Patent Application
20100330404
The present invention relates to a battery housing tray capable of safely housing a plurality of batteries in which, even if faults such as heat generation occur in a battery due to trouble in manufacturing facilities and the like during a manufacturing process of batteries, the faults do not affect other batteries, and to an assembled battery housing tray using the battery housing tray.
Recently, from the viewpoint of resource savings and energy savings, demands for secondary batteries employing nickel hydrogen, nickel cadmium or lithium ions, which can be used repeatedly, are increased. Among them, the lithium ion secondary battery has a high electromotive force and a large energy density although it has light weight. Therefore, the demand for the lithium ion secondary battery is expanded as a driving power source for various types of portable electronic apparatuses and mobile telecommunication apparatuses, for example, portable telephones, digital cameras, video cameras, and notebook-sized personal computers, and the like.
Generally, in a manufacturing process of secondary batteries, after batteries are assembled in the form of a battery itself, various treatment processes to obtain battery property are carried out, and then the batteries are commercialized. At that time, the treatment processes such as an initial charging and discharging process, an aging process, and a pre-shipment charging and discharging process are carried out. Thus, the presence or absence of a minor internal short circuit in a battery or functions of components constituting a battery are inspected, and a secondary battery having high performance and high reliability is provided. Such treatment processes are carried out in a state in which a plurality of batteries are housed in a tray in consideration of productivity.
However, in the above-mentioned treatment processes, an internal short circuit may occur in a battery, or an abnormal voltage may be applied to a battery because of a fault in a charging and discharging tester, and the like. In this case, in such batteries, abnormal heat generation or gas release due to rapid increase in the internal pressure of the battery can occur. At such a time, a safety mechanism provided in the battery cannot sufficiently work, and explosion or ignition may occur on rare occasion.
An example is disclosed in which batteries housed in a tray are monitored by an infrared ray monitor, a battery with abnormal heat generation is discriminated and eliminated in a charging and discharging process (see, for example, Patent Document 1).
Furthermore, an example is disclosed in which abnormality is detected by an odor sensor, a temperature sensor, and the like, and an inert gas or a fire-extinguishing agent is ejected to a whole device including a tray, thus preventing ignition or explosion of a battery from spreading, when a fault occurs in a battery housed in the tray in a charging and discharging process or an aging process (see, for example, Patent Documents 2 and 3).
In a temperature measurement device described in Patent Document 1, when heat generation occurs in a secondary battery housed in a tray, a battery with heat generation can be eliminated so as to prevent the influence on other batteries. However, Patent Document 1 does not describe a mechanism for preventing the influence on other batteries when a battery is abnormally heated and ignition or explosion occurs.
Furthermore, in Patent Documents 2 and 3, when a battery with a fault causes ignition or explosion in a battery depository or chamber space for carrying out a charging and discharging test, a fire-extinguishing agent is filled in the battery depository or the chamber space so as to extinguish the fire. Therefore, normal batteries existing in the battery depository or the chamber space are required to be disposed of or subjected to regenerating process when they are not disposed of. Furthermore, there is a problem that all charging and discharging devices in the battery depository or the chamber space become unusable. Furthermore, since the fire may be beyond the extinguishing ability of the facilities when the fire spreads, it is necessary to extinguish the fire while the fire is small.
A battery housing tray of the present invention houses a plurality of batteries each having a vent mechanism. The battery housing tray includes a housing member having an outer peripheral frame with a height exceeding a height of each of a plurality of batteries, and a bottom part; a barrier rib member configured to individually house the batteries in the housing member; and an opening opposite the bottom part. In the configuration, a height of the barrier rib member is more than 50% of the height of each of the batteries and less than the height of the outer peripheral frame of the housing member, and the batteries are housed in a manner that a vent mechanism side of each of the batteries faces the opening.
With such a configuration, it is possible to achieve a battery housing tray that is excellent in safety in which a flame produced by ignition of gas ejected from a vent hole of one of the batteries with a fault is dispersed in space above the barrier rib member, thus preventing the flame from spreading to the surrounding batteries or abnormally overheating in advance.
Furthermore, an assembled battery housing tray of the present invention has a configuration in which the above-mentioned battery housing trays are stacked. Thus, it is possible to achieve an assembled battery housing tray with safety and high reliability in which even when a plurality of battery housing trays are stacked in multiple stages, fire is less likely to spread.
