Patent Publication Number: US-11038212-B2

Title: Module for real-time thermal behavior analysis of secondary cell battery and method of operating the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Korean Patent Application No. 10-2017-0178739, filed on Dec. 22, 2017, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to modules for real-time thermal behavior analysis, and more particularly, to modules for real-time thermal behavior analysis of a secondary cell battery such as a lithium ion battery and methods of operating the modules. 
     2. Description of the Related Art 
     A lithium ion battery (LIB), which is a type of secondary battery, is used in various industries due to its high energy density. For example, LIBs are applied to various apparatuses, such as portable electronic devices, electric cars, power supply apparatuses, etc. 
     An LIB is a component for storage and supply of energy. Heat is generated in processes of storing energy in an LIB and discharging energy from an LIB. The heat generated from an LIB may be normal heat generated in a process of storing energy, that is, charging the LIB, and in a process of using energy, that is, discharging the LIB, but may be abnormal heat due to a structural change of an internal structure of the LIB. For example, the generation of abnormal heat from the LIB may be caused by structural instability in an overcharged state and consequent structural change, or electrode detachment from a current collector, etc. 
     SUMMARY 
     Some example embodiments include modules for real-time thermal behavior analysis of a secondary cell battery. 
     Some example embodiments include methods of operating the modules for real-time thermal behavior analysis of a secondary cell battery. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented example embodiments. 
     According to some example embodiments, a module for real-time thermal behavior analysis of a secondary cell battery includes: a region for mounting a sample battery; a region for mounting a reference battery; and a housing covering the two regions and having an adiabatic characteristic. 
     In the module, the region for mounting the sample battery may be defined by two partitions facing each other. Also, the region for mounting the reference battery may be defined by two partitions facing each other. 
     The region for mounting the sample battery may be a region configured to vertically or horizontally mount the sample battery. 
     The region for mounting the reference battery may be a region configured to vertically or horizontally mount the reference battery. 
     The module is configured to connect to a differential scanning calorimetry (DSC) and heat sensors included in the DSC may be exposed through the two regions, and the two regions may receive heat from the DSC. 
     The module for real-time thermal behavior analysis of a secondary cell battery may further include a first cover covering the region for mounting the sample battery and a second cover covering the region for mounting the reference battery. 
     The two regions may be provided in the same holder and through holes may be formed in the two regions of the holder, the through holes respectively having sizes which allow the sample battery and the reference battery to be supported therein. 
     Elastic members may respectively be arranged on surfaces of the two partitions facing each other. 
     According to some example embodiments, a method of analyzing a thermal behavior of a secondary cell battery in real time by using the module described above includes: mounting a sample battery in the region for mounting the sample battery and mounting a reference battery in the region for mounting the reference battery; charging and discharging the sample battery; and measuring a heat flux of the sample battery. 
     The mounting of the sample battery and the reference battery in the two regions may include mounting the sample battery and the reference battery in a vertical direction or a horizontal direction. 
     The charging and discharging of the sample battery may include increasing temperatures of the sample battery and the reference battery step by step while times for the charging and the discharging are maintained constant. 
     The charging and discharging of the sample battery may include changing a temperature of an environment of the sample battery and the reference battery while the sample battery is maintained in an idle state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a cross-sectional view of a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments; 
         FIG. 2  is a cross-sectional view of a partially modified version of the module of  FIG. 1 ; 
         FIG. 3  is a perspective view of the module of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of a module for real-time thermal behavior analysis of a secondary cell battery, according to another example embodiment; 
         FIG. 5  is a perspective view of the module of  FIG. 4 ; 
         FIG. 6  is a cross-sectional view of a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7 ′ of  FIG. 6 ; 
         FIG. 8  is a graph showing thermal behavior of a secondary cell battery on which charge and discharge operations are performed under a 3C condition by using a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments; 
         FIG. 9  is a magnified view of a first region of the graph of  FIG. 8 ; 
         FIGS. 10 through 13  are graphs showing thermal behaviors of a secondary cell battery when charge and discharge speeds of the secondary cell battery are varied by using a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments; 
         FIG. 14  is a graph showing thermal behavior measured from a secondary cell battery in an idle state in a temperature-changing environment by using a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments; 
         FIGS. 15 through 18  are graphs showing thermal behaviors of a secondary cell in an environment in which charge and discharge speeds of the secondary cell battery are kept constant and a temperature of an operational environment of the secondary cell battery is changed by using a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments; and 
         FIG. 19  is a cross-sectional view showing expansion of an application field of a module for real-time thermal behavior analysis of a secondary cell battery, according to some example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Heat generated from a secondary cell battery, such as an LIB may be one of reasons for reducing a performance and a lifetime of the secondary cell battery. Accordingly, as the understanding of materials (for example, cathode, anode, separation membrane, electrolyte, etc.) that constitute the secondary cell battery, charging and discharging processes of the secondary cell battery, and a heat generation phenomenon according to an operational environment of the secondary cell battery increase, it is easier to obtain solutions for reducing or minimizing abnormal heat generation or unexpected heat generation of the secondary cell battery, and as a result, a lifetime of the secondary cell battery may be increased. 
