Charging and discharging devices for secondary batteries

Abstract

This charge / discharge device 10 for secondary batteries serves to test the charging / discharging of multiple secondary batteries 11 and comprises a power source unit 12 and a contactor unit 14 that is mounted on, while being attachable / detachable to / from, a container 13 in which the second batteries 11 are accommodated. When in use, the power source unit 12 and the secondary batteries 11 accommodated in the container 13 are connected in series via the contactor unit 14.

Description

[Technical Field]

[0001] The present invention relates to a secondary battery charge / discharge device for simultaneously conducting charge / discharge tests on a plurality of secondary batteries. [Background technology]

[0002] Today, demand for secondary batteries (lithium-ion batteries) used in IT devices such as smartphones and electric vehicles is rapidly increasing. In the final process of mass-production factories for these secondary batteries, charge / discharge test equipment is widely used to activate and inspect the quality of the produced secondary batteries. This has made it possible to mechanize (automate) the activation and quality inspection of secondary batteries, which previously had been done manually, and has contributed to the realization of mass production of secondary batteries. However, in many conventional charge-discharge test equipment, the contact unit (also called a fixture unit) for electrically connecting the power supply unit and the secondary battery is installed in a housing separate from the power supply unit, and a cable is used to connect the two units. This has drawbacks such as heat generation from the cable, noise caused by the cable routing, and power loss due to increased resistance caused by long cables. To overcome these problems, Patent Document 1, for example, discloses a device that integrates a power supply unit and a contact unit, eliminating the need for cables or shortening them as much as possible, and also includes a cooling mechanism. This makes it possible to make the entire device more compact while still achieving stable operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-46615 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 employs a parallel connection method that has been primarily used in constant-current, constant-voltage (CC-CV) charge / discharge test equipment for secondary batteries. While this method is advantageous in terms of ensuring the safety of secondary batteries during charge / discharge tests, it requires a large, expensive, and high-performance charge / discharge power supply (power supply unit) capable of outputting and controlling high voltage and high current for constant-current charging and discharging, which can lead to the device becoming more complex, larger, and more expensive. In particular, when the secondary battery has a high current capacity, the corresponding power supply unit becomes even larger, which increases the weight of the entire device and complicates its structure, resulting in reduced ease of handling. Furthermore, the use of a high-output charge / discharge power supply during constant-voltage charging and discharging, which can normally be performed at low voltage and low current, can also lead to the problem of reduced test efficiency. Furthermore, because the power supply unit is integrated with the contact unit and probe, if the power supply unit breaks down, it is difficult to remove and repair the power supply unit alone or to replace the broken power supply unit with a new one, resulting in reduced maintainability. In particular, with the recent spread of electric vehicles, a variety of secondary batteries with different shapes and sizes are available on the used battery market. Testing these batteries requires the preparation of multiple devices for each type of target secondary battery. This hinders the expansion of the used battery market, resulting in the disposal of end-of-life secondary batteries and reusable secondary batteries without effective use. Furthermore, because the probes are fixed to a substrate, it is difficult for the probes to follow the electrode positional movement associated with the expansion and contraction of secondary batteries during charge / discharge tests, resulting in a lack of reliability and stability of the electrical connection. The present invention has been made in consideration of the above circumstances, and aims to provide a charging / discharging device for secondary batteries that simplifies the wiring of a contact unit that electrically connects a power supply unit to multiple secondary batteries, and that can accommodate testing of various types of secondary batteries simply by replacing the contact unit depending on the type of secondary battery, is easy to maintain and versatile, and has excellent energy-saving and testing efficiency, allowing the entire device to be made compact and running costs to be reduced. [Means for solving the problem]

[0005] A secondary battery charging / discharging device according to the present invention that meets the above-mentioned objective is a secondary battery charging / discharging device for performing charge / discharge tests on a plurality of secondary batteries, The device has a power supply unit and a contact unit that is detachably mounted on a container that houses multiple secondary batteries, and when in use, the power supply unit and the multiple secondary batteries housed in the container are connected in series via the contact unit.

