JP4778753B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module that can be suitably applied to a backup power source, and more particularly to a battery module in which a plurality of nickel metal hydride storage batteries are arranged in a case portion.

  Nickel-metal hydride storage batteries are clean and high-capacity and superior in long-term reliability compared to lithium-ion secondary batteries. Therefore, in addition to mobile power sources such as main power supplies and sub power supplies for various electric vehicles, communication for mobile phones, for example It is attracting attention as a stationary power source such as a backup power source in a base station and a power source for applications with little movement, and replacement with lead storage batteries and nickel cadmium storage batteries containing pollutants is progressing.

  A hydrogen storage alloy is used as the negative electrode active material of the nickel-metal hydride storage battery. As a characteristic of this material, since the stored hydrogen is released at the time of charging, the charging efficiency tends to decrease. Furthermore, since nickel hydroxide, which is a positive electrode active material, also has low charging efficiency at high temperatures, when a battery module is configured by connecting several cells or more in series, the battery is efficiently cooled and does not reach high temperature. It is necessary to consider so.

As a battery module structure with a cooling function, a plurality of batteries are arranged in parallel in a state where an appropriate air passage is formed between them, cooling air is fed from one end of the case, and from the other end of the case It is known that each battery is cooled by cooling air that flows through a ventilation passage formed in the case by discharging (see, for example, Patent Document 1 and Patent Document 2).
JP 2001-319697 A JP 2004-014421 A

  By the way, unlike a power source installed in a moving body such as an electric vehicle, a large amount of outside air is taken in and distributed as cooling air to the battery module. Since the battery module is installed in a closed space with relatively little, it is difficult to sufficiently cool the storage battery placed inside the case even if the air taken from the closed space is circulated in the case of the battery module. In addition, there is a problem that the life characteristics are remarkably deteriorated due to an increase in heat storage due to repeated charging and discharging.

  In addition, the stationary power supply for backup is configured to always maintain a fully charged state by performing trickle charging that always charges with a small current, so the degree of heat storage around the center of the storage battery and around the terminals is Therefore, even if the cooling air is circulated in the case where the storage battery is arranged, only the outer peripheral surface of the battery is cooled, so even if the heat at the center can be radiated to some extent, the cooling around the terminals at both ends is insufficient. Therefore, there is a problem that the life characteristics are remarkably deteriorated due to an increase in heat storage.

  In view of the above-described conventional problems, the present invention provides a battery module that can effectively cool the central portion and the terminal portions at both ends of a storage battery even when applied to a stationary power source, and can suppress a decrease in life characteristics due to increased heat storage. The purpose is to do.

The battery module of the present invention includes a battery group in which both end portions of a plurality of nickel hydride storage batteries are inserted into and integrated with a plurality of through holes provided in two support plates, and both end faces of the adjacent nickel hydride storage batteries. A plurality of connecting plates that sequentially connect the terminals of the battery, a case portion that covers the upper and lower surfaces of the battery group and the four sides of the side surface on which the support plate is disposed, and at least the lower edge of the support plate contacts, Between the both end faces of the nickel-metal hydride battery, comprising a front part disposed on one of the opening surfaces and having a vent and a back surface disposed on the other opening surface of the case part and provided with a fan. The length is A, the thickness of one of the support plates is B, and 0.2 ≦ 2B / A ≦ 0.4 , and the support plate has a thermal conductivity of 0.25 W / mK or more. It is.

  According to this configuration, by driving the fan on the back surface, air outside the case portion flows into the case from the vent hole in the front portion, and flows inside the case portion as cooling air to be discharged. The outer peripheral surface is cooled with cooling air to dissipate heat at the center of the nickel-metal hydride storage battery, and the heat at both ends of the nickel-metal hydride storage battery is transmitted to the case part via the support plate, thereby having a large heat dissipation area. Since the heat is radiated from the outside to the outside, both the central portion and the terminal portions at both ends of the nickel-metal hydride storage battery are effectively cooled, and the deterioration of the life characteristics due to increased heat storage can be effectively suppressed.

