JP2014053126A - Battery pack module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack module that can uniformize temperature dispersion of plural battery cells disposed in the battery pack module.SOLUTION: Cylindrical battery cells 206 are disposed in a battery pack module 201, and the temperature problem of the cylindrical battery cells 206 when charging/discharging operations are repeated can be solved by making battery cases 207 and 208 for accommodating the cylindrical battery cells 206 therein different in thermal conductivity. At this time, an air flow port through which cooling air flows is provided in the battery pack module.

Description

  The present invention relates to an assembled battery module in which a plurality of battery cells are connected.

  In the energy field, a battery having a large capacity and a high output has been demanded. For example, in the automobile industry, many batteries are used in a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an electric vehicle (EV). The battery used for that purpose is, for example, a large current of 100 A or more when discharging and charging from the battery when starting an EV car, when climbing steeply, or when charging quickly or when descending steeply Flows.

  When a battery with a large current flows, the battery itself generates heat and the temperature rises. At the same time, the temperature rises in summer due to environmental influences. When the temperature rises, not only does the electrical characteristics of the battery deteriorate, but the life is also shortened. For this reason, it is necessary to cool so that the temperature of the battery does not become higher than the specified temperature. However, the battery used is an assembled battery in which unit cells are electrically connected in combination of series and parallel. Therefore, it is very important to cool the unit cell uniformly. If there is a temperature difference between the unit cells inside the assembled battery, it causes deterioration of the assembled battery, and there is a problem of shortening the life.

  As a conventional battery case, a battery case as in Patent Document 1 is known. FIG. 5 is a diagram showing a conventional battery case described in Patent Document 1. In FIG.

  In FIG. 5, a power supply device in which a plurality of power supply modules 1 are housed in a holder case 2 in an arrangement in which the power supply modules 1 are vertically stacked in a plurality of stages, and the holder case 2 includes a plurality of case units 2A made of plastic molding. This is a laminated structure of a plurality of case units 2A. Each case unit 2A is formed of a molding material, and the thermal conductivity of the molding material forming the upper case unit 2A laminated on the upper stage is laminated on the lower stage than the upper case unit 2A. This shows a power supply device that is made larger than the molding material of the lower case unit 2A and that the heat conduction of the upper case unit 2A is larger than the heat conduction of the lower case unit 2A so as to be cooled more efficiently. Yes.

JP 2004-47361 A

  However, in the battery case described in Patent Document 1 as a technique for solving this problem, the structure of the assembled battery is assumed to be a multi-layered structure in the vertical direction, but the structure of the assembled battery is horizontally different from the vertical multi-stage structure. A laminated structure in the direction and a laminated structure in the upper and lower sides, etc., have a problem with assembled batteries other than the multistage structure in the upper and lower direction. Specifically, since cooling is performed by introducing cooling air, the outer shape becomes large in the necessary space, and because it becomes indirect cooling, heat removal is poor and the cooling performance due to steps is also being investigated, although differences are being investigated. However, there is a problem that the cooling capacity varies depending on the location.

  An object of the present invention is to solve the above-described conventional problems, and to provide an assembled battery module having a battery case that prevents the deterioration of performance of the assembled battery due to temperature uniformity and temperature variation of the cells inside the assembled battery. To do.

  In order to achieve the above object, an assembled battery module including a dissimilar metal battery case according to the present invention is an assembled battery module configured by inserting battery cells into a plurality of battery cases, respectively. The case is composed of a combination of metal cases having different thermal conductivities.

  This configuration is characterized in that the temperature of the battery cells inside the assembled battery module is made uniform by using heat transfer utilizing the difference in thermal conductivity between the battery cases.

  As described above, according to the assembled battery module including the dissimilar metal battery case of the present invention, it is possible to eliminate the temperature variation of the battery cells inside the assembled battery module and to prevent the performance deterioration of the assembled battery module.

Schematic sectional view of the assembled battery module of the dissimilar metal battery case in Embodiment 1 of the present invention Schematic sectional view of the assembled battery module of the dissimilar metal battery case in Embodiment 2 of the present invention Schematic sectional view of the assembled battery module of the dissimilar metal battery case in Embodiment 3 of the present invention Schematic sectional view of the assembled battery module of the dissimilar metal battery case in Embodiment 4 of the present invention The figure of the conventional assembled battery module described in patent document 1

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of an assembled battery module of a dissimilar metal battery case according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the assembled battery module 201 is configured by storing a plurality of cylindrical battery cells 206 in respective battery cases 207 and 208, and the battery cases 207 and 208 are further stored in a module case 202. Become. The module case 202 includes a cooling air supply port 203, a cooling air discharge port 204, and a cooling air blowing passage 205. Further, adjacent battery cases 207 and 208 are joined by welding or the like. In FIG. 1, the battery case 207 is made of a material having a thermal conductivity of K7, and the battery case 208 is made of a material having a thermal conductivity of K8.

  Hereinafter, the arrangement of the battery case 207 and the battery case 208 will be described.

