Abstract:
A battery unit and a battery module having stack battery units. The battery unit includes a battery cell including electrode terminals and a case for housing the battery cell. The case further includes: a spacer that is disposed on facing portions of an edge of the case and protrudes in a thickness direction of the case, an inlet guide portion for guiding air for cooling the battery cell, and an outlet guide portion for guiding air to be discharged toward the electrode terminals.

Description:
CLAIM OF PRIORITY 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0121468, filed on Dec. 1, 2010, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     An aspect of the present invention relates to a battery case and a battery pack. 
     2. Description of the Related Art 
     With the rapid development of electronic and communication industries, mobile electronic devices have recently come into wide use. Secondary batteries are widely used as power sources for the mobile electronic devices due to their economical efficiencies. The secondary batteries may also be used not only in cellular phones or notebook computers but also in medium and large-sized apparatuses such as machine tools, electric bicycles and automobiles, which requires high output and high power. The secondary batteries used in the medium and large-sized apparatuses are used as a battery pack obtained as a power source by connecting a plurality of bare cells in series and/or parallel. 
     As described above, the battery pack having the plurality of bare cells further includes various protection devices for the purpose of safety. Among these protection devices, a temperature measurement device measures a temperature of the battery pack and then transfers the temperature to a protection circuit module. If a predetermined temperature is sensed, the temperature measurement device transfers the sensed temperature to the protection circuit module so that current is cut off. Accordingly, the battery pack does not generate excessive heat which could cause a fire. 
     The above information disclosed in this Related Art section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments provide for a battery case and a battery pack using the same for enabling a temperature measurement device to be easily adhered closely to a bare cell by a compression member attached between the case and the temperature measurement device. 
     According to an aspect of the present invention, there is provided a battery pack that may include: a plurality of bare cells connected in series or parallel; a protection circuit module positioned at an outside of the bare cells and electrically connected to the bare cells; a temperature measurement device having one side connected to the protection circuit module and the other side positioned at an outer circumferential surface of the bare cell; and a case to house the bare cells, the protection circuit module and the temperature measurement device, wherein a compression member to compress the temperature measurement device is further formed between the case and the temperature measurement device. 
     The compression member may be integrally formed with the case. 
     The compression member may include an elastic body. 
     The elastic body may include sponge or rubber. 
     The temperature measurement device may include a temperature sensing portion to sense a temperature of the bare cells, a contact portion connected to the protection circuit module, and a connection portion to connect the temperature sensing portion and the connection portion. 
     The temperature sensing portion may be positioned at a bent portion of the bare cell. 
     The bent portion may be a space formed between outer circumferential surfaces of one bare cell and another bare cell, which are disposed adjacent to each other in parallel. 
     The compression member may be formed at a position corresponding to the temperature sensing portion. 
     A fixing member may be further formed on an upper surface of the connection portion, and both ends of the fixing member may be fixed to the outer circumferential surface of the bare cell. 
     The fixing member may include an adhesive tape. 
     An adhesive means may be formed between the bare cell and the temperature sensing portion. 
     The adhesive means may include an adhesive. 
     A heat transfer means may be formed between the bare cell and the temperature sensing portion. 
     The heat transfer means may include thermal silicon. 
     The temperature measurement device may further include an insulating member to surround the temperature sensing portion and the connection portion. 
     The temperature measurement device may be formed in a film type. 
     The contact portion of the temperature measurement device may be connected to the protection circuit module through soldering. 
     As described above, according to embodiments of the present invention, since a temperature measurement device is easily adhered closely to a bare cell by a compression member attached between a case and the temperature measurement device, the manufacturing process of a battery pack is simplified, so that it is possible to improve manufacturing efficiency and to reduce manufacturing cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
         FIG. 1  is a perspective view of a battery pack according to an embodiment of the present invention. 
         FIG. 2  is a perspective view of a core pack positioned in the interior of the battery pack shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional view taken along line I-I′ of  FIG. 1 . 
         FIG. 4  is a cross-sectional view showing a state that an insulating tape is further included in the battery pack of  FIG. 3 . 
         FIG. 5  is a cross-sectional view showing a state that thermal silicon is further included in the battery pack of  FIG. 3 . 
         FIG. 6  is a perspective view of a core pack according to another embodiment of the present invention. 