     In the related art, in order to understand a heat generation characteristic of a secondary cell battery like an LIB, elements that constitute the secondary cell battery are separated and then a thermal behavior, that is, a thermal change of each of the elements is analyzed. For this analysis, a differential scanning calorimeter (DSC) has been used. 
     The DSC is an apparatus that shows an energy difference between a sample material and a reference material as a function of temperature when temperatures of the sample material and the reference material are changed by applying the same temperature program. 
     In the DSC, the sample material and the reference material respectively are placed in metal containers referred to as pans. Variation of heat application and heat generation with respect to the sample material and the reference material may be observed through a thermal sensor configured of a thermocouple. Through the observation, physical and chemical changes of the sample material may be analyzed. 
     Variation of heat being emitted from a sample or variation of heat being absorbed by the sample while heating, cooling, or maintaining the sample at a constant temperature is detected by a DSC. Based on the detection, a phase change/decomposition, a chemical reaction, etc. of the sample material may be analyzed. 
     However, there is a limit in obtaining information from the analysis by using a DSC of the related art because the information is obtained from physical and chemical changes that occur in the corresponding sample as a result of applying a simple thermal change (heating and cooling) to raw materials to be analyzed. 
     In detail, although thermal behavior information according to thermal changes of respective constituent elements of a secondary cell battery like the LIB may be obtained by using a DSC of the related art, it is difficult to obtain thermal behavior information according to a thermal change of the secondary cell battery itself. 
     Furthermore, in the case of a secondary cell battery like the LIB, information about a thermal behavior of the secondary cell battery itself in various environments and various states in which the secondary cell battery is actually operated may be important. This information may be used as an important basal factor in designing a large cell battery or a battery for automobiles. However, it is difficult to obtain the information from a DSC of the related art. 
     Hereinafter, provided is a module for real-time thermal behavior analysis of a secondary cell battery in operation using a DSC of the related art. 
     Modules described below may be applied to a thermal behavior analysis of a secondary cell battery itself, and furthermore, may be applied to a thermal behavior analysis with respect to a unit structure (unit body) or a composite structure that shows a thermal behavior according to internal or external environment variation. For these applications, the size of the modules may be increased or reduced. 
     Hereinafter, a module for a real time thermal behavior analysis of a secondary cell battery according to an example embodiment and methods of operating the same will now be described in detail with reference to the accompanying drawings. In the drawings, thicknesses of layers and regions may be exaggerated for clarity of the specification. The methods of operation will be described together with the descriptions of the modules. 
       FIG. 1  is a cross-sectional view of a module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment. 