  The battery case 207 and the battery case 208 are arranged depending on the performance of the cylindrical battery cell 206. Specifically, as shown in FIG. 1, the cylindrical battery cell 206 is arranged inside the assembled battery module 201, and the temperature tendency of the cylindrical battery cell 206 when the charge / discharge operation is repeated is a cooling air blowing passage 205. When the temperature of the battery cell close to is high and the temperature of the cylindrical battery cell 206 at the center of the assembled battery module 201 is low, the relationship between the thermal conductivity of the battery case 207 and the battery case 208 is K7> K8. To do.

  With such an arrangement, the temperature of the cylindrical battery cell 206 in the vicinity of the cooling air blowing passage 205 having a high temperature is lowered by dissipating heat in the battery case 207 having a high thermal conductivity, and the assembled battery module 201 having a low temperature is used. The cylindrical battery cell 206 in the central part of the cylindrical battery cell 207 also has a low thermal conductivity, and the temperature variation of all the cylindrical battery cells 206 can be reduced by raising the temperature by reducing the heat radiation.

  On the other hand, due to the temperature of the cooling air supplied to the cooling air supply port 203, the temperature tendency of the cylindrical battery cell 206 is low, and the temperature of the battery cell close to the air flow path 205 of the cooling air is low. When the temperature of the cell 206 is high, the relationship between the thermal conductivity of the battery case 207 and the battery case 208 is configured to satisfy K7 <K8.

  With such a configuration, the temperature of the cylindrical battery cell 206 in the vicinity of the cooling air blowing passage 205 of the cooling air having a low temperature is lowered by reducing the heat radiation by the battery case 207 having a low thermal conductivity, and the temperature of the cylindrical battery cell 206 is increased. The cylindrical battery cell 206 at the center of the assembled battery module 201 that is high can also reduce the temperature variation of all the cylindrical battery cells 206 by increasing the heat radiation of the temperature by the battery case 207 having high thermal conductivity and decreasing the temperature.

  According to this configuration, the thermal conductivities of the battery case 207 and the battery case 208 are changed in accordance with the heat generation state due to charging / discharging of the cylindrical battery cell 206 of the assembled battery module 201 (that is, the arrangement of the battery case 207 and the battery case 208). )), The temperature variation of the cylindrical battery cell 206 arranged inside the assembled battery module 201 can be suppressed, and the performance deterioration of the assembled battery module can be prevented.

  In the present embodiment, the configuration in which the battery case 208 having the thermal conductivity K8 is surrounded by the battery case 207 having the thermal conductivity K7 is shown. However, the battery case 208 having the thermal conductivity K8 arranged continuously as shown in FIG. May be surrounded by a battery case 207 having a thermal conductivity of K7.

  Further, if the battery case has a three-stage structure as shown in FIG. 1, the first one in the center row is the battery case 207 having the thermal conductivity K7, and the subsequent cases are the battery case 208 having the thermal conductivity K8. Alternatively, the battery cases 207 having the rate K7 may be alternately arranged at the end with the battery cases 207 having the thermal conductivity K7, and the upper and lower stages may be sandwiched between the battery cases 207 having the thermal conductivity K7.

  In this embodiment, the cylindrical battery cell 206 is stored in the battery case, but a cylindrical capacitance may be used.

(Embodiment 2)
FIG. 2 is a schematic cross-sectional view of an assembled battery module of a dissimilar metal battery case according to Embodiment 2 of the present invention. In the first embodiment, a configuration in which the battery cases 207 and 208 containing the cylindrical battery cells 206 are stacked in a plurality of stages is shown. However, in this embodiment, the battery cases containing the square battery cells 302 are joined in one row. The assembled battery module comprised is shown. In FIG. 2, the same components as those in FIG.

  As shown in FIG. 2, the assembled battery module 301 includes a plurality of rectangular battery cells 302 housed in battery cases 303 and 304, and the battery case is housed in the module case 202. The module case 202 has a cooling air supply port 203, a cooling air discharge port 204, and the like. A cooling air blowing passage 205 is provided. Battery cases 303 and 304 are connected by welding or the like.

  Further, in FIG. 2, the battery case 303 is made of a material having a thermal conductivity of K3, and the battery case 304 is made of a material having a thermal conductivity of K4.

  As shown in the cross-sectional view of FIG. 3, when the prismatic battery cell 302 is arranged inside the assembled battery module 301 and the charge / discharge operation is repeated, the cooling air blowing passage 205 is caused by the temperature rise of the prismatic battery cell 302. The temperature of the cooling air flowing through the cooling air is the lowest near the cooling air supply port 203. As a result, the temperature of the cooling air gradually increases under the influence of the heat generation temperature of the prismatic battery cell 302, and the temperature of the cooling air near the cooling air outlet 204 becomes the highest.