         FIG. 7  is a sectional view of a battery pack taken along line II-II′ of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. In addition, when an element is referred to as being “on” another element, it can be directly on the another element or be indirectly on the another clement with one or more intervening elements interposed therebetween. Also, when an element is referred to as being “connected to” another element, it can be directly connected to the other element or be indirectly connected to the another element with one or more intervening elements interposed therebetween. Hereinafter, like reference numerals refer to like elements. In the drawings, the thickness or size of layers are exaggerated for clarity and not necessarily drawn to scale. 
     In order to clarify the present invention, elements extrinsic to the description are omitted from the details of this description, and like reference numerals refer to like elements throughout the specification. 
     In several exemplary embodiments, constituent elements having the same configuration are representatively described in a first exemplary embodiment by using the same reference numeral and only constituent elements other than the constituent elements described in the first exemplary embodiment will be described in other embodiments. 
     In general, a temperature measurement device for measuring a temperature of a battery pack has one side fixed to a protection circuit module through soldering and the other side positioned at a side of a bare cell so as to sense the temperature of the battery pack. In this instance, the other side to sense the temperature of the battery pack is fixed to an outer circumferential surface of the bare cell. However, the method of fixing the other side of the temperature measurement device to the bare cell using a separate adhesive means is complicated, and it is difficult to adhere the other side of the temperature measurement device closely to the bare cell. 
     Therefore, in the battery pack, a mechanism is required to solve problems in which manufacturing efficiency is lowered and that the temperature measurement device is not adhered closely to the bare cell. Hereinafter, embodiments of the present invention as the plan for solving such problems will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view of a battery pack according to an embodiment of the present invention.  FIG. 2  is a perspective view of a core pack positioned in the interior of the battery pack shown in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the battery pack  100  according to this embodiment includes a plurality of cylindrical bare cells  10 , a protection circuit module  40  positioned at an outside of the bare cells  10 , a temperature measurement device  30  and a case  50  to house them. The plurality of bare cells  10  are connected in series or parallel so as to be electrically connected to the protection circuit module  40 . 
     The temperature measurement device  30  measures a temperature of the bare cells  10  and transfers the temperature to the protection circuit module  40 . One side of the temperature measurement device  30  is fixed to the protection circuit module  40 , and the other side of the temperature measurement device  30  is positioned on an outer circumferential surface of the bare cell  10 . In this instance, the one side of the temperature measurement device  30  may be connected to the protection circuit module  40  through soldering. 
     The bare cell  10  includes an electrode assembly (not shown) formed by winding a positive electrode plate, a negative electrode plate and a separator interposed therebetween, and a case in which an electrolyte is accommodated. The bare cell  10  supplies electric energy generated by a chemical reaction of the electrode assembly and the electrolyte to the exterior thereof. For example, the bare cell  10  may be a lithium secondary battery. 
     The protection circuit module  40  may include a printed circuit board, a protection circuit device, and the like. One or more devices to connect the bare cells  10  to an external electronic device are mounted on the printed circuit board. The protection circuit module  40  is electrically connected to the bare cells  10  by a terminal tab  20 , and the terminal tab  20  may be formed of nickel, copper or the like. 
     The protection circuit module  40  may further include a connector  41  formed at one side thereof. The connector  41  is a portion fastened to the external electronic device, and the battery pack can be electrically connected to the external electronic device by the connector  41 . 
     Generally, the temperature measurement device  30  is a semiconductor formed by mixing two or three kinds of oxides and sintering the mixture so as to have a proper specific resistance and a proper temperature coefficient. Here, the two or three oxides include cobalt, copper, manganese, iron, nickel, titanium and the like. 
     The temperature measurement device  30  may be divided into a negative temperature coefficient (NTC) and a positive temperature coefficient (PTC). The NTC has a characteristic in which resistance decreases as temperature increases, and the PTC has a characteristic in which resistance increases as temperature decreases. Since a rapid change in resistance is generated by even a minute change in temperature due to a small heat capacity of the temperature measurement device  30 , the temperature measurement device  30  is frequently used as a sensor for temperature control. 
     In this embodiment, the temperature measurement device  30  senses a temperature of the plurality of bare cells  10  and transfers the temperature to the protection circuit module  40 . The temperature measurement device  30  includes a temperature sensing portion  31  to sense the temperature of the bare cells  10 , a contact portion  33  connected to the protection circuit module  40 , and a connecting portion  32  to connect the temperature sensing portion  31  to the contact portion  33 . 
