Secondary battery and battery module containing this

Abstract

Secondary battery (10), comprising: a cell body element (11) in which an electrode arrangement (12) is housed; and a heat-conducting element (30) arranged between the cell body element (11) and a cooling plate element (21) to form a heat path for transferring heat from the cell body element (11), wherein the cell body element (11) has a bag shape, wherein the heat-conducting element (30) is in contact with the cooling plate element (21), and wherein a contact area (A2) of the cooling plate element (21) and the heat-conducting element (30) is smaller than a cross-sectional area (A1) of the cell body element (11) parallel to a thickness direction (X) of the electrode arrangement (12), wherein the cell body element (11) comprises: a tapered portion (11a) whose cross-sectional area (A1) decreases parallel to the thickness direction (X) toward an end of the tapered portion (11a) adjacent to the cooling plate member (21).

Description

BACKGROUND1. AREA

[0001] The present disclosure relates to a secondary battery and a battery module including the same. 2. DESCRIPTION OF THE STATE OF THE ART

[0002] With the increasing demand for mobile devices, electric vehicles, and the like, as well as the development of related technologies, the demand for secondary batteries as a power source has increased rapidly. A secondary battery can be repeatedly charged and discharged because the conversion between chemical energy and electrical energy in a secondary battery is reversible. A cell body element of a secondary battery refers to a case with a laminated film for protecting an electrode assembly consisting of an anode, cathode, separator film, and electrolyte solution, which are the main components of a secondary battery.

[0003] However, such an electrode arrangement generates heat during the charging and discharging process, and a temperature rise due to the generated heat deteriorates the performance of the secondary battery.

[0004] Accordingly, the cell body member in which the electrode assembly is housed is arranged such that a cooling plate member for cooling, a heat sink, and the like are connected thereto.

[0005] However, there may be a problem that a form of cell body element that is cooled in conjunction with a conventional cold plate element and heat sink and a form of a heat-conducting element that can mediate between the cell body element and the cold plate element do not achieve optimal cooling performance.

[0006] In this context, the problem may also arise that production costs increase due to the use of expensive heat-conducting elements, sections of which are not used for heat conduction.

[0007] Therefore, there is an increasing demand for a secondary battery and a battery module containing it to solve the above-mentioned problems.

[0008] US 2019 / 0 393 570 A1 discloses a secondary battery in the form of a container comprising a cell body member housing an electrode assembly, and a member that generates clamping force upon insertion of the cell body member into the container, and that is in contact with the cooling plate member and can form a heat path. US 2012 / 0 301 773 A1 discloses a secondary battery comprising a cell body member having a side with a tapered portion toward the top of the cell, and a cover plate that covers and contacts the tapered portion at the top of the cell. SUMMARY

[0009] One aspect of the present invention is to provide a secondary battery capable of achieving optimal cooling performance without wasting cost or material of a heat-conducting member, and a battery module including the same.

[0010] According to the present invention, a secondary battery includes a cell body member housing an electrode assembly and provided adjacent to a cooling plate member; and a heat-conducting member provided between the cell body member and the cooling plate member to form a heat path for transferring heat from the cell body member, and provided to contact the cooling plate member with a contact area smaller than a cross-sectional area of at least a portion of the cell body member in a thickness direction. The cell body member has a bag shape and includes a tapered portion whose cross-sectional area decreases parallel to the thickness direction toward an end of the tapered portion adjacent to the cooling plate member.

[0011] In this case, an effective contact area ratio, a percentile ratio of a contact area of the cooling plate member and the heat-conducting member, may be 30% to 70% with respect to a cross-sectional area of the cell body member of a secondary battery parallel to the thickness direction.

[0012] In particular, an effective contact area ratio is defined as the percentile ratio of the contact area of the cooling plate member and the heat-conducting member to the cross-sectional area of the cell body member of the secondary battery parallel to the thickness direction of the electrode assembly. According to one embodiment, the effective contact area ratio may be 35% to 50%.

[0013] More specifically, according to an embodiment, a portion of the cell body member of the secondary battery adjacent to the cooling plate member may include a contact surface portion provided at one end of the tapered portion and forming a smallest cross-sectional area parallel to the thickness direction.

