TWI667828B - Battery pack - Google Patents

Abstract

In the battery pack, the battery case includes a first side surface formed with at least one abutting portion that protrudes inward. The battery module is placed inside the battery case. The bracket of the battery module is used to fix a plurality of battery cells. The heat dissipation pad covers one of the plurality of electrode sheets of the battery module on one side, and the other side of the battery module contacts the abutting portion of the battery case. A gap is formed between the heat dissipation pad of the battery module and the first side of the battery case, and the abutting portion contacts the heat dissipation pad of the battery module, so that the heat generated by the battery cells passes through the heat dissipation pad, the abutting portion and the battery case. Conducted to the outside.

Description

Battery

The present invention relates to a battery pack, and more particularly to a battery pack capable of conducting a heat conducting flame.

During the charging and discharging process of the battery core, the temperature of the battery core body rises due to the operation of electrons in the filling material. When the temperature continuously rises and exceeds the temperature of the battery working interval, it causes significant impact on the power supply efficiency and battery life of the battery core itself. Influence, so the heat energy generated should be taken away, and the battery core should be dissipated to keep the battery core running at its normal working temperature. The prior art battery heat conduction mode is as follows, including air convection and liquid circulation, and the additional equipment is not only complicated in structure, high in cost, difficult to maintain, and cannot be effectively and uniformly controlled. Chinese Patent Publication No. CN 105826631 A discloses dissipating heat to the battery by using the heat-dissipating block contact conduction, but when the battery core is internally short-circuited to generate an explosion flame eruption, the flame is dissipated in the battery module due to the blockage of the heat-dissipating block, and further Burning to the adjacent cell core causes a secondary explosion in the adjacent cell.

Chinese Patent Publication No. CN 105990622 A discloses a technique for uniformizing the temperature of each battery cell. Fig. 1 shows an exploded perspective view of a conventional battery module. As shown in FIG. 1 , the battery pack 10 includes a battery module 20 , a cover 23 , a top cover 31 , and a bottom cover 32 . The battery module 20 is placed in the cover 23 and includes a plurality of cylindrical battery cells 21, a heat dissipation plate 22, and a resin holder 23 that supports the cylindrical battery cells 21. The top cover 31 is mounted on the cover 23 On the upper side, the bottom cover 32 is mounted on the lower side of the heat dissipation plate 22. In the battery module 20, the cylindrical battery cell 21 is inserted into a plurality of through holes of the heat dissipation plate 22. By assembling the cylindrical battery cell 21 in the through hole of the heat dissipation plate 22, heat from the outer surface of the cylindrical battery cell 21 is transferred to the heat dissipation plate 22 by heat conduction to lower the temperature of the cylindrical battery cell 21 having a high temperature. At the same time, the heat of the heat dissipation plate 22 is transferred to the low temperature cylindrical battery cell 21 by heat conduction to raise the temperature of the low temperature cylindrical battery cell 21. In this manner, the heat dissipation plate 22 suppresses variations in temperature of the respective cylindrical battery cells 21.

A plurality of positive electrode bus bars 29 that connect the positive electrodes of the cylindrical battery cells 21 are mounted on the upper side of the cover 23, and a resin top cover 31 is mounted thereon. A negative bus bar assembly 30 that connects the electrodes on the negative side of the cylindrical battery cell 21 is mounted on the lower side of the heat dissipation plate 22. A bottom cover 32 is attached to the lower side of the negative electrode bus bar 30, and the bottom cover 32 is recessed in the center in a disk shape. The opening of the negative electrode bus bar 30 overlaps with the opening of the lower surface of the heat dissipation plate 22, and therefore, the negative electrode bus bar 30, the bottom cover 32, and the heat dissipation plate 22 form a flow path of the opening of the end surface of the communication chamber 50 and the heat dissipation plate 22, thereby allowing The cylindrical battery core 21 is exhausted.

As described above, it is possible to uniformly heat the respective cylindrical battery cells 21 in the battery pack 10. However, although the foregoing structure can make the temperature of each of the cylindrical battery cells 21 uniform and exhaust the cylindrical battery cells 21, the problem of dissipating heat and guiding the flame of the cylindrical battery cells 21 cannot be solved.

It is an object of the present invention to provide a battery pack that is capable of conducting heat and conducting flame. Another object of the present invention is to provide a battery pack which has better heat dissipation effect and can also utilize a flame guiding passage. Improve security.