In particular, the thickness of the support plate is 0.1 to 0.2 times the length between both end faces of the nickel metal hydride storage battery , and the support plate has a thermal conductivity of 0.25 W / mK or more. Thus, the heat of the terminal portion is reliably transmitted to the case portion via the support plate, and a cooling region by the cooling air is sufficiently secured between the support plates. When the thickness of the support plate is smaller than the above range, cooling around the terminals becomes insufficient, and when it is larger than the above range, cooling of the central portion becomes insufficient. Thus, the above configuration optimizes the heat dissipation balance between the central portion and both end terminal portions of the nickel-metal hydride storage battery, and can effectively suppress both the heat storage.

In addition, the support plate is made of a metal plate material, and if at least the through-hole portion has electrical insulation, heat can be effectively and reliably radiated through the support plate, and insulation between the storage batteries can be easily ensured. Therefore, it is preferable. The thermal conductivity of the support plate is more preferably 0.3 W / mK or more. As the material of the support plate, metal is preferable from the viewpoint of thermal conductivity, but it is difficult to ensure electrical insulation. Therefore, a resin having a high heat transfer coefficient such as a resin mainly composed of polyethylene terephthalate (PET) or polyphenylene oxide is preferable.

  Moreover, this invention is applied suitably with respect to the capacity | capacitance of a nickel hydride storage battery 30 Ah or more. That is, a storage battery of 30 Ah or more exhibits a great effect because the degree of heat storage is particularly high.

  The nickel-metal hydride storage battery includes a positive electrode using nickel hydroxide as an active material, a negative electrode, a separator, an electrolytic solution, and a battery case, and the positive electrode contains at least metals Co and Yb. In this case, since the metal Co is particularly conductive as a conductive agent for forming a conductive network in the positive electrode, the internal resistance can be greatly reduced, the Joule heat generation during charging / discharging can be suppressed, and the Yb compound is charged. The oxygen generation overvoltage of the positive electrode at the time can be increased, so the reaction resistance during charging especially in the high temperature range can be drastically suppressed, the Joule heat generation in the high temperature atmosphere of the battery can be suppressed, and the nickel metal hydride storage battery itself suppresses the heat generation By having a function, the effect is even greater.

  In addition, it is preferable that the content of metal Co is 4 to 8 parts by weight with respect to 100 parts by weight of the nickel hydroxide because the above-described effect can be obtained with certainty. When the content of the metal Co is less than the above range, the effect is not sufficiently exhibited. When the content is excessive, the ratio of nickel hydroxide as the active material is reduced and the capacity is reduced.

  Moreover, the said effect is acquired reliably and it is suitable that content of Yb is 1-6 weight part with respect to 100 weight part of said nickel hydroxide. When the content of the Yb compound is less than the above range, the effect is not sufficiently exerted, and when it is excessive, the ratio of nickel hydroxide as an active material is reduced, the capacity is lowered, and the conductivity is lowered.

  Moreover, it is preferable that electrolyte solution contains NaOH, KOH, and LiOH as a salt, and the dissolution amount is NaOH> = KOH> LiOH by molar ratio. Normally, the electrolyte is composed mainly of KOH having the highest degree of dissociation, that is, ionic conductivity, but by making NaOH having the effect of improving the high-temperature charging efficiency equal to or higher than KOH, particularly in the high temperature range. The reaction resistance at the time of charging can be drastically suppressed, the Joule heat generation under the high temperature atmosphere of the battery can be suppressed, and the reaction resistance can be reduced by adding a small amount of LiOH which has the effect of increasing the positive electrode utilization rate. It can be greatly reduced, and Joule heat generation during charging and discharging can be comprehensively suppressed.