[0014] In addition, according to one embodiment, the heat-conducting member of the secondary battery may be in contact with the contact surface portion and formed to have a surface area equal to the surface area of the contact surface portion.

[0015] The heat-conducting member of the secondary battery according to an embodiment may be formed to have a constant thickness until reaching the cooling plate member while having the same cross-sectional area as the contact surface portion.

[0016] The heat-conducting member of the secondary battery according to an embodiment may be in contact with a central portion of one end of the cell body member adjacent to the cooling plate member.

[0017] Furthermore, the cell body member of the secondary battery according to an embodiment may have a thickness percentile ratio with respect to a height of 5% to 25%.

[0018] In particular, the cell body element of the secondary battery according to one embodiment may have a thickness percentile ratio with respect to a height of 7.5% to 10%.

[0019] A battery module according to the present invention includes a cell body member in which an electrode assembly is housed, and a heat-conducting member provided between the cell body member and a cooling plate member; and a casing member that includes the cooling plate member for exchanging heat with the cell body member through the heat-conducting member, and in which a plurality of secondary batteries are housed, wherein the heat-conducting member contacts the cooling plate member with a contact area smaller than a cross-sectional area of at least a portion of the cell body member in a thickness direction. The cell body member has a bag shape and includes a tapered portion whose cross-sectional area decreases parallel to the thickness direction toward an end of the tapered portion adjacent to the cooling plate member.

[0020] The cell body member of the battery module according to an embodiment may include a contact surface portion provided at one end of the tapered portion and forming a smallest cross-sectional area parallel to the thickness direction.

[0021] In this case, the housing element can be provided with the cooling plate element at least in a bottom section. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The foregoing and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a cross-sectional view of a secondary battery of the present disclosure; Fig. 2 is a perspective view of a secondary battery of the present disclosure; Fig. 3 is a diagram showing an overlap of a contact area of a heat-conducting element and a maximum cross-sectional area of a cell body element of Fig. 2 presents a comparison; Fig. 4 is a cross-sectional view of another embodiment of a cell body member of a secondary battery; Fig. 5A and Fig. 5B are diagrams showing the optimum thermal resistance of a secondary battery while maintaining an optimum temperature of the secondary battery; Fig. 6 is a diagram illustrating an effective area ratio of a secondary battery cell for the optimum thermal resistance of a secondary battery; Fig. 7 is a diagram illustrating a thickness percentile ratio with respect to the height of a secondary battery cell for the optimum thermal resistance of a secondary battery; and Fig. 8 is a perspective view of a battery module of the present disclosure in a disassembled state. DETAILED DESCRIPTION

[0023] Embodiments of the present invention will now be described with reference to the accompanying drawings. The present invention is not limited to the embodiments, and it should be understood that changes may be made without departing from the scope of the present invention, which is defined by the appended independent claims. Shapes and sizes of elements in the drawings may be exaggerated for clarity of description.

[0024] Furthermore, an expression used in the singular also includes the plural expression, unless the context clearly indicates a different meaning. Identical or corresponding elements are given the same reference numbers.

[0025] The present invention relates to a secondary battery 10 and a battery module including the same, which can achieve optimal cooling performance without wasting cost or material of a heat-conducting member 30.

[0026] In other words, it is proposed to design the secondary battery 10 and the battery module containing it so as to minimize the use of the heat-conducting member 30 while maintaining the cooling effect and cooling performance compared to a conventional secondary battery and a battery module containing it.

[0027] With reference to the attached drawings, Fig. 1 is a cross-sectional view of the secondary battery 10 of the present disclosure and Fig. 2 is a perspective view of the secondary battery 10 of the present disclosure, while Fig. 3 is a diagram showing an overlap of a contact area A2 of a heat-conducting element 30 and a maximum cross-sectional area A1 of a cell body element 11 of Fig. 2 comparatively.

[0028] Fig. 4 is a cross-sectional view of another embodiment of the cell body member 11 of the secondary battery 10.