Hereinafter, exemplary embodiments of the present invention are described with reference to drawings in which the same reference numerals are given to the same components. Note here that the present invention is not limited to the embodiments mentioned below as long as it is based on the basic features described in the description. Furthermore, in the below description, a non-aqueous electrolyte secondary battery (hereinafter, referred to as a “battery”) such as a lithium ion battery is described as an example of a battery. Needless to say, however, the battery is not necessarily limited to this example.
As shown in
Herein, positive electrode layer 1b includes a lithium-containing composite oxide such as LiCoO2, LiNiO2, and Li2MnO4 or a mixture thereof or a composite compound thereof, as a positive electrode active material. Positive electrode layer 1b further includes a conductive agent and a binder. An example of the conductive agent may include graphites such as natural graphites and artificial graphites; and carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lampblack, thermal black, and the like. Furthermore, an example of the binder includes PVDF, polytetrafluoroethylene, polyethylene, polypropylene, aramid resin, polyamide, polyimide, and the like.
As positive current collector 1a used in positive electrode 1, aluminum (Al), carbon, conductive resin, and the like, can be used.
As the non-aqueous electrolyte, an electrolyte solution obtained by dissolving a solute in an organic solvent, or a so-called a polymer electrolyte layer including the electrolyte solution and immobilized by a polymer can be used. The solute of the nonaqueous electrolyte includes LiPF6, LiBF4, LiClO4, LiAlCl4, LiSbF6, LiSCN, LiCF3SO3, LiN(CF3CO2), LiN(CF3SO2)2, and the like. Furthermore, an example of the organic solvent may include ethylene carbonate (EC), propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate (DMC), diethyl carbonate, ethyl methyl carbonate (EMC), and the like.
Furthermore, as negative current collector 11 for negative electrode 2, a metal foil of, for example, stainless steel, nickel, copper, and titanium, and a thin film of carbon and conductive resin are used.
Furthermore, for negative electrode layer 15 of negative electrode 2, carbon materials such as graphite, silicon (Si), tin (Sn), or the like, can be used as a negative electrode active material capable of reversibly absorbing and releasing lithium ions. Si, Sn, or the like has a theoretical capacity density of more than 833 mAh/cm3.
Hereinafter, a battery housing tray in accordance with the first exemplary embodiment of the present invention is described in detail with reference to
As shown in
As shown in
That is to say, as shown in
Note here that the present invention is based on the findings that when the height of barrier rib member 120 is not more than 50% of the height of battery 130, ignition or explosion of a faulty battery may cause spread of fire to batteries in the surroundings. Furthermore, when a plurality of battery housing trays are used in a stacked state, ignition or energy of explosion of the battery is released into space formed by a barrier rib member and an outer peripheral frame thanks to the height of outer peripheral frame 115 of housing member 110 being made to be a height exceeding the height of battery. Thereby, accumulated heat is released, so that ignition or smoking in the surrounding batteries can be prevented.
At this time, it is preferable that the height of barrier rib member 120 is not less than 80% of the height of battery 130. This is preferable because a heat insulation effect by the barrier rib member can be enhanced.
Herein, the above-mentioned exemplary embodiment describes an example in which the materials of the housing member and the barrier rib member are polypropylene resin, but the material is not necessarily limited to this example. For example, phenol resin, UNILATE, glass epoxy resin, ceramic, and foaming resin may be used. At this time, it is preferable that the above-mentioned resin contains filler such as carbon fiber and glass fiber. The filler to be contained can prevent the strength of the housing member and the barrier rib member from deteriorating and can maintain the shapes thereof under high temperatures generated at the time of heat generation or ignition of a faulty battery. That is to say, when the shapes cannot be maintained, the faulty battery tends to fall toward the surrounding batteries. Thus, it is possible to reduce the influence of ignition or heat generation on the surrounding batteries and reduce the possibility of spread of fire. Furthermore, heat absorbing agent such as magnesium hydroxide (Mg(OH)2) may be added in the above-mentioned resin. Thus, by transferring heat to the battier rib member in the surroundings, it is possible to suppress temperature rise in the battier rib member around a faulty battery. Furthermore, by suppressing the temperature rise, it is possible to enhance the effect of preventing the strength from deteriorating and maintaining the shape in the barrier rib member and the like.
Alternatively, the housing member and the barrier rib member may have a configuration in which metal materials such as copper (Cu), aluminum (Al) and iron (Fe) are coated with the above-mentioned insulating resin. Thus, high heat transfer property can be achieved and the mechanical strength can be enhanced. When a short circuit due to contact with battery does not occur, the housing member and the barrier rib member may be formed of only metal materials. Furthermore, the metal material may have a mesh structure or a structure having a plurality of through holes. Thus, while the heat transfer property or mechanical strength can be maintained, the weight of the housing member and the barrier rib member can be reduced.
