JP2009301893A - Battery testing device and battery testing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery testing device and a battery testing method capable of appropriately verifying behavior when a battery is broken. <P>SOLUTION: Behavior when a secondary 2 battery is broken is appropriately verified by partially crushing the secondary battery 2 placed on a testing stand 3 with a pressing member, conducting good and bad candidate determination of the secondary battery 2 by measuring the temperature of the secondary battery 2. In addition, the partially broken secondary battery 2 is charged and discharged only the number of the prescribed cycles, and then the temperature of the secondary battery 2 is measured to determine good or bad of the secondary battery 2. As a result, behavior of the secondary battery 2 when the secondary battery 2 is continuously used after partially crushing is appropriately verified. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a test apparatus and a test method for evaluating the performance and safety of a rechargeable battery such as a lithium ion battery built in a portable device such as a mobile phone.

  A rechargeable secondary battery built in a portable device such as a mobile phone, for example, a lithium ion battery is composed of an organic electrolyte containing a lithium cobaltate compound as a positive electrode, graphite as a negative electrode, and a lithium salt as an electrolyte. . This secondary battery has a structure in which a positive electrode, a negative electrode, and a separator, which are electrically insulated from each other between a positive electrode and a negative electrode made of a thin thin film film, are wound. In particular, a prismatic lithium ion battery is formed by transforming a rolled one into a prismatic shape, inserting it into a prismatic aluminum can or the like, injecting an electrolyte, and sealing it.

  This lithium-ion battery is characterized by its small size, light weight, and high energy density. For this purpose, it uses a highly active cobalt acid compound or organic electrolyte solution, and has a thin positive electrode or negative electrode. A battery is constructed using a thin film. Furthermore, in order to reduce the size and weight of the battery, the above battery material is stored in a lightweight aluminum case.

In a lithium ion battery having this type of structure, the internal electrodes of the positive electrode and the negative electrode may be short-circuited due to damage to the internal electrodes of the battery due to external pressure, which may cause problems such as abnormal heat generation and smoke generation of the battery. Therefore, conventionally, a safety test has been performed in which a lithium ion battery is intentionally destroyed and safety is ensured in a destroyed state (see Patent Document 1). For example, in this type of safety test, a fully charged lithium ion battery is pressed from the outside with a metal bar (round bar) and completely crushed (total collapse), and the behavior of the battery after total collapse, for example, about Check if abnormal heat generation or fuming above 160 ° C occurs. Then, only the battery that does not become abnormal such as abnormal heat generation or smoke is judged as a non-defective battery (OK battery), thereby evaluating the safety of the battery.
JP 2005-327616 A

  However, it is rare that the battery is completely crushed by the external force encountered by a general lithium ion battery in a mobile phone or the like, and it is overwhelming that the battery is partially damaged (partial collapse). Too many. Therefore, it can be said that the total crushing test of the battery is an extreme test within a range generally used in a mobile phone or the like, but it is not appropriate as a test for behavior when the battery is broken.

  Further, even if a partial crushing test can be performed by partially damaging the battery using a conventional device, the evaluation immediately after the partial crushing is possible, but it cannot be verified until subsequent use. In particular, in the case of a secondary battery used for a mobile phone or the like, if the behavior immediately after dropping is normal, it is often used as it is. For example, even if a secondary battery is accidentally damaged while using a mobile phone, if the secondary battery can be used (it can be installed in a mobile phone and charged / discharged), it is usually Although use is prohibited, there are cases where the user continues to use the secondary battery by mistake. In addition, the conventional test apparatus and test method cannot verify a battery that has been used continuously after being damaged, and is not appropriate as a test for behavior when the battery is damaged.

  Therefore, an object of the present invention is to provide a battery test apparatus and a battery test method capable of appropriately verifying behavior when a battery is damaged.

  As a result of repeated studies for appropriately evaluating the safety of the battery, the inventor of the present application destroys the entire battery system when the battery is completely crushed, such as a lithium ion battery. On the other hand, if a battery such as a lithium-ion battery is partially damaged and an internal short circuit occurs, the battery system operates except for the damaged part, so internal heat generation due to the internal short circuit continues. The knowledge that it is easy to do was acquired. As a result, the inventor has found that when a battery such as a lithium ion battery is damaged by applying external force, partial collapse tends to cause instability of the battery (occurrence of abnormal heat generation or smoke generation). Obtained. Furthermore, even if the inventor of the present application is in a normal state in which charging is possible immediately after partial crushing, if the battery is continuously used as it is, the result of vibration, impact, aging, battery deterioration, swelling, etc. It was found that there is a possibility that abnormal events such as abnormal heat generation and smoke may occur due to internal short circuit of the battery. The present invention has been made based on this finding.