According to an embodiment of the invention, a battery pack includes: a battery case, at least one end cover, and a battery module. The battery case includes a first side surface formed with at least one abutting portion that protrudes inward. The battery module is disposed in the battery case and includes a plurality of battery cells, at least one bracket, a plurality of electrode sheets, and at least one heat dissipation pad. At least one bracket is used to fix the battery cells. The electrode sheets are respectively disposed at two ends of the battery cells, so that the battery cells form a plurality of battery cell arrays connected in parallel or in series. The heat dissipating pad covers one of the electrode sheets on one side and the other side of the battery case contacts the abutting portion of the battery case. A gap is formed between the heat dissipation pad of the battery module and the first side of the battery case, and the abutting portion contacts the heat dissipation pad of the battery module, so that the heat generated by the battery cells passes through the heat dissipation pad, the abutting portion and the battery case. Conducted to the outside.

In one embodiment, the array of cells further forms a gap between two adjacent cell arrays in the long axis direction of the battery cells. The battery case further includes a third side surface formed with a heat dissipating fin protruding inwardly, and the heat dissipating fin is inserted into the gap and does not fill the gap, so that the unfilled portion of the gap acts as a flame gap .

In one embodiment, the second side surface is formed with at least one abutting portion protruding inwardly and opposite to the first side surface, and the fourth side surface is formed with a heat dissipating fin protruding inwardly, and The three sides face each other.

In an embodiment, the top end of the abutting portion is used to contact the heat dissipation pad, and the bottom end of the abutting portion is from the first One side extends and the area of the top end of the abutment is larger than the area of the bottom end of the abutment.

In an embodiment, the top side portion of the abutment defines a flame channel.

In one embodiment, the abutting portion includes a first flat portion and a second flat portion; and a support portion. The support portion is located at a bottom side portion of the abutting portion and is simultaneously connected to the first flat plate portion and the second flat plate portion. Further, the flame guiding groove is located between the first flat plate portion and the second flat plate portion.

In one embodiment, an arc shape is formed between a side surface of the support portion and an inner surface of the first side surface, and an arc shape is formed between the lower surface of the flat portion and the side surface of the support portion.

In an embodiment, the battery case is integrally formed. Preferably, the battery case is made of aluminum, and is formed by an aluminum extrusion process to form an integrally formed structure.

In one embodiment, the heat dissipation pad is composed of a heat resistant material having heat and heat conduction properties and forming a porous structure after being heated at a high temperature. In one embodiment, the battery pack further includes at least one end cover disposed on at least one end of the battery case.

According to an embodiment of the invention, the first side of the battery case is formed with at least one abutting portion protruding inwardly, the abutting portion contacting the heat dissipation pad of the battery module, and between the battery module and the first side of the battery case , forming a gap. The abutting portion can form a gap for use as a flame guiding passage, and can also conduct heat generated by the battery core to the outside of the battery pack. In an embodiment, due to electricity The pool shell is integrally formed to increase the heat dissipation effect. Preferably, the area of the top end of the abutting portion is larger than the area of the bottom end of the abutting portion, so that the battery module and the first side surface can be formed with a gap with a large space when the same heat can be transmitted. Effective flame guiding function.

10‧‧‧Battery Pack

20‧‧‧Battery module

21‧‧‧Cylindrical battery core

22‧‧‧heating plate

23‧‧‧ Cover

29‧‧‧ positive bus bar

30‧‧‧negative bus bar

31‧‧‧Top cover

32‧‧‧ bottom cover

50‧‧‧Connecting room

100‧‧‧Battery Pack

120‧‧‧Battery module

121‧‧‧ battery core

123‧‧‧ bracket

124‧‧‧electrode

125‧‧‧Fast pad

130‧‧‧ battery case

131‧‧‧ first side

132‧‧‧ second side

133‧‧‧ third side

134‧‧‧ fourth side

135‧‧‧First end cap

136‧‧‧second end cap

210‧‧‧ guiding slot

211‧‧‧ battery core

220‧‧‧ gap

220a‧‧‧Inflammatory gap

234‧‧‧Support Department

310‧‧‧Heat fins

320‧‧‧Apartment

321‧‧‧ flame channel

322‧‧‧ gap

323‧‧‧ Flat Department

324‧‧‧Support Department

330‧‧‧ Guide rail

Fig. 1 shows an exploded perspective view of a conventional battery module.

Fig. 2 is a perspective view showing a battery pack in accordance with an embodiment of the present invention.

Fig. 3 is a perspective view showing a battery module in accordance with an embodiment of the present invention.