According to this exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the barrier rib member, thus preventing spread of fire to the surrounding batteries or abnormal overheating. Furthermore, by setting the height of the barrier rib member to a predetermined height, heating of an electrode group inside a battery case of the battery can be considerably suppressed, spread of fire, and the like, can be prevented.
Furthermore, with a structure in which the housing member and the barrier rib member are formed individually and separably from each other, only by preparing a barrier rib member corresponding to the shape of a battery, various types of batteries can be housed in the same housing member. As a result, it is possible to achieve a battery housing tray with high versatility capable of stacking batteries having different shapes in multiple stages.
The above-mentioned exemplary embodiment describes an example in which the housing member and the barrier rib member are formed individually and separably from each other, but a structure is not necessarily limited to this. For example, as shown in
This exemplary embodiment has the same configuration as that in the first exemplary embodiment except that through holes are provided in a bottom part of a housing member.
Similar to the first exemplary embodiment, as shown in
As shown in
According to this exemplary embodiment, battery housing tray 200 that houses batteries 230 is disposed in a charging and discharging tester. Thereby, the plus of a positive electrode cap of the battery and the minus on the bottom part of the battery case are connected to the tester via through hole 215 in housing member 210 so as to evaluate the battery. Thus, during a charging and discharging test, even if ignition or explosion of a faulty battery, and furthermore, explosion or ignition caused by an abnormal voltage or electric current due to a fault of the tester occur, it is possible to prevent fire from spreading to the surrounding batteries.
At this time, it is more preferable that through hole 215 is smaller than the diameter of the top portion of the positive electrode cap of battery 230. This structure can prevent a flame and the like from directly parching a battery disposed immediately above, when a flame occurs at the time of structuring an assembled battery housing tray in which battery housing trays are stacked, and the flame is ejected in the oblique direction from the vent hole provided on the side surface of the positive electrode cap of the battery, which is described in detail in the following exemplary embodiment.
As shown in
As shown in
The configurations and materials of the above-mentioned housing member, the barrier rib member, the rib portion, and the like, are the same as those in the first exemplary embodiment and the description therefor is omitted herein.
According to this exemplary embodiment, similar to the first exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the barrier rib member, thus preventing spread of fire to the surrounding batteries and preventing abnormal overheating.
Furthermore, according to this exemplary embodiment, with the rib portions provided on the housing member and the barrier rib member, positioning of batteries to be housed can be carried out easily. Thus, the distance between the neighboring batteries can be kept uniform. Thus, the influence of heat generation or ignition of a faulty battery on the neighboring batteries can be made to be uniform. Therefore, the influence of heat generation and the like can be further suppressed as compared with the case in which rib portions are not provided.
Furthermore, according to the exemplary embodiment of the present invention, with the rib portions provided on the housing member and the barrier rib member, a circulation passage of air and the like is formed, so that a temperature around the batteries can be made to be uniform during, for example, an aging process.
The above-mentioned exemplary embodiment describes an example in which through holes are provided in the bottom part of the housing member, but through holes may not be provided when a charging and discharging test is not carried out. Furthermore, the exemplary embodiment describes an example in which rib portions are provided on the bottom part of the housing member, but these are not particularly necessary when only positioning of the battery is intended.
As shown in
That is to say, as shown in
Thus, space 402 is formed between, for example, bottom part 112B of battery housing tray 100B and outer peripheral frame 115C of battery housing tray 100C. As a result, energy generated when ignition or explosion of a faulty battery occurs can be dispersed to space 402. Thus, abnormal overheating or concentration of a flame on the surrounding batteries can be reduced, and an induced explosion or spread of fire can be prevented. The same is true to the relation between battery housing tray 100B and battery housing tray 100A. In addition, in battery housing tray 100A, since the upper part of battery 130 is opened, the influence on the surrounding batteries can be further reduced.
According to this exemplary embodiment, it is possible to achieve an assembled battery housing tray with high safety and high reliability in which the influence of heat generation or ignition of a faulty battery can be prevented even when a plurality of battery housing trays are stacked.
In the above mention, an example in which the battery housing trays of the first exemplary embodiment are stacked is described. However, the configuration is not necessarily limited to this example, and the battery housing trays of the second or third exemplary embodiment may be stacked. In this case, the same effect can be also obtained.