  A battery test apparatus according to the present invention includes a first test unit for performing a crushing test of a rechargeable battery, and a second test unit for performing a charge / discharge test of the battery. The unit includes a test stand on which the battery is installed, a pressing member that crushes the battery, a pressing means that controls the pressing force of the pressing member so that the battery is partially collapsed, and the temperature of the partially collapsed battery. And a first measurement unit that measures at least one of the voltage, and the second test unit includes a power control unit that alternately repeats charging and discharging of the battery partially collapsed by the pressing member; And second measuring means for measuring the temperature of the battery that has been repeatedly charged and discharged by the control means.

  The total collapsed state of the battery is a condition that occurs very rarely in the situation where a mobile device such as a mobile phone is used.In addition, the total collapsed state of the battery is the worst condition in determining an abnormality caused by an internal short circuit or the like. Therefore, the behavior when the battery was damaged could not be properly verified. However, according to the present invention, since the temperature and voltage are measured in a state in which the battery is partially collapsed, it is possible to appropriately verify the behavior when the battery is damaged. Furthermore, even if it is normal immediately after partial crushing, an abnormal event may occur if the battery is used continuously thereafter. However, according to the present invention, it is possible to appropriately verify the behavior of the battery when the battery is continuously used after partial collapse.

  Furthermore, it is preferable that the second test unit further includes a thermostatic device that maintains the temperature of the environment surrounding the partially collapsed battery at a predetermined temperature. By providing the thermostatic device, the test environment by the second test unit can be maintained at a temperature that assumes the actual use environment of the secondary battery, and the battery when the battery is used continuously after partial collapse Can be verified appropriately.

  Furthermore, it is preferable that the thermostatic device keeps the temperature of the ambient environment of the battery at an arbitrary temperature between −5 ° C. and + 50 ° C. It is possible to appropriately verify the behavior of the battery at a temperature assuming the actual usage environment of the secondary battery.

  Furthermore, the battery is rectangular and has a rectangular pair of flat portions and a side portion surrounding the pair of flat portions, and the pressing means is configured such that at least one of the flat portion and the side portion of the battery is predetermined by the pressing member. It is preferable that the battery is pressed with the pressing member until the depth becomes. By defining the predetermined depth, it becomes possible to perform tests on a plurality of batteries under the same conditions.

  Furthermore, the short side of the plane portion is longer than the width of the side surface portion, which is the distance between the pair of plane portions, and the predetermined depth in the plane portion is in the range of 1/8 to 1/4 of the width of the side surface portion. The predetermined depth in the side surface portion is preferably included in a range of ¼ to ½ of the length of the short side of the plane portion. Since the partial crushing depth is likely to occur in the secondary battery in an actual usage mode, a more realistic test can be performed and the behavior of the battery can be appropriately verified.

  Furthermore, it is preferable that the power control means can set the amount of discharge in one cycle to an arbitrary amount equal to or less than the amount from full charge to complete discharge. The user may charge the secondary battery after complete discharge, or may charge the secondary battery before full discharge. Each of these cases can be flexibly handled.

  In addition, the battery test method according to the present invention includes a partial crushing step in which a battery to be tested is placed on a test bench, and a pressing force is applied to the battery so that the battery is incompletely crushed. A first detection step for detecting at least one of temperature and voltage; a first determination step for determining a good product candidate if a detection result in the first detection step is equal to or less than a threshold for determining a good product candidate; A power control step in which charging and discharging are alternately repeated for a predetermined number of cycles for a battery determined as a good product candidate in one determination step, and charging and discharging are repeated for a predetermined number of cycles in the power control step. A second detection step for detecting the temperature of the battery, and a non-defective product if the temperature detected in the second detection step is equal to or less than a predetermined threshold value for determining a good product Characterized in that it comprises a second determination step that.

  According to the present invention, it is possible to appropriately verify the behavior when a battery is damaged. Furthermore, it is possible to appropriately verify the behavior of the battery when the battery is continuously used after partial collapse.

  Furthermore, it is preferable that the predetermined threshold for determining good product candidates is 160 ° C. When an internal short circuit occurs due to partial crushing of a battery, particularly a secondary battery, the temperature of the secondary battery rises due to Joule heat due to the short circuit current, and the temperature of the secondary battery becomes the critical temperature (the material of the secondary battery 2). When the temperature reaches a temperature at which the thermal decomposition of the secondary battery 2 starts, the thermal decomposition of the electrode of the secondary battery 2 and the battery material itself of the electrolytic solution starts, thereby starting a thermal runaway. Therefore, since it is most desirable to monitor whether or not the temperature of the secondary battery reaches the seaside temperature as a criterion for determining a defective battery, the predetermined threshold is preferably set to 160 ° C.