Fig. 4 is a perspective view showing a battery can according to an embodiment of the present invention.

Fig. 5 is a cross-sectional view showing a battery can according to an embodiment of the present invention.

Figure 6 is a cross-sectional view showing a battery pack in accordance with an embodiment of the present invention.

Fig. 2 is a perspective view showing a battery pack in accordance with an embodiment of the present invention. As shown in FIG. 2, the battery pack 100 includes a battery module 120, a battery case 130, a first end cover 135, and a second end cover 136. The first end cover 135 and the second end cover 136 are disposed at two ends of the battery case 130 and define a cavity for accommodating the battery module 120.

Fig. 3 is a perspective view showing a battery module in accordance with an embodiment of the present invention. As shown in FIG. 3, the battery module 120 includes a plurality of cylindrical battery cells 121, at least one cell holder 123, and a plurality of electrodes. The sheet 124 and at least one heat sink pad 125. The brackets 123 define a plurality of accommodating spaces for placing and fixing the battery cores 121, and the battery cores 121 are respectively stacked in the longitudinal direction x and the width direction z of the brackets 123. The electrode sheets 124 are respectively disposed at two ends of the battery core 121 for forming the battery cells 121 in parallel or in series to form a plurality of battery core arrays. One surface of the at least one heat dissipation pad 125 covers the electrode pads 124 , and the other surface of the battery pad 130 contacts the abutting portion 320 of the inner surface of the battery case 130 for conducting heat generated by the battery cells 121 to the battery case 130 and is dissipated to The outside of the battery pack 100 is used to achieve a cooling effect while reducing the temperature difference between the batteries to maintain good power supply efficiency and battery life. At least one guiding groove 210 is defined on an end surface of a portion of the brackets 123. Further, a gap 220 is formed between two adjacent battery cell arrays in the longitudinal direction y of the battery cell 121.

Fig. 4 is a perspective view showing a battery can according to an embodiment of the present invention. Fig. 5 is a cross-sectional view showing a battery can according to an embodiment of the present invention. As shown in FIGS. 4 and 5, the battery case 130 includes a first side surface 131 and a second side surface 132 that face each other, and a third side surface 133 and a fourth side surface 134 that face each other. At least one abutting portion 320 projecting inward is formed on the inner surfaces of the first side surface 131 and the second side surface 132, respectively. Each abutting portion 320 defines a flame guiding groove 321 . Heat dissipation fins 310 projecting inward are formed on the inner surfaces of the third side surface 133 and the fourth side surface 134, respectively. In this embodiment, the inner surface of the third side 133 and the fourth side 134 are further formed with at least one guiding rail 330 protruding inward, wherein the protruding length of the heat dissipating fin 310 is greater than the protruding length of the guiding rail 330. With such a structure, the battery module 120 can be guided to be placed in the battery case 130 so that the heat dissipation fins 310 can be placed in the gap 220 relatively smoothly. In an embodiment, the guide rails 330 may also be disposed on the first side surface 131 and the second side surface 132.

Figure 6 is a cross-sectional view showing a battery pack in accordance with an embodiment of the present invention. As shown in Figure 6, according to this implementation In the battery pack 100 of the example, the battery module 120 is placed in the battery case 130, a guiding rail 330 is inserted into a guiding slot 210, and the heat dissipating fins 310 are inserted into the gap 220. The abutting portion 320 is in contact with the heat dissipation pad 125 adjacent to the first side surface 131 and the second side surface 132 for conducting heat generated by the battery core 121 to the external environment. The heat dissipation fins 310 are in contact with a portion of the heat dissipation pad 125 defining the gap 220, and the length of the heat dissipation fins 310 is less than half the distance H between the third side surface 133 and the fourth side surface 134, preferably less than four points of the distance H One, by which a portion of the gap 220 is retained, so that the portion that is not filled is used as the flame gap 220a.

In an embodiment, the battery case 130 is integrally formed. Since the battery case 130 is integrally formed, the contact portion 320 and the heat dissipation fins 310 and the heat dissipation pad 125 that they are in contact with each other have almost no contact thermal resistance, so that the abutting portion 320 and the heat dissipation fins 310 can be better. heat radiation. The heat formed by the battery core 121 can be dissipated into the external environment through the heat dissipation pad 125, the abutting portion 320, and the heat dissipation fins 310. In one embodiment, the top end of the abutting portion 320 is for contacting the heat dissipation pad 125, and the bottom end of the abutting portion 320 extends from the first side surface 131 and the second side surface 132, and the area of the top end of the abutting portion 320 It is larger than the area of the bottom end of the abutting portion 320. Since the contact portion 320 and the heat dissipation pad 125 have a high thermal contact resistance, and the abutting portion 320 has almost no contact thermal resistance between the first side surface 131 and the second side surface 132, when the same heat is transmitted, The area of the bottom end of the abutting portion 320 may be smaller than the area of the tip end of the abutting portion 320. According to such a design, the gap 322 having a large space can be formed between the battery module 120 and the first side surface 131 and the second side surface 132, and can be used as a flame.