     In the temperature measurement device  30 , the temperature sensing portion  31  may be positioned at a bent portion  11  between bare cells  10   a  and  10   b . Here, the bent portion  11  may be a space formed between outer circumferential surfaces of the bare cells  10   a  and  10   b  disposed adjacent to each other in parallel. That is, the temperature sensing portion  31  may be positioned at a concave portion formed between the outer circumferential surfaces of the one bare cell  10   a  and the other bare cell  10   b.    
     In the temperature measurement device  30 , the contact portion  33  is soldered to the protection circuit module  40 , and the temperature sensing portion  31  and the connection portion  32  are positioned at the bent portion  11  to be vertical to the length direction of the bare cell  10 . Since the outer circumferential surface of the bare cell  10  is formed in a round shape, the temperature measurement device  30  may be lifted off from the outer circumferential surface of the bare cell  10 . Therefore, a compression member  51  (see  FIG. 3 ) may be further provided so as to easily fix the temperature measurement device  30  to the bare cell  10 . 
     The compression member  51  is positioned between the temperature measurement device  30  and the case  50  to house the core pack  200  so as to compress the temperature measurement device  30 . The compression member  51  will be described in detail later with reference to the following drawings. 
     In the temperature measurement device  30 , the temperature sensing portion  31  to sense the temperature of the bare cell  10  may be connected to the contact portion  33  soldered to the protection circuit module  40  the temperature sensing portion  31  to sense the temperature of the bare cell  10  may be connected to the contact portion  33  soldered to the protection circuit module  40  by the connection portion  32 . The temperature measurement device  30  may be formed in a film type, and may further include an insulating member  34  formed in a flat shape to surround outer surfaces of the temperature sensing portion  31  and the connection portion  32 . Accordingly, the temperature measurement device  30  is adhered closely to the bare cell  10 , and therefore, its twist is prevented. Thus, it is possible to improve the manufacturing management and workability of the core pack  200 . 
       FIG. 3  is a cross-sectional view taken along line I-I′ of  FIG. 1 . In  FIG. 3 , descriptions of components identical to those in  FIGS. 1 and 2  will be omitted. 
     Referring to  FIG. 3 , the battery pack  100  according to this embodiment includes a plurality of bare cells  10 , and a protection circuit module  40  positioned at an outside of the bare cells  10  and electrically connected to the bare cells  10 . The battery pack  100  is also provided with a temperature measurement device  30  having one side connected to the protection circuit module  40  and the other side positioned at an outer circumferential surface of the bar cell  10 . The battery pack  100  further includes a case  50  to house the plurality of bare cells  10 , the protection circuit module  40  and the temperature measurement device  30 . 
     As described above, the temperature measurement device  30  may include a temperature sensing portion  31  to sense the temperature of the bare cells  10 , a contact portion  33  fixed to the protection circuit module  40  through soldering, and a connecting portion  32  to connect the temperature sensing portion  31  to the contact portion  33 . In the temperature measurement device  30 , the contact portion  33  is fixed to the protection circuit module  40 , and the temperature sensing portion  31  is positioned at an outer circumferential surface of the bare cell  10 . The connection portion  32  is positioned along an outer circumferential surface of a bare cell  10   a  to be vertical to the length direction of the bare cell  10 . 
     The temperature sensing portion  31  may be positioned at a bent portion  11  between two bare cells  10   a  and  10   b  connected in parallel among the plurality of bare cells  10 . More specifically, the bent portion  11  refers to a space formed between the one bare cell  10   a  and the other bare cell  10   b  disposed adjacent to each other in parallel. The case  50  to house the core pack may further include a compression member  51  formed in a space between outer circumferential surfaces of the bare cells  10   a  and  10   b . That is, the compression member  51  is formed between the case  50  and the temperature measurement device  30  so as to compresses the temperature measurement device  30 . Accordingly, the temperature measurement device  30  can be adhered closely to the outer circumferential surface of the bare cell  10   a.    
     Here, the compression member  51  may be integrally formed with the case  50 , or may be separately manufactured so as to be formed at a position corresponding to the temperature sensing portion  31 . The compression member  51  may be formed of an elastic body, and the elastic body may include, for example, sponge or rubber. 