     Referring to  FIG. 1 , reference numeral  20  may be a furnace block of a DSC. First and second protrusions  20 A and  20 B are present on an upper surface of the furnace block  20 . The first and second protrusions  20 A and  20 B may have a constant shape. The first and second protrusions  20 A and  20 B are upwardly perpendicular to the upper surface of the furnace block  20 . The first and second protrusions  20 A and  20 B are separated from each other. The first and second protrusions  20 A and  20 B may have the same length or different lengths from each other. The first and second protrusions  20 A and  20 B may be regions on which the module for real-time thermal behavior analysis of a secondary cell battery according to an example embodiment is mounted or coupled. Here, the mounted and coupled may include a case of inserting the module for a real time thermal behavior analysis of a secondary cell battery. For example, the first and second protrusions  20 A and  20 B may be members that are inserted or plugged into the modules for real-time thermal behavior analysis of a secondary cell battery. A first heater  52  may be included in the first protrusion  20 A. A first heat sensor  40  is arranged on the first heater  52 . The first heater  52  and the first heat sensor  40  are spaced apart from each other. The first heat sensor  40  may be provided in the first protrusion  20 A in a buried state. In this case, a surface of the first heat sensor  40  may be exposed. The exposed surface of the first heat sensor  40  may contact a sample battery C 1 . The exposed surface of the first heat sensor  40  may have a height as the same level to an upper surface of the first protrusion  20 A. The first heat sensor  40  may be arranged to cover an entire upper surface of the first protrusion  20 A not in a buried state. 
     A second heater  54  is included in the second protrusion  20 B. A second heat sensor  42  is arranged on the second heater  54 . The second heater  54  and the second heat sensor  42  are spaced apart from each other. An arrangement of the second heat sensor  42  may be the same arrangement as the first heat sensor  40 . 
     The module for real-time thermal behavior analysis of a secondary cell battery is arranged on the upper surface of the furnace block  20  around the first and second protrusions  20 A and  20 B. 
     In detail, two external walls  50  are arranged on the upper surface of the furnace block  20 . The external walls  50  are spaced apart from each other.  FIG. 1  is a cross-sectional view, and thus, the two external walls  50  are depicted as separated from each other, but actually, the two external walls  50  are a single unit that surrounds the first and second protrusions  20 A and  20 B. The first and second protrusions  20 A and  20 B are arranged between the two external walls  50 . First and second partitions  30  and  32  are respectively arranged on both sides of the first protrusion  20 A. The first partition  30  is arranged between the left-side external wall  50  and the first protrusion  20 A. A lower part of a vertical part of the first partition  30  covers an entire left-side surface of the first protrusion  20 A, and an upper surface of the first partition  30  extends upwards greater than a height of the first protrusion  20 A. A horizontal part of the first partition  30  contacts the left-side external wall  50 . The first partition  30  and the left-side external wall  50  may have the same height. The vertical part of the first partition  30  may parallel to the left-side external wall  50 . The second partition  32  is arranged between the first and second protrusions  20 A and  20 B. A vertical part of the second partition  32  is parallel to the vertical part of the first partition  30 . A lower part of the vertical part of the second partition  32  covers an entire right-side surface of the first protrusion  20 A, and an upper surface of the second partition  32  extends upwards greater than a height of the first protrusion  20 A. The second partition  32  includes a horizontal part extending in a right-side direction on the upper surface of the furnace block  20 . The horizontal part of the second partition  32  is shared with an adjacent fourth partition  36 . A space having a slot shape is defined above an upper surface of the first protrusion  20 A by upper parts of the vertical parts of the first and second partitions  30  and  32 . The sample battery C 1  is inserted into the space. The sample battery C 1  contacts the first heat sensor  40 . Also, the sample battery C 1  may contact the first and second partitions  30  and  32 . When it is necessary to increase a temperature of the sample battery C 1  in a process of measuring a thermal behavior of the sample battery C 1 , the sample battery C 1  may receive heat from the first heater  52 . 
     Next, a third partition  34  is arranged between the second protrusion  20 B and the right-side external wall  50 . The fourth partition  36  is arranged between the second protrusion  20 B and the second partition  32 . The second partition  32  and the fourth partition  36  are connected to each other through a horizontal part therebetween. A vertical part of the third partition  34  is parallel to the right-side external wall  50 . The horizontal part of the third partition  34  covers the upper surface of the furnace block  20  between the third partition  34  and the right-side external wall  50 . The horizontal part of the third partition  34  contacts the right-side external wall  50 . A lower part of the third partition  34  covers an entire right-side surface of the second protrusion  20 B. An upper unit of the third partition  34  upwardly extends higher than the second protrusion  20 B. A lower part of a vertical part of the fourth partition  36  covers an entire left side surface of the second protrusion  20 B. An upper part of the fourth partition  36  upwardly extends higher than the second protrusion  20 B. A space above the upper surface of the second protrusion  20 B is a defined space having a slot shape, due to the upper parts of the third partition  34  and the fourth partition  36  arranged on both sides of the second protrusion  20 B. A reference battery C 2  is inserted into the defined space, and the reference battery C 2  contacts the second heat sensor  42 . Also, the reference battery C 2  contacts the third partition  34  and the fourth partition  36 . 