[0006] In the secondary battery charge / discharge device according to the present invention, it is preferable that the contact unit is replaceable depending on the type of the secondary battery.

[0007] In the secondary battery charging / discharging device according to the present invention, it is preferable that the power supply unit has a pair of + terminal and - terminal, and the contact unit includes a plurality of contact probes that, in use, are electrically connected to the + electrode and - electrode of each secondary battery housed in the container, respectively, a + side connection terminal electrically connected to the + terminal, and a - side connection terminal electrically connected to the - terminal.

[0008] In the secondary battery charging / discharging device of the present invention, it is preferable that the contact unit is equipped with a tracing mechanism that moves each of the contact probes in accordance with the movement of each of the + electrodes and each of the - electrodes that accompanies the expansion and contraction of each of the secondary batteries during charging and discharging. [Effects of the Invention]

[0009] The secondary battery charging / discharging device of the present invention can miniaturize the power supply unit and reduce power consumption, making it energy-efficient. In addition, by replacing the contact unit, it can accommodate testing of various types of secondary batteries, making it easy to maintain and versatile. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a side view showing a state in which a secondary battery charging / discharging device according to an embodiment of the present invention is used. [Figure 2] 3 is a plan view showing a state in which a plurality of secondary batteries are housed in a container of the secondary battery charging / discharging device. FIG. [Figure 3] 3 is a side view showing a state in which a plurality of secondary batteries are housed in a container of the secondary battery charging / discharging device. FIG. [Figure 4] FIG. 2 is a front view of the container of the secondary battery charging / discharging device. [Figure 5] 4 is a plan view showing a contact unit of the secondary battery charge / discharge device. FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along the line AA in FIG. 5. [Figure 7] FIG. 6 is a cross-sectional view taken along the line BB in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, with reference to the accompanying drawings, an embodiment of the present invention will be described to help understand the present invention. 1 shows a secondary battery charging / discharging device 10 according to one embodiment of the present invention, which is used in testing secondary batteries 11 such as lithium ion batteries, and is used to simultaneously charge and discharge a plurality of secondary batteries 11. The left-right direction and depth direction of FIG. 1 (directions perpendicular to the paper surface) correspond to the front-rear direction and width direction of the secondary battery charging / discharging device 10, respectively. This secondary battery charging / discharging device 10 has a power supply unit 12 and a contact unit 14 that is detachably mounted on a container 13 that houses multiple secondary batteries 11, and when in use, the power supply unit 12 and the multiple secondary batteries 11 housed in the container 13 are connected in series via the contact unit 14.

[0012] Here, the power supply unit 12 is composed of an AC-DC converter, a DC-DC converter, etc., but if the secondary battery 11 is a lithium ion battery, it is desirable that the power supply unit 12 be capable of CC-CV (constant current constant voltage) charging and discharging. The secondary battery charge / discharge device 10 is controlled by a charge / discharge controller 15. A computer equipped with a storage means such as a hard disk, a display means such as a display, and an input means such as a keyboard, a mouse, a touch panel, or a touch pad is preferably used as this charge / discharge controller 15, and various controls such as commands to start and end a test and setting test conditions can be performed through dedicated software stored in the storage means. The charge / discharge controller and the power supply unit may be connected by wire using an electric wire for transmitting and receiving electric signals, or may be connected wirelessly using Wi-Fi communication or the like. In this embodiment, the secondary battery charging / discharging device 10 is composed of one power supply unit 12, one container 13, one contact unit 14, and one charge / discharge controller 15, but it is also possible to have multiple sets of power supply units 12, containers 13, and contact units 14 and control them with one charge / discharge controller 15.

[0013] As shown in Figures 1 to 4, the container 13 has a base portion 17 and a front plate 18 and a rear plate 19 erected on either side of the base portion 17 in the longitudinal direction (the front-to-rear direction of the secondary battery charging / discharging device 10, and the left-to-right direction in Figures 1 to 3). The front plate 18 and the rear plate 19 are connected at both sides in the width direction by two upper and lower cylindrical side connecting members 20, 21. As shown in Figures 1 to 3, a plurality of secondary batteries 11 and spacers 23 are housed on the base portion 17 along the longitudinal direction of the container 13, arranged alternately in the thickness direction. Engagement portions 24, 25 are formed at two locations, top and bottom, on both outer sides of the spacer 23 in the width direction, to engage with the side connecting members 20, 21 so as to sandwich the side connecting members 20, 21 from above and below. As a result, the spacer 23 is guided by the side connecting members 20, 21, and can slide smoothly on the base portion 17 together with the secondary batteries 11 in the longitudinal direction of the container 13. The cross-sectional shape, number and arrangement of the side connecting members are not limited to this embodiment but may be selected as appropriate, and accordingly, the shape, number and arrangement of the engaging portions of the spacer may also be selected as appropriate. Furthermore, in this embodiment, the spacer 23 is formed in an approximately U-shape when viewed in a plane, but the shape is not limited to this and can be selected as appropriate. For example, the spacer 23 may be formed in an approximately I-shape when viewed in a plane, or simply in the shape of a flat plate.

[0014] Next, a pressing means 26 is attached to the inside of the front plate 18 of the container 13. A hydraulic cylinder or the like is preferably used as this pressing means 26, and a flat pressing portion 28 is attached to the tip of the rod 27 of the pressing means 26. This allows the pressing portion 28 to be driven to press against the spacer 23 closest to the front plate 18, pressing the alternatingly arranged multiple secondary batteries 11 and spacers 23 toward the rear plate 19 with a constant force. As a result, the secondary batteries 11 and spacers 23 can be arranged at approximately equal intervals in the initial state. Furthermore, even if each secondary battery 11 repeatedly expands and contracts during charging and discharging, the pressing force of the pressing means 26 is kept constant, so that the spacing between the secondary batteries 11 and spacers 23 repeatedly expands and contracts approximately evenly, maintaining approximately equal spacing regardless of location. The pressing means need only be capable of pressing the secondary batteries and spacers housed in the container with a certain force, and its structure, arrangement, etc. may be selected as appropriate. For example, two pressing means may be arranged facing each other on the inside of the front plate and the inside of the rear plate, so that the secondary batteries and spacers are pressed by the pressing means from the front and rear of the container, or a pressing means may be installed on a charge / discharge stage on which the container is placed, so that the secondary batteries and spacers are pressed from outside the container by the pressing means penetrating the front plate (or rear plate).

[0015] As shown in Fig. 1, the power supply unit 12 has a pair of + terminal 30 and - terminal 31. As shown in Fig. 2, a + electrode 32 and a - electrode 33 are arranged side by side on the top surface of each secondary battery 11 housed in the container 13, although only the - electrode 33 on the front side is visible in Figs. 1 and 3. As shown in Fig. 5, the contact unit 14 has multiple contact probes 35a, 35b corresponding to the + electrode 32 and - electrode 33 (see Fig. 2) of each secondary battery 11 housed in the container 13. As a result, the multiple contact probes 35a, 35b are electrically connected to the + electrode 32 and - electrode 33 of each secondary battery 11 housed in the container 13 during use, although only the contact probe 35b on the front side is visible in Fig. 1. The contact probe 35a corresponding to the + electrode 32 incorporates a positive electrode current output line and a positive electrode voltage detection line, and the contact probe 35b corresponding to the - electrode 33 incorporates a negative electrode current output line and a negative electrode voltage detection line, making it possible to charge / discharge and measure the voltage of each secondary battery 11.

[0016] 5 to 7, the contact unit 14 is equipped with a copying mechanism 36 that moves the contact probes 35a, 35b in accordance with the movement of the positive electrodes 32 and negative electrodes 33 that accompany the expansion and contraction of each secondary battery 11 during charging and discharging. This copying mechanism 36 is housed within a frame 37 of the contact unit 14 that is rectangular in plan view. The copying mechanism 36 has two round rod-shaped guide members 38 on the left and right that are arranged along the front-to-rear direction of the contact unit 14 (the thickness direction of each secondary battery 11, and the left-to-right direction in FIGS. 1 to 3, 5, and 6), and a plurality of probe holder members 39 that hold pairs of contact probes 35a, 35b that correspond to the positive electrodes 32 and negative electrodes 33 of each secondary battery 11, respectively. Each probe holding member 39 is formed at two locations in the width (left-right) direction, and has fitting holes 40 passing through the probe holding member 39 in the front-rear direction. Guide members 38 are inserted into the fitting holes, and each probe holding member 39 is held so as to be slidable in the front-rear direction of the contact unit 14 along the guide members 38. Positioning pins 41 that protrude downward are attached to the bottom surface of each probe holding member 39 at two locations in the width (left-right) direction. As shown in FIG. 2, positioning holes 42 are formed in the top surface of each spacer 23 at two locations in the width (left-right) direction, corresponding to the two positioning pins 41 (see FIG. 5) of each probe holding member 39. Therefore, when using the secondary battery charging / discharging device 10, as shown in FIG. 1, the contact unit 14 is placed above the container 13 that houses the secondary batteries 11, and the positioning pins 41 of each probe holding member 39 are inserted into the positioning holes 42 of each spacer 23, thereby positioning and electrically connecting the contact probes 35a, 35b held by each probe holding member 39 to the + electrode 32 and - electrode 33 of each secondary battery 11.

[0017] Furthermore, the upper end of contact probe 35a held by the frontmost probe holding member 39 is electrically connected to + terminal 30 as + side connection terminal 43 by cable 44, and the upper end of contact probe 35b held by the rearmost probe holding member 39 is electrically connected to - terminal 31 as - side connection terminal 45 by cable 46. At this time, as shown in Fig. 5, upper end 47 of contact probe 35b of the front probe holding member 39 and upper end 48 of contact probe 35a of the rear probe holding member 39, which are adjacent in the front-to-rear direction of contact unit 14, are connected in advance in sequence by cable (or flexible conductor) 50. Therefore, when in use, as described above, the tips of the contact probes 35a, 35b held by each probe holding member 39 are brought into contact with the + electrode 32 and - electrode 33 of each secondary battery 11 to establish an electrical connection, and the + side connection terminal 43 and - side connection terminal 45 of the contact unit 14 are electrically connected to the + terminal 30 and - terminal 31 of the power supply unit 12 via cables 44, 46, respectively, thereby connecting the power supply unit 12 and multiple secondary batteries 11 in series.

[0018] As explained above, as each secondary battery 11 expands and contracts during charging and discharging, the positive electrodes 32 and negative electrodes 33 move in the front-to-rear direction of the container 13. However, by inserting the positioning pins 41 of the probe holding members 39 into the positioning holes 42 of the spacers 23, the spacers 23 and the probe holding members 39 are integrated, and the contact probes 35a, 35b move together with the spacers 23 in response to the movement of the positive electrodes 32 and negative electrodes 33, thereby maintaining a stable electrical connection. At this time, the lengths of the cables 44, 46, 50 take into consideration the movement of the probe holding members 39 (contact probes 35a, 35b) and are initially slack. Therefore, even if the probe holding members 39 move, no load is applied to the cables 44, 46, 50 or the contact probes 35a, 35b, etc., preventing breakage. The copying mechanism only needs to be able to move the contact probes in accordance with the movement of the positive and negative electrodes that accompany the expansion and contraction of the secondary batteries during charging and discharging, and its structure is not limited to that of this embodiment. For example, the number and arrangement of the guide members and fitting holes can be selected as appropriate, and fitting grooves may be used instead of fitting holes.

[0019] 7, the vertical frame members 51 of the frame body 37 of the contact unit 14 are formed to have a circular cross section, and rectangular cutout portions 52 are formed on both sides in the width direction (left and right) of the upper surfaces of the front panel 18 and rear panel 19 of the container 13, as shown in FIGS. 1 to 4. This makes it possible to hold (fix) the contact unit 14 in a predetermined position on the container 13 by engaging the vertical frame members 51 with the cutout portions 52 when loading the contact unit 14 into the container 13, but the structure (holding method) for loading the contact unit into the container is not limited to this and may be selected as appropriate. In this secondary battery charging / discharging device 10, the contact unit 14 for electrically connecting the power supply unit 12 and the multiple secondary batteries 11 housed in the container 13 is independent of the power supply unit 12 and the container 13 and is configured to be detachably mounted on the container 13, so that multiple types of containers and contact units can be prepared and combined as appropriate to accommodate various forms (types) of secondary batteries. In particular, in the second-hand market where various types of secondary batteries are available, there is no longer a need to prepare a secondary battery charging / discharging device for each type of secondary battery, which reduces costs and enables wider distribution.

[0020] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the above embodiments, and also includes other embodiments and modifications that are possible within the scope of the claims. [Industrial Applicability]

[0021] The secondary battery charging / discharging device of the present invention simplifies the wiring of the contact unit that electrically connects the power supply unit and multiple secondary batteries, and can accommodate testing of various types of secondary batteries simply by replacing the contact unit depending on the type of secondary battery.It is easy to maintain and has excellent versatility, and by connecting the power supply unit and multiple secondary batteries in series, it is possible to make the entire device more compact and reduce running costs, thereby contributing to the widespread use of secondary batteries. [Explanation of symbols]

[0022] 10: secondary battery charge / discharge device, 11: secondary battery, 12: power supply unit, 13: container, 14: contact unit, 15: charge / discharge controller, 17: base portion, 18: front plate, 19: rear plate, 20, 21: side connecting member, 23: spacer, 24, 25: engagement portion, 26: pressing means, 27: rod, 28: pressing portion, 30: positive terminal, 31: negative terminal, 32: positive electrode, 33: negative electrode, 35a, 35b: contact probe, 36: copying mechanism, 37: frame body, 38: guide member, 39: probe holding member, 40: fitting hole, 41: positioning pin, 42: positioning hole, 43: positive side connection terminal, 44: cable, 45: negative side connection terminal, 46: cable, 47, 48: upper end portion, 50: cable, 51: vertical frame member, 52: notch portion

Claims

1. A secondary battery charging / discharging device for performing charge / discharge tests on a plurality of secondary batteries, A charging / discharging device for secondary batteries, comprising: a power supply unit; and a contact unit that is detachably mounted on a container that houses a plurality of the secondary batteries, wherein, during use, the power supply unit and the plurality of secondary batteries housed in the container are connected in series via the contact unit.

2. 2. The secondary battery charge / discharge device according to claim 1, wherein the contact unit is replaceable depending on the type of the secondary battery.

3. 3. The charging / discharging device for secondary batteries according to claim 1 or 2, wherein the power supply unit has a pair of positive and negative terminals, and the contact unit comprises a plurality of contact probes that, when in use, are electrically connected to the positive and negative electrodes of each of the secondary batteries housed in the container, respectively, a positive side connection terminal electrically connected to the positive terminal, and a negative side connection terminal electrically connected to the negative terminal.

4. 4. The charging / discharging device for secondary batteries according to claim 3, wherein the contact unit is provided with a tracing mechanism that moves each of the contact probes in accordance with the movement of each of the + electrodes and each of the - electrodes that accompanies the expansion and contraction of each of the secondary batteries during charging and discharging.

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