Hereinafter, another example of an assembled battery housing tray in accordance with the fourth exemplary embodiment is described with reference to
That is to say, as shown in
Thus, it is possible to achieve an assembled battery housing tray that prevents displacement in the battery housing trays to be stacked and improves stability at the time of stacking.
In the above mention, an example in which a first concave portion is provided on the outer peripheral frame and a second convex portion is provided on the bottom part in the housing member is described. However, the configuration is not necessarily limited to this example. For example, a configuration in which a first convex portion is provided on the outer peripheral frame and a second concave portion is provided on the bottom part in the housing member may be employed. In this case, the same effect can be obtained.
In the above mention, an example in which a second convex portion is provided on the battery housing tray on the bottom stage is described, but it may not be particularly provided.
Furthermore, the above-mentioned exemplary embodiment describes a configuration in which an upper part of the battery housing tray on the top stage is opened, but the configuration is not necessarily limited to this example. For example, a lid is formed from the housing member from which the outer peripheral frame is removed and which includes bottom part and a second convex portion, and the battery housing tray on the top stage is lidded by the above-mentioned lid. Such a configuration may be acceptable. Thus, even if ignition or explosion occurs in a faulty battery on the battery housing tray on the top stage, scattering thereof can be securely prevented by the lid.
As shown in
That is to say, as shown in
According to this exemplary embodiment, at the time of stacking, a battery to be stacked is not disposed immediately above another battery. Therefore, the length between the stacked batteries can be increased, and the influence of ignition or explosion caused by a gas ejected from a faulty battery can be further reduced.
Note here that, as shown in
Hereinafter, the first to fifth exemplary embodiments of the present invention are specifically described with reference to examples. Note here that the present invention is not necessarily limited to the following the examples, and modifications can be made by changing materials to be used and the like within the scopes of the summary of the present invention.
Firstly, cylindrical batteries each having a height of 65 mm, an outer diameter of 18 mm, and a battery capacity of 2600 mAh are used. A three-row and three-column battery housing tray including a barrier rib member with a height of 32.6 mm (a height of more than 50% of the height of the battery) and an outer peripheral frame with a height of 67 mm is prepared. Nine batteries described above are housed in the battery housing tray. This is designated as sample 1.
Example 2 is carried out the same as Example 1 except that the height of the barrier rib member is 39 mm (a height of 60% of the height of the battery). This is designated as sample 2.
Example 3 is carried out the same as Example 1 except that the height of the barrier rib member is 52 mm (a height of 80% of the height of the battery). This is designated as sample 3.
Example 4 is carried out the same as Example 1 except that the height of the barrier rib member is 65 mm (a height of 100% of the height of the battery). This is designated as sample 4.
Comparative Example 1 is carried out the same as Example 1 except that the height of the barrier rib member is 26 mm (a height of 40% of the height of the battery). This is designated as sample C1.
The battery housing trays produced as mentioned above are evaluated as follows while housing a plurality of batteries.
Firstly, a battery from which safety mechanisms other than a vent mechanism are removed is produced. Nine of such batteries are housed and disposed in a three-row and three-column battery housing tray. Next, assuming that trouble in charging equipment occurs in only a battery in the center part, charging is carried out until the voltage of the battery in the center part becomes 5V to make it to eject gas. The gas is ignited to produce a flame.
At this time, thermocouples are respectively attached to the surrounding batteries at the opposite side of the surface facing the battery in the center part, and the increased temperature is measured. Furthermore, after the test is finished, each battery is decomposed, and a short-circuit state in an electrode group is observed. Furthermore, an opening state of the vent mechanism provided in each battery is observed.
Then, the influence of ignition of the battery in the center part on the surrounding batteries is evaluated with respect to the maximum increased temperature, the number of short-circuited batteries, the number of batteries whose vent mechanism is opened, and presence or absence of ignition or explosion.
Hereinafter, parameters and evaluation results of samples 1 to 4 and sample C1 are shown in Table 1.
As shown in Table 1, comparison among samples 1 to 4 and sample C1 is carried out. In battery housing trays partitioned by barrier rib member whose height is more than 50% of the height of the battery, opening of a vent mechanism, which may cause ignition or explosion in the surrounding batteries, is not observed. However, as sample C1, in a battery housing tray having a barrier rib member whose height is about 40% of the height of the battery, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries by ignition or explosion of the battery in the center part, is observed in five batteries out of eight batteries. In some batteries, ignition or explosion occurs. This is thought to be because by providing a barrier rib member having a predetermined height, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries, does not occur, and therefore ejection of an electrolytic solution can be efficiently prevented.
Furthermore, as shown in Table 1, comparison among sample 1, sample 2 and sample C1 is carried out. In the surrounding batteries, a battery with a short circuit is observed because a separator contracts due to temperature rise in an electrode group in the battery. In particular, in sample C1, all of the surrounding batteries are short-circuited. On the other hand, in the batteries of samples 1 and 2, a short circuit in an electrode group occurs in a part of the surrounding batteries. This is thought to be because opening of the vent mechanism does not occur but a heat insulation effect of suppressing heat of ignited battery is not sufficient in a barrier rib member having a height of about 60% of the battery height.
Furthermore, as shown in Table 1, in samples 3 and 4, even if ignition or explosion occurs in a battery in the center part, temperature rise is small and a short circuit in an electrode group or opening of a vent mechanism is not observed. That is to say, it is shown that when the height of the barrier rib member is made to be 80% or more of the battery height, even a fault occurs in some batteries, the influence of the fault on the surrounding batteries can be considerably suppressed.
Hereinafter, a battery housing tray in accordance with a sixth exemplary embodiment of the present invention is described with reference to
This exemplary embodiment is different from the first exemplary embodiment in the following points. A housing member includes a barrier rib member on an inner surface of a bottom part of the housing member, which is defined as a first barrier rib member, and further includes a second barrier rib member on an outer surface of the bottom part of the housing member in a position corresponding to the first barrier rib member. An air hole is provided in the second barrier rib member in a direction along the outer surface of the housing member. The sum of the height of the first barrier rib member and the height of the second barrier rib member is not less than the height of the battery. Other configurations are the same as those in the first exemplary embodiment.
As shown in
Furthermore, as shown in
As shown in
With the above-mentioned configuration, as shown in
Note here that the present invention is based on the findings that when the height of first barrier rib member 1120 is not more than 50% of the height of battery 1130, due to ignition or explosion of a faulty battery, fire spreads to the batteries in the surroundings. Furthermore, with a configuration in which the height of outer peripheral frame 1115 of housing member 1110 is made to exceed the height of the battery, when a plurality of battery housing trays are stacked, energy of ignition or explosion of the battery is released to space formed by bringing first barrier rib member 1120 into contact with second barrier rib member 1122, it is possible to disperse the accumulated heat via air hole 1125 and to prevent the ignition or smoking of the surrounding batteries.
Furthermore, when a battery housing tray is used singly, in particular, it is preferable that height K1 of first barrier rib member 1120 is not less than 80% of height D of battery 1130. This is preferable because that a heat insulation effect by the barrier rib member can be increased.
Herein, the above-mentioned exemplary embodiment describes an example in which the materials of the housing member, the first barrier rib member and the second barrier rib member are polypropylene resin, but the material is not necessarily limited to this example. For example, phenol resin, UNILATE, glass epoxy resin, ceramic, and foaming resin may be used. At this time, it is preferable that the above-mentioned resin contains filler such as carbon fiber and glass fiber. The filler to be contained can prevent the strength of the housing member and the first and second barrier rib members from deteriorating and can maintain the shapes thereof at high temperatures at the time of heat generation or ignition of a faulty battery. Otherwise, when the shapes cannot be maintained, the faulty battery tends to fall toward the surrounding batteries. Thus, it is possible to reduce the influence of ignition and heat generation on the surrounding batteries and reduce the possibility of spread of fire. Furthermore, heat absorbing agent such as magnesium hydroxide (Mg(OH)2) may be added in the above-mentioned resin. Thus, by transferring heat to the first and second barrier rib members in the surroundings, it is possible to suppress temperature rise in the battier rib member(s) around a faulty battery. Furthermore, by suppressing the temperature rise, it is possible to enhance the effect of preventing the strength of the first and second barrier rib members and the like from deteriorating and maintaining the shape.
Furthermore, the housing member and the first and second barrier rib members may have a configuration in which metal materials such as copper (Cu), aluminum (Al) and iron (Fe) are coated with the above-mentioned insulating resin. Thus, high heat transfer property can be achieved and the mechanical strength can be enhanced. When a short circuit due to contact with battery does not occur, the housing member and the barrier rib members may be formed of only metal materials. Furthermore, the metal material may have a mesh structure or a structure having a plurality of through holes. Thus, while the heat transfer property or mechanical strength can be maintained, the weight of the housing member and the first and second barrier rib members can be reduced.
According to this exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the first barrier rib member, thus preventing spread of fire to the surrounding batteries or abnormal overheating. Furthermore, by setting the height of the first barrier rib member to a predetermined height, heating of an electrode group inside a battery case of the battery can be considerably suppressed, spread of fire, and the like, can be prevented.
Note here that the above-mentioned exemplary embodiment describes an example of a structure in which the housing member, and the first and second barrier rib members are integrated with each other, but the structure is not particularly limited to this example. For example, as shown in
This exemplary embodiment is different from the sixth exemplary embodiment in that a through hole penetrating from an inner surface to an outer surface of a bottom part of a housing member is provided. Note here that other configurations are the same as those in the sixth exemplary embodiment.
As shown in
Furthermore, as shown in
As shown in
According to this exemplary embodiment, battery housing tray 1200 in a state of housing batteries 1230 is disposed on a charging and discharging tester, in which the plus of a positive electrode cap of the battery and the minus on the bottom part of the battery case are connected to the tester via through hole 1215 in housing member 1210. Thus, the battery can be evaluated. During a charging and discharging test, even if ignition or explosion of a faulty battery, furthermore, explosion or ignition caused by an abnormal voltage or an electric current due to a fault of the tester may occur, it is possible to prevent the fire from spreading to the surrounding batteries by first barrier rib member 1220 similar to the sixth exemplary embodiment.
At this time, it is further preferable that through hole 1215 is smaller than the diameter of the top portion of the positive electrode cap of battery 1230. This is preferable because a flame and the like can be prevented from directly parching a battery disposed immediately (directly) above when a flame occurs at the time of structuring an assembled battery housing tray in which battery housing trays are stacked, and the flame is ejected in the oblique direction from the vent hole provided on the side surface of the positive electrode cap of the battery, which is described in detail in the following exemplary embodiment.
As shown in
As shown in
The configurations and materials of the above-mentioned housing members, the first and second barrier rib members, the rib portions, and the like, are the same as those in the sixth exemplary embodiment, and the description therefor is omitted herein.
According to this exemplary embodiment, similar to the sixth exemplary embodiment, a flame occurring at the time of ignition or explosion of gas ejected from a vent hole of a faulty battery can be dispersed into space above the first barrier rib member, thus preventing spread of fire to the surrounding batteries or preventing abnormal overheating.
Furthermore, according to this exemplary embodiment, with the rib portions provided on the housing member and the first barrier rib member, positioning of batteries to be housed can be carried out easily. Furthermore, the distance between the neighboring batteries can be kept uniform. Thus, the influence of heat generation or ignition of a faulty battery on the neighboring batteries can be made to be uniform. Therefore, the influence of heat generation and the like can be further suppressed as compared with the case in which rib portions are not provided.
Furthermore, according to the exemplary embodiment of the present invention, with the rib portions provided on the housing member and the first barrier rib member, a circulation passage of air and the like is formed, so that a temperature around the batteries can be made to be uniform during, for example, an aging process.
The above-mentioned exemplary embodiment describes an example in which through holes are provided in the bottom part of the housing member, but through holes may not be provided when a charging and discharging test is not carried out. Furthermore, the exemplary embodiment describes an example in which rib portions are provided on the inner surface of the bottom part of the housing member, but they are not particularly necessary when only positioning of the battery is intended.
As shown in
That is to say, as shown in
Note here that
Consequently, by dispersing energy generated by ignition or explosion of a faulty battery to space 1402 shared via air hole 1125B, abnormal overheating or concentration of a flame on the surrounding batteries can be reduced and thus an induced explosion or spread of fire can be prevented. In battery housing tray 1000B, an influence on the surrounding battery can be reduced because an upper part of battery 1130 is opened.
According to this exemplary embodiment, it is possible to achieve an assembled battery housing tray with safety and high reliability in which the influence of heat generation or ignition of a faulty battery can be prevented even when a plurality of battery housing trays are stacked.
In the above mention, a configuration in which the battery housing trays of the sixth exemplary embodiment are stacked is described, but the configuration is not necessarily limited to this example. The battery housing trays of the seventh or eighth exemplary embodiment may be stacked. In such cases, the same effect can be obtained.
Hereinafter, another example 1 of the assembled battery housing tray in accordance with the ninth exemplary embodiment of the present invention is described with reference to
That is to say, as shown in
Thus, it is possible to achieve an assembled battery housing tray capable of preventing battery housing trays to be stacked from being displaced and of improving stability at the time of stacking.
