JP4148416B2 - Insulated container and assembled battery including the same - Google Patents

Description

The present invention relates to a heat insulating container that houses secondary batteries that operate at a high temperature, such as a plurality of sodium-sulfur batteries, and an assembled battery that includes the same.

Conventionally, an assembled battery in which a plurality of single cells are assembled has been used. There is a battery using a sodium-sulfur battery as a unit cell of such an assembled battery. The sodium-sulfur battery is a secondary battery used for power storage, electric vehicle drive power supply, etc., and the sodium in the negative electrode chamber becomes a sodium ion in a state heated to an operating temperature of 290 ° C. to 350 ° C. It passes through the electrolyte tube and reacts with sulfur in the positive electrode chamber to generate sodium polysulfide and discharge is performed. At the time of charging, sodium ions and sulfur are reversibly generated from sodium polysulfide in the positive electrode chamber, and the sodium ions are solid. It passes through the electrolyte tube and returns to the negative electrode chamber. Therefore, an assembled battery using a sodium-sulfur battery as a unit cell contains a plurality of unit cells of sodium-sulfur battery to maintain an operating temperature at a constant temperature of 290 ° C. to 350 ° C. Some have a heat insulating container that suppresses the heat of reaction from radiating to the outside.
As such a heat insulation container, Patent Document 1 states that “sodium sulfur which is abutted at a joint formed on the edge of a box-shaped vacuum heat insulation container with a plurality of batteries standing inside and having an open top. A battery insulation container "is disclosed.
Patent Document 2 states that “a box-shaped container whose upper surface is opened and a box-shaped lid whose lower surface is opened are crowned. The container and the lid are made of stainless steel plates on the outer wall and the inner wall. There is disclosed a heat-insulating container in which a vacuum heat-insulating board in which a fibrous material made of a material having low thermal conductivity such as glass fiber or rock wool is solidified into a plate shape is loaded in a hollow container.
On the other hand, as a fuel cell provided with a heat insulating container, Patent Document 3 discloses that “a vacuum heat insulating container having a bell-shaped shape having an outer wall and an inner wall is covered with a fuel cell stack placed on a flat heat insulating material. And a high-temperature fuel cell in which a vacuum heat insulating container is attached to a heat insulating material at a joint between an outer wall and an inner wall formed at the lower edge of the vacuum heat insulating container.
Patent Document 4 states that “a heating device for an assembled battery in which a plurality of heating wires are wound around a peripheral surface of a core member made of an insulating plate, and an insulating thin plate is arranged on both sides thereof, and An “assembled battery in which the heating device is disposed on the inner bottom surface of the heat insulating container” is disclosed.

Japanese Patent Laid-Open No. 10-83832 JP 2000-21364 A JP-A-8-138721 JP 11-162507 A

However, the above prior art has the following problems.
(1) In the heat insulation containers of Patent Documents 1 and 2, since heat is radiated to the outside through the portion where the seam is formed and the vacuum heat insulation board, there is a problem that the heat insulation is lacking.
(2) Since the heat insulating containers of Patent Documents 1 and 2 are formed in a rectangular box shape, when the hollow portion between the outer wall and the inner wall is formed in a vacuum, stress is applied to a part of the container due to negative pressure. In order to concentrate, it lacks durability, and in order to improve durability, when a reinforcing member is formed in the hollow part or filled with a filler, heat is radiated to the outside through the reinforcing member or filler. It had the subject of lacking heat insulation.
(3) In the heat insulation containers of Patent Documents 1 and 2, a plurality of sodium-sulfur battery cells are arranged in parallel in the heat insulation container at regular intervals in the horizontal and vertical directions. In addition to the increase in size of the container and lack of space-saving properties, the increase in the surface area of the heat-insulating container caused a problem that the heat-insulating property was lowered.
(4) In the high-temperature fuel cell of Patent Document 3, since the opening at the lower end of the bell-shaped vacuum heat insulating container is only closed by a flat heat insulating material, the outer wall and the inner wall of the lower end of the vacuum heat insulating container There has been a problem that a great amount of heat is radiated from the heat insulating material in contact with the joint and the lower end and lacks heat insulation.
(5) Since the high-temperature fuel cell of Patent Document 3 operates at a high temperature of 650 ° C. to 1000 ° C., water molecules and hydrogen molecules adsorbed on the wall surface of the vacuum insulation container are desorbed during operation, and the degree of vacuum in the vacuum portion is reduced. However, there was a problem that the heat insulating property was lowered.
(6) In the high-temperature fuel cell of Patent Document 3, the fuel gas and air enter and exit the vacuum heat insulating container and dissipate to the outside as sensible heat of the fuel gas and air. Had the problem of lacking.
(7) In the assembled battery of Patent Document 4, the heat insulating container is formed so that the thermal conductivity is not relatively reduced, and the temperature in the heat insulating container is compensated by the heat radiated from the heat insulating container by the heating by the heating device. Is maintained at a predetermined operating temperature. Therefore, power to be supplied to the heating device at a predetermined time interval is required, and energy loss occurs when the power of the assembled battery is supplied, or cost is increased when inexpensive power is supplied from the outside. There was a problem of lack of cost.