In one embodiment, the cross section of the abutting portion 320 forms a shape of approximately Y, and a flame guiding groove 321 is defined at a top side portion of the abutting portion 320. In this embodiment, the abutting portion 320 includes two flat portions. 323 and a support portion 234, both flat plate portions 323 are connected to the support portion 234 and are located at the top side portion of the abutment portion 320, the support portion 234 is located at the bottom side portion of the abutment portion 320, and the flame guide groove 321 is formed at two Between the flat portions 323. The flame guiding groove 321 has a function of guiding a flame, and can increase the space of the flame guiding. The abutting portion 320 can fix the battery module 120 in addition to the heat transfer function, and prevent the battery module 120 from rattling in the battery case 130.

In one embodiment, the battery case 130 is integrally formed, and the contact thermal resistance between the components is small, which has a better heat dissipation effect. In addition, since the heat dissipation effect is better, the thickness of the wall of the battery can 130 can be reduced, for example, to less than 1 cm, preferably 4 mm, without affecting the heat dissipation function of the battery pack 10. The overall weight of the battery pack 10. In one embodiment, the battery case 130 is made of aluminum and is formed into an integrally formed structure by an aluminum extrusion process. Aluminum is corrosion-resistant and low-density. It is a light metal with a density of only about one-third of that of iron. Therefore, the overall weight of the battery pack 10 can be further reduced.

Please refer to the enlarged view of the abutting portion 320 of FIG. 5 . In one embodiment, the side surface of the support portion 324 at the bottom of the abutting portion 320 and the inner surface of the first side surface 131 and the second side surface 132 form an arc shape R1. In one embodiment, an arc shape R2 is formed between the lower surface of the flat plate portion 323 at the distal end of the abutting portion 320 and the side surface of the support portion 324 at the bottom of the abutting portion 320. In an embodiment, the flame guiding groove 321 is also in the shape of a circular arc. Preferably, each corner of the outer surface of the abutting portion 320 is formed in an arc shape and does not form an acute angle. Since a corner of the outer surface of the abutting portion 320 is formed into a circular arc shape, it is easier to form by an aluminum extrusion process, and the yield of the process is high.

In one embodiment, the holder 123 exposes both ends of the battery core 121 and is formed of a heat resistant material such as phenolphthalein foam (electric wood) or ceramic foam. A portion of the heat dissipation pad 125 corresponding to both ends of the battery cell 121 forms a weakened structure. The strength of the weakened structural portion of the thermal pad 125 is less than the strength of other portions of the thermal pad 125 that are not weakened. When an abnormality occurs in a battery cell 121 and a rapid temperature rises, a high voltage is generated inside the battery cell 121, and a gas or a flame inside the battery cell 121 can be released from the weakened structures. The holder 123 and the heat dissipation pad 125 may be made of a polymer material, and have a high heat transfer coefficient in the use state to dissipate heat. In an embodiment, the thermal pad may have a thermal conductivity of 0.5 to 10 W/mK. However, in the abnormal state, when the temperature of the flame generated by the battery cell 121 is high, the heat dissipation pad 125 is fired into a porous structure, thereby having a heat insulating function.

Therefore, when the flame of the battery cell 121 is ejected, it can be guided by the flame guiding groove 210 or the flame guiding gaps 322 and 220a, and is not restricted to the vicinity of the abnormal battery cell 121, so that other normal batteries can be reduced as much as possible. The influence of the core 121 further limits the flame to the accommodation space of the abnormal battery core 121 and the flame guide grooves 210 or the flame guide gaps 322 and 220a. In this way, the abnormal battery cell 211 can be isolated from the other normal battery cells 211 for a period of time, and after the internal energy consumption of the abnormal battery cell 211 is consumed, the temperature can be slowly lowered by itself, and the other normal battery cells 211 can be prevented. Excessive heat is applied, and spontaneous combustion occurs, so that the portion where the bracket 123 is burned is limited only to a local area, thereby improving safety.

In summary, in an embodiment, since the battery case 130 is integrally formed, the heat dissipation effect can be increased. Preferably, the area of the top end of the abutting portion 320 is larger than the area of the bottom end of the abutting portion 320, so that the battery module 120 and the first side can also be provided in the case where the same amount of heat can be transmitted. Between the 131 and the second side 132, a gap 322 having a large space is formed to achieve an effective flame guiding function.

An object of an embodiment of the present invention is to economically and efficiently conduct heat to the battery core 121 so that the battery core 121 can operate at its normal working interval temperature and reduce the temperature difference between the battery cells 121 to maintain good power supply efficiency. The life of the battery core 121. When the battery core 121 is internally short-circuited to generate an explosion flame eruption, the battery pack 100 has a flame guiding passage (for example, the flame guiding gap 220a between the battery cell arrays in the battery pack 10, the battery module 120 and the first side 131 and the first The gap 322 between the two sides 132 and the guiding groove 210), so that the flame is dissipated in the battery pack 100, avoiding the burning to the adjacent battery core 121, causing a secondary explosion of the adjacent battery.

In addition, when the flame is turbulent in the flame guiding passage, the flame is blocked by the heat-dissipating pad 125 that is fired into the porous structure, and the flame can be prevented from directly heating the adjacent battery cells 121, causing the temperature of the adjacent battery cells 121 to rise. High secondary explosion. In addition, when the flame is turbulent in the flame guiding passage, the heat of high temperature can also be conducted by the heat radiating fins 310, the abutting portion 320 and the entire battery case 130 and dissipated into the ambient air.

Claims (10)

A battery pack comprising: a battery case, comprising a heat dissipating material and comprising a first side surface formed with at least one abutting portion protruding inward; and a battery module disposed in the battery case and comprising: a plurality of batteries a core; at least one bracket for fixing the battery cells; a plurality of electrode sheets respectively disposed at two ends of the battery cores for connecting the battery cells in parallel or in series to form a plurality of battery core arrays; and at least one a heat-dissipating pad covering one of the electrode pads on one side and the other surface of the battery case contacting the at least one abutting portion of the battery case, wherein a gap is formed between the at least one heat-dissipating pad of the battery module and the first side of the battery case And the at least one abutting portion contacts the at least one heat dissipating pad of the battery module, so that heat generated by the battery cells is conducted to the heat through the at least one heat dissipating pad, the at least one abutting portion, and the battery case Externally, and the top side portion of the at least one abutting portion defines a flame guiding groove. The battery pack according to claim 1, wherein a top end of the at least one abutting portion is for contacting the at least one heat dissipating pad, and a bottom end of the at least one abutting portion extends from the first side surface, and the The area of the top end of the at least one abutting portion is larger than the area of the bottom end of the at least one abutting portion. The battery pack according to claim 1, wherein the battery cell array further has a gap formed between two adjacent battery cell arrays in a long axis direction of the battery cells, and the battery case further includes a third side Forming a heat sink fin protruding inward, the heat sink fin The sheet is inserted into the gap and does not fill the gap such that the unfilled portion of the gap acts as a flame gap. The battery pack according to claim 3, wherein the battery case further comprises: a second side surface formed with at least one abutting portion protruding inwardly, and facing the first side surface, and a fourth side surface thereof A heat dissipating fin protruding inward is formed and opposed to the third side. The battery pack according to any one of claims 1 to 4, wherein the battery can is integrally formed. The battery pack according to claim 5, wherein the at least one abutting portion comprises: a first flat plate portion and a second flat plate portion at a top side portion of the at least one abutting portion; and a support portion located at the The bottom side portion of the at least one abutting portion is simultaneously connected to the first flat plate portion and the second flat plate portion, and the flame guiding groove is located between the first flat plate portion and the second flat plate portion. The battery pack according to claim 6, wherein a side surface of the support portion and an inner surface of the first side surface form an arc shape, and the lower surface of the flat plate portion and the side surface of the support portion Form an arc shape between them. The battery pack according to claim 7, wherein the battery case is made of aluminum, and is formed by an aluminum extrusion process to form an integrally formed structure. The battery pack according to claim 1, wherein the at least one heat-dissipating pad is composed of a heat-resistant material having heat-resistant and heat-conductive properties and forming a porous structure after being heated at a high temperature. The battery pack according to claim 1, further comprising: at least one end cover disposed at at least one end of the battery case.