[0029] With reference to Fig. 1 to Fig. 4, a secondary battery 10 includes a cell body member 11 in which an electrode assembly 12 is housed, and a heat-conducting member 30 provided between the cell body member 11 and the cooling plate member 21 to form a heat path for transferring heat from the cell body member 11, and provided to be in contact with the cooling plate member 21 with a contact area A2 smaller than a cross-sectional area A1 of at least a portion of the cell body member 11 in the thickness direction X of the electrode assembly 12. Fig. The electrode assembly 12 shown in Figure 1 may have a generally rectangular prism shape extending in a thickness direction X, a height direction Y, and a length direction Z.

[0030] In other words, an amount of a heat-conducting material is reduced by making the contact area A2 of the heat-conducting member 30 smaller than a maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X, compared to a case where the contact area A2 is formed equal to the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X.

[0031] The cell body member 11, which is provided with the electrode assembly 12 accommodated therein, can serve to protect the latter. That is, the cell body member 11 can provide an interior space for accommodating the electrode assembly 12 comprising the anode, cathode, separator film, electrolyte solution, and the like, which is then sealed.

[0032] The cell body member 11 may be provided as a bag-shaped member (according to the invention) or a can-shaped member (not according to the invention). The bag-shaped member is a shape in which the electrode assembly 12 is housed on three surfaces, that is, a member configured to be in the shape in which the electrode assembly 12, while housed inside, overlaps and adheres to the three surfaces of an upper surface and both side surfaces, mainly excluding a lower surface.The can-shaped member has a shape in which the electrode assembly 12 is sealed and housed on one surface, that is, a member configured to be mainly in the shape in which the electrode assembly 12, while housed inside, overlaps and adheres to the one surface, substantially excluding the three surfaces of the bottom surface and the two side surfaces.

[0033] The cell body member 11 is fabricated to be coupled to the cell conductive member 30, which has a contact area A2 with the cooling plate member 21 that is smaller than a maximum cross-sectional area A1 of the cell body member 11 in the thickness direction X, and is then provided to be in contact with the cooling plate member 21. This can facilitate a reduction in the manufacturing cost and time of a battery module by enabling easy installation of a plurality of secondary batteries 10 including the cell body member 11 and the electrode assembly 12 into a housing member 20 including the cooling plate member 21.

[0034] Further, in order to manufacture the heat-conducting member 30 so that the heat-conducting member 30, which is formed to have a contact area A2 with the cooling plate member 21 that is smaller than a maximum cross-sectional area A1 of the cell body member 11 in a thickness direction X, can be coupled to the cell body member 11, followed by being fixed to the cooling plate member 21, the cell body member 11 may include a tapered portion 11a and a contact surface portion 11b.

[0035] That is, the cell body member 11 of the secondary battery 10 according to the invention includes a tapered portion 11a in the shape in which a cross-sectional area A1 parallel to the thickness direction X decreases toward one end of the tapered portion in contact with the cooling plate member 21; and may include a contact surface portion 11b provided at one end of the tapered portion 11a and forming a smallest cross-sectional area A1 parallel to the thickness direction X.

[0036] As described above, the tapered portion 11a, which is a portion where the cross-sectional area A1 of the cell body member 11 is formed to decrease parallel to the thickness direction compared to the maximum cross-sectional area A1 of the cell body member 11, is formed with the contact surface portion 11b at its end. That is, the tapered portion 11a has inclined side surfaces and a flat end where the contact surface portion 11b is formed.

[0037] As explained above, the contact area A2, which is smaller than the maximum cross-sectional area A1 parallel to the thickness direction X of the cell body portion 11, can facilitate the formation of the heat-conducting member 30 in contact with the cooling plate member 21.

[0038] That is, even in the case where the heat-conducting member 30 is formed by a process of spraying or painting a heat-conducting material on the contact surface portion 11b, the contact surface portion 11b is still smaller than the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X. As such, the heat-conducting member 30 formed to correspond to a surface area of the contact surface portion 11b may also be formed to be smaller than the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X, thereby facilitating the formation of the heat-conducting member 30.

[0039] In addition, as described above, the one end of the cell body member 11 in which the contact surface portion 11b is formed may be flat as shown in Fig. 1. As shown in Fig. However, as shown in Figure 4, one end may be formed in the shape of a recess 11c. In this case, the contact surface portion 11b in which the heat-conducting member 30 is formed may be a portion of the cell body member 11 excluding the recess 11c.

[0040] The electrode assembly 12 as a secondary battery 10 is a battery capable of repeated charging and discharging due to the reversible conversion between chemical energy and electrical energy. Any conventionally used secondary battery 10 can be configured as the electrode assembly 12 without any restrictions. For example, the electrode assembly 12 may be configured in a manner in which a cathode and an anode are cross-stacked so that the surfaces coated with the respective electrode active materials face each other, while a separator film is provided therebetween as a boundary.

[0041] The electrode assembly 12 contains an electrolyte solution and is housed in the cell body element 11 to be used. The electrolyte solution may contain an organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), or the like, together with a lithium salt such as LiPF6, LiBF4, or the like. Furthermore, the electrolyte solution may be liquid, solid, or gel-like.

[0042] The cooling plate member 21 serves to release heat generated in the electrode assembly 12 housed in the cell body member 11. For this purpose, the cooling plate member 21 can absorb the heat from the cell body member 11, which is transferred through the heat-conducting member 30 or the like, and dissipates the heat to an external heat sink S or the like, while being in contact with the external heat sink S, so that the cell body member 11 in which the electrode assembly 12 is housed is cooled.

[0043] The heat-conducting element 30 serves to dissipate the heat generated during charging and discharging of the electrode assembly. For this purpose, the heat-conducting element 30 can be provided between the cell body element 11, in which the electrode assembly 12 is housed, and the cooling plate element 21 in contact with the heat sink S.

[0044] The heat-conducting member 30 can be made smaller by making the contact area A2 with the cooling plate member 21 smaller than the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X, compared to a case where the contact area A2 is made equal to the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X.

[0045] In this case, the contact area A2 formed by the heat-conducting member 30 can be proposed by adjusting its percentile ratio with respect to the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X, which will be described below with reference to Fig. 5 and Fig. 6 is described.

[0046] In addition, the heat-conducting member 30 of the secondary battery 10 according to an embodiment of the present disclosure may be in contact with the contact surface portion 11b and formed to have the same surface as the contact surface portion 11b.

[0047] That is, the heat-conducting member 30 may be formed on the contact surface portion 11b by spraying or painting a heat-conducting material. In this case, the heat-conducting member 30 may be formed to have the same surface area as the contact surface portion 11b. Since the contact surface portion 11b is smaller than the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X, the heat-conducting member 30 formed to correspond to the surface of the contact surface portion 11b may be formed to be smaller than the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X.

[0048] The heat-conducting member 30 can be manufactured to be coupled to the cell body member 11, which facilitates the installation of a plurality of secondary batteries 10 into the housing member 20, thereby reducing the manufacturing cost and time of a battery module.

[0049] Furthermore, the heat-conducting member 30 of the secondary battery 10 according to an embodiment is formed to have a constant thickness t2 until it reaches the cooling plate member 21 while having the same cross-sectional area A1 as the contact surface portion 11b.

[0050] As described above, when the thickness t2 of the heat-conducting member 30 is constant, the use of the heat-conducting material constituting the heat-conducting member 30 can be minimized while maximally securing a path for heat exchange between the cell body member 11 and the cooling plate member 21.

[0051] That is, when the heat-conducting member 30 has a tapered shape in which the cross-sectional area A1 varies parallel to the thickness direction X, a maximum cross-sectional area A1 and a minimum cross-sectional area A1 are formed parallel to the thickness direction X. In this case, the heat exchange path lies in the minimum cross-sectional area A1, and accordingly, a portion representing a difference between the maximum cross-sectional area A1 and the minimum cross-sectional area A1 is wasted, resulting in consumption of heat-conducting material that serves no purpose. In this regard, the present disclosure is configured to avoid such waste by forming the heat-conducting member 30 to be constant parallel to the thickness direction X.

[0052] The heat-conducting member 30 of the secondary battery 10 according to an embodiment is in contact with a central portion of one end of the cell body portion 11 adjacent to the cooling plate member 21.

[0053] In other words, when the cell body member 11 forms a constant cross-sectional area A1 parallel to the thickness direction X, or the end of the cell body member 11 adjacent to the cooling plate member 21 has a larger cross-sectional area A1 compared to the other end, the cell body member 11 is formed to have a smaller cross-sectional area A1 compared to the end of the cell body member 11. This is the case where the heat-conducting member 30 is formed in the central portion of the end of the cell body member 11.

[0054] In such a case, the heat conduction speed can be increased compared to a case where the heat-conducting member 30 is oriented toward one side from the end of the cell body member 11. In other words, heat is evenly dissipated in a radiation direction from the central portion of the end of the cell body member 11, whereby the heat conduction speed can be increased compared to the case where the heat-conducting member 30 is oriented toward one side.

[0055] Fig. 5A and Fig. 5B are diagrams describing the optimum thermal resistance of a secondary battery 10 while maintaining an optimum temperature of the secondary battery, and Fig. 6 is a diagram illustrating an effective area ratio of a secondary battery cell 10 for the optimum thermal resistance of a secondary battery, while Fig. 7 is a diagram illustrating a thickness t1 percentile ratio with respect to the height h of a secondary battery cell 10 for the optimum thermal resistance of a secondary battery 10.

[0056] The diagrams of the Fig. 5 to 7 illustrate a case where a secondary battery cell 10 having a thermal conductivity of 5 W / mK to 30 W / mK is used.

[0057] With reference to the Fig. 5 to 7, according to an embodiment, an effective contact area ratio, which is a percentile ratio of a contact area A2 of the cooling plate member 21 and the heat-conducting member 30, may be 30% to 70% with respect to a cross-sectional area A1 of at least a portion of the cell body member 11 of the secondary battery 10.

[0058] That is, the heat-conducting member 30 can be configured with a reduced size by forming the contact area A2 with the cooling plate member 21 smaller than the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X, compared with a case where the contact area A2 is formed to be equal to the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X. In this case, the cooling performance can be maintained by adjusting the percentile ratio of the contact area A2 formed by the heat-conducting member 30 with respect to the maximum cross-sectional area A1 of the cell body member 11 parallel to the thickness direction X.

[0059] The thermal resistance data to maintain cooling performance are in Fig. 5A and Fig. 5B. That is, the thermal resistance for maintaining a temperature below about 60°C, which is an overheating limit of a conventional secondary battery 10, is about 2.0 K / W, and the effective area ratio is defined based thereon.

[0060] In this case, the thermal resistance is determined by dividing a temperature rise K of the secondary battery 10 by the heat generation W of the secondary battery 10. In other words, the thermal resistance is a value representing the temperature rise corresponding to the heat generation of the secondary battery 10 and is used as an index indicating the cooling performance of the secondary battery 10.

[0061] Furthermore, to determine the reference thermal resistance, only the thermal resistance is changed, while the other conditions, which may be variable, are fixed to derive the overheating temperature of the secondary battery 10 as the resultant value.

[0062] That is, the thermal conductivity of the cell of the secondary battery 10 was limited to 5 W / mK to 30 W / mK, and a shape of the cell body member 11 was defined as a bag-like member in which the electrode assembly 12 is sealed on three receiving surfaces, or a can-like member in which the electrode assembly 12 is sealed on one receiving surface.

[0063] Additionally, heat generation (RI 2 ) is used to calculate the thermal resistance 10W, which indicates a case where the input current (I) is 100A and the resistance (R) of the secondary battery cell is 10 1 mΩ.

[0064] A lower surface of the cell body member 11 of the secondary battery cell 10, which exchanges heat with the cooling plate member 21, was set as the lowest temperature measurement point, and an upper surface of the cell body member 11 was set as the highest temperature measurement point to measure the highest and lowest temperatures, and a difference therebetween was used as a temperature increase to calculate the thermal resistance.

[0065] As explained above, when determining the effective contact area fraction at 2.0 K / W thermal resistance, the effective contact area fraction of the cell can be adjusted to be as shown in Fig. 6, has a lower limit of at least 30%. As in Fig. As shown in Figure 6, the thermal resistance does not produce a significant change when the effective contact area fraction of the cell exceeds 70%, which makes it possible to establish an upper limit of the effective contact area fraction.

[0066] In particular, according to one embodiment, an effective contact area ratio, which is a percentile ratio of the contact area A2 of the cooling plate member 21 and the heat-conducting member 30, may be 35% to 50% with respect to the cross-sectional area A1 of at least a portion of the cell body member 11 of the secondary battery 10.

[0067] The further specified effective contact area fraction as stated above results from the setting of 35% as the lower limit - the effective contact area fraction corresponding to about 1.8 K / W, ie, an average thermal resistance between about 2.0 K / W, a thermal resistance at a lower limit of 30%, and about 1.3 K / W, a thermal resistance at an upper limit of 70% - and 50% as the upper limit - the effective contact area fraction corresponding to about 1.5 K / W.

[0068] The lower limit of the effective contact area fraction of 35%, further specified as described above, is kept at a certain distance from a thermal resistance threshold of 2 K / W to ensure a stable temperature rise range. The upper limit of 50% can be used to further reduce the area of the thermally conductive member 30 while avoiding a range where the thermal resistance does not produce a significant change.

[0069] It is understood that the effective contact area ratio is identical to a percentile ratio of a length t2 of the cooling plate member 21 and the heat-conducting member 30 parallel to the thickness direction X with respect to a length t1 of at least the portion of the cell body member 11 parallel to the thickness direction X, based on the assumption that the cell body member 11 and the heat-conducting member 30 have the same length.

[0070] The cell body member 11 of the secondary battery 10 according to an embodiment may have a percentage of a thickness t1 of 5% to 25% with respect to a height h.

[0071] This is a specified cell body element 11 for maintaining the temperature at 60°C or less, the overheating limit of a conventional secondary battery 10.

[0072] In other words, the percentile ratio of the thickness t1 with respect to the height h of the cell body member 11 is defined so that the thermal resistance for maintaining a temperature of about 60°C or lower, the overheating limit of a conventional secondary battery 10, is kept at about 2.0 K / W.

[0073] As described above, the percentile ratio of the thickness t1 with respect to the height h of the cell body element 11 is defined as the thermal resistance of 2.0 K / W, the percentile ratio of the thickness t1 with respect to the height h of the cell body element 11 can be as shown in Fig. 7, have a lower limit of 5% or more. As in Fig. 7, the thermal resistance does not produce a significant change when the percentile ratio of the thickness t1 with respect to the height h exceeds 25%, which makes it possible to establish an upper limit of the percentile ratio of the thickness t1 with respect to the height h.

[0074] In particular, according to one embodiment, the cell body member 11 of the secondary battery 10 may have a percentage of a thickness t1 of 7.5% to 10% with respect to the height h.

[0075] The further specified percentage of a thickness t1 with respect to a height h as stated above results from the setting 7.5% as the lower limit - the percentage of a thickness t1 with respect to a height h corresponding to about 1.5 K / W, ie, an average thermal resistance between about 2.0 K / W, a thermal resistance with a lower limit of 5%, and about 0.5 K / W, a thermal resistance with an upper limit of 25% - and 10% as the upper limit - the percentage of a thickness t1 with respect to a height h corresponding to about 1.0 K / W.

[0076] 7.5%, the lower limit of the percentage of a thickness t1 with respect to a height h, further specified above, is kept at a certain distance from a threshold of 2 K / W of thermal resistance to ensure a stable temperature rise range. The upper limit of 10% can be used to significantly slim down the cell body while avoiding a range where the thermal resistance does not produce a significant change, thereby further increasing the stacking efficiency of a variety of secondary batteries.

[0077] Fig. 8 is a perspective view of a battery module of the present disclosure in a disassembled state. Referring to Fig.8, a battery module according to the present invention includes a cell body member 11 in which an electrode assembly 12 is housed, and a heat-conducting member 30 provided between the cell body member 11 and a cooling plate member 21; and a casing member 20 including the cooling plate member 21 for heat exchange with the cell body member 11 mediated by the heat-conducting member 30, and in which a plurality of secondary batteries 10 are housed. The heat-conducting member 30 is in contact with the cooling plate member 21 with a contact area A2 smaller than a cross-sectional area A1 of at least a portion of the cell body member 11 in a thickness direction X.

[0078] The secondary battery 10 contained in the battery module may include the properties of the secondary battery 10 described above.

[0079] In particular, the secondary battery 10 is configured to include the cell body member 11, which is cooled by the cooling plate member 21 mediated by the heat-conducting member 30. According to the invention, the heat-conducting member 30, which is in contact with the cell body member 11, is in contact with the cooling plate member 21 with a contact area A2 smaller than the cross-sectional area A1 of at least a portion of the cell body member 11 parallel to the thickness direction X, thereby reducing the consumption of a heat-conducting material while maintaining the cooling performance.

[0080] The cell body member 11 of the battery module includes a tapered portion 11a in the shape in which a cross-sectional area A1 parallel to the thickness direction X decreases toward one end of the tapered portion in contact with the cooling plate member 21; and may include a contact surface portion 11b provided at one end of the tapered portion 11a and forming a smallest cross-sectional area A1 parallel to the thickness direction.

[0081] As described above, the tapered portion 11a, which is a portion where the cross-sectional area A1 of the cell body member 11 is formed to decrease parallel to the thickness direction compared to the maximum cross-sectional area A1 of the cell body member 11, is formed with the contact surface portion 11b at its end. That is, the tapered portion 11a has inclined side surfaces and a flat end where the contact surface portion 11b is formed.

[0082] Therefore, the contact area A2, which is smaller than the maximum cross-sectional area A1 parallel to the thickness direction X of the cell body member 11, can facilitate the formation of the heat-conducting member 30 in contact with the cooling plate member 21. This is the same as the secondary battery 10 described above.

[0083] In this case, when a plurality of secondary batteries 10 are installed in the housing member 20, the associated heat-conducting member 30 is also present in a plurality. In one embodiment, adjacent heat-conducting members 30 are spaced apart from each other, forming gaps to allow additional air cooling, thereby further improving the cooling performance.

[0084] Due to the configuration in which multiple secondary batteries are installed, the housing member 20 serves to protect the secondary batteries 10 while dissipating the electrical energy generated by the secondary batteries 10 to the outside or to an external heat sink S for cooling.

[0085] Furthermore, a bottom portion can be formed from the cooling plate element 21, which forms a lower portion of the housing element 20.

[0086] That is, the housing element 20 of the battery module according to another embodiment may include the cooling plate element 21 at least in the bottom portion.

[0087] Additionally, a side wall member 22 constituting a side portion of the case member 20 may be provided at an edge of the cooling plate member 21, and the cooling plate member 21 may be formed to extend to the side wall member 22. A pressing member 24 is provided in an inner side surface of the side wall member 22 to further firmly protect the secondary batteries 10.

[0088] In addition, the housing member 20 may include a cover member 23 provided at an upper end of the side wall member 22 to protect an upper end of the secondary batteries 10.

[0089] The housing element 20 may be provided with additional equipment, such as a bus bar for electrically connecting the secondary battery 10 to the outside or the like.

[0090] According to the above embodiments, the secondary battery and the battery module including the secondary battery are advantageous in that the cooling performance can be optimally achieved without wasting the cost or material of a heat-conducting member.

[0091] The various advantages and advantageous effects of the present disclosure are not limited to those described above. Other advantages and advantageous effects may be understood in light of the present disclosure.

[0092] While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that changes and variations may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