  Therefore, by setting the thermal conductivity of the material of the battery case 303 and the material of the battery case 304 to K3 <K4, the temperature of the prismatic battery cell 302 near the cooling air supply port 203 having a low temperature can be increased. The battery case 303 with low conductivity is used to reduce heat dissipation and raise the temperature of the cylindrical battery cell 206. Then, the square battery cell 302 in the vicinity of the cooling air outlet 204 having a high temperature is heated by the battery case 304 having a high thermal conductivity to decrease the temperature, thereby reducing the temperature inside the assembled battery module 201. It is possible to prevent temperature variations of all the battery cells 302.

  According to this configuration, the prismatic battery cell inside the assembled battery module 201 is changed by changing the thermal conductivity of the battery case 303 and the battery case 304 in accordance with the heat generation state due to charging / discharging of the battery cell 302 of the assembled battery module 201. The temperature variation of 302 can be prevented, and the performance deterioration of the assembled battery module can be prevented.

  In this embodiment, the rectangular battery cell 302 is housed in the battery case, but a square capacitance may be used.

(Embodiment 3)
FIG. 3 is a schematic cross-sectional view of an assembled battery module of a dissimilar metal battery case according to Embodiment 3 of the present invention. In the third embodiment, a heat dissipation layer is disposed outside the battery case 207 in the first embodiment. In FIG. 3, the same components as those in FIG.

  FIG. 3 shows a structure in which a heat dissipation layer 401 is arranged around the surfaces of the battery cases 207 and 208. The heat dissipation layer may be any layer having a higher thermal conductivity than a metal such as a graphite material.

  Further, when the thermal conductivity of the battery case 207 is K7, the thermal conductivity of the battery case 208 is K8, and the thermal conductivity of the heat radiation layer is K9, the configuration is such that “K9> K7> K8”. Thus, the temperature of the cylindrical battery cell 206 disposed in the center of the assembled battery module 201 can be radiated to the cooling air blowing passage 205. As a result, temperature variation of all the cylindrical battery cells 206 inside the assembled battery module 201 can be prevented.

  In addition, even if any of the cylindrical battery cells 206 inside the assembled battery module 201 is abnormally heated, the generated heat can be transferred to the entire battery case and dissipated, so that the peripheral cylindrical battery cells 206 can be dissipated. It can also prevent the roasting.

(Embodiment 4)
FIG. 4 is a schematic cross-sectional view of an assembled battery module of a dissimilar metal battery case according to Embodiment 4 of the present invention. In the fourth embodiment, a heat dissipation layer is disposed outside the battery case 208 close to the cooling air outlet 204 of the first embodiment. 4, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 4 shows a heat dissipation layer 401 arranged around the surfaces of the battery cases 303 and 304. The heat dissipation layer may be any layer having a higher thermal conductivity than a metal such as a graphite material.

  Further, when the thermal conductivity of the battery case 303 is K3, the thermal conductivity of the battery case 304 is K4, and the thermal conductivity of the heat dissipation layer is K9, K3 <K4 <K9 so that the above-described second embodiment. In contrast, the temperature of the battery case 304 can be radiated by the heat dissipation layer 401 to reduce the temperature of the prismatic battery cell 302. Note that the idea of this embodiment is effective when the temperature of the prismatic battery cell 302 housed in the battery case 304 is high.

  The assembled battery module of the dissimilar metal battery case of the present invention has a function of making the temperature of the battery cells inside the assembled battery uniform, and various power supply devices such as an assembled battery combining battery cells and a power supply device combining super capacitors It can also be used for applications where the internal temperature is uniform.

201, 301 Battery module 202 Module case 203 Cooling air supply port 204 Cooling air discharge port 205 Cooling air blowing passage 206 Cylindrical battery cell 207, 208, 303, 304 Battery case

Claims (8)

A battery module configured by inserting battery cells into a plurality of battery cases, wherein the plurality of battery cases are made of a combination of metal cases having different thermal conductivities,
An assembled battery module. Among the plurality of battery cases,
A metal case having a high thermal conductivity is disposed on the outer periphery of the battery case, and a metal case having a low thermal conductivity is disposed at the center of the battery case.
The assembled battery module according to claim 1. Among the plurality of battery cases,
A metal case having a low thermal conductivity is disposed at the outer periphery of the battery case, and a metal case having a high thermal conductivity is disposed at the center of the battery case.
The assembled battery module according to claim 1. A metal case made of copper having higher thermal conductivity than aluminum is arranged around the metal case made of aluminum.
The assembled battery module according to claim 2. A metal case made of aluminum having a lower thermal conductivity than copper is arranged around a metal case made of copper.
The assembled battery module according to claim 3. The assembled battery module according to any one of claims 1 to 5,
Further comprising a blower opening for blowing cooling air into the assembled battery module;
The thermal conductivity of the battery case close to the air outlet is lower than the thermal conductivity of the battery case far from the air outlet,
The assembled battery module as described in any one of Claims 1-5. A heat dissipation layer is provided on the surface of the battery case,
The assembled battery module according to any one of claims 1 to 6, wherein the heat dissipation layer has a higher thermal conductivity than a material of the metal case. The assembled battery module according to claim 7, wherein the heat dissipation layer is formed of carbon fiber.

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