  According to the battery module of the present invention, the outer peripheral surface of the nickel-metal hydride storage battery is reliably cooled by the cooling air flowing in the case part, and the heat of the center part of the nickel-metal hydride storage battery is dissipated, and at both ends of the nickel-metal hydride storage battery Heat is reliably transmitted to the case part via the support plate having the required thickness, and heat is radiated to the outside from the case part having a large heat radiation area, so both the center part and the terminal parts at both ends of the nickel-metal hydride battery are effective. It is possible to effectively suppress a decrease in life characteristics due to increased heat storage.

  Hereinafter, an embodiment of a battery module of the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a backup power source for a mobile phone communication base station. A device arrangement space 3 for arranging a charger, a discharger, a control board, and the like is provided in an upper portion of the case 2. A battery arrangement space 4 is provided in the lower part of the inside, and two sets of power supply batteries 5 each including four battery modules 10 are arranged in parallel. Each power supply battery 5 is configured by connecting four battery modules 10 in series, and each battery module 10 is configured by connecting ten cylindrical nickel hydride storage batteries 11 in series. Since the output voltage of the cylindrical nickel-metal hydride storage battery 11 is 1.2V, the output voltage of the power supply battery 5 is 48V.

  In the battery module 10, as shown in FIGS. 2 to 4, both end portions of the ten cylindrical nickel-metal hydride storage batteries 11 are respectively inserted into through holes 13 provided in the two support plates 12 and integrated. Thus, a battery group 14 is configured. In the battery group 14, a plurality of connection plates 15 are arranged along the outer surface of the support plate 12 in order to sequentially connect terminals at both ends of adjacent cylindrical nickel-metal hydride storage batteries 11 in series. In addition, by providing a gap between the connection plate 15 and the support plate 12, the support plate 12 can be electrically insulated even when the support plate 12 has conductivity. In addition, connection terminals 16 are joined to terminals at both ends of the cylindrical nickel-metal hydride storage battery 11 connected in series. For the connection plate 15 and the connection terminal 16, a thin plate made of a highly conductive material such as iron or nickel can be used.

  An upper case 17 is disposed so as to cover the upper surface of the battery group 14 and both side surfaces parallel to the support plate 12, and a lower case 18 is disposed in contact with the lower surface of the battery group 14, and the upper case 17 and the lower case 18 are arranged. A case portion 19 is formed to cover the upper and lower surfaces of the battery group 14 and the four surfaces on both sides. A front surface portion 21 provided with a vent hole 20 is disposed on one opening surface of the case portion 19, and a back surface portion 23 provided with a fan 22 is disposed on the other opening surface of the case portion 19. In addition, the rear surface portion 23 is provided with a terminal opening 24 through which the connection terminal 16 protrudes to the outside. As shown in FIG. 3, the support plate 12 may be configured so that there is a gap between the upper edge and the ceiling surface of the upper case 17, but as shown in FIG. It is preferable to contact the ceiling surface of the upper case 17 and transfer heat directly from the support plate 12 to the upper case 17.

  In a state where the battery group 14 is accommodated and disposed in a space surrounded by the case part 19, the front part 21, and the back part 23, between each cylindrical nickel-metal hydride storage battery 11, 11, and the cylindrical nickel-metal hydride storage battery 11, A gap serving as a cooling passage 25 is formed between the case portion 19, the front portion 21, and the back portion 23. Thus, by operating the fan 24, the external air introduced from the vent hole 20 of the front part 21 passes through the cooling passage 25 and is discharged to the outside from the back part 23. At this time, each cylindrical nickel-metal hydride storage battery 11 is discharged. The outer peripheral surface between the support plates 12 and 12 is cooled by the air flow that flows through the cooling passage 25.

