Secondary battery charging / discharging device with internal pressure explosion-proof structure and internal pressure explosion-proof method

Abstract

A charging / discharging device and an internal pressure explosion prevention method for a secondary battery that can save space and reduce costs and has an internal pressure explosion prevention structure that can control the internal pressure. [Solution] A secondary battery charging / discharging device (10) has a battery storage chamber (11) that stores and charges / discharges secondary batteries and has an internal pressure explosion-proof structure, and is equipped with a main scavenging flow path (12) that scavenges compressed gas with a gauge pressure of 0.2 MPa or more into the battery storage chamber (11), an internal pressure maintaining flow path (13) that branches off from the main scavenging flow path and is equipped with a regulator that reduces the pressure of the compressed gas from the main scavenging flow path (12), and supplies the reduced-pressure gas into the battery storage chamber (11) that has been scavenged by the main scavenging flow path (12) and a safety valve, an internal pressure measuring means that measures the internal pressure of the battery storage chamber (11), and an internal pressure control means that controls the internal pressure of the battery storage chamber (11), and the internal pressure control means controls the regulator of the internal pressure maintaining flow path (13) based on the actual measurement value of the internal pressure measuring means, thereby maintaining the pressure inside the battery storage chamber (11) at or above a predetermined pressure.

Description

[Technical Field]

[0001] The present invention relates to a charging / discharging device and an internal pressure explosion-proof method for a secondary battery, in which a battery storage chamber for storing and charging / discharging a secondary battery has an internal pressure explosion-proof structure. [Background technology]

[0002] In charging / discharging devices, secondary batteries are stored in a battery storage chamber to perform charging / discharging inspections and tests, but since there is a risk of hydrogen gas being generated from the secondary batteries during charging / discharging, it is necessary to make the battery storage chamber explosion-proof. Explosion-proof structures applicable to electrical equipment include, for example, pressure-resistant explosion-proof structures, intrinsically safe explosion-proof structures, and pressurized explosion-proof structures. However, in charge-discharge devices, since charging and discharging are performed by connecting to secondary batteries, Joule heat from the current passing through them is applied to the contact points, generating high temperatures exceeding 200°C, so it is appropriate to adopt a pressurized explosion-proof structure.

[0003] Here, the internal pressure explosion-proof structure is a structure in which the internal pressure of the battery housing chamber is made higher than the pressure of the external atmosphere to prevent explosive gas from entering the inside from the outside. For example, Patent Document 1 describes an explosion-proof device that scavenges clean air into a chamber that is provided to surround electrical equipment, increasing the pressure inside the chamber so that the pressure inside the chamber is positive relative to the outside. However, in order to ensure a large scavenging flow rate at low pressure, it is necessary to increase the diameter of the piping (thicken the piping), which may result in a need to ensure installation space and an increase in manufacturing costs.

[0004] Here, it is conceivable to ensure the scavenging flow rate by reducing the pipe diameter (thinning the pipe) and increasing the pressure during scavenging, but in this case, a new structure is required to protect the internal pressure explosion-proof structure from a high-pressure state, which may complicate the device configuration and increase costs (see, for example, Patent Document 2). In particular, in a charging / discharging device, secondary batteries must be carried in and out of the battery housing chamber, and the battery housing chamber is provided with an opening / closing door or the like that closes the carrying-in / carry-out opening. Therefore, for example, if the internal pressure of the battery housing chamber reaches 200 Pa in gauge pressure, a pressure of 20 kgf will be applied to the opening / closing door or the like, and the internal pressure cannot be increased excessively.

[0005] It is possible to ensure the necessary internal pressure by supplying gas into the battery storage chamber while venting it, but when charging or discharging the secondary battery, for example, the temperature inside the battery storage chamber may rise, and even if the gas inside the battery storage chamber is simply vented, there is a risk that the internal pressure explosion-proof structure cannot be maintained stably unless the internal pressure can be controlled (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-336797 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-326726 [Patent Document 3] Japanese Patent Publication No. 2020-8913 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a secondary battery charge / discharge device and an internal pressure explosion prevention method that can save space and reduce costs and that have an internal pressure explosion prevention structure that can control the internal pressure. [Means for solving the problem]

[0008] The inventors have conducted various studies and have found that by providing an internal pressure maintaining flow path branching off from a main scavenging flow path that scavenges compressed gas having a gauge pressure of 0.2 MPa or more into the battery storage chamber, and supplying reduced-pressure gas from the internal pressure maintaining flow path into the battery storage chamber that has been scavenged with compressed gas from the main scavenging flow path, the main scavenging flow path can be made smaller in diameter, thereby achieving space savings and cost reductions, and that the internal pressure of the battery storage chamber can be controlled by an internal pressure control means controlling the regulator of the internal pressure maintaining flow path based on the actual measurement value of an internal pressure measurement means that measures the internal pressure of the battery storage chamber, thereby completing the present invention.

[0009] That is, the present invention is as follows. [1] A charging / discharging device for a secondary battery that stores a secondary battery and charges / discharges the battery chamber by scavenging gas into the battery chamber, and increasing the internal pressure of the battery chamber to a level higher than the pressure of the external atmosphere, thereby making the battery chamber an internal pressure explosion-proof structure, a main scavenging flow path for scavenging compressed gas having a gauge pressure of 0.2 MPa or more into the battery housing chamber; an internal pressure maintaining flow path that is branched from the main scavenging flow path and has a regulator that reduces the pressure of compressed gas from the main scavenging flow path, and that supplies the gas that has been reduced in pressure by the regulator into the battery housing chamber that has been scavenged by the main scavenging flow path; an internal pressure measuring means provided in the battery housing chamber for measuring the internal pressure of the battery housing chamber; an internal pressure control means for controlling the internal pressure of the battery housing chamber, The charging / discharging device for a secondary battery equipped with an internal pressure explosion-proof structure is characterized in that the internal pressure control means controls a regulator of the internal pressure maintaining flow path based on the actual measurement value of the internal pressure measurement means, thereby maintaining the pressure inside the battery storage chamber at or above a predetermined pressure.

[0010] [2] A charging / discharging device for a secondary battery equipped with an internal pressure explosion-proof structure as described in [1] above, characterized in that a pressure loss member that causes a pressure loss in the compressed gas whose pressure has been reduced by the regulator is provided in the internal pressure maintenance flow path downstream of the regulator provided in the internal pressure maintenance flow path. [3] The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure described in [2] above, characterized in that the regulator is an electro-pneumatic regulator, and an opening / closing valve is provided in the internal pressure maintaining flow path between the electro-pneumatic regulator and the pressure loss member. [4] The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to [2] or [3] above, wherein the pressure loss member is a small-diameter pipe.

[0011] [5] A charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to any one of [1] to [4] above, characterized in that it comprises a gas release means provided in the battery storage chamber to release gas inside the battery storage chamber to the outside and maintain the pressure inside the battery storage chamber at or below a predetermined level. [6] The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to [5] above, wherein the gas release means is a gravity-type safety valve.

[0012] [7] A charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to any one of [1] to [6] above, characterized in that it comprises a gas suction / exhaust means provided in the battery storage chamber for sucking gas from the battery storage chamber and discharging it to the outside.

[0013] [8] A charging / discharging device for a secondary battery having an internal pressure explosion-proof structure according to any one of [1] to [7] above, characterized in that the internal pressure control means maintains a gauge pressure in the battery storage chamber of 50 Pa or more and 2.5 kPa or less.

[0014] [9] A method for preventing internal pressure explosion in a battery storage chamber that stores a secondary battery and performs charging and discharging by scavenging gas into the battery storage chamber, and increasing the internal pressure of the battery storage chamber above the pressure of the external atmosphere, comprising: a scavenging step of scavenging the battery housing chamber with compressed gas having a gauge pressure of 0.2 MPa or more through a scavenging main flow path and releasing the gas from a safety valve; an internal pressure maintaining step of supplying gas whose pressure has been reduced by an internal pressure maintaining flow path, the internal pressure maintaining flow path being branched off from the main scavenging flow path and having a regulator for reducing the pressure of compressed gas from the main scavenging flow path, into the battery housing chamber scavenged by the main scavenging flow path, In the internal pressure maintaining step, an internal pressure control means controls a regulator of the internal pressure maintaining flow path based on an actual measurement value of an internal pressure measuring means that measures the internal pressure of the battery storage chamber, thereby maintaining the pressure inside the battery storage chamber at or above a predetermined pressure. [Effects of the Invention]

[0015] According to the charging / discharging device for a secondary battery having an internal pressure explosion-proof structure and the internal pressure explosion-proof method of the present invention, it is possible to reduce space and costs, and also to control the internal pressure. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an explanatory diagram of a secondary battery charge / discharge device having an internal pressure explosion-proof structure according to one embodiment of the present invention; [Figure 2] 10 is an explanatory diagram showing the operation of a gravity type safety valve of the secondary battery charge / discharge device having the internal pressure explosion-proof structure. FIG. [Figure 3] FIG. 1A is a perspective view of a scavenging passage according to a reference example, FIG. 1B is a plan view of the scavenging passage, FIG. 1C is a perspective view of a main scavenging passage according to an embodiment, and FIG. 1D is a plan view of the main scavenging passage. DETAILED DESCRIPTION OF THE INVENTION

[0017] The charging / discharging device for a secondary battery having an internal pressure explosion-proof structure of the present invention is a charging / discharging device for a secondary battery that scavenges a gas inside a battery storage chamber that stores a secondary battery and performs charging / discharging, and increases the internal pressure of the battery storage chamber above the pressure of the external atmosphere, thereby making the battery storage chamber have an internal pressure explosion-proof structure, The battery storage device is characterized by comprising: a main scavenging flow path that scavenges compressed gas having a gauge pressure of 0.2 MPa or more into the battery storage chamber; an internal pressure maintaining flow path that branches off from the main scavenging flow path and is provided with a regulator that reduces the pressure of the compressed gas from the main scavenging flow path, and supplies gas that has been reduced in pressure by the regulator into the battery storage chamber scavenged by the main scavenging flow path; internal pressure measuring means that is provided in the battery storage chamber and measures the internal pressure of the battery storage chamber; and internal pressure control means that controls the internal pressure of the battery storage chamber, and the internal pressure control means controls the regulator of the internal pressure maintaining flow path based on the actual measurement value of the internal pressure measuring means, thereby maintaining the inside of the battery storage chamber at a predetermined pressure or higher.

[0018] The charging / discharging device for secondary batteries (hereinafter also simply referred to as the charging / discharging device) with an internal pressurization explosion-proof structure of the present invention is a device that includes a battery storage chamber for storing secondary batteries, and stores the secondary batteries in this battery storage chamber to perform, for example, charge / discharge inspections and tests. This charging / discharging device is equipped with various devices for charging / discharging secondary batteries, and is equipped with one or more battery storage chambers for storing secondary batteries. The manner in which the secondary batteries are stored in the battery storage chambers is not particularly limited, but from the viewpoint of work efficiency, it is preferable to use, for example, a tray that stores multiple secondary batteries.

[0019] The battery storage chamber has, for example, an opening that opens toward the front, and is configured so that the secondary battery can be carried in (inserted) and carried out (removed) from the front through this opening. After the secondary battery is housed in the battery housing chamber, the opening is closed with a closing member to charge and discharge the secondary battery. Examples of this closing member include a door member that can be opened and closed horizontally toward the front of the battery housing chamber using a hinge, and a gate member that moves up and down inside the battery housing chamber.

[0020] The secondary battery to be stored in the battery storage chamber is not particularly limited as long as it is configured to be rechargeable and can be, for example, a lithium ion battery or a nickel-metal hydride battery. The size is also not particularly limited, and can be, for example, a small battery such as an SMD (surface mounted) all-solid-state battery, and the shape can be, for example, a rectangular parallelepiped, thin plate, disk, cube, or cylinder.

[0021] When a charging / discharging device has multiple battery storage chambers (when multiple blocking members as described above are provided), for example, if all battery storage chambers are connected to each other, specifically, if all battery storage chambers are structured so that they have the same level of internal pressure, all battery storage chambers can be made to have an internal pressure explosion-proof structure by making the charging / discharging device itself (casing) an internal pressure explosion-proof structure, and each of the multiple battery storage chambers can also be made to have an internal pressure explosion-proof structure individually.

[0022] An example of a standard for a battery storage chamber to have an internal pressurized explosion-proof structure is "Electrical machinery and equipment for use in explosive atmospheres - Part 2: Internal pressurized explosion-proof structure "p"" described in JIS C 60079-2 (2008).

[0023] By using the charging / discharging device for a secondary battery equipped with the internal pressure explosion-proof structure of the present invention, compressed gas having a gauge pressure of 0.2 MPa or more can be scavenged into the battery housing chamber, allowing a compact, small-diameter main scavenging passage to be used without using a large-diameter scavenging passage. Furthermore, because compressed gas having a gauge pressure of 0.2 MPa or more is scavenged into the battery housing chamber through the small-diameter main scavenging passage, scavenging of the battery housing chamber can be completed in a short time. Furthermore, by supplying compressed gas, whose pressure has been reduced by a regulator from the main scavenging passage into the battery housing chamber after scavenging through the main scavenging passage, through the small-diameter internal pressure maintaining passage, the internal pressure of the battery housing chamber can be maintained without excessive increase. Furthermore, by controlling the regulator based on the actual measurement value of the internal pressure measuring means provided in the battery housing chamber, the internal pressure of the battery housing chamber can be maintained at a predetermined pressure or higher, and the internal pressure of the battery housing chamber can be maintained without excessive increase. Therefore, space and costs can be saved, and the internal pressure can be controlled.

[0024] Hereinafter, each component of the charging / discharging device for a secondary battery having an internal pressure explosion-proof structure of the present invention will be described. [Main flow path for scavenging] The main scavenging passage is a passage that scavenges compressed gas with a gauge pressure of 0.2 MPa or more into the battery compartment (see Figure 1).

[0025] The compressed gas to be scavenged from the main scavenging passage into the battery housing chamber is not particularly limited as long as it is not a flammable gas, and examples thereof include inert gases such as nitrogen gas and argon, and air, and from the viewpoint of economy, air is preferred. The pressure of the compressed gas can be adjusted, for example, so as to ensure a flow rate based on the above-mentioned standard, and is preferably 0.3 MPa or more, more preferably 0.4 MPa or more, in terms of gauge pressure. On the other hand, the upper limit is not particularly limited, but, for example, taking into consideration the internal pressure required for the battery housing chamber and the equipment cost, the gauge pressure is preferably 1.0 MPa or less, more preferably 0.8 MPa or less, and even more preferably 0.6 MPa or less.

[0026] [Internal pressure maintaining flow path] The internal pressure maintaining flow path is a flow path that branches off from the main scavenging flow path and is provided with a regulator that reduces the pressure of the compressed gas from the main scavenging flow path, and is a flow path that supplies the reduced-pressure gas into the battery storage chamber that has been scavenged by the main scavenging flow path (see FIG. 1).

[0027] The low-pressure gas supplied from the internal pressure maintaining flow path into the battery storage chamber is not particularly limited as long as it is not a flammable gas, and examples thereof include inert gases such as nitrogen gas and argon, and air, with air being preferred from an economical standpoint. The pressure of the reduced-pressure gas supplied from the internal pressure maintaining flow path into the battery housing chamber is approximately the same as the internal pressure maintained in the battery housing chamber, and can be adjusted, for example, based on the above-mentioned standards. The gauge pressure is preferably 50 Pa or more and 2.5 kPa or less, more preferably 50 Pa or more and 2.0 kPa or less, even more preferably 50 Pa or more and 1.5 kPa or less, particularly preferably 50 Pa or more and 1.0 kPa or less, and most preferably 100 Pa or more and 500 Pa or less.

[0028] The regulator provided in the internal pressure maintaining passage is a device for reducing the pressure of the compressed gas from the main scavenging passage. The regulator may be, for example, an electro-pneumatic regulator capable of feedback control.

[0029] It is preferable that the internal pressure maintenance flow path further includes a pressure loss member downstream of the regulator provided in the internal pressure maintenance flow path, which generates a pressure loss in the compressed gas whose pressure has been reduced by the regulator. Examples of pressure loss components include small-diameter pipes that are smaller than the other pipes that make up the internal pressure maintenance flow path, and orifices that can be placed within the pipes, and small-diameter pipes that have a simple structure are particularly preferred.

[0030] When an electro-pneumatic regulator is used as the regulator, it is difficult to control low pressures, so it is effective to use the pressure loss member described above, which makes it easier to control the regulator and improves the accuracy of control.

[0031] Furthermore, when an electropneumatic regulator is used as the regulator, it is preferable to provide an open / close valve downstream of the electropneumatic regulator in the internal pressure maintaining flow path (between the electropneumatic regulator and the pressure loss member). This makes it possible to make the electro-pneumatic regulator less susceptible to the pressure of the compressed gas flowing through the main scavenging passage.

[0032] [Internal pressure measurement method] The internal pressure measuring means is provided in the battery housing chamber and measures the internal pressure of the battery housing chamber. The internal pressure measuring means is not particularly limited as long as it can detect that the pressure inside the battery storage chamber is higher than the pressure of the external atmosphere, specifically atmospheric pressure (0 Pa in gauge pressure), and examples thereof include a differential pressure gauge and a pressure gauge, with the use of a differential pressure gauge being particularly preferred from the standpoint of measurement accuracy.

[0033] [Internal pressure control means] The internal pressure control means controls the regulator of the internal pressure maintaining flow path to control the internal pressure of the battery housing chamber. The internal pressure control means is not particularly limited as long as it controls the regulator of the internal pressure maintaining flow path based on the actual measured value of the internal pressure measuring means and can maintain the pressure inside the battery storage chamber at or above a predetermined level, and examples thereof include a computer. Here, the predetermined pressure must be greater than 0 Pa in gauge pressure, since it is necessary to make the internal pressure of the battery storage chamber higher than the pressure of the external atmosphere. Preferably, the predetermined pressure is set to, for example, 50 Pa or more, in accordance with the standards for making the battery storage chamber have an internal pressure explosion-proof structure.

[0034] (Preferred embodiment 1) The battery chamber preferably includes a gas release means for releasing gas from within the battery chamber to the outside, thereby maintaining the pressure within the battery chamber at or below a predetermined level. The gas release means is preferably provided as a countermeasure against unstable fluctuations in the internal pressure of the battery housing, and examples of the gas release means include weight-type, lever-type, and spring-type means. In particular, a gravity-type safety valve made of rubber is preferred in terms of manufacturing costs and maintenance. When providing a gravity-type safety valve in the battery housing, one valve may be provided, or two or more valves may be provided. Providing multiple valves reduces the noise of gas being released from the battery housing to the outside and enables gas to be released according to the conditions inside the battery housing. As a result, when scavenging the battery storage chamber with compressed gas, even if the compressed gas is scavenged into the battery storage chamber until the internal pressure of the battery storage chamber reaches a predetermined pressure or higher, the gravity safety valve can easily and quickly prevent the internal pressure of the battery storage chamber from becoming high, thereby shortening the scavenging time of the battery storage chamber.

[0035] (Preferred embodiment 2) The battery housing chamber preferably includes a gas suction / exhaust means for sucking gas from within the battery housing chamber and discharging it to the outside. The gas suction and exhaust means is a means capable of forcibly sucking gases generated from a secondary battery during charging and discharging from inside the battery storage chamber and exhausting them outside the battery storage chamber, and examples of the gas suction and exhaust means include blower-type suction and exhaust means. The internal pressure control means described above makes it possible to control the internal pressure in the battery storage chamber, and therefore it is possible to easily eliminate internal pressure disturbance factors from within the battery storage chamber, such as an increase in ambient temperature when charging or discharging a secondary battery.

[0036] <Internal pressure explosion prevention method of the present invention> The internal pressure explosion-proofing method of the present invention is a method for internal pressure explosion-proofing a battery accommodating chamber by scavenging a gas into the battery accommodating chamber which accommodates a secondary battery and is used for charging and discharging, and increasing the internal pressure of the battery accommodating chamber to be higher than the pressure of the external atmosphere, a scavenging step of scavenging a battery housing chamber with a compressed gas having a gauge pressure of 0.2 MPa or more through a main scavenging passage and discharging the gas from a safety valve provided in the battery housing chamber; and an internal pressure maintaining step of supplying gas whose pressure has been reduced by an internal pressure maintaining passage, which is provided branching from the main scavenging passage and is provided with a regulator for reducing the pressure of the compressed gas from the main scavenging passage, into the battery housing chamber scavenged by the main scavenging passage, The internal pressure control means controls the regulator of the internal pressure maintaining flow path based on the actual measurement value of the internal pressure measuring means that measures the internal pressure of the battery housing chamber, thereby maintaining the pressure inside the battery housing chamber at or above a predetermined level.

[0037] The internal pressure explosion prevention method of the present invention may include other steps before, after, or between the scavenging step and the internal pressure maintaining step.

[0038] Here, in the scavenging step and / or the internal pressure maintaining step, it is preferable that the gas inside the battery housing chamber is released to the outside by a gas release means provided in the battery housing chamber, and the internal pressure of the battery housing chamber is maintained at a predetermined pressure or less, thereby shortening the scavenging time in the scavenging step and preventing the internal pressure of the battery housing chamber from becoming excessively high in the internal pressure maintaining step.

[0039] In addition, in the internal pressure maintaining step, it is preferable that the gas inside the battery housing chamber is sucked and discharged to the outside by a gas suction and discharge means provided in the battery housing chamber, thereby enabling factors causing internal pressure disturbances to be removed from the battery housing chamber quickly and easily.

[0040] Hereinafter, embodiments of a charging / discharging device for a secondary battery having an internal pressure explosion-proof structure of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these embodiments. Here, Fig. 1 is an explanatory diagram of a charging / discharging device for a secondary battery (hereinafter also simply referred to as a charging / discharging device) 10 having an internal pressure explosion-proof structure according to one embodiment of the present invention, and shows a battery storage chamber 11 provided in the charging / discharging device 10 having an internal pressure explosion-proof structure. In addition, the battery storage chamber 11 has an opening at the front for loading and unloading a secondary battery, and this opening is provided with an opening / closing door. A detailed explanation is given below. Note that the gas pressure is a gauge pressure unless otherwise specified.

[0041] As shown in Figure 1, a charging / discharging device 10 for secondary batteries with an internal pressure explosion-proof structure is a device that scavenges gas from a battery housing chamber 11, which houses and charges / discharges secondary batteries, and increases the internal pressure of the battery housing chamber 11 above the pressure of the external atmosphere, thereby making the battery housing chamber 11 internal pressure explosion-proof. Note that secondary batteries are usually replaced in the battery housing chamber 11 at intervals of about one hour, so that the battery housing chamber 11 must be made internal pressure explosion-proof each time. Here, the pressurized explosion-proof structure adopted is the "Electrical machinery and equipment for use in explosive atmospheres - Part 2: Pressurized explosion-proof structure "p"" described in the aforementioned JIS C 60079-2 (2008), and Group II Type Px is used as the standard requirement.

[0042] The conditions for the internal pressure explosion-proof structure are listed below. 1) The internal pressure of the battery compartment must be between 50 Pa and 2.5 kPa. 2) When the battery compartment door is opened, the power is automatically cut off. 3) Scavenging of the battery compartment is carried out at a flow rate five times the internal volume of the battery compartment. 4) The internal pressure of the battery compartment is monitored, and when the internal pressure drops, the protective device is activated. 5) Before opening the battery compartment door, safely release the internal pressure.

[0043] In this embodiment, the internal pressure of the battery housing chamber 11 is adjusted to about 200 Pa, and the maximum pressure is set to 300 Pa, based on condition 1).

[0044] The charging / discharging device 10 includes a main scavenging flow path 12, an internal pressure maintaining flow path 13, a differential pressure gauge (internal pressure measuring means), and an internal pressure control means, and a supply flow path 14 equipped with a primary regulator is connected to the upstream end of the main scavenging flow path 12. Here, the main scavenging flow path 12 is mainly composed of a 15A (outer diameter 21.7 mm) high-pressure pipe, the internal pressure maintaining flow path 13 is mainly composed of a 10A (outer diameter 17.3 mm) pipe, and the supply flow path 14 is mainly composed of a 15A high-pressure pipe.

[0045] An open / close valve A and a flow meter are sequentially provided in the scavenging main passage 12 from its upstream side to its downstream side, and a silencer is provided at the downstream end of the scavenging main passage 12 protruding into the battery housing chamber 11. The section of the scavenging main passage 12 between the flow meter and the silencer is configured with a 25A (outer diameter 34 mm) pipe. Here, the on-off valve A is opened when scavenging the battery housing chamber with compressed gas, and is closed after scavenging is completed. The flow meter measures the flow rate (cumulative flow rate) of the compressed gas flowing through the scavenging main flow path 12. The silencer reduces the sound generated when the compressed gas is scavenged into the battery housing chamber 11. The opening and closing operation of the opening and closing valve A is performed by the internal pressure control means, and the actual measured value (data) of the flow meter is sent to the internal pressure control means.

[0046] The internal pressure maintaining flow path 13 has an upstream end connected to the main scavenging flow path 12 upstream of an on-off valve A provided in the main scavenging flow path 12, and a downstream end connected to the main scavenging flow path 12 outside the battery housing chamber 11, between a flow meter and a silencer provided in the main scavenging flow path 12. An electropneumatic regulator (regulator), an on-off valve B, and a small-diameter pipe (pressure loss member) are sequentially provided in the internal pressure maintaining flow path 13 from its upstream side to its downstream side. The portion of the internal pressure maintaining flow path 13 downstream of the small-diameter pipe is composed of a pipe with an outer diameter of 10 mm. Here, the on-off valve B is in an open state when supplying low-pressure gas to the battery housing chamber 11, and is in a closed state when not supplying gas. The small-diameter pipe is smaller in diameter than the pipe 10A that constitutes the internal pressure maintaining flow path 13, and has an outer diameter of about 8 to 10 mm. The control of the electropneumatic regulator and the opening and closing operation of the opening and closing valve B are performed by an internal pressure control means.

[0047] The battery housing chamber 11 is provided with a differential pressure gauge, a thermometer, a safety valve, and a gas suction and discharge means. Here, the actual measured values ​​(data) of the differential pressure gauge and the thermometer are sent to the internal pressure control means, and the gas suction and discharge means is controlled by the internal pressure control means. Also, if the safety valve is configured to require control, it is controlled by the internal pressure control means, and if control is not required, there is no need to connect it to the internal pressure control means.

[0048] 2 is a safety valve that does not require control and includes a cylindrical discharge portion 21 having an opening communicating with the inside of the battery housing chamber 11, a rubber valve portion 22 that is arranged above the discharge portion 21 so as to be able to move up and down, and a guide rod 23 that guides the lifting and lowering of the valve portion 22. When the internal pressure of the battery housing chamber 11 rises abnormally, the valve portion 22 that has been in contact with the upper end of the discharge portion 21 rises, releasing gas from inside the battery housing chamber 11, and when the internal pressure of the battery housing chamber 11 drops, the valve portion 22 that had been rising drops and abuts against the upper end of the discharge portion 21, preventing the release of gas from inside the battery housing chamber 11. Here, by adjusting the weight of the valve portion 22 in advance, the internal pressure of the battery housing chamber 11 can be maintained at or below a preset pressure (for example, condition 1) of the internal pressure explosion-proof structure).

[0049] Next, embodiments of the internal pressure explosion prevention method of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these embodiments. The internal pressure explosion-proofing method according to one embodiment of the present invention is a method for internal pressure explosion-proofing the battery storage chamber 11 by scavenging gas inside the battery storage chamber 11, which stores a secondary battery and performs charging and discharging, and increasing the internal pressure of the battery storage chamber 11 above the pressure of the external atmosphere, and includes a scavenging process and an internal pressure maintaining process.

[0050] In the secondary battery charge / discharge device 10, a secondary battery is housed in the battery housing chamber 11, and therefore an opening of the battery housing chamber 11 for carrying in and out the secondary battery is provided with an openable door. In the battery housing 11, the following procedure is carried out every time a secondary battery that is charged and discharged is replaced. After charging and discharging of the battery storage chamber 11 is completed, the power supply to the charging and discharging device 10 is cut off, the internal pressure of the battery storage chamber 11 is released, the secondary battery that has completed charging and discharging is removed and a secondary battery to be charged and discharged is brought in (hereinafter also referred to as battery replacement), air is scavenged inside the battery storage chamber 11, the scavenged air is stopped, the internal pressure of the battery storage chamber 11 is maintained, the power supply to the charging and discharging device 10 is turned on, and the secondary battery is charged and discharged, all of these steps are repeated in sequence. Here, the detailed procedure for battery replacement is to cut off the power supply to the charging / discharging device 10 to release the internal pressure in the battery storage chamber 11, check the internal pressure in the battery storage chamber 11, unlock the opening / closing door, open the opening / closing door, and replace the battery.

[0051] (Scavenging process) The compressed gas flowing through the supply passage 14 at a pressure of 0.6 MPa or less is reduced in pressure to 0.4 MPa by a primary regulator, and then this reduced-pressure compressed gas is sent to the main scavenging passage 12 . In the scavenging main flow path 12, the on-off valve A is opened, and compressed gas of 0.4 MPa is released from the silencer into the battery housing chamber 11 while measuring the cumulative air volume required by the standard with a flow meter. At this time, the gas inside the battery housing chamber 11 is released to the outside through the safety valve, thereby scavenging the inside of the battery housing chamber 11. When the cumulative air volume measured by the flow meter reaches the cumulative air volume required by the standard, the on-off valve A is closed and scavenging is completed.

[0052] (Internal pressure maintaining process) The on-off valve B provided in the internal pressure maintaining flow path 13 is opened, and the electropneumatic regulator is controlled based on the actual measurement value of the differential pressure gauge to supply the reduced-pressure compressed gas into the battery housing chamber 11. At this time, the compressed gas reduced in pressure by the electropneumatic regulator is further subjected to a pressure loss through the small-diameter piping, thereby reducing the pressure to approximately 200 Pa, which is the target internal pressure of the battery housing chamber 11. This allows the pressure inside the battery housing chamber 11 to be maintained at approximately 200 Pa.

[0053] As described above, the charging / discharging device and internal pressure explosion-proof method for secondary batteries equipped with the internal pressure explosion-proof structure of the present invention are useful for battery storage rooms in which secondary batteries are frequently carried in and out, i.e., in which the opening that serves as the secondary battery carrying in / out port is frequently opened and closed with a blocking member. [Example]

[0054] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. Here, Fig. 3 shows (a) a perspective view of a scavenging passage according to a reference example, (b) a plan view of the same scavenging passage, (c) a perspective view of a main scavenging passage according to an example, and (d) a plan view of the same main scavenging passage.

[0055] (Reference example) In the reference example, the scavenging passage scavenges compressed gas of 200 Pa into the battery housing chamber, and the internal pressure of the battery housing chamber is set to 200 Pa. In this case, since it was necessary to ensure a gas flow rate necessary for scavenging the inside of the battery housing chamber, the scavenging flow path was configured with a 65A pipe (outer diameter 76.3 mm).

[0056] (Example) In the embodiment, compressed gas of 0.4 MPa is scavenged into the battery storage chamber through the main scavenging flow path, and then the 0.4 MPa compressed gas is reduced in pressure to 200 Pa by an electropneumatic regulator and small-diameter piping provided in the internal pressure maintaining flow path, and supplied to the battery storage chamber, thereby setting the internal pressure of the battery storage chamber to 200 Pa. In this case, since it was necessary to ensure the gas flow rate required for scavenging the battery housing chamber, the main scavenging passage was constructed with a 15A (outer diameter 21.7 mm) pipe.

[0057] (Comparison between Reference Example and Working Example) In the working example, the diameter of the pipe used for scavenging can be significantly reduced compared to the reference example. This allows for a significant reduction in the cost of the flowmeter to be installed in the pipe, which increases as the diameter of the pipe increases, thereby achieving cost reduction. The space required for installation is 980cm for the scavenging air passage in the reference example. 2 (=56cm x 17.5cm) (see Fig. 3(b)), and the main scavenging passage according to the embodiment is 223cm 2 (=24.8cm x 9cm) (see Figure 3(d)), which means that the area ratio is 23%, confirming that space saving is possible.

[0058] While the present invention has been described above with reference to one embodiment, the present invention is not limited to the configuration described in the above embodiment and includes other embodiments and modifications that are conceivable within the scope of the claims. For example, a charging / discharging device and an internal pressure explosion-proof method for a secondary battery equipped with the internal pressure explosion-proof structure of the present invention, which are constructed by combining some or all of the above-described embodiments and modifications, are also within the scope of the present invention. [Industrial Applicability]

[0059] The charging / discharging device and method for preventing internal pressure explosion of a secondary battery according to the present invention are industrially useful because they can save space and reduce costs, and can control internal pressure. [Explanation of symbols]

[0060] 10: secondary battery charge / discharge device with internal pressure explosion-proof structure, 11: battery storage chamber, 12: main scavenging flow path, 13: internal pressure maintaining flow path, 14: supply flow path, 20: safety valve, 21: discharge portion, 22: valve portion, 23: guide rod

Claims

1. A charging / discharging device for a secondary battery, which stores a secondary battery and charges / discharges the battery chamber, and scavenges the gas in the battery chamber to increase the internal pressure of the battery chamber above the pressure of the external atmosphere, thereby making the battery chamber an internal pressure explosion-proof structure, a main scavenging flow path for scavenging compressed gas having a gauge pressure of 0.2 MPa or more into the battery housing chamber; an internal pressure maintaining flow path that is branched from the main scavenging flow path and has a regulator that reduces the pressure of compressed gas from the main scavenging flow path, and that supplies the gas that has been reduced in pressure by the regulator into the battery housing chamber that has been scavenged by the main scavenging flow path; an internal pressure measuring means provided in the battery housing chamber for measuring the internal pressure of the battery housing chamber; an internal pressure control means for controlling the internal pressure of the battery housing chamber, The charging / discharging device for a secondary battery equipped with an internal pressure explosion-proof structure is characterized in that the internal pressure control means controls a regulator of the internal pressure maintaining flow path based on the actual measurement value of the internal pressure measurement means, thereby maintaining the pressure inside the battery storage chamber at or above a predetermined pressure.

2. 2. A charging / discharging device for a secondary battery with an internal pressure explosion-proof structure as described in claim 1, characterized in that a pressure loss member that causes a pressure loss in the compressed gas whose pressure has been reduced by the regulator is provided in the internal pressure maintenance flow path downstream of the regulator provided in the internal pressure maintenance flow path.

3. 3. The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to claim 2, wherein the regulator is an electro-pneumatic regulator, and an opening / closing valve is provided in the internal pressure maintaining flow path between the electro-pneumatic regulator and the pressure loss member.

4. 4. The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to claim 2, wherein the pressure loss member is a small-diameter pipe.

5. 2. The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to claim 1, further comprising a gas release means provided in the battery storage chamber for releasing gas within the battery storage chamber to the outside, thereby maintaining the pressure within the battery storage chamber at or below a predetermined level.

6. 6. A secondary battery charge / discharge device with an internal pressure explosion-proof structure according to claim 5, wherein the gas release means is a gravity type safety valve.

7. 2. The charging / discharging device for a secondary battery with an internal pressure explosion-proof structure according to claim 1, further comprising a gas suction / exhaust means provided in the battery accommodating chamber for suctioning gas within the battery accommodating chamber and discharging it to the outside.

8. 2. The secondary battery charge / discharge device with an internal pressure explosion-proof structure according to claim 1, wherein the internal pressure control means maintains the gauge pressure inside the battery housing chamber at 50 Pa or more and 2.5 kPa or less.

9. A method for preventing internal pressure explosion of a battery storage chamber that stores a secondary battery and performs charging and discharging by scavenging a gas into the battery storage chamber, and increasing the internal pressure of the battery storage chamber to be higher than the pressure of the external atmosphere, comprising: a scavenging step of scavenging the battery housing chamber with compressed gas having a gauge pressure of 0.2 MPa or more through a scavenging main flow path and releasing the gas from a safety valve; an internal pressure maintaining step of supplying gas whose pressure has been reduced by an internal pressure maintaining flow path, the internal pressure maintaining flow path being branched off from the main scavenging flow path and having a regulator for reducing the pressure of compressed gas from the main scavenging flow path, into the battery housing chamber scavenged by the main scavenging flow path, In the internal pressure maintaining step, an internal pressure control means controls a regulator of the internal pressure maintaining flow path based on an actual measurement value of an internal pressure measuring means that measures the internal pressure of the battery storage chamber, thereby maintaining the pressure inside the battery storage chamber at or above a predetermined pressure.

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