In the above mention, an example in which a first concave portion is provided on an outer peripheral frame of a housing member and a second convex portion is provided on the bottom part side. However, the configuration is not necessarily limited to this example. For example, a configuration in which the first convex portion is provided on the outer peripheral frame of the housing member and the second concave portion is provided on the bottom part may be employed. With such a configuration, the same effect can be obtained.
The above-mentioned exemplary embodiment describes an example in which a second convex portion and a second barrier rib member are provided on battery housing tray on the bottom stage. However, as shown in another example 2 of the assembled battery housing tray in
Furthermore, the above-mentioned exemplary embodiment describes an example in which a first concave portion is provided on the outer peripheral frame of the housing member is provided, and a second convex portion is provided on the outer surface of the bottom part of the housing member. However, the configuration is not necessarily limited to this example. For example, as shown in another example 1 of
Similar to the above, these configurations make it easy to stack battery housing trays and to securely prevent side slip and the like. Furthermore, it is possible to improve the airtightness of space formed by the first barrier rib member and the second barrier rib member, and to effectively prevent a flame from diffusing between the contact surfaces of the first barrier rib member and the second barrier rib member.
As shown in
That is to say, as shown in
According to this exemplary embodiment, at the time of stacking one battery to be stacked is not disposed immediately above another battery. Therefore, the distance between the stacked batteries is increased, and the influence of ignition or explosion caused by a faulty battery can be further reduced.
In this exemplary embodiment, battery housing region 2004 surrounded by first barrier rib member 1920 of second battery housing tray 1900 is disposed so as to span four battery housing regions 2002 of first barrier rib member 1820 of first housing tray 1800. However, the configuration is not necessarily limited to this example. For example, battery housing region 2004 of first barrier rib member 1920 of second battery housing tray 1900 may be disposed so as to span two battery housing regions 2002 of first barrier rib member 1820 of first battery housing tray 1800. Any disposition is possible as long as battery housing region 2002 of first battery housing tray 1800 and battery housing region 2004 of second battery housing tray 1900 are not overlapped to each other (do not coincide with each other).
Note here that the shapes of the air hole of the second barrier rib member described in the assembled battery housing tray in the above-mentioned eighth or ninth exemplary embodiment include any shapes such as circular-shaped air hole 2010 or rectangular-shaped air hole 2020 as shown in
Furthermore, when the height of first barrier rib member 2120 of battery housing tray 2100 on the lower stage of the assembled battery housing tray is not less than 80% of the height of the battery, as shown in
Hereinafter, the sixth to tenth exemplary embodiments of the present invention are specifically described with reference to examples. Note here that the present invention is not necessarily limited to the following examples, and modifications can be made by changing materials to be used and the like within the scopes of the present invention.
Firstly, cylindrical batteries each having a height of 65 mm, an outer diameter of 18 mm, and a battery capacity of 2600 mAh are used. A three-row and three-column battery housing tray including a first barrier rib member having a height of 32.6 mm (a height exceeding 50% of a height of the battery) and a second barrier rib member provided with an air hole and having a height of 34.4 mm is produced. The thus obtained battery housing trays are stacked to form an assembled battery housing tray, and nine batteries described above are housed in a three-row and three-column battery housing tray on at least the lower stage. This is designated as sample 5.
Example 6 is carried out the same as Example 5 except that the height of the first barrier rib member is 39 mm (a height of 60% of the height of the battery) and the height of the second barrier rib member is 28 mm. This is designated as sample 6.
Example 7 is carried out the same as Example 5 except that the height of the first barrier rib member is 52 mm (a height of 80% of the height of the battery) and the second barrier rib member is 15 mm. This is designated as sample 7.
Example 8 is carried out the same as Example 5 except that the height of the barrier rib member is 65 mm (a height of 100% of the height of the battery), the height of the second barrier rib member is 2 mm, and air holes are provided in the vicinity of shorter side of the first barrier rib (at height of 55 mm). This is designated as sample 8.
Example 9 is carried out the same as Example 5 except that the height of the first barrier rib member is 26 mm (a height of 40% of the height of the battery), the height of the second barrier rib member is 36 mm, and the battery housing trays are stacked via the outer peripheral frame with a height of 67 mm, and a gap (5 mm) is provided between the first barrier rib member and the second barrier rib member. This is designated as sample 9.
Example 10 is carried out the same as Example 5 except that the height of the barrier rib member is 32.6 mm (a height of more than 50% of the height of the battery) and the height of the second barrier rib member is 0 mm. This is designated as sample 10.
Example 11 is carried out the same as Example 5 except that the height of the barrier rib member is 52 mm (a height of 80% of the height of the battery) and the height of the second barrier rib member is 0 mm. This is designated as sample 11.