     When it is necessary to supply heat to the reference battery C 2  in a process of measuring a thermal behavior, heat may be supplied to the reference battery C 2  by the second heater  54 . A temperature-maintaining operation or a temperature-increasing operation of cells C 1  and C 2 , that is, the sample battery C 1  and the reference battery C 2  may be performed by the first heater  52  and the second heater  54 . 
     Whole of the members  30 ,  32 ,  34 ,  36 , and  50  arranged on the upper surface of the furnace block  20  around the first and second protrusions  20 A and  20 B may be a single body. Also, the members  30 ,  32 ,  34 ,  36 , and  50  arranged on the upper surface of the furnace block  20  may be, as a whole, a holder that supports the sample battery C 1  and the reference battery C 2  and may constitute a module used for analyzing thermal behavior of the secondary cell battery in real time. 
     The whole members  30 ,  32 ,  34 ,  36 , and  50  arranged on the first and second protrusions  20 A and  20 B and the upper surface of the furnace block  20  around the first and second protrusions  20 A and  20 B are covered by a housing  46 . The housing  46  may be transparent. The housing  46  may be a housing formed of a material having a high adiabatic property, that is, a high adiabatic characteristic. The housing  46  may be a constituent part of the module. The housing  46  may cover the furnace block  20 . That is, the housing  46  may tightly contact side surfaces of the furnace block  20  and simultaneously adiabatic property is maintained between the housing  46  and the side surfaces of the furnace block  20 . With the aid of the adiabatic property of the housing  46 , a whole internal space of the housing  46  may be maintained at a constant temperature. Accordingly, the members  30 ,  32 ,  34 ,  36 , and  50 , the sample battery C 1 , and the reference batteries C 2  that are covered by the housing  46  may be placed at a constant temperature atmosphere. 
     Reference numeral  48  is a device that provides a charge/discharge atmosphere to the sample battery C 1 , and may be a potentiostat. The device  48  may be arranged on an outside of the housing  46 . In order to provide a charge/discharge atmosphere to the sample battery C 1 , the device  48  may be connected to the first and second partitions  30  and  32  (solid lines). Also, as indicted by dashed lines, the device  48  may be directly connected to the sample battery C 1 . The lines that connect the device  48  to the first and second partitions  30  and  32  are very fine, and the device  48  and the first and second partitions  30  and  32  may be connected through a lower part of the housing  46 . 
       FIG. 2  is a cross-sectional view of a partially modified version of the module of  FIG. 1 . 
     Referring to  FIG. 2 , elastic members  60  and  62  respectively are arranged on surfaces of the upper part of the first partition  30  and the upper part of the second partition  32  facing each other. The elastic members  60  and  62  are separated from the first protrusion  20 A. With the aid of the elastic members  60  and  62 , the sample battery C 1  inserted between the first and second partitions  30  and  32  may be smoothly and fixedly held. Also, elastic members  64  and  66  may be provided on surfaces of the upper parts of the third and fourth partitions  34  and  36  facing each other. The elastic members  64  and  66  are separated from the second protrusion  20 B. With the aid of the elastic members  64  and  66 , the reference battery C 2  may be smoothly mounted and may be fixedly held compared to when the elastic members  64  and  66  are not present. 
       FIG. 3  is a perspective view of the module of  FIG. 1 . 
     Referring to  FIG. 3 , the external wall  50  has a cylindrical shape that surrounds the first through fourth partitions  30 ,  32 ,  34 , and  36 . 
       FIG. 4  is a cross-sectional view of a module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment. 
     Referring to  FIG. 4 , first and second supporters  72  and  74  are arranged on a furnace  70 . The furnace  70  and the first and second supporters  72  and  74  are spaced apart from each other. The sample battery C 1  is mounted on the first supporter  72 . The reference battery C 2  is mounted on the second supporter  74 . First and second columns  76  and  78  that connect the furnace  70  and the first and second supporters  72  and  74  are arranged between the furnace  70  and the first and second supporters  72  and  74 . The first column  76  supports the first supporter  72 . Also, the first column  76  performs a function of transferring heat from the furnace  70  to the sample battery C 1  in a process of measuring a thermal behavior. Accordingly, the first column  76  may be formed of a material suitable for heat transfer. The first column  76  may be arranged so that an upper surface thereof contacts the sample battery C 1  through the first supporter  72 . A height of the upper surface of the first column  76  may be the same as an upper surface of the first supporter  72 . The second column  78  supports the second supporter  74 . The second column  78  may be arranged so that an upper surface thereof is exposed through the second supporter  74 . A height of an upper surface of the second column  78  may be the same as the upper surface of the second supporter  74 . Accordingly, the upper surface of the second column  78  may contact the reference battery C 2  placed on the second supporter  74 . In a process of measuring a thermal behavior, heat supplied from the furnace  70  may be supplied to the reference battery C 2  through the second column  78 . Accordingly, the second column  78  may be formed of a material suitable for heat transfer. 
     The first supporter  72  and the sample battery C 1  are covered by a first cover  86 . The second supporter  74  and the reference battery C 2  are covered by a second cover  88 . The first cover  86  covers a whole upper surface of the first supporter  72  and may cover side surfaces of the first supporter  72 . The first cover  86  may be tightly coupled with the first supporter  72 . For this purpose, both the first cover  86  and the first supporter  72  may be coupled by using a coupling method, such as a screw. 
     The second supporter  74  and the reference battery C 2  are covered by the second cover  88 . The second cover  88  may covers a whole upper surface of the second supporter  74  and may cover side surfaces of the second supporter  74 . The second cover  88  may be tightly coupled with the second supporter  74 . For this purpose, the second cover  88  may be coupled with the second supporter  74  by using a coupling method, such as a screw. 
     The first and second supporters  72  and  74  and the first and second covers  86  and  88  may be holders that accommodate and hold the sample battery C 1  and the reference battery C 2 . 
     The first column  76  and the second column  78  may extend into the furnace  70 . The furnace  70  may include heaters that heat the first column  76  and the second column  78  to supply heat to the sample battery C 1  and the reference battery C 2 . The heaters may be provided in a form surrounding the first column  76  and the second column  78 . The furnace  70  may include a fixing plate  84  for fixing the first column  76  and the second column  78 . First and second heat sensors  80  and  82  may be arranged on lower parts of the first column  76  and the second column  78 , respectively. The first and second heat sensors  80  and  82  detect heat generated from the sample battery C 1  and the reference battery C 2 , respectively, in a process of measuring a thermal behavior. The first and second heat sensors  80  and  82  may be located under the heaters. The furnace  70 , the first and the second columns  76  and  78 , the first and second supporters  72  and  74 , the sample battery C 1 , the reference battery C 2 , and the first and second covers  86  and  88  may be covered by a housing  90 . The housing  90  may have the same adiabatic characteristic as the housing  46  of  FIG. 1 . 
       FIG. 5  is a three-dimensional view of the module described with reference to  FIG. 4 . 
     Referring to  FIG. 5 , the first and second covers  86  and  88  have a shape similar to a cylindrical cover, and are screw coupled with the first and second supporters  72  and  74 . 
       FIG. 6  is a cross-sectional view of a module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment. 
     Referring to  FIG. 6 , a holder  100  has a battery mounting region  102 . The sample battery C 1  and the reference battery C 2  are mounted in the battery mounting region  102 . The sample battery C 1  and the reference battery C 2  are separated from each other in a horizontal direction. 
       FIG. 7  is a cross-sectional view of the module of  FIG. 6  cut in a 7-7′ direction. 
