power, and the control unit can perform control to switch the polarity of the power applied to the thermoelectric element according to the temperature of the cell stack. In addition, the control unit can individually control the operation of at least some of the plurality of thermoelectric elements.

According to one embodiment of the present invention, by releasing heat generated inside a module housing through a thermoelectric element installed on the outer surface of a cooling plate, it is possible to obtain an effect of reducing temperature deviation of a cell stack (battery cell) and uneven heat dissipation of battery cells according to the position installed in the battery module, thereby improving the overall cooling performance of the battery module.

In addition, according to one embodiment of the present invention, by arranging thermoelectric elements in areas where the temperature of the cell stack (battery cell) and/or the coolant is high, particularly in areas adjacent to the outlet, heat dissipation performance in areas where the temperature of the cell stack (battery cell) and/or the coolant is high can be improved. In particular, by relatively concentrating thermoelectric elements in areas where the temperature of the cell stack (battery cell) and/or the coolant is high, cost increases due to the installation of a large number of thermoelectric elements can be minimized.

In addition, according to one embodiment of the present invention, the heat dissipation and cooling efficiency through the thermoelectric element can be improved by providing a structure in which the protrusion (protrusion and/or bulkhead) and the module housing come into thermal contact. In particular, the heat dissipation efficiency can be improved by allowing the heat transferred from the module housing to the thermoelectric element to be transferred to the pack housing via the heat transfer member.

In addition, according to one embodiment of the present invention, by installing a thermoelectric element using a protrusion (dimple) or a partition wall installed on a cooling plate, an effect can be obtained in which a thermoelectric element can be easily installed using the existing shape of the cooling plate.

And, according to one embodiment of the present invention, when the external temperature or the temperature of the battery cell is low, by applying power of the opposite polarity to the power applied to the thermoelectric element when performing heat dissipation of the battery module, the temperature of the battery cell is increased, thereby enabling stable operation of the battery module. In particular, by controlling each thermoelectric element to be turned on/off through the control unit, when cooling through the thermoelectric element is required, the thermoelectric element can be selectively driven, and when the cooling efficiency is reduced in a certain area or when a temperature increase is required, the thermoelectric element corresponding to the relevant area can be selectively driven.

In addition, according to one embodiment of the present invention, by forming a wire installation groove for installing a wire that supplies power to a thermoelectric element in a portion of a cooling plate adjacent to a protrusion or a region adjacent to the protrusion, an effect of facilitating wiring of the thermoelectric element can be obtained.

Figure 1 is a perspective view of a battery module according to one embodiment of the present invention.
Figure 2 is an exploded perspective view of the battery module illustrated in Figure 1.
Figure 3 is a cross-sectional view along line II' of Figure 1.
Fig. 4 is a perspective view of the cooling unit illustrated in Fig. 2.
FIG. 5 is a cross-sectional view showing a modified example of the battery module shown in FIGS. 2 and 3.
Figures 6 to 8 are plan views and cross-sectional views showing various modified examples of the cooling unit shown in Figures 2 and 3.
Fig. 9 is a temperature distribution diagram showing the temperature distribution of a cell stack when a refrigerant flows in a cooling plate having the euro structure shown in Fig. 6 without the thermoelectric element being driven.
Fig. 10 is a schematic diagram illustrating heat flow in the battery module illustrated in Fig. 3.
Fig. 11 is a cross-sectional view of a battery pack according to one embodiment of the present invention.
Fig. 12 is a cross-sectional view showing a modified example of the battery pack shown in Fig. 11.
Fig. 13 is a cross-sectional view of a battery pack according to another embodiment of the present invention.
Fig. 14 is a cross-sectional view of a battery pack according to another embodiment of the present invention.

Before going into a detailed description of the present invention, it should be noted that the terms and words used in this specification and claims described below should not be construed as limited to their typical or dictionary meanings, but should be construed with meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best way. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the drawings. Furthermore, detailed descriptions of well-known functions and structures that may obscure the gist of the present invention will be omitted. For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted, and the sizes of each component do not fully reflect their actual sizes.

In addition, the expressions such as upper, upper, lower, lower, side, front, rear, etc. in this specification are expressed based on the direction shown in the drawing, and it is to be noted in advance that they may be expressed differently if the direction of the object in question changes.

Hereinafter, a battery module (100) according to one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a battery module (100) according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the battery module (100) illustrated in FIG. 1, FIG. 3 is a cross-sectional view taken along line I-I' of FIG. 1, and FIG. 4 is a perspective view of a cooling unit (140) illustrated in FIG. 2. In addition, FIG. 5 is a cross-sectional view showing a modified example of the battery module (100) shown in FIGS. 2 and 3, and FIGS. 6 to 8 are plan views and cross-sectional views showing various modified examples of the cooling unit (140) shown in FIGS. 2 and 3, and FIG. 9 is a temperature distribution diagram showing the temperature distribution of the cell stack (110) when the refrigerant flows in a state where the thermoelectric element (141) is not driven for the cooling plate (150) having the flow path structure shown in FIG. 6, and FIG. 10 is a schematic diagram showing the heat flow (Q) in the battery module (100) shown in FIG. 3. FIG. 9 shows a state where the module housing (120) and the cooling unit (140) installed on the bottom of the module housing (120) are omitted in order to clearly show the temperature distribution of the battery cell (111).