The present invention solves the above-described conventional problems, and suppresses heat dissipation even when the efficiency of the secondary battery accommodated therein is high, that is, even when the internal resistance is small and the amount of Joule heat generated by discharging and charging is small. It is an object of the present invention to provide a thermally insulated container that is capable of thermally independent operation and that is excellent in safety and can promote heat dissipation to the outside and prevent a high temperature when the temperature becomes higher than a predetermined temperature .

In addition, the present invention solves the above-described conventional problems, and it is possible to operate in a thermally independent manner while suppressing heat dissipation and to increase the energy density because the cells can be densely and efficiently disposed. In addition, the combination of the number of cells in series and the number of parallel cells can be connected to AC 200V without using a transformer. Further, when the temperature becomes higher than a predetermined temperature, heat dissipation to the outside is promoted and the temperature is increased. An object of the present invention is to provide an assembled battery excellent in safety that can be prevented .

In order to solve the above conventional problems, the present invention has the following configuration.
The heat insulation container according to claim 1 of the present invention is a sealed heat insulation container in which a secondary battery operating at a high temperature such as a sodium-sulfur battery is accommodated, and is erected from a gantry part and the gantry part. A lower container in which a heat insulating part is laid on the gantry part, a top plate part, a body part, and a lower opening part in the lower part, and an outer wall part and an inner wall part. The upper container is formed in a double wall structure formed in a vacuum, and the lower opening is in contact with the heat insulating part of the lower container and is inserted into the lower container, and the inner wall of the upper container And an inner wall melting part that forms a hole in the inner wall part by melting at a predetermined temperature .
This configuration has the following effects.
(1) Since the upper container is formed in a double wall structure and the inside of the double wall is formed in a vacuum, the thermal conductivity of the upper container is set to 0.001 W / mK to 0.02 W / mK. Even when the efficiency of the secondary battery accommodated in the upper container is high, that is, when the internal resistance is small and the amount of Joule heat generated by discharging and charging is small, the heater can be suppressed. It is possible to operate in a thermally independent manner without the need for heating.
(2) Since the upper container includes a cylindrical body portion and a curved surface top plate portion, the structural strength is high, and a reinforcing member is provided in the hollow portion of the double wall structure. Since it is not necessary to fill with a filler for maintaining the strength, heat is not radiated to the outside through the reinforcing member or the filler, and the thermal conductivity of the upper container can be made extremely small.
(3) In the vicinity of the top plate inside the upper container, the temperature rises due to convection of heat generated by Joule heat generation, reaction heat, or the like of the housed secondary battery or a module in which the secondary battery is assembled. A lower opening is formed in the lower part of the upper container, and since no opening is formed on the top plate part side of the upper container where the temperature rises, heat radiation to the outside can be suppressed.
(4) The lower container has a gantry part, a peripheral wall part erected from the gantry part, and a heat insulating part laid on the gantry part, and the lower opening of the upper container is brought into contact with the heat insulating part of the lower container Therefore, the heat radiation from the lower opening side of the upper container can be suppressed. In particular, heat transfer from the joint portion (lower end sealing portion) between the outer wall portion and the inner wall portion for sealing the hollow portion at the lower end portion of the upper container to the lower container can be prevented by the heat insulating portion, and heat dissipation can be suppressed. .
(5) Installation work is possible because the power line for taking out the power from the secondary battery placed in the lower container and the measurement line for measuring the voltage and current can be drawn out from the base part of the lower container. It is easy to manufacture the upper container without the need to provide a hole or opening for taking out the power line or measurement line in the upper container, and the double wall structure is not provided with a hole or opening. Therefore, the heat insulation of the upper container can be prevented from lowering.
(6) The upper container and the lower container can be joined in an airtight manner to seal the heat insulating container, the air tightness in the heat insulating container can be maintained, and the heat insulating property can be improved.
(7) When the inside of the heat insulation container becomes a high temperature of a predetermined temperature or more due to leakage of the active material of the secondary battery, the inner wall melting part melts and the gas inside the heat insulation container flows into the hollow part, and the vacuum of the hollow part The temperature decreases and the thermal conductivity of the upper container increases, so heat dissipation to the outside can be promoted and high temperatures can be prevented.