     Referring to  FIG. 7 , first and second through holes  104  and  106  are formed in the holder  100 . The first through hole  104  is formed in a region where the sample battery C 1  is mounted, and the second through hole  106  is formed in a region where the reference battery C 2  is mounted. When the sample battery C 1  and the reference battery C 2  are mounted, the first through hole  104  is covered by the sample battery C 1  and the second through hole  106  is covered by the reference battery C 2 . The first through hole  104  has a diameter less than that of the sample battery C 1 . The second through hole  106  also has a diameter less than that of the reference battery C 2 . Accordingly, the sample battery C 1  and the reference battery C 2  respectively are supported by circumferential parts of the first and second through holes  104  and  106  of the holder  100 . 
     Referring to  FIGS. 6 and 7 , the battery mounting region  102  is lower than an upper surface of the holder  100  around the battery mounting region  102 . That is, the battery mounting region  102  in the holder  100  is concaved. Accordingly, when the sample battery C 1  and the reference battery C 2  are mounted in the holder  100 , portions of side surfaces of the sample battery C 1  and the reference battery C 2  are covered by the holder  100 . 
     In the module of  FIGS. 6 and 7 , heat sensors may be arranged on a lower side of the sample battery C 1  and the reference battery C 2 , respectively, and contact the sample battery C 1  and the reference battery C 2 . The heating of the sample battery C 1  and the reference battery C 2  may be performed below the sample battery C 1  and the reference battery C 2  through the first and second through holes  104  and  106 , respectively. 
     Hereinafter, a measurement result of a thermal behavior of the sample battery C 1  by using the module for real-time thermal behavior analysis of a secondary cell battery according to an example embodiment will be described. The sample battery C 1  used for obtaining the measurement result is a battery including only a cathode. At this point, a cathode material was, for example, LiNi 0.33 Co 0.33 Mn 0.33 O 2 . The reference battery C 2  includes only a battery case that does not include internal constituent members. Also, a potentiostat was used as a charge/discharge device with respect to the sample battery C 1 . 
       FIG. 8  is a graph showing a thermal behavior of a secondary cell battery to which charge and discharge operations are performed under a 3C condition by using a module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment. Here, 1C denotes that a time required for charging and discharging is one hour. The 3C condition denoted that the charge and discharge may be performed with a speed of three times faster than 1C. 
     In  FIG. 8 , a first graph (an upper graph)  8 G 1  shows a voltage variation when charge and discharge of the sample battery C 1  are performed. A second graph (a lower graph)  8 G 2  indicates a heat flux showing a thermal behavior of the sample battery C 1  when the sample battery C 1  is charged and discharged. 
     In  FIG. 8 , a horizontal axis indicates time (minute), a left-vertical axis indicates voltage, and a right-vertical axis indicates a heat flux, which are the same in  FIGS. 9 through 13  and in  FIGS. 15 through 17 . 
     In the first graph  8 G 1 , a first peak  8 P 1  is a downward peak when the sample battery C 1  is discharged. In the second graph  8 G 2 , a second peak  8 P 2  indicates a peak in response to discharging of the sample battery C 1 , and a third peak  8 P 3  indicates a peak in response to charging of the sample battery C 1 . 
     Referring to  FIG. 8 , at the same 3C charge/discharge condition, a heat flux generated from the sample battery C 1  during four cycles shows a high reproducibility and reversibility. 
       FIG. 9  is a magnified view of a first region  8 A 1  corresponding to a charge/discharge time of 200 minutes to 400 minutes of the graph of  FIG. 8 . 
     Referring to  FIG. 9 , heat peaks  8 P 3  and  8 P 2  correspond to a charge section  9 R 1  and a discharge section  9 R 2 , respectively. In an idle section of the sample battery C 1 , that is, in a section in which charging and discharging of the sample battery C 1  are not implemented, a heat peak is not generated. 
       FIGS. 10 through 13  are graphs showing a heat flux that indicates thermal behaviors of a secondary cell battery when charge and discharge speeds are varied by using a module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment. 
       FIG. 10  shows a heat flux with respect to the sample battery C 1  when a charging and discharging speed with respect to the sample battery C 1  is 0.5C.  FIGS. 11, 12 and 13  show heat fluxes when charge and discharge speeds are 10, 3C, and 5C, respectively. 