  The support plate 12 preferably has a thermal conductivity of 0.25 W / mK or more, and its thickness B is 0, where A is the length between the terminal surfaces at both ends of the cylindrical nickel-metal hydride storage battery 11. .2 ≦ 2B / A ≦ 0.4 is set. As a result, the central portion of the cylindrical nickel-metal hydride storage battery 11 is cooled by the air flow flowing through the cooling passage 25, and the vicinity of the terminals at both ends of the cylindrical nickel-metal hydride storage battery 11 is connected to the case portion 19 via the support plate 12. As a result of heat transfer to the outside, heat is radiated from the case portion 19 to the outside air and cooled. If the thickness B of the support plate 12 is smaller than the above range, cooling in the vicinity of the terminals of the cylindrical nickel-metal hydride storage battery 11 becomes insufficient. Conversely, if the thickness B is larger than this range, cooling of the central part of the cylindrical nickel-metal hydride storage battery 11 is insufficient. It becomes insufficient, and by setting within this range, the vicinity of the terminal and the center of the cylindrical nickel-metal hydride storage battery 11 are cooled with good balance.

  As the support plate 12, a metal plate having a high thermal conductivity is suitable, so that a metal plate is generally conceivable. However, it is difficult to ensure electrical insulation in terms of structure. Therefore, a general resin has a thermal conductivity of about 0.2 W / mK, whereas a resin having a thermal conductivity of 0.25 W / mK or more, more preferably 0.3 W / mK or more as described above. It is good to use. For example, a resin composed mainly of polyethylene terephthalate (PET) or polyphenylene oxide is preferably used. As a specific example, trade name “Unilate” (mixture of PET, glass fiber and mica) manufactured by Kyodo Co., Ltd. may be mentioned, and its thermal conductivity is 0.31 to 0.51 W / mK. Moreover, as the case part 19, the iron-type material with high heat dissipation is suitable.

  In this embodiment, an example in which a resin plate having electrical insulation is used has been shown. However, a metal plate material having high thermal conductivity such as an aluminum alloy, or a press-formed product or sheet metal product of a metal thin plate such as a thin steel plate. The material of the through hole 13 may be combined with a material having electrical insulation and high thermal conductivity. Further, heat transfer between the contact surfaces is performed by interposing a sealing material having high thermal conductivity between the cylindrical nickel-metal hydride storage battery 11 and the through hole 13 or between the contact surfaces between the support plate 12 and the case portion 19. It is preferable to improve the rate.

  As shown in FIG. 5, the cylindrical nickel-metal hydride storage battery 11 accommodates an electrode plate group 34 formed by winding a positive electrode plate 31 and a negative electrode plate 32 with a separator 33 in a metal cylindrical case 35 together with an electrolyte. The opening of the cylindrical case 35 is hermetically sealed with a sealing plate 37 provided with a safety valve 36 while being electrically insulated from the cylindrical case 35. The outermost periphery of the negative electrode plate 32 is brought into contact with the inner periphery of the cylindrical case 35, the bottom surface of the cylindrical case 35 forms a negative electrode terminal, and the positive electrode plate 31 is sealed through a lead (not shown). The sealing plate 37 is connected to the plate 37 and constitutes a positive electrode terminal. The cylindrical case 35 is preferably made of iron plated with nickel, and the outer peripheral surface of the cylindrical case 35 is covered with an insulating film, so that the cylindrical nickel-metal hydride storage battery 11, the support plate 12, and the case portion 19 can be easily formed. In addition, electrical insulation can be ensured.

The positive electrode plate 31 is coated with a positive electrode material mainly composed of nickel hydroxide (in this specification, Ni (OH) ₂ is also used for a solid solution or coating of Co or the like). It is configured to be worn and held. In this embodiment, the positive electrode material mainly composed of nickel hydroxide contains a metal Co and a Yb compound such as Yb ₂ O ₃ or Yb (OH) ₃ . Specifically, metal Co is, Ni (OH) containing 4-8 parts by weight with respect to ₂ 100 parts by weight, Yb compounds, Ni (OH) 1 to 6 parts by weight contained against ₂ 100 parts by weight ing. As a specific example, the positive electrode material is composed of Ni (OH) ₂ : 100 parts by weight, metal Co: 5 parts by weight, Yb ₂ O ₃ : 4 parts by weight, and ZnO: 2.5 parts by weight.

  The negative electrode plate 32 is configured by coating and holding a negative electrode material mainly composed of a hydrogen storage alloy on Ni punching metal. The separator 33 is made of a polyamide-based or polyolefin-based nonwoven fabric that has been subjected to a hydrophilic treatment (such as a sulfonation treatment) as necessary.

  The electrolytic solution is composed of a mixed solution of three components of NaOH, KOH, and LiOH, and the composition satisfies NaOH ≧ KOH> LiOH. As a specific example, NaOH: KOH: LiOH = 4: 2.5: 1. In addition, the density | concentration of electrolyte solution is 7.5 mol / L.

  In the cylindrical nickel-metal hydride storage battery 11 configured as described above, since the additive material of the positive electrode plate 31 includes metal Co, even if the area of the positive electrode plate 31 is large, the positive electrode plate 31 is present due to the presence of highly conductive metal Co. The electrical resistance of the battery can be reduced, heat generation during charging and discharging can be suppressed, and the long-term reliability of the battery can be improved.

  Further, the inclusion of the Yb compound in the additive material of the positive electrode plate 31 can increase the oxygen generation overvoltage of the positive electrode at the time of charging. The life characteristics under the atmosphere can be improved.

  Furthermore, the electrolytic solution is composed of three components of NaOH, KOH, and LiOH, and its composition is NaOH: KOH: LiOH = 4: 2.5: 1, and the amount of NaOH having high conductivity at high temperature is increased. In particular, heat generation during charging in a high temperature range can be suppressed, and the life characteristics of the battery in a high temperature atmosphere can be improved.

  Below, the Example and comparative example of the battery module which concern on this invention are demonstrated.

Example 1
The positive electrode plate 31 is prepared by filling a foamed nickel three-dimensional porous body with a mixture in which 5 parts by weight of metal Co, 4 parts by weight of Yb ₂ O _{3 and} 0.5 part by weight of a fluororesin are added to 100 parts by weight of nickel hydroxide. Produced. The negative electrode plate 32 is 0.3 parts by weight of acetylene black with respect to 100 parts by weight of a hydrogen storage alloy represented by the general formula MmNi _3.55 Co _0.75 Mn _0.4 Al _0.3 (Mm is a mixture of La, Ce, Nd, and Pr). A mixture obtained by adding 0.7 parts by weight of a styrene-butadiene copolymer and 0.2 parts by weight of carboxymethyl cellulose was applied to a punching metal obtained by applying nickel plating to iron. Separator 33 used was a non-woven fabric made of polypropylene and sulfonated. These positive electrode plate 31 and negative electrode plate 32 are wound through a separator 33 to form an electrode plate group 34, which is housed in a cylindrical case 35 in which nickel is plated on iron, and then NaOH: KOH: LiOH = 4. A cylindrical nickel-metal hydride storage battery 11 having a diameter of 60 mm and a length (distance between both terminals) of 176 mm was prepared by injecting an electrolytic solution having a composition of 2.5: 1.

  Through holes provided on two support plates 12 (“unilate”, details are described above) having 10 cylindrical nickel-metal hydride storage batteries 11 and each having both end portions 20 mm thick (2B / A = 0.23) The battery group 14 was configured by being inserted into and fitted in 13 and arranged in 5 horizontal rows and 2 vertical rows so that the gap between the batteries was 5 mm, and connected in series with the connection plate 15. The battery group 14 is installed on a lower case 18, an upper case 17 that covers the upper surface and both side surfaces of the battery group 14 is disposed, the case portion 19 covers the four surfaces of the battery group 14, and the front ends are opened at both ends. The battery module 10 was produced by arranging the part 21 and the back part 23.

(Examples 2 and 3)
A battery module 10 similar to that of Example 1 was produced except that the thickness of the support plate 12 was changed to 13 mm (2B / A = 0.15) and 35 mm (2B / A = 0.4), respectively.

(Examples 4 to 7)
A battery module 10 similar to that of Example 1 was produced, except that the amount of metallic Co added to the positive electrode plate mixture was changed to 3 parts by weight, 4 parts by weight, 8 parts by weight, and 10 parts by weight, respectively.

(Examples 8 to 11)
A battery module 10 similar to that of Example 1 was prepared, except that the amount of Yb ₂ O ₃ added to the positive electrode plate mixture was changed to 0.5 parts by weight, 1 part by weight, 6 parts by weight, and 8 parts by weight, respectively. did.

(Examples 12 to 14)
Example 1 except that the composition of the electrolyte (NaOH: KOH: LiOH) was changed to 3.25: 3.25: 1, 2.5: 4: 1, and 4: 1.5: 1, respectively. The battery module 10 was produced.

(Comparative Examples 1 and 2)
A battery module 10 similar to that of Example 1 was produced except that the thickness of the support plate 12 was changed to 10 mm (2B / A = 0.11) and 40 mm (2B / A = 0.45), respectively.

  About the battery modules 10 of Examples 1 to 14 and Comparative Examples 1 and 2 described above, rate characteristic evaluation and life characteristic evaluation were performed.

  In the rate characteristic evaluation, each battery module 10 was charged at a current value of 20 A for 5 hours in a 25 ° C. atmosphere, and then discharged until 19 V was reached at 19 A. Then, after similarly charging, it discharged until it reached 10V at 95A. The ratio (%) of the 95A discharge capacity to the 19A discharge capacity at that time was measured. 90% or more was evaluated as excellent, 85% or more as good, and 80% or more as acceptable.

The life characteristic evaluation is a charge / discharge cycle in which each battery module 10 placed in an atmosphere of 50 ° C. is charged at a current value of 20 A for 5 hours and then discharged at a current value of 30 A (the final voltage is 10 V). The discharge capacity retention rate (ratio to the initial capacity) (%) was measured repeatedly after 300 cycles. In addition, as the fan 22 used for cooling the battery module 10, a cooling fan having a maximum air volume of 1.5 m ³ / min was used. 84% or more was evaluated as excellent, 83% was evaluated as good, 80% or more was acceptable, and less than 80% was evaluated as unacceptable.

以上の実施例１〜１４及び比較例１、２について、電池の理論容量と、正極合剤における金属ＣｏとＹｂ₂ Ｏ₃ の添加重量部と、電解液の組成と、両端子間距離Ａと、支持板の厚さＢと、２Ｂ／Ａと、レート特性評価と寿命特性評価の評価結果を表１に示した。

For Examples 1 to 14 and Comparative Examples 1 and 2 described above, the theoretical capacity of the battery, the addition parts by weight of metal Co and Yb ₂ O ₃ in the positive electrode mixture, the composition of the electrolytic solution, the distance A between both terminals, Table 1 shows the evaluation results of the thickness B of the support plate, 2B / A, rate characteristics evaluation and life characteristics evaluation.

  From each example and comparative example in Table 1, the life characteristics evaluation is good in each example in which 2B / A is in the range of 0.2 to 0.4, but from the range as in the comparative example. It can be seen that evaluation is impossible even if it is small or larger than the range. Moreover, from Examples 1-3, it turns out that lifetime characteristic evaluation falls and it is the best in the middle when it approaches the upper and lower limits of the said range.

  In addition, from Examples 1 and 4-7, the addition amount of metal Co is 3 to 10 parts by weight, and the results of the rate characteristics evaluation and the life characteristics evaluation “OK” are obtained. Thus, it can be seen that the result of “good” or “excellent” in the rate characteristic evaluation and the life characteristic evaluation can be obtained by using 4 to 8 parts by weight.

In addition, from Examples 1 and 8 to 11, the result of “Yes” is obtained as the rate characteristic evaluation and the life characteristic evaluation when the addition amount of Yb ₂ O ₃ is 0.5 to 8 parts by weight. It can be seen that by using 1 to 6 parts by weight as in 10, the rate characteristic evaluation and the life characteristic evaluation are “good” or “excellent”. Further, from Examples 8 and 11, it can be seen that when the amount of Yb ₂ O ₃ added is small, the life characteristic evaluation is lowered, and when it is increased, the rate characteristic evaluation is lowered.

  Further, when the composition of the electrolytic solution from Example 1 is NaOH> KOH> LiOH, the rate characteristic evaluation and the life characteristic evaluation are “excellent”. From Example 12, when the NaOH = KOH> LiOH, the life characteristic is obtained. Although the evaluation is “excellent”, the rate characteristic evaluation is somewhat inferior. In the case of NaOH <KOH >> LiOH as in Example 13, the rate characteristic evaluation is conversely “excellent”, but the life characteristic is The evaluation is considerably inferior, and when NaOH >> KOH <LiOH as in Example 14, the rate characteristic evaluation is considerably inferior and the life characteristic evaluation is also somewhat inferior.

  In the battery module of the present invention, the heat at the center of the nickel-metal hydride storage battery is radiated by the cooling air flowing through the case, and the heat at both ends is reliably transmitted to the case through the support plate having the required thickness. Therefore, both the central part and the terminal part of both ends of the nickel-metal hydride storage battery are effectively cooled and the deterioration of the life characteristics due to increased heat storage can be effectively suppressed. Useful for battery power supply.

The principal part structure of the power supply for backup to which the battery module which concerns on this invention is applied is shown, (a) is a front view, (b) is a vertical side view. The structure of the battery module of one Embodiment of this invention is shown, (a) is a disassembled perspective view, (b) is an external appearance perspective view. The longitudinal section side view which looked at the battery module of the embodiment from the opposite side to FIG. FIG. 4 is a partial cross-sectional view taken along arrow AA in FIG. 3. The partial exploded perspective view of the cylindrical nickel hydride storage battery in the battery module of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Battery module 11 Cylindrical nickel metal hydride storage battery 12 Support plate 13 Through-hole 14 Battery group 15 Connection board 19 Case part 20 Vent 21 Front part 22 Fan 23 Rear part

Claims (7)

A battery group in which both ends of a plurality of nickel metal hydride storage batteries are inserted into and integrated with a plurality of through holes provided in two support plates, and terminals on both end faces of the adjacent nickel metal hydride storage batteries are sequentially connected in series. A plurality of connecting plates, a case portion that covers four surfaces of the battery group, the upper and lower surfaces and the side surface on which the support plate is disposed, and at least the lower edge of the support plate is in contact, and is disposed on one opening surface of the case portion And a rear portion disposed on the other opening surface of the case portion and provided with a fan, the length between both end surfaces of the nickel-metal hydride battery being A, the support If the thickness of one plate is B, 0.2 ≦ 2B / A ≦ 0.4 ,
The battery module , wherein the support plate has a thermal conductivity of 0.25 W / mK or more . The battery module according to claim 1, wherein the support plate is made of a metal plate material , and at least a through hole portion has electrical insulation.   The battery module according to claim 1, wherein the nickel-metal hydride storage battery has a capacity of 30 Ah or more.   The nickel metal hydride storage battery includes a positive electrode using nickel hydroxide as an active material, a negative electrode, a separator, an electrolytic solution, and a battery case, and the positive electrode contains at least metals Co and Yb. The battery module according to claim 1.   5. The battery module according to claim 4, wherein the content of metal Co is 4 to 8 parts by weight with respect to 100 parts by weight of the nickel hydroxide.   The battery module according to claim 4, wherein the content of Yb is 1 to 6 parts by weight with respect to 100 parts by weight of the nickel hydroxide.   5. The battery module according to claim 4, wherein the electrolytic solution contains NaOH, KOH, and LiOH as salts, and the dissolved amount is NaOH ≧ KOH> LiOH in terms of molar ratio.

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