Comparative Example 2 is carried out the same as Example 5 except that the height of the first barrier rib member is 26 mm (a height of 40% of the height of the battery), the height of the second barrier rib member is 0 mm, and the battery housing trays are stacked via the outer peripheral frame with a height of 67 mm, and a gap (41 mm) is provided between the first barrier rib member and the second barrier rib member. This is designated as sample C2.
The battery housing trays produced as mentioned above while housing a plurality of batteries are evaluated as follows.
Firstly, a battery from which safety mechanisms other than a vent mechanism are removed is produced. Nine of such batteries are housed and disposed in a three-row and three-column battery housing tray. Next, assuming that trouble in charging equipment occurs in only a battery in the center part, the battery in the center part is charged until the battery voltage becomes 5V to eject gas. The gas is ignited to produce a flame.
At this time, thermocouples are respectively attached to the surrounding batteries at the opposite side of the surface facing the battery in the center part, and the increased temperature is measured. Furthermore, after the test is finished, each battery is decomposed, and a short-circuit state of an electrode group is observed. Furthermore, an opening state of the vent mechanism provided in each battery is observed.
Then, the influence of ignition of the battery in the center part on the surrounding batteries is evaluated with respect to the maximum increased temperature, the number of short-circuited batteries, the number of batteries whose vent mechanism is opened, and presence or absence of ignition or explosion.
Hereinafter, parameters and evaluation results of samples 5 to 11 and sample C2 are shown in Table 2.
As shown in Table 2, in samples 5 to 9, temperature rise, a short circuit in an electrode group, and opening of a vent mechanism do not occur in the surrounding batteries. This is thought to be because battery housing trays are stacked and batteries are housed in space surrounded by the first barrier rib member and the second barrier rib member, so that the influence of a fault can be considerably suppressed in each barrier rib member even if a fault occurs in a part of batteries.
Furthermore, as shown in Table 2, when comparison among sample 10, sample 11 and sample C2 is carried out, in the battery housing tray partitioned by the first barrier rib member whose height is more than 50% of the height of the battery, even in a case where a battery housing tray is used singly or used in a top stage, opening of a vent mechanism, which may cause ignition or explosion in the surrounding batteries, is not observed. In particular, as sample 7, it is shown that by setting the height of the first barrier rib member to be not less than 80% of the height of the battery, a short circuit in the electrode group in the surrounding batteries can be suppressed sufficiently.
However, as sample C2, in a battery housing tray having a first barrier rib member whose height is about 40% of the height of the battery, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries by ignition or explosion of the battery in the center part, is observed in five batteries out of eight batteries. In some batteries, ignition or explosion occurs. This is thought to be because by providing a first barrier rib member having a predetermined height, opening of a vent mechanism, which may cause an induced explosion or ignition in the surrounding batteries, does not occur, and therefore ejection of an electrolytic solution can be efficiently prevented.
From the above mention, it is shown that when batteries are housed in the battery housing trays that are stacked, an assembled battery housing tray capable of securing sufficient safety can be obtained when the height of the first barrier rib member in the battery housing tray in at least the top stage of the stacked trays is made to be the height exceeding 50% of the height of the battery. In the battery housing trays other than that in the top stage, batteries can be housed inside of the first barrier rib member and the second barrier rib member. Therefore, it is shown that when an air hole is provided or formed, the ratio of the height of each barrier rib member to the height of the battery is not particularly considered.
Furthermore, as shown in Table 2, when comparison between samples 5 to 8 and sample 9 is carried out, the temperature rise in the surrounding batteries is slightly larger in sample 9. This is thought to be because a gap portion, which is formed between the first barrier rib member with a height is about 40% of the height of the battery and the second barrier rib member, is used as an air hole, so that more heat is applied to the vicinity of the electrode group in the battery as compared with a battery housing tray having an air hole in the vicinity of an exhaust air valve of the battery. However, when the gap portion is about 5 mm, it is thought that safety is secured.
The present invention is useful as a battery housing tray for housing a battery and the like, which requires high reliability and safety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-030255 | Feb 2008 | JP | national |
| 2008-030256 | Feb 2008 | JP | national |
This application is a 371 application of PCT/JP2009/000494 having an international filing date of Feb. 9, 2009, which claims priority to JP2008-030255 filed on Feb. 12, 2008 and JP2008-030256 filed on Feb. 12, 2008, the entire contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2009/000494 | 2/9/2009 | WO | 00 | 8/6/2010 |