     In  FIG. 10 , a first graph (an upper graph)  10 G 1  shows a voltage variation of the sample battery C 1  when the sample battery C 1  is charged and discharged. A second graph (a lower graph)  10 G 2  indicates a heat flux showing a thermal behavior of the sample battery C 1  when the sample battery C 1  is charged and discharged. A heat peak  10 P 2  appears in the second graph  10 G 2  in response to a downward voltage peak  10 P 1  of the first graph  10 G 1  when the sample battery C 1  is discharged. 
     In  FIG. 11 , a first graph (an upper graph)  11 G 1  shows a voltage variation of the sample battery C 1  when the sample battery C 1  is charged and discharged. A second graph (a lower graph)  11 G 2  indicates a heat flux showing a thermal behavior of the sample battery C 1  when the sample battery C 1  is charged and discharged. A heat peak  11 P 2  appears in the second graph  11 G 2  in response to a downward voltage peak  11 P 1  of the first graph  11 G 1  when the sample battery C 1  is discharged. 
     In  FIG. 12 , a first graph (an upper graph)  12 G 1  shows a voltage variation of the sample battery C 1  when the sample battery C 1  is charged and discharged. A second graph (a lower graph)  12 G 2  indicates a heat flux showing a thermal behavior of the sample battery C 1  when the sample battery C 1  is charged and discharged. A heat peak  12 P 2  appears in the second graph  12 G 2  in response to a downward voltage peak  12 P 1  of the first graph  12 G 1  when the sample battery C 1  is discharged. A heat peak  12 P 3  also appears in response to a charge section  12 R 1 . 
     In  FIG. 13 , a first graph (an upper graph)  13 G 1  shows a voltage variation of the sample battery C 1  when the sample battery C 1  is charged and discharged. A second graph (a lower graph)  13 G 2  indicates a heat flux showing a thermal behavior of the sample battery C 1  when the sample battery C 1  is charged and discharged. A heat peak  13 P 2  appears in the second graph  13 G 2  in response to a downward voltage peak  13 P 1  of the first graph  13 G 1  when the sample battery C 1  is discharged. A heat peak  13 P 3  also appears in response to a charge section. 
     Referring to  FIGS. 10 through 13 , as moved from  FIG. 10  to  FIG. 13 , that is, as the charge and discharge speeds with respect to the sample battery C 1  increase, it is seen that a change quantity of the heat flux increases in the charge and discharge sections. The result indicates that a larger amount of heat is generated under a rapid charge condition, such as a high speed charge. 
       FIG. 14  shows a heat flux showing a thermal behavior of the sample battery C 1  when temperatures of the sample battery C 1  and the reference battery C 2  are increased while the sample battery C 1  is maintained at an idle state, that is, charge and discharge operations with respect to the sample battery C 1  are not performed. At this point, a battery that includes all internal constituent elements of a battery was used as the sample battery C 1 . Also, in order to increase the temperatures of the sample battery C 1  and the reference battery C 2 , a heater (for example, the first heater  52  or the second heater  54 ) included in the furnace of a DSC was used. A temperature increasing rate was maintained at 5° C. per minute. 
     In  FIG. 14 , a horizontal axis indicates temperature, and a vertical axis indicates heat flux. 
     In  FIG. 14 , a first peak  14 P 1  is resulted from a reaction of an electrolyte and a lithium salt, and a downward second peak  14 P 2  is resulted from melting of a separation film as a temperature increase. A third peak  14 P 3  which is a relatively large peak is resulted from the heat generation due to a cathode (binder+active material+LiPF6/electrolyte) reaction. A first section  14 R 1  of the graph is resulted from dissolution of the electrolyte as the temperature increase. 
     As depicted in  FIG. 14 , when the module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment is used, a heat flux change due to state changes of internal constituent elements (for example, an electrolyte, a separation film, a cathode, etc.) of a sample battery C 1  according to a temperature atmosphere change of the sample battery C 1  may be measured in a single measurement. 