  Further, prior to the partial crushing step, charging and discharging are alternately repeated for a predetermined number of cycles without partially crushing the battery to be tested, and a preliminary test step for determining the relationship between the battery capacity and the number of cycles Preferably, the predetermined cycle number in the power control step is defined based on the relationship between the deteriorated battery capacity of the battery and the cycle number in the preliminary test step. By performing the preliminary test step, the predetermined number of cycles can be defined based on the relationship between the number of cycles and the deteriorated battery capacity of the battery that is not partially collapsed.

  Further, from the relationship between the deteriorated battery capacity of the battery and the number of cycles in the preliminary test step, the reference cycle number at which the deteriorated battery capacity is initially included in the range of 50% to 25% is obtained. In the power control step, It is preferable that charging and discharging are alternately repeated by the number of reference cycles. The quality of the battery can be determined based on the case where the deteriorated battery capacity is included in the range of 50% to 25%.

  According to the present invention, it is possible to appropriately achieve a behavior when a battery is damaged.

  Hereinafter, preferred embodiments of a battery test apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram schematically illustrating the battery testing apparatus according to the first embodiment. As shown in FIG. 1, the battery test apparatus 100 is a first test for a partial crush test for examining the behavior when a rechargeable secondary battery 2 such as a lithium ion battery or a lithium polymer battery is partially crushed. A unit 101 and a second test unit 103 for a charge / discharge test for examining the behavior of the secondary battery 2 when charging and discharging of the partially collapsed secondary battery 2 are repeated.

  As shown in FIG. 1 and FIG. 2, the first test unit 101 crushes the secondary battery 2 by contacting the secondary battery 2 with the test table 3 on which the secondary battery 2 to be tested is installed. A round bar (pressing member) 5 that is connected to a movable plate 7 that moves the round bar 5 up and down relative to the secondary battery 2, and a pressure device (pressurizing unit) that controls the pressing force of the round bar 5 on the secondary battery 2 Pressure means) 9, a temperature sensor 11 in contact with the secondary battery 2 placed on the test table 3, and a measuring device (first measuring means) 13 connected to the temperature sensor 11. In the present embodiment, the behavior of the collapsed secondary battery 2 is verified based on the temperature detected by the temperature sensor 11, but the voltage of the secondary battery 2 is measured instead of the temperature, A first measuring unit that measures both voltages may be provided, and the behavior of the collapsed secondary battery 2 may be verified based on the measurement result.

  A pair of guide bars 3a are erected on the test table 3 so as to sandwich a predetermined portion where the secondary battery 2 is installed, and the movable plate 7 moves up and down along a predetermined track while being guided by the guide bar 3a. . A round bar fixing bar 7a protrudes from the lower surface of the movable plate 7. The round bar 5 is fixed to the lower end of the round bar fixing bar 7a so as to be horizontal (perpendicular to the round bar fixing bar 7a). Yes.

  The pressurizing device 9 includes a control circuit 9a composed of a CPU, a RAM, a ROM, and the like, a drive motor 9b that moves the movable plate 7 up and down, and an operation unit 9c that receives an operation input from a tester. For example, when the control circuit 9a receives the type of the secondary battery 2 through the operation unit 9c, the control circuit 9a controls the drive motor 9b so that the pressing force corresponding to the secondary battery 2 can be applied. The secondary battery 2 is partially crushed by 5.

  The measurement device 13 includes a measurement circuit 13a including a CPU, a RAM, a ROM, and the like, and an output unit 13b such as a display that outputs measurement results. The measuring device 13 is connected to the temperature sensor 11 by wire or wirelessly, and outputs a measurement result by the temperature sensor 11 from the output unit 13b. Furthermore, the measuring device 13 determines whether or not the measurement result is a predetermined threshold value, for example, 160 ° C. or less.

  The measuring device 13 and the pressurizing device 9 are connected so that signals can be transmitted and received. The pressurizing device 9 presses the secondary battery 2 with a specified pressing force that causes partial collapse, and notifies the measuring device 13 of data relating to the pressing force. The measuring device 13 receives data related to the pressing force and outputs information necessary for the quality determination of the secondary battery 2 from the output unit 13b.