     As described above, the compression member  51  compresses the temperature measurement device  30 , particularly the temperature sensing portion  31 , so that it is possible to prevent the temperature measurement device  30  from being lifted off from the outer circumferential surface of the bare cell  10   a . Thus, the temperature measurement device  30  can be easily, adhered closely to the bare cell  10   a . Accordingly, since the temperature measurement device  30  is fixed to the bare cell  10   a  by using the compression member  51 , the manufacturing process of the battery pack  100  is simplified, so that it is possible to improve manufacturing efficiency and to reduce manufacturing cost. 
       FIG. 4  is a cross-sectional view showing a state that an insulating tape is further included in the battery pack of  FIG. 3 . 
     Referring to  FIG. 4 , a fixing member  52  such as an adhesive tape may be further formed on an upper surface of the connection portion  32  of the temperature measurement device  30 . That is, both ends of the fixing member  52 , are fixed to the outer circumferential surface of the bare cell  10   a , so that the connection portion  32  can be attached to the bare cell  10   a . Accordingly, in addition to the temperature sensing portion  31 , the connection portion  32  can be adhered closely to the outer circumferential surface of the bare cell  10   a . As described above, the fixing member  52  is formed on the connection portion  32 , so that the temperature measurement device  30  can be more firmly and stably fixed to the bare cell  10   a.    
       FIG. 5  is a cross-sectional view showing a state that thermal silicon is further included in the battery pack of  FIG. 3 . 
     Referring to  FIG. 5 , the temperature sensing portion  31  is positioned at the bent portion  11  of the bare cell  10   a , and is compressed and fixed by the compression member  51 . In this instance, an adhesive means such as an adhesive may be formed between the temperature sensing portion  31  and the bare cell  10   a . Thus, the temperature sensing portion  31  can be more firmly fixed to the bare cell  10   a  by the adhesive means  53 . 
     A heat transfer means such as thermal silicon may be formed between the temperature sensing portion  31  and the bare cell  10   a . Accordingly, heat generated from the bare cell  10   a  can be more precisely transferred to the temperature sensing portion  31 . At the same time, the temperature sensing portion  31  can be fixed to the bent portion  11  of the bare cell  10   a  by the heat transfer means. 
       FIG. 6  is a perspective view of a core pack according to another embodiment of the present invention.  FIG. 7  is a sectional view of a battery pack taken along line II-II′ of  FIG. 6 . 
     Referring to  FIGS. 6 and 7 , the core pack  300  according to this embodiment includes a plurality of prismatic bare cells  10 ′, a protection circuit module  40 ′ and a temperature measurement device  30 ′. The battery pack  100 ′ further includes a case  50 ′ to house the prismatic bare cells  10 ′, the protection circuit module  40 ′ and the temperature measurement device  30 ′. Here, the section of the prismatic bare cell  10 ′ in the length direction may be formed in an elliptical shape. 
     One side of the temperature measurement device  30 ′ is connected to the protection circuit module  40 ′, and the other side of the temperature measurement device  30 ′ is positioned at an outer circumferential surface of the bare cell  10 ′. That is, a contact portion  33 ′ of the temperature measurement device  30 ′ is vertically connected to the protection circuit module  40 ′. The temperature measurement device  30 ′ connected as described above is positioned at the outer circumferential surface of the bare cell  10 ′ so as to be vertical to the length direction of the bare cell without bending. Accordingly, a connection portion  32 ′ to connect the contact portion  33 ′ to a temperature sensing portion  31 ′ may be positioned while coming in contact with the outer circumferential surface of the bare cell  10 ′. 
     A compression member  51 ′ to compress the temperature measurement device  30 ′ is further formed between the case  50 ′ and the temperature measurement device  30 ′. The compression member  51 ′ may be formed at a position corresponding to the temperature sensing portion  31 ′ in the temperature measurement device  30 ′. Here, the temperature sensing portion  31 ′ may be positioned at a bent portion  11 ′ that is a space formed between outer circumferential surfaces of bare cells  10   a ′ and  10   b ′ disposed adjacent to each other in parallel. Alternatively, the temperature sensing portion  31 ′ may be positioned at the outer circumferential surface of the bare cell  10   a′.    
     The compression member  51 ′ may be integrally formed with the inner surface of the case  50 ′, or may be separately manufactured so as to be formed between the case  50 ′ and the temperature measurement device  30 ′. In a case where the compression member  51 ′ is integrally formed with the case  50 ′, the bare cells  10 ′ may be housed by the case  50 ′, and the temperature measurement device  30 ′ may be simply fixed to an outer surface of the bare cell  10   a ′ by the compression member  51 ′. 
     While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof.