JP2012133890A - Antirust system for secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antirust system for a secondary battery, which prevents the occurrence of dew condensation in a secondary battery and thus can reliably prevent the secondary battery from rusting.SOLUTION: The antirust system for a secondary battery comprises: cell temperature measuring means 14 for measuring cell temperatures of secondary cells 1 housed in a housing 10; a cooling mechanism 13 for supplying an outside air G to the peripheries of the secondary cells 1 in the housing 10 to cool the secondary cells 1; atmospheric temperature measuring means 15 for measuring atmospheric temperatures on the peripheries of the secondary cells 1, through which the outside air G passes; and control means 16 for performing control so that the atmospheric temperatures are equal to or lower than the cell temperatures.

Description

  The present invention relates to a secondary battery rust prevention system for preventing corrosion from occurring in electrode terminals of a secondary battery.

  Conventionally, secondary batteries (battery cells) such as lithium ion secondary batteries are stored in series and in parallel in a housing (battery housing case) to form a battery module, and a plurality of battery modules are arranged in series and in parallel. Then, the battery pack is housed in a separate housing together with a battery control board or the like, and the battery pack is mounted on a vehicle or the like and used as a power source for various devices.

  In addition, secondary batteries generate heat during use and the temperature rises, but when the temperature rises too much, the deterioration rapidly proceeds. For this reason, the assembled battery requires a cooling mechanism for cooling the secondary battery that has generated heat. Conventionally, as this type of cooling mechanism, a secondary battery is provided by attaching a fan or the like to the battery housing case of the battery module and circulating outside air (external air) taken into the housing between adjacent secondary batteries. Is forcibly cooled, and the temperature is controlled to be maintained at about 40 to 50 ° C.

  On the other hand, for example, in a mobile body such as a forklift or an electric vehicle, there is a high possibility that each secondary battery of the assembled battery (battery module) mounted will come into contact with the outside air, and it is necessary to use unair-conditioned outside air as cooling air is there. For this reason, there is a high possibility that outside air with high humidity is taken into the housing by the cooling mechanism, and condensation may occur in the secondary battery depending on the humidity of the outside air and the temperature of the outside air and the secondary battery. And if rust (corrosion) occurs in the pair of positive and negative electrode terminals exposed by the secondary battery due to this dew condensation, the resistance value of the electrode terminals increases and the performance deteriorates. In particular, large secondary batteries used in mobile objects such as forklifts and electric vehicles have larger current flow than small secondary batteries, and the degree of loss increases due to rusting. It is.

  On the other hand, a method for preventing the occurrence of corrosion by coating the electrode terminal with a corrosion inhibiting film (coating material) and suppressing the contact of moisture has been proposed and put into practical use (for example, Patent Document 1, Patent) Reference 2). Some air conditioners and the like include a system that prevents the occurrence of condensation by detecting the temperature and humidity (dew point) of the outside air and controlling the temperature and humidity of the taken outside air.

JP 2008-192323 A JP 2005-183070 A

  Here, the secondary battery is expected to be applied to a wide variety of applications. For example, the secondary battery contains a lot of foreign substances such as corrosive substances and dusts in tropical areas, seaside areas, the sea, factory areas, urban areas, deserts, etc. It is also assumed that the outside air that is included is used as cooling air.

  For example, when using a system that controls the temperature and humidity of the outside air to prevent condensation and thus rusting of the electrode terminals, if the outside air contains foreign matter, the dew point obtained from the temperature and humidity is the type of foreign matter. It becomes difficult to control appropriately so that dew condensation does not occur due to deviations depending on the amount of water and the amount. For this reason, when such a system for controlling the temperature and humidity of the outside air is employed as a rust prevention system for a secondary battery, it is difficult to perform highly reliable rust prevention. Further, if the temperature and humidity of the outside air are controlled in consideration of the type and amount of foreign matter in the outside air and the reliability as the rust prevention system is ensured, the cost increases.

  The rust prevention system for a secondary battery according to the present invention includes a battery temperature measuring unit that measures a battery temperature of a secondary battery housed in a housing, and supplies outside air around the secondary battery in the housing. A cooling mechanism for cooling the secondary battery, an ambient temperature measuring means for measuring the ambient temperature around the secondary battery through which the outside air flows, and a control means for controlling the ambient temperature to be equal to or lower than the battery temperature. It is characterized by having.

  In this invention, by controlling the cooling mechanism and the secondary battery by the control means so that the ambient temperature around the secondary battery is equal to or lower than the battery temperature of the secondary battery, dew condensation occurs in the secondary battery. It can be surely prevented. That is, in comparison with the conventional case where humidity is measured in addition to the temperature of the outside air and control is performed so that condensation does not occur depending on the temperature and humidity of the outside air (and the temperature of the secondary battery), the temperature and humidity of the outside air are compared. Therefore, it is possible to prevent the occurrence of condensation easily and reliably based on the ambient air and the temperature of the secondary battery without being affected by properties such as the type and amount of foreign matter contained.

  In the secondary battery anti-corrosion system of the present invention, it is easy and reliable based on the temperature of the outside air and the secondary battery without being affected by the properties such as the temperature and humidity of the outside air and the type and amount of foreign matter contained. In addition, since it is possible to prevent the occurrence of dew condensation, it is possible to provide a rust prevention system that is less expensive and more reliable than the conventional one.

1 is a perspective view showing a secondary battery according to an embodiment of the present invention. It is a top view which shows the antirust system (battery module) of the secondary battery which concerns on one Embodiment of this invention.

  Hereinafter, with reference to FIG.1 and FIG.2, the antirust system of the secondary battery which concerns on one Embodiment of this invention is demonstrated. The present embodiment particularly relates to a rust prevention system for preventing rusting of a pair of positive and negative electrode terminals of a secondary battery such as a lithium ion secondary battery.

  First, as shown in FIG. 1, the secondary battery (battery cell) 1 of the present embodiment accommodates an electrode body 4 configured by laminating a plurality of positive electrode plates 2 and negative electrode plates 3, and the electrode body 4. A battery can 5 and a pair of positive and negative electrode terminals 6, 7 provided penetrating from the inside of the battery can 5 to the outside are provided. Moreover, the positive electrode plate 2 and the negative electrode plate 3 have tabs 2a and 3a for connecting to corresponding electrode terminals 6 and 7, respectively. The tabs 2a of the positive electrode plate 2 are bundled together and the tabs 3a of the negative electrode plate 3 are bundled together to form a tab bundle, which is connected to the corresponding electrode terminals 6 and 7 via the tab bundle.

  As shown in FIG. 2, a plurality of the secondary batteries 1 are arranged in series and in parallel and accommodated in a housing (battery accommodation case) 10 to form a battery module 11, and the battery modules 11 are arranged in series and in parallel. The assembled battery is configured by arranging and housing it in a separate housing together with a battery control board and the like. Further, in the secondary battery 1 of the plurality of battery modules 11 housed in the housing, the electrode terminals 6 and 7 are connected to each other by the bus bar 12.

  In addition, the battery module 11 takes in the outside air G into the housing 10 and causes the outside air G to flow between the secondary batteries 1 as cooling air, thereby forcibly cooling each secondary battery 1. Is provided. Further, each secondary battery 1 includes a battery temperature measuring means 14 such as a temperature sensor (thermistor) for measuring the battery temperature T1 of the secondary battery 1, and electrode terminals 6 and 7, as in the conventional battery module 11. A terminal voltage measuring means (not shown) for measuring the voltage of the battery and a container voltage measuring means (not shown) for measuring the voltage of the battery can 5 are provided.

  And the rust prevention system A of the secondary battery of this embodiment is a temperature sensor that measures the ambient temperature T2 around the secondary battery 1 in which the outside air G circulates and the cooling mechanism 13 and the battery thermometer side means 14. Or the like, a control means 16 for controlling the ambient temperature T2 to be equal to or lower than the battery temperature T1, and a heating means 17 such as a heater attached to the secondary battery 1.

  In the present embodiment, a plurality of secondary batteries 1 are housed in the housing 10. In the secondary battery rust prevention system A of the present embodiment, the battery temperatures T1 of the plurality of secondary batteries 1 are respectively measured by the battery temperature measuring means 14, and the control means 16 is the secondary battery having the lowest battery temperature T1. Control is performed based on the battery 1. Moreover, the control means 16 is comprised so that the temperature difference of the battery temperature T1 of the some secondary battery 1 may be made small by heating the secondary battery 1 with low battery temperature T1 with the heating means 17. FIG.

  Further, in the present embodiment, the ambient temperature measuring means 15 measures the ambient temperature T2 at a plurality of locations in the housing 10 such as the outside air G supply port side, the central portion, and the outside air G discharge port side. A plurality are provided.

  And in the rust prevention system A of the secondary battery which consists of the said structure, the measurement result of the battery temperature measurement means 14 which measures the battery temperature T1 of each secondary battery 1, and the atmospheric temperature measurement means 15 which measures atmospheric temperature T2 Is sent to the control means 16, and based on these measurement results, the control means 16 controls the ambient temperature T2 to be equal to or lower than the battery temperature T1.

  Here, when the thin metal body and the thick metal body are exposed to the same air environment in which the temperature and humidity fluctuate appropriately, the thin metal body has a more ambient atmosphere than the thick metal body. They have obtained knowledge that they follow the temperature quickly and are not easily corroded. In other words, the inventors of the present application have obtained the knowledge that, if the temperature of the metal body is higher than the ambient atmosphere temperature, condensation does not occur regardless of humidity (dew point).

  In the secondary battery anti-corrosion system A of the present embodiment, based on this knowledge, the temperature and humidity are not controlled as in the prior art, but the control means 16 causes the ambient temperature T2 to be equal to or lower than the battery temperature T1. By controlling only the temperature, it is possible to reliably prevent the secondary battery 1 from being condensed. That is, in the rust prevention system A for the secondary battery of the present embodiment, the temperature and humidity of the outside air G are compared with the case where the temperature and humidity of the outside air G are measured and controlled so as not to cause condensation as in the conventional case. Condensation is prevented reliably and easily based on the ambient air G and the temperatures T1 and T2 of the secondary battery 1 without being affected by properties such as the type and amount of foreign matter contained.

  At this time, in this embodiment, the control means 16 controls the driving of the cooling mechanism 13 and the operation / stop of each secondary battery 1, for example, so that the ambient temperature T2 becomes equal to or lower than the battery temperature T1. . Furthermore, if the battery temperature T1 rises too much, the secondary battery 1 deteriorates rapidly. Therefore, the control means 16 sets the ambient temperature T2 to be equal to or lower than the battery temperature T1, and the battery of the secondary battery 1. Control is performed so that the temperature T1 is equal to or lower than a set temperature T3 of about 40 to 50 ° C., for example.

  Further, there may naturally be a difference in the battery temperatures T1 of the plurality of secondary batteries 1 housed in the housing 10. Therefore, in this embodiment, the battery temperature T1 of each of the plurality of secondary batteries 1 is measured by the battery temperature measuring unit 14, and the control unit 16 performs control based on the secondary battery 1 having the lowest battery temperature T1. Then, the ambient temperature T2 around the secondary battery 1 is secondary with respect to the secondary battery 1 having the lowest battery temperature T1 among the plurality of secondary batteries 1 housed in the housing 10 in this way. By performing the control so that the battery temperature of the battery 1 is equal to or lower than the battery temperature T1, the occurrence of dew condensation is reliably prevented for all the secondary batteries 1.

  Moreover, some secondary batteries 1 may become high temperature according to the installation place etc. of the secondary battery 1 (assembled battery), and when the remarkable temperature difference arises in battery temperature T1 of the some secondary battery 1 The temperature T2 of the outside air G circulating in the housing 10 is increased by the high temperature secondary battery 1 so that the ambient temperature T2 around the secondary battery 1 becomes equal to or lower than the battery temperature T1 of the secondary battery 1. It can be difficult to control.

  On the other hand, in the rust prevention system A for the secondary battery of the present embodiment, the control means 16 that detects that a significant temperature difference has occurred in the battery temperatures T1 of the plurality of secondary batteries 1 is the battery temperature T1. The low secondary battery 1 is controlled to be forcibly heated by the heating means 17, and the temperature difference between the plurality of secondary batteries 1 is reduced. Thus, the ambient temperature T2 around the secondary battery 1 is reliably and stably controlled so as to be equal to or lower than the battery temperature T1 of the secondary battery 1.

  Therefore, in the secondary battery rust prevention system A of the present embodiment, the control unit 16 controls the cooling mechanism 13 and the secondary battery 1 so that the ambient temperature T2 becomes equal to or lower than the battery temperature T1. It is possible to reliably prevent dew condensation on the secondary battery 1. That is, instead of controlling the temperature and humidity as in the prior art, the temperature and humidity of the outside air G and the contained foreign substances are not controlled by controlling only the temperature so that the ambient temperature T2 becomes equal to or lower than the battery temperature T1. It is possible to easily and reliably prevent the occurrence of dew condensation based on the ambient air G and the temperature of the secondary battery 1 without being affected by the properties such as the type and amount.

  Therefore, according to the rust prevention system A of the secondary battery of the present embodiment, it is possible to make a rust prevention system with low cost and high reliability as compared with the conventional one.

  Further, in the secondary battery rust prevention system A of the present embodiment, the atmosphere is determined based on the secondary battery 1 having the lowest battery temperature T1 among the plurality of secondary batteries 1 accommodated in the housing 10. By controlling the temperature T2 to be equal to or lower than the battery temperature T1, it is possible to reliably prevent dew condensation from occurring in all the secondary batteries 1.

  Furthermore, the secondary battery 1 with a low battery temperature T1 can be forcibly heated by the heating means 17 to reduce the temperature difference between the plurality of secondary batteries 1, and the ambient temperature T2 can be kept below the battery temperature T1. Thus, it becomes possible to perform control reliably and stably.

  As mentioned above, although one Embodiment of the rust prevention system of the secondary battery which concerns on this invention was described, this invention is not limited to said one Embodiment, It can change suitably in the range which does not deviate from the meaning. .

  For example, in the present embodiment, the rust prevention system A of the battery module 11 in which a plurality of secondary batteries 1 are accommodated in the housing 10 has been described. Of course, the present invention is applied to one secondary battery 1. Even if the rust prevention system A is applied, the same effect can be obtained.

  Further, when a plurality of secondary batteries 1 are accommodated in the housing 10, the housing 10 is divided into a plurality of blocks, and the ambient temperature T2 around the secondary battery 1 is the secondary battery 1 in each block. The battery temperature may be controlled to be equal to or lower than the battery temperature T1 to prevent the plurality of secondary batteries 1 from being condensed and rusting.

  Further, the driving of the cooling mechanism (fan) 13 is controlled, and the control is performed so that the ambient temperature T2 around the secondary battery 1 becomes equal to or lower than the battery temperature T1 of the secondary battery 1 by changing the air volume of the outside air (cooling air) G. When performing, the control may be performed so that the ambient temperature T2 becomes equal to or lower than the battery temperature T1 by providing a plurality of fans (cooling mechanisms) 13 and controlling each fan 13 to be selectively driven.

  Further, in the present embodiment, FIG. 2 illustrates that the cooling air G is circulated in the lateral direction by the cooling mechanism 13 with respect to the secondary battery 1 accommodated in the housing 10. The cooling mechanism 13 may be provided so as to distribute the cooling air G from below to above, and the distribution direction of the cooling air G is not particularly limited.

  Further, in the present embodiment, the ambient temperature measuring means 15 measures the ambient temperature T2 at a plurality of locations in the housing 10 such as the outside air G supply port side, the central portion, and the outside air discharge side in the housing 10. However, if it is possible to limit the place where the highest ambient temperature T2 is provided in the housing 10, one atmosphere temperature measuring means 15 is provided at that place. It may be.

  Furthermore, the temperature and humidity of the outside air G, the measurement result of the battery temperature measurement means 14 (the temperature (operation status) of each secondary battery 1), the physical properties of the components such as the housing 10, the measurement result of the ambient temperature measurement means 15 and the like Based on the above, the temperature distribution in the housing 10 is calculated and obtained, and the ambient temperature T2 around the secondary battery 1 is controlled to be equal to or lower than the battery temperature T1 of the secondary battery 1 based on this temperature distribution. Also good.

1 Secondary battery (battery cell)
2 positive electrode plate 2a tab 3 negative electrode plate 3a tab 4 electrode body 5 battery can 6 electrode terminal 7 electrode terminal 10 housing (battery housing case)
11 Battery module 12 Bus bar 13 Cooling mechanism (fan)
14 Battery temperature measuring means 15 Atmospheric temperature measuring means 16 Control means 17 Heating means A Rust prevention system G for secondary battery Outside air (cooling air)

Claims (3)

  A battery temperature measuring means for measuring a battery temperature of the secondary battery housed in the housing; a cooling mechanism for cooling the secondary battery by supplying outside air around the secondary battery in the housing; and the outside air And a control means for controlling the ambient temperature to be equal to or lower than the battery temperature. Rust prevention system. In the rust prevention system of the rechargeable battery according to claim 1,
A plurality of secondary batteries are housed in the housing, and the battery temperature of each of the plurality of secondary batteries is measured by the battery temperature measuring unit, and the control unit performs control based on the secondary battery having the lowest battery temperature. A rust prevention system for a secondary battery. In the rust prevention system for the secondary battery according to claim 1 or 2,
A plurality of secondary batteries are housed in the housing, and a heating unit is provided for heating a secondary battery having a low battery temperature to reduce a temperature difference between the battery temperatures of the plurality of secondary batteries. A rust prevention system for a secondary battery.

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