  As shown in FIGS. 1 and 3, the second test unit 103 accommodates the secondary battery 2 partially collapsed by the first test unit 101, and has a predetermined environment surrounding the secondary battery 2. A constant temperature device 25 that maintains the temperature is provided. In the case of a mobile phone as a representative mobile device, charging is possible in the range of −5 ° C. to + 50 ° C., but charging is prohibited in other temperature ranges (see FIG. 7). In accordance with this temperature setting, the thermostatic device 25 is set to maintain an arbitrary temperature within the range of −5 ° C. to + 50 ° C. as the environmental temperature (test temperature).

  The second test unit 103 includes a charger / discharger (power control means) 27, a temperature sensor 29, a measuring device 31, and an output device 33.

  The charger / discharger 27 charges and discharges the secondary battery 2 under specified conditions. The charger / discharger 27 includes cords 27a and 27b connected to the positive terminal 2f and the negative terminal 2g of the secondary battery 2, respectively. When charging, the current flows in the direction of the charging current I1, In this case, a current flows in the direction of the discharge current I2. Further, the charger / discharger 27 controls power so that charging and discharging are repeated for a predetermined number of cycles.

  Further, the charger / discharger 27 can perform power control so that the amount of discharge in one cycle is an arbitrary amount equal to or less than the amount from full charge to complete discharge. Therefore, for example, from the state where the secondary battery 2 is repeatedly fully charged and fully discharged (K = 100%) to the continuously charged state (K = 0%: the charged amount is always fully charged, a minute current of several mA or less is continuously applied. The discharge amount K can be defined in consideration of an appropriate amount up to the “trickle charge state” in which charging is performed in a continuous manner. In a mobile device such as a mobile phone in which the secondary battery 2 is used, the user may charge the secondary battery after complete discharge, or may charge the secondary battery before full discharge. is there. According to the charger / discharger 27, since it is possible to perform power control with an amount of discharge in one cycle equal to or less than the amount from full charge to complete discharge, each case according to the usage mode of the user can be controlled. The charge / discharge test can be performed flexibly.

  The temperature sensor 29 is installed in the secondary battery 2 and detects the temperature of the secondary battery 2. The measuring device 31 monitors the temperature sensor 29, measures the temperature from the value detected by the temperature sensor 29, and notifies the charging / discharging device 27 of the measurement result. The output device 33 outputs the temperature measured by the measuring device 31.

  Next, a battery test method will be described with reference to FIG. FIG. 4 is a flowchart showing the procedure of the battery test according to the present embodiment.

  In this battery test, a partial crush test is first performed, and then a charge / discharge test is performed. As shown in FIG. 4, when starting the partial crush test, the tester first selects the secondary battery 2 to be tested, and prepares the selected secondary battery 2 in a fully charged state. . Furthermore, the pressure breakdown direction and depth D of the secondary battery 2 are determined. Further, cycle conditions (discharge amount K, number of end cycles Nend, environmental temperature T) for repeatedly performing charging and discharging are determined (step S1).

  As shown in FIGS. 5 and 6, the secondary battery 2 is a hexagonal prism, and the peripheral surface of the secondary battery 2 includes a pair of plane portions 2a and side portions 2b other than the plane portions 2a. Have. The planar portion 2a is a region having the maximum area in each surface. The side surface portion 2b is an area surrounding the planar portions 2a so as to communicate with each other, and is extremely narrow compared to the planar portion 2a. The planar portion 2a of the secondary battery 2 is rectangular, and in FIGS. 5 and 6, the dimension in the horizontal direction (long side) is “A”, and the dimension in the vertical direction (short side) is “B”. Further, the distance (height dimension) between the pair of plane portions 2a is indicated by “C”. Therefore, the length B of the short side of the flat surface portion 2a is longer than the distance C that is the width of the side surface portion that is the distance between the pair of flat surface portions 2a. Further, the crushing depth is indicated by “D”, and the crushing test is performed by changing the depth D, whereby the secondary battery 2 is partially broken (partially crushed). In the state shown in FIG. 5, the total collapse occurs when the depth D becomes the same as the battery height C, and in the state shown in FIG. 6, the total collapse occurs when the depth D becomes the same as the battery height A. .

  Next, determination of the crushing direction will be described. 5 and 6 show a case where the secondary battery 2 is attached to the test table 3 so that the crushing surface is on the upper side. The determination of the crushing direction means that the surface to which the round bar 5 comes into contact is determined, and when the crushing direction is determined to be the plane portion 2a (see FIG. 5), the plane portion 2a is directed upward. The test table 3 is installed. As a result, the round bar 5 comes into contact with the flat portion 2a and mainly crushes the flat portion 2a. When the side surface portion 2b is determined (see FIG. 6), the side surface portion 2b is placed on the test table 3 with the upper side facing upward. As a result, the round bar 5 comes into contact with the side surface portion 2b and mainly crushes the side surface portion 2b.

  Next, the predetermined depth D when partial crushing is described. In the case of a mobile device such as a mobile phone, daily goods such as an iron, a notebook PC, a chair, and a desk can be assumed as an abnormal load pressure encountered in a daily use range (actual usage mode). Such a daily load is about 100 kgf to 500 kgf. As shown in FIG. 8, assuming such a load, the predetermined depth D in the case of partial crushing with respect to the planar portion 2a of the secondary battery 2 is 1/8 to the width C of the side surface portion 2b. The predetermined depth D in the case of partial crushing with respect to the side surface portion 2b is 1/4 to 1/2 of the short side length B of the flat surface portion 2a. Becomes the depth of the range. Therefore, in the present embodiment, in order to match the partial collapse depth D that is likely to occur in the secondary battery 2 in an actual usage mode, the predetermined depth when the flat portion 2a of the secondary battery 2 is partially collapsed is used. D is defined as an arbitrary depth in the range of 1/8 to 1/4 of the width C of the side surface portion 2b, and the predetermined depth D when the side surface portion 2b is partially crushed is a plane portion. It is defined to an arbitrary depth in the range of ¼ to ½ of the short side length B of 2a.

  As shown in FIG. 4, when the selection of the secondary battery 2 and the like (step S1) is completed, the secondary battery (test target battery) 2 is replaced with the first test unit 101 based on the crushing direction determined in step S1. Is attached to the test table 3 (step S2).

  Next, the tester performs a round bar crushing operation by starting the pressurizing device 9. The control circuit 9a of the pressurizing device 9 controls the drive motor 9b, lowers the round bar 5, presses the secondary battery 2, and performs partial collapse (step S3). In addition, the predetermined depth D at the time of partial crushing is an arbitrary depth within a range of 1/8 to 1/4 of the width of the side surface portion 2b when the flat portion 2a is partially crushed by the round bar 5. When the side surface portion 2b is partially crushed by the round bar 5, an arbitrary depth within the range of 1/4 to 1/2 of the short side length B of the flat surface portion 2a is set. It is prescribed in advance. Step S3 corresponds to a partial crushing step.

  Next, the measurement circuit 13a of the measurement device 13 measures the battery temperature T of the partially crushed secondary battery 2 based on the detection value of the temperature sensor 11, and outputs the detection result to the output unit 13b. Furthermore, when the measurement circuit 13a outputs the detection result to the output unit 13b, the measurement circuit 13a notifies the pressurizer 9 of data indicating the end of measurement, and lifts the round bar 5 to release the pressure on the secondary battery 2. The tester determines whether the measurement result exceeds a predetermined threshold, for example, 160 ° C. (step S4). Step S4 corresponds to a first detection step and a first determination step. When the tester determines in step S4 that the temperature exceeds 160 ° C., the tester determines that the secondary battery 2 to be tested is a defective battery (step S5) and ends the battery test. On the other hand, when determining that the temperature is 160 ° C. or less, the tester determines that the secondary battery 2 to be tested is a good product candidate, removes the good product candidate battery from the test table 3, and performs the subsequent charge / discharge test. .

  Here, determination of a predetermined threshold value (160 ° C.) serving as a reference for determining whether there is an abnormality in the partially crushed secondary battery 2 will be described. FIG. 9 shows the temperature change of the secondary battery 2 after the collapse. As shown in FIG. 9, when the secondary battery 2 was crushed, it was confirmed that there were three modes of temperature change (behavior) from patterns 1 to 3.

  The pattern 1 is a pattern in which no short circuit occurs between the positive electrode and the negative electrode inside the secondary battery 2 and the temperature does not change even when the secondary battery 2 is crushed. In the pattern 2, a short circuit occurs between the positive electrode and the negative electrode inside the secondary battery 2, and the battery temperature T of the secondary battery 2 rises due to Joule heat due to the short circuit current, but the critical temperature (secondary battery 2 This is a pattern in which the battery temperature T decreases after reaching the peak because the short circuit current itself converges without reaching the temperature at which the thermal decomposition of the material starts (about 150 ° C. to 160 ° C.). In Pattern 3, a short circuit occurs between the positive electrode and the negative electrode inside the secondary battery 2, the temperature of the secondary battery 2 rises due to Joule heat due to the short circuit current, and the temperature of the secondary battery 2 is critical. The temperature (temperature at which the thermal decomposition of the material of the secondary battery 2 begins: about 150 ° C. to 160 ° C.) starts thermal decomposition of the electrode of the secondary battery 2 and the battery material itself of the electrolyte solution, thereby causing thermal runaway It starts with a pattern.

  Due to the thermal runaway of the pattern 3, the secondary battery 2 itself causes abnormal heat generation or smoke generation around 500 ° C. In the present embodiment, when the secondary battery 2 is partially collapsed and behaves as a pattern 1 or pattern 2, it is determined that the battery is in the category of a good or bad candidate battery, and when the pattern 3 behaves, I decided to define it as a bad battery. Therefore, since it is most desirable to monitor whether or not the battery temperature T of the secondary battery 2 reaches the seaside temperature as a criterion for determining a defective battery, the battery temperature T serving as a criterion for determining whether there is an abnormality is set to 160 ° C. By determining, the occurrence of thermal runaway can be accurately confirmed.

  In the present embodiment, the tester performs the pass / fail candidate determination for the secondary battery 2 based on the value output from the output unit 13b of the measurement device 13. However, the test device 13 sets a value that satisfies the safety standard to the measurement device 13. A message indicating “non-defective product” is set in advance, and the quality determination of the battery is performed by comparing the value obtained by the measurement circuit 13a in step S3 with the value satisfying the safety standard. May be output from the output unit 13b, and a message indicating “defective” may be output from the output unit 13b when it is determined that the battery is defective.

  Returning to FIG. 4, when the secondary battery 2 is determined to be a good product candidate (step S <b> 4), the tester performs the second operation on the secondary battery 2 determined to be a good product candidate in order to perform a charge / discharge test. It is installed in the thermostat 25 of the test unit 103 and connected to the temperature sensor 29 and the cords 27a and 107b of the charger / discharger 27 (step S6).

  When the installation of the secondary battery 2 in the second test unit 103 is completed, the tester performs an input operation on the charger / discharger 27 and stores “N =” in a memory storing data indicating the cycle number N. Set to 0 ”. When the charger / discharger 27 receives an input operation by the tester, the charger / discharger 27 performs power control for one cycle of charging and discharging (step S7). Step S7 corresponds to a power control step.

  The amount of discharge by the charger / discharger 27 is specified in advance, and the charging operation including the charging operation is alternately performed by energizing the charging current (I1) and the discharging current (I2) based on the discharging amount for a predetermined time. To do. An expression for obtaining the time for supplying the charging current (I1) or the discharging current (I2), that is, the charging time T1 or the discharging time T2, will be described with reference to FIG. FIG. 10 is a graph showing the relationship between the operation time and the battery charge state when the charging operation and the discharging operation are alternately repeated. In the charge / discharge test, charging and discharging of the secondary battery 2 are set as one cycle, and charging and discharging are repeatedly performed according to a discharge amount K (%) specified in advance. The charging time (T1) and discharging time (T2) in one cycle are defined by the following equations, where the battery capacity is Q (Ah), the charging current is I1 (A), and the discharging current is I2 (A).

T1 (h) = K (%) × Q (Ah) / I1 (A)
T2 (h) = K (%) × Q (Ah) / I2 (A)

  The battery capacity Q (Ah) decreases as the charge / discharge cycle proceeds and the battery deteriorates, so that the charging time T1 and the discharging time T2 are decreased. Further, a cycle (charging, discharging, resting) may be performed by putting a rest period (resting time) between charging and discharging shown in FIG.

  Subsequently, as shown in FIG. 4, the charger / discharger 27 confirms the data set in the cycle number N, and if it is less than the end cycle number Nend, it indicates that the end cycle number Nend has not been reached. Data to be shown is notified to the measuring device 31. The measuring device 31 measures the temperature of the secondary battery 2 through the temperature sensor 29 in all processes in the cycle, and the data indicating that the number of end cycles Nend has not been reached from the charger / discharger 27. When accepted, the output device 33 is made to output the temperature at that time. The tester determines whether or not the temperature output by the output device 33 is 160 ° C. or lower (step S8). Step S8 corresponds to a second detection step and a second determination step.

  In step S8, when determining that the temperature is 160 ° C. or lower, the tester performs a data input process for adding “1” to the memory having the cycle number N of the charger / discharger 27 (step S10). If the tester determines that the temperature output from the output device 33 exceeds 160 ° C., the tester determines that the secondary battery 2 to be tested is a defective battery and ends the battery test method. To do.

  When the cycle number N is updated, the charger / discharger 27 determines whether or not the new cycle number N has reached the end cycle number Nend (step S8). Information indicating a non-defective battery is displayed on the output device 33. When information indicating a non-defective battery is displayed on the output device 33, the tester determines that the secondary battery 2 to be tested is a non-defective battery and ends the battery test.

  In the present embodiment, the tester performs the pass / fail determination of the secondary battery 2 based on the temperature output from the output device 33. However, a temperature that satisfies the safety standard is set in the measuring device 31 in advance. The measuring device 31 compares the temperature obtained in step S7 with the temperature satisfying the safety standard, and determines whether the battery is good. If it is determined that the battery is a good battery, a message indicating “good” is output from the output device 33. When the battery is determined to be defective, a message indicating “defective” may be output from the output device 33.

  Next, a preliminary test for determining the number of end cycles Nend will be described. FIG. 11 is a graph showing the result of the preliminary test and showing the relationship between the number of cycles N and the battery capacity Q (Ah% conversion). In FIG. 11, the horizontal axis indicates the number of cycles (N), and the vertical axis indicates the battery capacity Q (Ah) corresponding thereto. The preliminary test is performed before the partial crush test. The preliminary test is a test for measuring the deterioration characteristics of the battery by causing the secondary battery 2 to be tested to perform a predetermined cycle operation. In the preliminary test, charging and discharging are alternately repeated for a predetermined number of cycles without partially crushing the secondary battery 2 to be tested, and the relationship between the deteriorated battery capacity and the number of cycles N as shown in FIG. (Preliminary test step). The end cycle number Nend is defined based on the relationship between the deteriorated battery capacity and the cycle number obtained in the preliminary test. Specifically, the case where the battery capacity of the secondary battery 2 decreases to a range of 50% to 25% is considered as the battery life. As shown in FIG. 11, in the preliminary test, the secondary battery 2 The cycle number (reference cycle number) N in which the battery capacity of the battery is reduced to the range included in 50% to 25% corresponds to the end cycle number Nend.

  In the battery testing apparatus 100 and the battery testing method according to the present embodiment, the secondary battery 2 is not completely crushed from one direction (totally crushed) and the temperature and voltage are not measured, but in an incomplete partial collapse state. Measure temperature and voltage. In terms of secondary battery 2 crushing, partial crushing rather than full crushing is possible in situations that are close to the forces encountered during the use of mobile phones, etc. Is likely to occur. Furthermore, in the case of mainly lithium ion batteries, the total collapsed state of the battery is not the worst condition in determining an abnormality caused by an internal short circuit or the like, and the behavior when the battery is broken cannot be properly verified. That is, the partial crushing test is more advantageous than the total crushing test as a method for confirming safety by strictly testing the secondary battery 2. In the battery testing apparatus 100 and the battery testing method, the secondary battery 2 is evaluated by the partial crushing test, so that it is possible to appropriately verify the behavior when the secondary battery 2 is damaged.

  Furthermore, even if it is normal immediately after partial crushing, an abnormal event may occur if the battery is used continuously thereafter. However, according to the battery test apparatus 100 and the battery test method, since the charge / discharge test is performed after the partial crush test, the secondary battery 3 in the case where the secondary battery 3 is continuously used after the partial crush is used. The behavior can also be verified appropriately.

  Furthermore, the second test unit 103 includes a constant temperature device 25 that maintains the temperature of the surrounding environment of the secondary battery 2 partially collapsed by the round bar (pressing member) 5 at a predetermined temperature. The test environment by the unit 103 can be maintained at a temperature that assumes the actual use environment of the secondary battery 2, and the behavior of the battery when the battery is continuously used after partial collapse can be more appropriately verified.

  Further, the pressurizing device 9 presses the secondary battery 2 with the round bar 5 until at least one of the flat surface portion 2 a and the side surface portion 2 b of the secondary battery 2 reaches a predetermined depth D. By defining the predetermined depth D, it becomes possible to perform tests on the plurality of secondary batteries 2 under the same conditions.

  In addition, this invention is not limited only to said embodiment. For example, in the present embodiment, the tester installs the secondary battery 2 in the first test unit 101 and removes the secondary battery 2, and installs the secondary battery 2 in the second test unit 103. Although the secondary battery 2 has been removed, these may be automated.