       FIGS. 15 through 17  are graphs showing thermal behaviors of a secondary cell battery measured by using a module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment, when charge and discharge speeds of the secondary cell battery are kept constant and a temperature of an operational atmosphere of the secondary cell battery is changed. The sample battery C 1  used for obtaining the results of  FIGS. 15 through 17  may be the same as the sample battery C 1  used for obtaining the result of  FIG. 8 . 
     In each of  FIGS. 15 through 17 , first graphs  15 G 1 ,  16 G 1 , and  17 G 1  are charge and discharge graphs with respect to the sample battery C 1 , and second graphs  15 G 2 ,  16 G 2 , and  17 G 2  indicate heat fluxes showing thermal behavior the sample battery C 1 . 
       FIG. 15  shows a result when a temperature atmosphere of the sample battery C 1  is 30° C.,  FIG. 16  shows a result when a temperature atmosphere of the sample battery C 1  is 50° C., and  FIG. 17  shows a result when a temperature atmosphere of the sample battery C 1  is 80° C. 
     Referring to  FIGS. 15 through 17 , heat peaks appear when the sample battery C 1  is charged and discharged, and no heat peaks appear when the sample battery C 1  is in an idle state between the charge and discharge of the sample battery C 1 . 
       FIG. 18  shows a heat flux of the sample battery C 1  when a temperature atmosphere of the sample battery C 1  is 30° C., 50° C., and 80° C. A first graph  18 G 1  indicates a result when the temperature atmosphere is 30° C., a second graph  18 G 2  indicates a result when the temperature atmosphere is 50° C., and a third graph  18 G 3  indicates a result when the temperature atmosphere is 80° C. In each graph, a left-side peak indicates a heat peak appeared when the sample battery C 1  is charged, and a right-side peak indicates a heat peak appeared when the sample battery is discharged. 
     Referring to  FIG. 18 , it is seen that the heat flux variation of the sample battery C 1  according to the variation of a temperature atmosphere of the sample battery C 1  is not large. 
     The module for real-time thermal behavior analysis of a secondary cell battery, according to an example embodiment, may be used for other purposes in addition to the use for analyzing thermal behavior. As an example, as depicted in  FIG. 19 , the variation of pressure or thickness of a battery may be measured by using the module for real-time thermal behavior analysis of a secondary cell battery. 
     Referring to  FIG. 19 , a first penetrating member  122  that penetrates through the upper part of the vertical part of the first partition  30 , a second penetrating member  124  that penetrates through the upper part of the vertical part of the second partition  32 , a third penetrating member  126  that penetrates through the upper part of the vertical part of the third partition  34 , and a fourth penetrating member  128  that penetrates through the upper part of the vertical part of the first partition  36  are provided. The first and second penetrating members  122  and  124  may be configured to face each other with the sample battery C 1  as a center. The third and fourth penetrating members  126  and  128  may be configured to face each other with the reference battery C 2  as a center. The first penetrating member  122  and the second penetrating member  124  may be used for measuring the variation of pressure or thickness of the sample battery C 1 . A measuring device  120  is connected to the first penetrating member  122 . The measuring device  120  is an apparatus for measuring the variation of pressure or thickness of the sample battery C 1 . The sample battery C 1  may be a pouch type battery. 
     When the sample battery C 1  and the reference battery C 2  are heated by using the first heater  52  and the second heater  54 , a thickness change or an expansion pressure of the sample battery C 1  may vary according to an inner configuration of the sample battery C 1 . Through real-time measurement of the variation of thickness and pressure of the sample battery C 1  by using the measuring device  120 , a relationship between internal constituent elements of the sample battery C 1  and a pressure variation of the sample battery C 1 , or between internal constituent elements of the sample battery C 1  and a thickness variation of the sample battery C 1  may be seen. 
     The module for real-time thermal behavior analysis of a secondary cell battery according to an example embodiment measures a thermal behavior with respect to a whole secondary cell battery, that is, a secondary cell battery itself. Accordingly, a thermal behavior of a secondary cell battery may be analyzed in real time, and a state of a thermal behavior of the secondary cell battery may be observed under various atmospheres in which the secondary cell battery is used. This analysis result may provide useful information in designing a secondary cell battery having an improved or optimum thermal behavior, and may provide useful information in designing a larger capacity battery and a battery for cars. 
     While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.