Referring to FIGS. 1 to 10, a battery module (100) according to one embodiment of the present invention may be configured to include a cell stack (110), a module housing (120), and a cooling unit (140).

First, as illustrated in FIGS. 2 and 3, the cell stack (110) is configured by stacking a plurality of battery cells (111). In the present embodiment, the battery cells (111) are stacked in the left-right direction (or horizontal direction). However, it is also possible to stack the battery cells (111) in the vertical direction as needed.

Each battery cell (111) may be configured as a pouch-type secondary battery, for example, and may have a structure in which the electrode lead (111a) protrudes outward.

The battery cell (111) may be configured in a form in which an electrode assembly (not shown) and an electrolyte (not shown) are accommodated in a pouch (external material) formed in a container shape. The electrode assembly includes a plurality of electrode plates and is accommodated in the pouch. Here, the electrode plates include a positive electrode plate and a negative electrode plate, and the electrode assembly may be configured in a form in which the positive and negative electrode plates are laminated with a separator interposed therebetween, with the wide surfaces of the positive and negative electrode plates facing each other. The plurality of positive and negative electrode plates are each provided with electrode tabs, and can be connected to the same electrode lead (111a) by contacting each other with the same polarity. In the case of the battery cell (111) illustrated in FIG. 2, the two electrode leads (111a) are illustrated as being arranged facing opposite directions, but they may also be arranged facing the same direction but at different heights. In addition, the pouch (not shown) is formed in a container shape and provides an internal space in which the electrode assembly and the electrolyte (not shown) are accommodated. At this time, a portion of the electrode lead (111a) of the electrode assembly may be exposed to the outside of the pouch.

The battery cell (111) configured in this manner may be a nickel-metal hydride (Ni-MH) battery or a lithium-ion (Li-ion) battery that can be charged and discharged. In addition, in an embodiment of the present invention, the battery cell (111) may be a pouch-type secondary battery having a three-sided sealing structure. The pouch-type secondary battery having a three-sided sealing structure has the advantage of being able to be stacked in a housing without a separate structure by sealing the area where the electrode lead (111a) is exposed to the outside and the area corresponding to the upper portion when stacked by a thermal compression method, but not forming a sealing portion in the area corresponding to the lower portion when stacked, and has the advantage of being able to stably dissipate heat through a large contact area with a heat transfer member (TA). However, the present invention is not limited thereto, and may also be configured as a pouch-type secondary battery having a four-sided sealing structure, or a can-type secondary battery having a square or circular shape.

Referring to FIGS. 1 to 3, the module housing (120) forms the exterior of the battery module (100) and is placed on the exterior of a cell stack (110) formed by stacking a plurality of battery cells (111) to protect the battery cells (111) from the external environment.

As an example, the module housing (120) may be configured to include a housing body (121) having a cross-sectional shape with one side open, and a housing cover (125) that is combined with the housing body (121) to form an internal space.

Additionally, an end plate (126) may be coupled to the longitudinal front and rear sides of the module housing (120) to cover the internal space formed by the housing body (121) and the housing cover (125).

A cell stack (110) may be arranged in the internal space of the module housing (120). At least one surface of the module housing (120) may function as a heat dissipation plate that dissipates heat generated from the battery cells (111) to the outside.

The housing body (121) may include a lower plate (122) that supports the lower portion of the battery cell (111) to form a U-shaped cross-section with one side open, and a side plate (123) that extends upward and downward (upper side in FIG. 2) from both ends of the lower plate (122) in the width direction and supports the side surface of the battery cell (111).

At this time, the housing body (121) may have a structure in which the lower plate (122) and the side plate (123) are formed as an integral part. In addition, the housing body (121) may have a shape in which the widthwise cross-section is constant along the lengthwise direction, and in this case, the housing body (121) may be manufactured by an extrusion process. However, if necessary, it is also possible to form the housing body (121) by forming the side plate (123) and the lower plate (122) as independent components and then combining/attaching them. The side plate (123) supports the side surface of the battery cell (111) corresponding to the side surface (wide surface) of the cell stack (110) that is stacked left and right. At this time, the side surface of the battery cell (111) may be in direct contact with the side plate (123), but it is also possible for a heat dissipation pad or a buffer pad (not shown) to be interposed between the side plate (123) and the side surface of the battery cell (111). In addition, the housing cover (125) is positioned opposite the lower plate (122) and can be connected to the upper end of the side plate (123). Therefore, when the housing cover (125) is coupled to the housing body (121) in a form that covers the side plate (123), the housing cover (125) and the housing body (121) have the shape of a tubular member with an empty interior.

The housing body (121) may be made of a material with high thermal conductivity, such as metal. For example, the housing body (121) may be made of aluminum. However, the material of the housing body (121) is not limited thereto, and various materials may be used as long as they have strength and thermal conductivity similar to metal, even if they are not metal. In addition, the housing cover (125), like the housing body (121), may be made of a material with high thermal conductivity, such as metal. As an example, the housing cover (125) may be made of aluminum. However, the material of the housing cover (125) is not limited thereto, and various materials may be used as long as they have strength and thermal conductivity similar to metal, even if they are not metal.

In addition, the combination of the housing body (121) and the housing cover (125) can be performed by welding (e.g., laser welding, etc.) the contact surface of the side plate (123) and the housing cover (125). However, the combination of the housing body (121) and the housing cover (125) is not limited to the welding combination described above, and various modifications are possible, such as combining by sliding or bonding, or combining using fixing members such as bolts or screws.

Meanwhile, the end plate (126) may be configured to be coupled to both sides where the electrode leads (111a) of the battery cell (111) are arranged, i.e., the longitudinal front and rear sides of the module housing (120), respectively, to cover the open front and rear sides of the module housing (120). As illustrated in FIG. 2, the end plate (126) is coupled to the housing body (121) and the housing cover (125) to form the exterior of the battery module (100) together with the housing body (121) and the housing cover (125).

The end plate (126) may be formed of a metal such as aluminum and may be manufactured through processes such as die casting or extrusion/pressing. In addition, the end plate (126) may be provided with a through hole (126a) for exposing the connection terminal (132) of the insulating cover (130) described below to the outside. The end plate (126) may be coupled to the housing body (121) and the housing cover (125) through a fixing member such as a screw or bolt. However, the coupling method of the end plate (126) is not limited thereto.

Referring to Fig. 2, an insulating cover (130) may be interposed between the end plate (126) and the cell stack (110). The insulating cover (130) is coupled to one or both sides where the electrode leads (111a) of the battery cells (111) are arranged. The electrode leads (111a) penetrate the body of the insulating cover (130) and are interconnected with the same polarity by a bus bar (not shown) on the outside of the insulating cover (130). For this purpose, the insulating cover (130) may be provided with a plurality of through holes (not given a drawing symbol) into which the electrode leads (111a) are inserted and arranged.

In addition, the insulating cover (130) may be provided with a connection terminal (132) for connection to the outside. Accordingly, the battery cell (111) is electrically connected to the outside through the connection terminal (132), and for this purpose, the electrode lead (111a) may be electrically connected to the connection terminal (132) through a circuit wiring (not shown) provided in the insulating cover (130). This circuit wiring may perform electrical connection according to the series/parallel connection of the module through a bus bar made of the same material. The connection terminal (132) is exposed to the outside through a through hole (126a) formed in the end plate (126), as illustrated in FIG. 2. Therefore, the through hole (126a) may be formed in a size corresponding to the size and shape of the connection terminal (132).

Meanwhile, a heat transfer member (TA) may be installed between the battery cell (111) and the lower plate (122) of the housing body (121) so as to effectively transfer heat generated from the battery cell (111) to the module housing (120). The heat transfer member (TA) has one side (upper side) in contact with the battery cell (111) and the other side (lower side) in contact with the module housing (120) so as to transfer heat generated from the battery cell (111) to the module housing (120).

A heat transfer member (TA) may be positioned between the lower surface (surface where no sealing portion is formed) of the battery cell (111) and the inner surface of the module housing (120) to dissipate heat from the battery cell (111) to the cooling plate (150). In this way, when the surface where no sealing portion is formed is connected to the module housing (120) through the heat transfer member (TA) over a wide area, heat generated in the battery cell (111) can be easily released through the module housing (120).

The heat transfer member (TA) may be configured to include at least some of thermal grease, thermal adhesive, thermal conductive epoxy, and heat dissipation pad to ensure good heat transfer, but is not limited thereto. In addition, the heat transfer member (TA) may be formed in the form of a pad between the lower surface of the battery cell (111) and the upper surface of the lower plate (122). It can be placed, or applied in a liquid or gel state. In this way, the heat generated in the battery cell (111) can be effectively transferred to the lower plate (122) due to the high thermal conductivity of the heat transfer member (TA), and then sufficient heat can be dissipated through the cooling unit (140). In addition, the heat transfer member (TA) of the present embodiment can also be configured to have high insulation, and for example, a material having a dielectric strength in the range of 10 to 30 KV/mm can be used. In the case where a material having high insulation is used, even if the insulation in the battery cell (111) is partially destroyed, the insulation between the battery cell (111) and the module housing (120) can be maintained by the heat transfer member (TA) placed around the battery cell (111).

Next, the cooling unit (140) will be described with reference to FIGS. 2 to 10.

The cooling unit (140) is attached to the module housing (120) and cools the module housing (120) using a refrigerant. The refrigerant may be formed of cooling water or a cooling liquid with an additive added to the cooling water. The cooling unit (140) may include a cooling plate (150), a thermoelectric element (141) installed on the outer surface of the cooling plate (150), and a first heat transfer member (145) arranged between the thermoelectric element (141) and the outer surface of the cooling plate (150).

The cooling plate (150) may have a body portion (151) that is sunken in order to form a passage space (153) through which the refrigerant flows. That is, a base portion (152) that is sunken in is formed in the body portion (151) of the cooling plate (150), and the sunken portion forms the passage space (153). In addition, the cooling plate (150) has an inlet port (IN of FIGS. 6 to 9) through which the refrigerant flows in and an outlet port (OUT of FIGS. 6 to 9) through which the refrigerant flows out, and may be connected to a cooling system (not shown) including a pump, a refrigerant tank, etc. The cooling system may have a structure through which a large amount of refrigerant can circulate.

The cooling plate (150) may include a base portion (152) and a protrusion (154, 155) that protrudes from the base portion (152) toward the cell stack (110) or the flow path space (153) and forms a recessed space on the outer surface.

The protrusions (154, 155) may be configured to include a plurality of protrusions (e.g., dimple structures) (155) that form an irregular flow in the refrigerant as it flows through the flow path space (153) through the inlet (IN), so that the heat transferred from the module housing (120) to the cooling unit (140) is evenly absorbed by the refrigerant. The protrusions (155) may be configured to support the module housing (120) in order to maintain the shape of the flow path space (153).

In addition, the protrusions (154, 155) may be configured to include a baffle portion (154) that guides the flow of the refrigerant so that the refrigerant can flow from the inlet (IN) to the outlet (OUT). The baffle portion (154) has a shape that protrudes from the base portion (152) toward the cell stack (110) and may be configured to support the module housing (120) to maintain the shape of the flow path space (153). This baffle portion (154) has a shape that extends along the flow direction of the refrigerant to partition the flow path space (153) and partitions the flow path space (153) into a plurality of sections.

For example, the partition wall (154) may be configured to divide an area into which refrigerant flows in from an inlet (IN) and an area into which refrigerant flows out from an outlet (OUT), as illustrated in FIGS. 2 to 8. That is, in the embodiments of FIGS. 2, 4, 6, and 7, the cooling plate (150) has a structure in which both an inlet (IN) and an outlet (OUT) are formed on one side of the body (151), and the partition wall (154) can guide the flow of the refrigerant so that the refrigerant forms a U-shaped flow path. Alternatively, a plurality of partition walls (154) may be formed on the body (151) to divide the flow path space (153) so that the refrigerant flowing in from the inlet (IN) is separated into a plurality of areas and flows. The refrigerant may flow through the flow path space (153) between the partition walls (154) and then be discharged through the outlet (OUT). For example, in the embodiment of FIG. 8, the cooling plate (150) may have a structure in which an inlet (IN) is formed on one side of the body part (151) and an outlet (OUT) is formed on the other side of the body part (151), and the partition wall part (154) guides the flow of refrigerant from the inlet (IN) toward the outlet (OUT).

In addition, the cooling plate (150) may be provided with both a protrusion (155) and a partition wall (154) as shown in FIGS. 2 to 7, or may be provided with only a partition wall (154) as shown in FIG. 8. FIG. 8 illustrates a configuration in which only a partition wall (154) is installed on the cooling plate (150), but a protrusion (155) may also be provided in the space between the partition walls (154).

Meanwhile, the installation positions and number of inlets (IN) and outlets (OUT) formed on the cooling plate (150), and the installation positions, shapes, and numbers of bulkheads (154) and protrusions (155) can be changed in various ways.

These protrusions (155) and partition walls (154) can be formed through a pressing process or the like, and accordingly, a sunken space can be formed on the outer surface of the protrusions (155) and partition walls (154).

Meanwhile, FIGS. 2 to 4 and 6 to 8 illustrate a case in which the body part (151) of the cooling plate (150) is formed of a single plate and is coupled to the module housing (120), and a flow path space (153) is formed between the body part (151) of the cooling plate (150) and the module housing (120), but the structure of the cooling plate (150) is not limited thereto. For example, as illustrated in FIG. 5, the body part (151) of the cooling plate (150) may be formed by joining a first body (151a) and a second body (151b) composed of two upper and lower plates, and may have a structure in which a flow path space (153) is formed between the first body (151a) and the second body (151b). For example, a base portion (152) and a protrusion portion (154) are formed in the first body (151a), and a second body (151b) is configured to cover the first body (151a) so that a flow path space (153) can be formed between the first body (151a). A heat transfer member (TM) made of a heat transfer material such as silicone can be placed between the lower surface of the module housing (120) and the upper surface of the second body (151b) to improve thermal conductivity.

The cooling plate (150) may have a structure in which it is attached to the module housing (120) through brazing or the like so that heat from the module housing (120) can be transferred to the refrigerant flowing in the passage space (153). In addition, the cooling plate (150) is made of a thermally conductive metal material so that it can release the heat of the refrigerant flowing in the passage space (153) to the outside.

Meanwhile, the cooling plate (150) may be placed at the bottom of the battery module (100), but is not limited thereto, and may be placed at the top of the battery module (100), or at both the top and bottom.

The thermoelectric element (141) is installed in the sunken space of the protrusions (154, 155) and can release heat generated in the battery cell (111) and transferred to the module housing (120) to the outside. The thermoelectric element (141) forms a temperature difference between the first part (142) and the second part (142) that face each other depending on the power supply. For example, either the first part (141) or the second part (142) of the thermoelectric element (141) can form a high-temperature part having a relatively high temperature, and the other can form a low-temperature part having a relatively low temperature. Accordingly, the thermoelectric element can generate or heat through either the first part (141) or the second part (142) depending on the electrical input, and absorb or cool through the other one.

The thermoelectric element (141) may be configured such that at least some of the protrusions (155) and the partition walls (154) are in thermal contact with the module housing (120) so that heat transferred from the battery cell (111) to the module housing (120) can be easily transferred to the thermoelectric element (141).

The term "thermal contact" in this specification and claims means that heat of the module housing (120) is transferred to the protrusion (155) or the partition wall (154) by heat conduction, and includes not only cases where the protrusion (155) or the partition wall (154) directly contacts the module housing (120) and heat is transferred, but also cases where the protrusion (155) or the partition wall (154) indirectly contacts the module housing (120) and heat is transferred through a heat transfer member or other component. In addition, the protrusion (155) and the partition wall (154) may not be in thermal contact with the module housing (120) over the entire opposing area, but may be in thermal contact with the module housing (120) in some areas of the opposing area.

The thermoelectric element (141) can be installed over the entire bulkhead (154) and protrusion (155) of the cooling plate (150), but in order to reduce installation costs, it can be installed only over a part or a portion of the bulkhead (154) and the protrusion (155).

Referring to Fig. 9, when the temperature distribution of the cell stack (110) is examined when the refrigerant flows while the thermoelectric element (141) is not driven, the temperature of the portion of the cell stack (110) adjacent to the outlet (OUT) is formed higher than that of the portion of the cell stack (110) adjacent to the inlet (IN) based on the flow path of the refrigerant. The refrigerant introduced into the inlet (IN) flows through the flow path (153) and exchanges heat with the module housing (120) to be discharged through the outlet (OUT) with its temperature increased. At this time, the temperature of the lower surface of the cell stack (110) where the cooling unit (140) is installed decreases through heat exchange with the refrigerant, and the temperature of the side surface of the cell stack (110) decreases through heat exchange with the air around the module housing (120). Therefore, as shown in FIG. 9, a high temperature area (HA) may be formed in an area of the cell stack (110) adjacent to the outlet (OUT) at a slight distance, rather than in the area of the cell stack (110) at the outlet (OUT). In this way, the temperature of the refrigerant may also increase in an area where the cell stack (110) becomes the high temperature area (HA).

Considering the temperature distribution of the cell stack (110) and/or the refrigerant, the thermoelectric element (142) may be installed asymmetrically on the outer surface of the base portion (152).

In addition, the thermoelectric elements (141) may be installed more on the outer surface of the base portion (152) corresponding to the area where the refrigerant flows out of the passage space (153) than on the outer surface of the base portion (152) corresponding to the area where the refrigerant flows in to the passage space (153). That is, the thermoelectric elements (142) may be installed on a greater number of protrusions (155) or baffles (154) in an area adjacent to the outlet (OUT) than in an area adjacent to the inlet (IN), i.e., an area where the temperature of the cell stack (110) and/or the refrigerant is high.

For example, the part indicated in bold in FIG. 4, the part indicated by a circle in the plan view of FIG. 6, and the part indicated by a square in the plan view of FIG. 7 represent a protrusion (155) on which a thermoelectric element (141) is installed, and an embodiment is illustrated in which more thermoelectric elements (141) are installed in the part adjacent to the outlet (OUT) than in the part adjacent to the inlet (IN).

Referring to Fig. 8, the thermoelectric element (141) may be installed in an area where the refrigerant flows out of the flow passage space (153) among the sunken spaces of the partition wall portion (154). For example, the length (L1) from the inlet (IN) to the position where the thermoelectric element (141) is installed in the sunken space of the partition wall portion (154) may be set to a position that is more than half of the total length (L) of the flow passage space (153). In addition, as illustrated in Fig. 8, the thermoelectric element (141) may have a structure in which it is installed long along the longitudinal direction of the partition wall portion (154). However, Fig. 8 illustrates one embodiment, and a plurality of small-sized thermoelectric elements (141) (e.g., the size of a thermoelectric element installed in a protrusion) may be installed in a row or spaced apart from each other in the bulkhead portion (154), and it is also possible for a thermoelectric element (141) to be installed in an area of the bulkhead portion (154) adjacent to the inlet (IN). In addition, a thermoelectric element (141) may also be installed in the bulkhead portion (142) of the embodiments illustrated in Figs. 2 to 7.

Meanwhile, the protrusion (155) may have a circular or angular cross-section perpendicular to the direction in which it protrudes from the base (152). For example, the protrusion (155) may have various shapes such as a cylinder, a frusto-conical shape, a prismatic shape, a pyramidal shape, a hemispherical shape, etc., and it is also possible for various shapes of protrusions (155) to be formed on the cooling plate (150). At this time, in order to facilitate the manufacture of the thermoelectric element (141) installed in the protrusion (155), the protrusion (155) on which the thermoelectric element (141) is installed may have a columnar structure such as a cylinder or a prismatic column, as illustrated in FIGS. 6 and 7. In addition, in order to facilitate the manufacture of the thermoelectric element (141), it may have a square prism structure, as illustrated in FIG. 7.

In addition, the first heat transfer member (145) is arranged between the thermoelectric element (141) and the protrusions (154, 155) so that heat transferred from the module housing (120) to the thermoelectric element (141) can be easily discharged to the outside through the protrusions (154, 155) via the first heat transfer member (145).

The first heat transfer member (145) may be made of a material having thermal conductivity and adhesiveness to ensure good heat transfer and to allow the thermoelectric element (141) to be installed in the sunken space of the protrusion (154, 155). For example, the first heat transfer member (145) may be configured to include at least some of thermal grease, thermal adhesive, thermal conductive epoxy, and heat dissipation pad, but is not limited thereto. In addition, in the form of a pad It can be placed, applied in a liquid or gel state.

Referring to FIG. 3 and FIG. 10, heat generated in the battery cell (111) is transferred to the module housing (120) through the heat transfer member (TA), and the heat transferred to the module housing (120) is transferred to the protrusions (154, 155) that are in thermal contact with the housing body (121) of the module housing (120). At this time, when the thermoelectric element (141) is driven so that the first part (142) of the thermoelectric element (141) becomes a low-temperature part and the second part (143) becomes a high-temperature part, the heat transferred to the protrusions (154, 155) is absorbed by the first part (heat absorption part) (142) of the thermoelectric element (141) and then released to the outside through the second part (heat dissipation part) (143). Since the second part (143) is in contact with the first heat transfer member (145), heat is dissipated through the first heat transfer member (145), and as described later with reference to FIGS. 11 and 12, heat can be released to the outside of the battery pack (200) through the second heat transfer member (230) and the lower housing (211) of the pack housing (210). Meanwhile, FIG. 10 illustrates a configuration in which the first heat transfer member (145) is installed only in the second part (143) in which heat is dissipated, but as illustrated in FIG. 8, it is also possible for the first heat transfer member (145) to be installed in both the first part (142) and the second part (143).

In this way, by dissipating heat generated inside the module housing (120) to the outside through the thermoelectric element (141) installed on the outer surface of the cooling plate (150) and the first heat transfer member (145) in contact with the thermoelectric element (141), the temperature deviation of the cell stack (110) (or battery cell) and the uneven heat dissipation of the battery cell (111) depending on the position installed in the battery module (100) can be reduced, and the overall cooling performance of the battery module (100) can be improved. In particular, by arranging a plurality of thermoelectric elements (141) in an area adjacent to the outlet (OUT) where the temperature of the cell stack (110) and/or the coolant is high, or arranging them more densely than in other areas, the heat dissipation performance in the area where the temperature of the cell stack (110) and/or the coolant is high can be improved.

In addition, referring to FIG. 10, the cooling plate (150) can form a wire installation groove (H) for installing a wire (W) that supplies power to the thermoelectric element (141) in the protrusion (154, 155) or an area adjacent to the protrusion (154, 155). This wire installation groove (H) can be formed along the wiring structure of the wire (W). By forming the wire installation groove (H) in this way, the wiring work of the thermoelectric element (141) becomes easy.

Next, a battery pack (200) according to one embodiment of the present invention will be described with reference to FIGS. 11 to 14.

FIG. 11 is a cross-sectional view of a battery pack (200) according to one embodiment of the present invention, FIG. 12 is a cross-sectional view showing a modified example of the battery pack (200) shown in FIG. 11, FIG. 13 is a cross-sectional view of a battery pack (200) according to another embodiment of the present invention, and FIG. 14 is a cross-sectional view of a battery pack (200) according to another embodiment of the present invention.

The battery pack (200) illustrated in FIGS. 11 to 13 is configured to include a battery module (100) and a pack housing (210) that accommodates a plurality of battery modules (100) therein. In contrast, the battery pack (200) illustrated in FIG. 14 has a structure in which the cell stack (110) is installed directly in the pack housing (210) without forming the battery module (100). That is, the battery pack (200) illustrated in FIG. 14 has a structure (Cell to Pack structure) in which the cell stack (110) is installed directly in the pack housing (210) without being installed inside the module housing (120).

The pack housing (210) is formed by combining a lower housing (211) and an upper housing (215) to form a space for accommodating a plurality of battery modules (100) therein. The lower housing (211) may have a box structure with an open upper side, including a lower plate (212) and a side play (213) extending upward along an edge of the lower plate (212).

The embodiment of the battery pack (200) illustrated in FIG. 11 illustrates an example in which the battery module (100) illustrated in FIG. 3 is installed, and the embodiment of the battery pack (200) illustrated in FIG. 12 illustrates an example in which the battery module (100) illustrated in FIG. 5 is installed.

In addition, a second heat transfer member (230) may be arranged between the lower surface of the cooling plate (150) constituting the cooling unit (140), that is, the outer surface of the base portion (152), and the inner surface of the pack housing (210) to facilitate heat transfer from the cooling unit (140) to the pack housing (210). Accordingly, heat transferred from the module housing (120) to the protrusions (154, 155) is absorbed by the first part (heat absorption part) (142) of the thermoelectric element (141), and then transferred to the second heat transfer member (230) through the second part (heat dissipation part) (143) and the first heat transfer member (145), and finally released to the outside of the battery pack (200) through the lower housing (211) of the pack housing (210).

At this time, the second heat transfer member (230) may have a thickness thicker than the first heat transfer member (145) so that heat can be easily dissipated through a wide area of the pack housing (210) after sufficient heat is absorbed through the second heat transfer member (230).

In addition, in order to facilitate heat transfer from the first heat transfer member (145) to the second heat transfer member (230), the first heat transfer member (145) and the second heat transfer member (230) may have a structure in which they are connected to each other.

The second heat transfer member (230) may be configured to include at least some of thermal grease, thermal adhesive, thermal conductive epoxy, and heat dissipation pad, but is not limited thereto. In addition, the second heat transfer member (230) may be formed in the form of a pad between the outer surface of the base portion (152) and the inner surface of the pack housing (210). It can be placed, applied in a liquid or gel state.

Meanwhile, the embodiment of the battery pack (200) illustrated in FIG. 13 is the same as the embodiments of FIGS. 11 and 12 in that the battery module (100) is provided inside the pack housing (210), but is different in that it additionally includes a pack cooling unit (240) installed inside the pack housing (210) for cooling the battery module (100). That is, the embodiment of the battery pack (200) illustrated in FIG. 13 does not include a cooling unit in the battery module (100) installed inside the pack housing (210), but cools the battery module (100) through the pack cooling unit (240) installed in the pack housing (210).

Since the cooling unit (140) is not provided in the battery module (100) and cooling can be performed through the pack cooling unit (240), the pack cooling unit (240) may be configured between the battery module (100) and the pack housing (210). However, as illustrated in FIG. 14, the cell stack (110) may be mounted on the pack housing (210) without configuring the battery module, and the pack cooling unit (240) may be configured to be positioned at the bottom of the pack housing (210). In this case, the cell stack (110) may be mounted on the pack housing (210) through a heat transfer member (TA).

The pack cooling unit (240) may include a cooling plate (250) in which a flow path space (253) for refrigerant flow is formed, a thermoelectric element (241) installed on the outer surface of the cooling plate (250), and a first heat transfer member (245) arranged between the thermoelectric element (241) and the outer surface of the cooling plate (250). In addition, the cooling plate (250) may include a base portion (252), and a protrusion portion (255) protruding from the base portion (252) toward the cell stack (110) to form a recessed space on the outer surface.

The base portion (252) may correspond to the lower surface of the body portion (251). The body portion (251) of the cooling plate (250) may be configured by joining a first body (251a) and a second body (251b) composed of two upper and lower plates, and may have a structure in which a flow path space (253) is formed between the first body (251a) and the second body (251b). The first body (251a) of the cooling plate (250) may have a shape corresponding to the body portion (151) of the cooling plate (150) described with reference to FIGS. 2 to 4 and FIGS. 6 to 8. For example, the first body (251a) may be formed with a base portion (252), a flow path space (253), and a protrusion (255), and the protrusion (255) may include a protrusion and a partition wall. To avoid unnecessary duplication, a detailed description of the first body (251a) will be omitted and replaced with the description of the body portion (151) described above.

In addition, the second body (251b) may be configured to cover the first body (251a) to form a flow path space (153) between it and the first body (251a). A heat transfer member (TM) made of a heat transfer material such as silicon may be placed between the lower surface of the module housing (120) and the upper surface of the second body (251b) to improve thermal conductivity.

In the case of the thermoelectric element (241) and the first heat transfer member (245), the configuration may correspond to the thermoelectric element (141) and the first heat transfer member (145) provided in the battery module (100) described with reference to FIGS. 1 to 10. In order to avoid unnecessary duplication, a detailed description of the thermoelectric element (241) and the first heat transfer member (245) will be omitted and replaced with the description of the thermoelectric element (141) and the first heat transfer member (145) described above.

In addition, a second heat transfer member (230) may be arranged between the outer surface of the base portion (252) of the lower surface of the cooling plate (250) constituting the pack cooling member (240) and the inner surface of the pack housing (210) so that heat transfer from the cooling member (240) to the pack housing (210) can be easily performed. Accordingly, heat transferred from the module housing (120) to the protrusion (255) is absorbed by the first part (heat absorption part) (242) of the thermoelectric element (241), and then transferred to the second heat transfer member (230) through the second part (heat dissipation part) (243) and the first heat transfer member (245), and finally can be released to the outside of the battery pack (200) through the lower housing (211) of the pack housing (210).

At this time, the second heat transfer member (230) may have a thickness thicker than the first heat transfer member (245) so that heat can be easily released through a wide area of the pack housing (210) after sufficient heat is absorbed through the second heat transfer member (230).

In addition, in order to facilitate heat transfer from the first heat transfer member (245) to the second heat transfer member (230), the first heat transfer member (245) and the second heat transfer member (230) may have a structure in which they are connected to each other.

Meanwhile, the battery pack (200) according to one embodiment of the present invention may additionally include a control unit (not shown) that controls the operation of the thermoelectric elements (141, 241). The control unit may correspond to a battery management system (BMS) provided in a typical battery pack (200). The thermoelectric elements (141, 241) may be connected to a low-voltage line of a vehicle or energy storage system (ESS) in which the battery pack (200) is installed to receive power.

The control unit can perform control to switch the polarity of the power applied to the thermoelectric element (141, 241) according to the temperature of the cell stack (110) so as to enable stable operation of the battery module (100) in response to winter or an environment with low external temperature (e.g., polar regions). That is, when the external temperature or the temperature of the battery cell (111) is low, power having a polarity opposite to that applied to the thermoelectric element (141, 241) when performing heat dissipation of the battery module (100) is applied to the thermoelectric element (141, 241) to increase the temperature of the battery cell (111), thereby enabling stable operation of the battery module (100).

In addition, the control unit can individually control the operation of at least some of the plurality of thermoelectric elements (141, 241). That is, by controlling the on/off of each thermoelectric element (141, 241) through the control unit, when cooling through the thermoelectric element (141, 241) is required, each thermoelectric element (141, 241) or a group of thermoelectric elements (141, 241) can be selectively operated. In addition, when the cooling efficiency is reduced in some area among the cell stack (110) or when a temperature increase is required, a thermoelectric element equivalent to the area can be selectively operated. In order to perform such control, the temperature measured by a temperature sensor (not shown) provided inside the battery module (200) can be utilized.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations are possible within a scope that does not depart from the technical spirit of the present invention described in the claims.

For example, the above-described embodiments may be implemented by deleting some of the components, and the embodiments may be implemented in combination with each other.

100... battery module 110... cell stack
111... Battery cell 111a... Electrode lead
120... module housing 121... housing body
122... Lower plate 123... Side plate
125... Housing cover 126... End plate
126a... through hole 130... insulation cover
132... Connection terminal 140... Cooling unit
141... Thermoelectric element 142... Part 1
143... Second part 145... First heat transfer member
150... Cooling plate 151... Body
151a... First body 151b... Second body
152... Base section 153... Euro space
154... Protrusion (bulkhead) 155... Protrusion (protrusion)
200... Battery Pack 210... Pack Housing
211... Lower housing 212... Lower plate
213... Side plate 215... Upper housing
230... Second heat transfer member 240... Pack cooling unit
241... Thermoelectric element 242... Part 1
243... Second part 245... First heat transfer member
250... Cooling plate 251... Body
251a... first body 251b... second body
252... Base section 253... Euro space
255... Protrusion (protrusion) H... Wire installation groove
HA... high temperature area IN... inlet
L... length of the euro space
L1... Length from the inlet to the thermoelectric element installation location
OUT... outlet Q... heat flow
TA, TM... heat transfer member W... wire

Claims (19)

A cell stack formed by stacking multiple battery cells;
a module housing accommodating the cell stack therein; and
A cooling unit having a cooling plate having a flow path formed therein for cooling the above module housing and a thermoelectric element installed on the outer surface of the cooling plate;
Includes,
The cooling plate includes a base portion and a protrusion that protrudes from the base portion toward the cell stack to form a sunken space,
The above thermoelectric element is a battery module installed in the sunken space of the above protrusion. In the first paragraph,
A battery module having a structure that supports the module housing, wherein the protrusion is above. In the first paragraph,
The above protrusion is a battery module in thermal contact with the module housing. In the first paragraph,
A battery module in which the thermoelectric element is asymmetrically installed on the outer surface of the base portion. In the first paragraph,
The above protrusion includes a plurality of protrusions spaced apart from each other on the base portion,
A battery module in which the thermoelectric element is installed on at least a portion of the protrusion. In paragraph 5,
A battery module in which the above protrusion has a circular or square cross-section perpendicular to the direction in which it protrudes from the base. In paragraph 5,
A battery module in which the thermoelectric elements are installed more on the outer surface of the base portion corresponding to the area where the refrigerant flows out of the flow path space than on the outer surface of the base portion corresponding to the area where the refrigerant flows into the flow path space. In the first paragraph,
The above protrusion includes a baffle portion having a shape extending along the flow direction of the refrigerant to form a sunken space by protruding from the base portion toward the cell stack and guide the flow of the refrigerant.
A battery module in which the thermoelectric element is installed in at least a portion of the sunken space of the bulkhead. In paragraph 8,
The above thermoelectric element is a battery module installed in an area where the coolant flows outward from the cavity space among the sunken spaces of the bulkhead. In the first paragraph,
The above thermoelectric element forms a temperature difference between the first and second parts that are opposed to each other according to the power supply,
A battery module in which a first heat transfer member is positioned between at least one of the first part and the second part and the protrusion. In the first paragraph,
A battery module in which the cooling plate has a wire installation groove formed in the protrusion or an area adjacent to the protrusion for installing a wire that supplies power to the thermoelectric element. In the first paragraph,
A battery module in which the cooling plate includes a first body having the base portion and the protrusion portion formed therein, and a second body coupled to the first body to form the flow path space between the first body and the first body.
A cell stack formed by stacking multiple battery cells;
a pack housing accommodating the cell stack therein; and
A pack cooling unit installed in the pack housing to cool the cell stack;
Includes,
The above pack cooling unit includes a cooling plate having a flow path space formed through which a refrigerant flows, and a thermoelectric element installed on the outer surface of the cooling plate.
The cooling plate includes a base portion and a protrusion that protrudes from the base portion toward the cell stack to form a sunken space,
The above thermoelectric element is a battery pack installed in the sunken space of the above protrusion. In Article 13,
A battery pack wherein the cell stack is mounted on the pack housing through a heat transfer member, and the pack cooling unit is located at the lower portion of the pack housing. In Article 13,
A battery pack further comprising a module housing that accommodates the cell stack therein, wherein the pack cooling unit is located between the module housing and the pack housing. In Article 15,
A first heat transfer member is positioned between the thermoelectric element and the protrusion,
A second heat transfer member is positioned between the outer surface of the base portion and the pack housing,
A battery pack wherein the thickness of the second heat transfer member has a value greater than the thickness of the first heat transfer member. In Article 16,
A battery pack in which the first heat transfer member and the second heat transfer member are connected to each other. In Article 14 or 15,
A control unit that controls the operation of the above thermoelectric element;
In addition, it includes:
The above thermoelectric element is connected to a low voltage line and supplied with power,
A battery pack in which the control unit can perform control to switch the polarity of the power applied to the thermoelectric element according to the temperature of the cell stack. In Article 18,
A battery pack in which the control unit can individually control the operation of at least some of the plurality of thermoelectric elements.