Battery module and battery pack

Abstract

Disclosed herein are a battery module and a battery pack. The battery module, having a plurality of battery cells, includes a unit module stack configured to have a structure in which a plurality of unit modules, each of which has a structure in which the battery cells are mounted to a cartridge, are stacked in a vertical direction on the basis of a ground, an upper end plate and a lower end plate for supporting an upper end and a lower end of the unit module stack, respectively, the upper end plate being provided with first fastening holes, the lower end plate being provided with second fastening holes, and a module housing provided with third fastening holes communicating with the second fastening holes, wherein first fastening members and second fastening members are inserted and fastened into the first fastening holes, the second fastening holes, and the third fastening holes.

Claims

1. A battery module having a plurality of battery cells, the battery module comprising: a unit module stack configured to have a structure in which a plurality of unit modules, each of which has a structure in which the battery cells are mounted to a cartridge, are stacked in a vertical direction on the basis of a ground, the cartridge being provided with one or more through holes; an upper end plate and a lower end plate for supporting an upper end and a lower end of the unit module stack, respectively, the upper end plate being provided with first fastening holes communicating with the through holes, the lower end plate being provided with second fastening holes communicating with the through holes; a module housing for surrounding at least one lateral side of the unit module stack mounted on the lower end plate and a bottom of the lower end plate, the module housing being provided with third fastening holes communicating with the second fastening holes; first fastening members having hollow parts, through which second fastening members are inserted, formed along a central axis thereof, the first fastening members being coupled into the second fastening holes through the first fastening holes and the through holes; and the second fastening members coupled into the third fastening holes through the hollow parts of the first fastening members, wherein each of the first fastening members comprises: a head having an outer diameter greater than an inner diameter of a corresponding one of the first fastening holes; a fastening bar inserted through a corresponding one of the first fastening holes and a corresponding one of the through holes; and a first fastening end having a screw thread formed at an outer surface thereof, the screw thread being coupled into a corresponding one of the second fastening holes, and a hollow part is formed through the head, the fastening bar, and the first fastening end along central axes of the head, the fastening bar, and the first fastening end.

2. The battery module according to claim 1, wherein each of the second fastening members comprises: a head having an outer diameter greater than an inner diameter of the hollow part of the first fastening member; an insertion bar inserted through the hollow part of the first fastening member; and a second fastening end protruding from a lower end of the hollow part of the first fastening member, the second fastening end having a screw thread formed at an outer surface thereof, the screw thread being coupled into a corresponding one of the third fastening holes.

3. The battery module according to claim 1, wherein the head of each of the first fastening members is provided with a depressed part, in which the head of a corresponding one of the second fastening members is located, and the fastening bar is provided at an inside of an upper end thereof with a wrenching bolt structure.

4. The battery module according to claim 3, wherein the depressed part is depressed by at least a height of the head of each of the second fastening members.

5. The battery module according to claim 2, wherein the head of each of the second fastening members is provided with a wrenching bolt structure.

6. The battery module according to claim 1, wherein the cartridges, the upper end plate, and the lower end plate are coupled to one another by inserting the first fastening members therethrough and then coupled to the module housing by fastening the second fastening members into the third fastening holes through the hollow parts.

7. The battery module according to claim 1, wherein the second fastening holes and the third fastening holes each are provided with a screw structure, into which the first fastening end of a corresponding one of the first fastening members and the second fastening end of a corresponding one of the second fastening members are threadedly engaged.

8. The battery module according to claim 1, wherein the first fastening members and the second fastening members each are made of a metal material.

9. The battery module according to claim 1, wherein the upper end plate and the lower end plate each are made of a metal material.

10. The battery module according to claim 1, wherein the cartridge is configured to have a rectangular structure corresponding to the battery cells such that the battery cells are mounted to the cartridge and is provided at four corners thereof with through holes, through which the first fastening members are inserted to fix the unit module stack.

11. The battery module according to claim 1, wherein each of the battery cells is a pouch-shaped battery cell having an electrode assembly mounted in a battery case made of a laminate sheet comprising a resin layer and a metal layer.

12. The battery module according to claim 11, wherein the laminate sheet is configured to have a structure comprising a thermally bondable inner resin layer, an isolation metal layer, and an outer resin layer exhibiting high durability.

13. A battery pack comprising two or more battery modules according to claim 1.

14. The battery pack according to claim 13, wherein the battery pack is used as a power source of an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Description

DESCRIPTION OF DRAWINGS

(1) The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

(2) FIG. 1 is a perspective view showing a battery cell, which will be mounted in a battery module;

(3) FIG. 2 is an exploded typical view showing the battery cell of FIG. 1;

(4) FIG. 3 is an exploded perspective view showing a unit module stack according to an embodiment of the present invention;

(5) FIG. 4 is a perspective view showing the unit module stack of FIG. 3;

(6) FIG. 5 is an exploded perspective view showing a battery module according to an embodiment of the present invention;

(7) FIG. 6 is a perspective view showing the battery module of FIG. 5;

(8) FIG. 7 is a perspective view showing a fastening member according to an embodiment of the present invention;

(9) FIG. 8 is a side view, a plan view, and a bottom view showing the fastening member of FIG. 7; and

(10) FIG. 9 is a perspective view showing a second fastening member according to an embodiment of the present invention.

BEST MODE

(11) Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted, however, that the scope of the present invention is not limited by the illustrated embodiments.

(12) FIG. 1 is a perspective view typically showing an exemplary battery cell, which will be mounted in a unit module of the present invention, and FIG. 2 is an exploded typical view showing the battery cell of FIG. 1.

(13) Referring to these figures, a plate-shaped battery cell 200 is configured to have a structure in which an electrode assembly, including positive electrodes, negative electrodes, and separators disposed respectively between the positive electrodes and the negative electrodes, is mounted in a pouch-shaped battery case 100 in a sealed state such that two electrode terminals 222 and 232 electrically connected to positive electrode and negative electrode tabs 220 and 230 of the electrode assembly are exposed outward.

(14) The battery case 100 includes a case body 140 having a depressed receiving part 142, in which the electrode assembly 210 is located, and a cover 150 integrally connected to the case body 140.

(15) The positive electrode tabs 220 and the negative electrode tabs 230 of the electrode assembly 210, which has a stacked type structure or a stacked/folded type structure, are respectively coupled to the electrode terminals 222 and 232 by welding. In addition, insulative films 240 are attached to the top and bottom of each of the electrode terminals 222 and 232 in order to prevent the occurrence of a short circuit between a thermal welding device and the electrode terminals 222 and 232 and to secure sealing between the electrode terminals 222 and 232 and the battery case 100 when a surplus part 144 of the case body 140 and the cover 150 are thermally welded to each other using the thermal welding device.

(16) The case body 140 and the cover 150 each include an outer resin layer 110, an isolation metal layer 120, and an inner resin layer 130. The inner resin layer 130 of the case body 140 and the inner resin layer 130 of the cover 150 are fixed to each other in tight contact due to heat and pressure applied to the outer surface of the case body 140 and the outer surface of the cover 150 from the thermal welding device (not shown).

(17) The surplus part 144 of the case body 140 and the cover 150 are thermally welded to each other in a state in which the electrode assembly 210, which is impregnated with an electrolyte, is located in the receiving part 142. As a result, a sealed portion is formed at the battery case 100.

(18) FIG. 3 is an exploded perspective view showing a unit module stack according to an embodiment of the present invention, FIG. 4 is a perspective view typically showing the unit module stack of FIG. 3, FIG. 5 is an exploded perspective view showing a battery module according to an embodiment of the present invention, and FIG. 6 is a perspective view typically showing the battery module of FIG. 5.

(19) Referring to these figures, a battery module 500 according to the present invention includes a unit module stack 300 including a plurality of cartridges 20 stacked in a vertical direction on the basis of the ground in a state in which battery cells 200 are mounted to each of the cartridges 20, an upper end plate 10 and a lower end plate 30 for supporting the uppermost one and the lowermost one of the cartridges 20, respectively, and a module housing 70 having a structure for surrounding lateral sides of the unit module stack 300 mounted on the lower end plate 30 and the bottom of the lower end plate 30.

(20) Each of the cartridges 20 is provided at four corners thereof with through holes 21. The upper end plate 10 is provided at regions thereof corresponding to the through holes 21 with first fastening holes 11 such that the first fastening holes 11 communicate with the respective through holes 21. In the same manner, the lower end plate 30 is provided at regions thereof corresponding to the through holes 21 with second fastening holes (not shown) such that the second fastening holes communicate with the respective through holes 21.

(21) The module housing 70 is provided at regions thereof corresponding to the second fastening holes with third fastening holes 71 such that the third fastening holes 71 communicate with the respective second fastening holes. The second fastening holes and the third fastening holes 71 each are provided at an inner circumference thereof with a screw structure (not shown), into which a first fastening end 54 (see FIG. 7) and a second fastening end 63 (see FIG. 7) formed at a first fastening member 50 and a second fastening member 60 are threadedly engaged. Consequently, the first fastening end 54 of the first fastening member 50 is coupled into each of the second fastening holes, and the second fastening end 63 of the second fastening member 60 is easily coupled into each of the third fastening holes 71 of the module housing 70.

(22) FIG. 7 is a perspective view showing a fastening member according to an embodiment of the present invention, FIG. 8 is a side view, a plan view, and a bottom view typically showing the fastening member of FIG. 7, and FIG. 9 is a perspective view typically showing a second fastening member according to an embodiment of the present invention.

(23) Referring to these figures together with FIGS. 1 to 6, a fastening member according to the present invention includes a first fastening member 50 and a second fastening member 60.

(24) The first fastening member 50 includes a head 51 having an outer diameter W2 greater than an inner diameter W1, a fastening bar 52 inserted through each of the first fastening holes 11 and each of the through holes 21, and a first fastening end 54 having a screw thread formed at the outer surface thereof, the screw thread being coupled into each of the second fastening holes. In addition, a hollow part 55 is formed through the head, the fastening bar, and the first fastening end along central axes of the head, the fastening bar, and the first fastening end.

(25) The head 51 of the first fastening member 50 is provided with a depressed part 57, in which a head 61 of the second fastening member 60 is stably located. The fastening bar 52 is provided at the inside of the upper end thereof with a wrenching bolt structure 56 for easy fastening.

(26) In addition, the second fastening member 60 includes a head 61 having an outer diameter W1 greater than an inner diameter W3 of the hollow part 55 of the first fastening member 50, an insertion bar 62 inserted through the hollow part 55 of the first fastening member 50, and a second fastening end 63 protruding from the lower end of the hollow part 55, the second fastening end 63 having a screw thread formed at the outer surface thereof, the screw thread being coupled into each of the third fastening holes 71. The head 61 is provided with a wrenching bolt structure 66 for easy fastening.

(27) Consequently, the first fastening members 50 are inserted into the second fastening holes (not shown) of the lower end plate 30 through the first fastening holes 11 of the upper end plate 10 and the through holes 21 of the cartridges 20. As a result, the unit module stack 300 including the cartridges 20, the upper end plate 10, and the lower end plate 30 are coupled to one another. Subsequently, the second fastening members 60 are inserted through the respective first fastening members 50 without interference with the respective first fastening members 50, and then the second fastening ends 63 of the second fastening members 60 are threadedly coupled into the third fastening holes 71 formed at the module hosing 70. As a result, the unit module stack 300, the upper end plate 10, the lower end plate 30, and the module housing 70 are securely fixed.

(28) Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.