[1] Secondary battery (10), comprising: a cell body element (11) in which an electrode arrangement (12) is housed; and a heat-conducting element (30) arranged between the cell body element (11) and a cooling plate element (21) to form a heat path for transferring heat from the cell body element (11), wherein the cell body element (11) has a bag shape, wherein the heat-conducting element (30) is in contact with the cooling plate element (21), and wherein a contact area (A2) of the cooling plate element (21) and the heat-conducting element (30) is smaller than a cross-sectional area (A1) of the cell body element (11) parallel to a thickness direction (X) of the electrode arrangement (12), wherein the cell body element (11) comprises: a tapered portion (11a) whose cross-sectional area (A1) decreases parallel to the thickness direction (X) toward an end of the tapered portion (11a) adjacent to the cooling plate member (21). [2] The secondary battery (10) according to claim 1, wherein an effective contact area ratio is 30% to 70%. [3] The secondary battery (10) according to claim 1, wherein an effective contact area ratio is 35% to 50%. [4] A secondary battery (10) according to claim 1, wherein the cell body member (11) comprises: a contact surface portion (11b) at one end of the tapered portion (11a) forming a smallest cross-sectional area (A1) of the cell body member (11) parallel to the thickness direction (X). [5] The secondary battery (10) according to claim 4, wherein the heat-conducting member (30) is in contact with the contact surface portion (11b) and has a surface equal to a surface of the contact surface portion (11b). [6] The secondary battery (10) according to claim 5, wherein the heat-conducting member (30) has a constant thickness (t2) until reaching the cooling plate member (21) while having the same cross-sectional area (A1) as the contact surface portion (11b). [7] The secondary battery (10) according to claim 1, wherein the heat-conducting member (30) is in contact with a central portion of an end of the cell body member (11) adjacent to the cooling plate member (21). [8] The secondary battery (10) according to claim 1, wherein the cell body member (11) has a thickness (t1) percentile ratio with respect to a height (h) of 5% to 25%. [9] The secondary battery (10) according to claim 1, wherein the cell body member (11) has a thickness (t1) percentile ratio with respect to a height (h) of 7.5% to 10%. [10] Battery module, comprising: a cell body element (11) in which an electrode assembly (12) is housed, and a heat-conducting element (30) arranged between the cell body element (11) and a cooling plate element (21); and a housing element (20) comprising the cooling plate element (21) for heat exchange with the cell body element (11) mediated by the heat-conducting element (30), and in which a plurality of secondary batteries (10) are accommodated, wherein the cell body element (11) has a bag shape, wherein a contact area (A2) between the heat-conducting element (30) and the cooling plate element (21) is smaller than a cross-sectional area (A1) of the cell body element (11) parallel to the thickness direction (X) of the electrode assembly (12), wherein the cell body element (11) comprises: a tapered portion (11a) whose cross-sectional area (A1) decreases parallel to the thickness direction (X) toward an end of the tapered portion (11a) adjacent to the cooling plate member (21). [11] Battery module according to claim 10, wherein the cell body element (11) comprises: a contact surface portion (11b) at one end of the tapered portion (11a) forming a smallest cross-sectional area (A1) parallel to the thickness direction (X). [12] Battery module according to claim 10, wherein the cooling plate element (21) is arranged at least in a bottom portion of the housing element (20). [13] Secondary battery (10), comprising: a cell body element (11) housing an electrode assembly (12) and comprising a side disposed adjacent to a cooling plate element (21), the side having a tapered portion (11a) terminating in a contact surface portion (11b); and a heat-conducting element (30) provided between and in contact with the contact surface portion (11b) and the cooling plate element (21) for transferring heat generated by the electrode assembly (12) to the cooling plate element (21), wherein the cell body element (11) has a bag shape, wherein the contact surface portion (11b) is smaller than a cross-sectional area (A1) of the electrode arrangement (12) parallel to a thickness direction (X) of the electrode arrangement (12), and wherein the tapered portion (11a) has a shape in which a cross-sectional area (A1) parallel to the thickness direction (X) decreases toward an end of the tapered portion (11a) adjacent to the cooling plate member (21). [14] The secondary battery (10) according to claim 13, wherein an effective contact area ratio is 30% to 70%. [15] The secondary battery (10) according to claim 13, wherein an effective contact area ratio is 35% to 50%. [16] The secondary battery (10) according to claim 13, wherein the contact surface portion (11b) is arranged at one end of the tapered portion (11a) and forms a smallest cross-sectional area (A1) parallel to the thickness direction (X). [17] The secondary battery (10) according to claim 13, wherein the heat-conducting member (30) has a constant thickness (t2) until reaching the cooling plate member (21), while having the same cross-sectional area (A1) as the contact surface portion (11b).

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