It is a figure showing the outline of the battery testing device concerning a 1st embodiment of the present invention. It is a figure which shows the outline of a 1st test unit. It is a figure which shows the outline of a 2nd test unit. It is a flowchart which shows the procedure of a battery test method. It is a perspective view which shows the state which partially collapsed the plane part of the secondary battery. It is a perspective view which shows the state which partially collapsed the side part of the secondary battery. It is a figure which shows the charging operation possible temperature range in the case of the mobile telephone as a representative of a mobile device. It is a graph which shows the relationship between the test pressure provided to a secondary battery in a crushing test, and the amount of crushing deformation. It is a graph which shows the relationship between progress of time (test time) after pressing a round bar and partial crushing, and battery temperature. It is a graph which shows the relationship between the operation time in the case of repeating charging operation and discharge operation alternately, and a battery charge state. It is a graph which shows the relationship between the cycle number at the time of repeating charging and discharging alternately in a preliminary test, and a deterioration battery capacity.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Secondary battery, 2a ... Plane part, 2b ... Side part, 3 ... Test stand, 5 ... Round bar (pressing member), 9 ... Pressurizing device (pressurizing means), 13 ... Measuring device (1st measurement) Means), 27... Charger / discharger (power control means), 31... Measuring device (second measuring means), 25 .. thermostatic device, 100... Battery test apparatus, 101. D: predetermined depth, B: length of short side of flat part of secondary battery, C: width of side part of secondary battery.

Claims (10)

A first test unit for performing a crush test of the rechargeable battery;
A second test unit for performing a charge / discharge test of the battery,
The first test unit comprises:
A test stand on which the battery is installed;
A pressing member for crushing the battery;
Pressurizing means for controlling the pressing force of the pressing member so that the battery is partially collapsed;
First measuring means for measuring at least one of temperature and voltage of the partially collapsed battery,
The second test unit includes:
Power control means for alternately charging and discharging the battery partially collapsed by the pressing member;
And a second measuring means for measuring the temperature of the battery that has been repeatedly charged and discharged by the power control means. The second test unit includes:
The battery test apparatus according to claim 1, further comprising a thermostatic device that maintains a temperature of a surrounding environment of the partially collapsed battery at a predetermined temperature.   3. The battery testing apparatus according to claim 2, wherein the thermostatic device maintains the temperature of the ambient environment of the battery at an arbitrary temperature between -5 [deg.] C. and +50 [deg.] C. The battery is rectangular and has a rectangular pair of flat portions and a pair of side portions surrounding the flat portions,
The pressurizing means presses the battery with the pressing member until at least one of the planar portion and the side surface portion of the battery reaches a predetermined depth by the pressing member. The battery test apparatus according to any one of the above. The short side of the plane portion is longer than the width of the side portion, which is the distance between the pair of plane portions,
The predetermined depth in the plane portion is included in a range of 1/8 to 1/4 of the width of the side portion, and the predetermined depth in the side portion is 1 of the length of the short side of the plane portion. The battery test apparatus according to any one of claims 1 to 4, wherein the battery test apparatus is included in a range of / 4 to 1/2.   4. The power control unit according to claim 1, wherein the amount of discharge in one cycle can be an arbitrary amount equal to or less than an amount from full charge to complete discharge. Battery testing equipment. A partial crushing step of placing a battery to be tested on a test bench and applying a pressing force to the battery so that the battery is incompletely crushed;
A first detection step of detecting at least one of the temperature and voltage of the partially collapsed battery;
A first determination step for determining a good product candidate if the detection result in the first detection step is equal to or less than a threshold for determining a good product candidate;
A power control step of alternately repeating charging and discharging for a predetermined number of cycles for the battery determined as the good product candidate in the first determination step;
A second detection step of detecting the temperature of the battery in which charging and discharging are repeated a predetermined number of cycles in the power control step;
A second determination step for determining a non-defective product if the temperature detected in the second detection step is equal to or lower than a predetermined threshold for determining the non-defective product;
A battery test method comprising:   The battery test method according to claim 7, wherein the predetermined threshold value for determining the good product candidate is 160 ° C. Prior to the partial crushing step, charging and discharging are alternately repeated for a predetermined number of cycles without partial crushing of the battery to be tested, and a preliminary test for determining the relationship between the deteriorated battery capacity of the battery and the number of cycles. Further comprising steps,
The battery test according to claim 7 or 8, wherein the predetermined number of cycles in the power control step is defined based on a relationship between a deteriorated battery capacity of the battery and the number of cycles in the preliminary test step. Method. From the relationship between the deteriorated battery capacity of the battery and the number of cycles in the preliminary test step, the reference cycle number at which the deteriorated battery capacity is initially included in the range of 50% to 25% is obtained.
The battery test method according to claim 9, wherein in the power control step, charging and discharging are alternately repeated by the number of reference cycles.

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