Here, metals such as stainless steel (SUS) and general structural rolled steel (SS) are used as the material of the upper container. The degree of vacuum in the hollow part of the upper container is preferably 100 Pa or less, and preferably 10 Pa or less in absolute pressure. Thereby, the thermal conductivity of the upper container can be reduced to 0.001 W / mK to 0.02 W / mK. As the degree of vacuum becomes higher than 10 Pa, the thermal conductivity of the upper container becomes higher, so that a thermally independent operation cannot be performed. When the degree of vacuum is higher than 100 Pa, the tendency becomes remarkably remarkable.
The lower container is formed of a metal such as SUS or SS, or a hard heat insulating material or a material having high heat resistance and low thermal conductivity. Moreover, you may form a lower container in the double wall structure which has a metal outer wall and inner wall, and made the hollow part between them into the vacuum state. As the heat insulating portion laid on the bottom of the lower container, one or a plurality of flat plate-like, sheet-like heat insulating materials, vacuum heat insulating plates, or combinations thereof can be used. Moreover, a heat insulating material and a vacuum heat insulating plate can be laminated and used.
When the upper container and the lower container are hermetically joined, the body part of the upper container and the upper end part of the peripheral wall part of the lower container are welded, or a flange part is provided on each of them and is welded or screwed with a bolt and nut. Means are used. When welding the upper container body and the upper end of the peripheral wall of the lower container, the outer diameter of the upper container and the inner diameter of the lower container are formed substantially the same, and the upper container is inserted into the lower container without any gap. It is preferred that Moreover, when screwing with a bolt nut, it joins via heat resistant packing etc.

Moreover, you may arrange | position a radiant heat reflection part in at least 1 surface of the inner surface or the outer surface of the inner wall part of an upper container, or the inner surface of an outer wall part. Thereby, it can suppress leaking outside by reflecting the radiant heat which generate | occur | produced from the secondary battery accommodated in the inside of a heat insulation container by a radiant heat reflection part. As the radiant heat reflecting portion, a plate-like body formed of copper or aluminum, or a layer formed by plating or vapor deposition of copper or aluminum is used. Alternatively, the inner side surface and the outer side surface of the inner wall portion and the inner side surface of the outer wall portion can be polished and integrally formed on each wall surface.
It is also possible to use a heat insulation method in which a foil-like reflector formed of aluminum or the like and a spacer such as glass wool are alternately laminated in the hollow portion of the upper container, so-called super insulation, and heat insulation can be used. Can be increased.
Moreover, you may arrange | position the getter which consists of granular materials and aggregates, such as a zirconia alloy and a titanium alloy, in the hollow part between the outer wall part and inner wall part of an upper container. Thereby, by providing the getter that absorbs the gas remaining in the hollow part of the upper container, the vacuum degree of the hollow part can be extremely lowered and the heat insulation of the upper container can be improved.

As the inner wall melting portion, one formed of an aluminum alloy or the like is used. In addition, when using a material with low bondability with an inner wall as an inner wall melting part when forming an inner wall melting part, it is preferable to plate nickel or aluminum etc. in the hole of the inner wall which joins an inner wall melting part.
  The inner wall melting portion is preferably formed on the top wall of the upper container, particularly the top wall of the curved top plate. A temperature sensor may be provided in parallel with the inner wall melting portion. Thereby, since an upper part becomes high temperature by the convection in a heat insulation container, the temperature rise in a heat insulation container can be detected with a temperature sensor, and abnormality of a secondary battery can be detected at an early stage.

The heat insulating container includes a lower flange portion provided around an upper end portion of the peripheral wall portion of the lower container, and an upper flange portion provided around the body portion of the upper container, and the upper flange portion. By sealing and sealing to the lower flange part, it has the following effects.
(1) Since the upper container is provided with the upper flange portion and the lower container is provided with the lower flange portion, the upper flange portion of the upper container can be hermetically joined to the lower flange portion of the lower container, and the heat insulating container can be sealed. The inside airtightness is maintained and the heat insulating property can be improved.
(2) Since the upper flange portion and the lower flange portion are provided, even if the outer diameter of the upper container and the inner diameter of the lower container are slightly different, the upper flange portion and the lower flange portion are joined together by welding or the like. Can be sealed.

Further, the heat insulating container, by a configuration including the cylindrical fitting insulating part which is disposed above the heat insulating portion is fitted into the lower opening of the upper container of the lower container, as follows It has an effect.
(1) Since the lower opening of the upper container can be closed by the fitting heat insulating part, heat is dissipated from the lower end of the upper container, in particular, heat from the joined part of the outer wall part and the inner wall part and the heat insulating part of the bottom part of the lower container. Can be suppressed.

  Here, when a vacuum heat insulating plate is used as the fitting heat insulating portion, heat dissipation can be further suppressed, and heat transmitted through the side wall of the vacuum heat insulating plate can be blocked by the heat insulating portion laid on the lower portion thereof, so that the heat insulating property is remarkably enhanced. be able to.

A method for manufacturing the heat insulating container includes a heating step of heating the upper container to a temperature equal to or higher than an operating temperature of the secondary battery, and a vacuum portion between the outer wall portion and the inner wall portion in a state where the upper container is heated. It has the structure provided with the vacuum deaeration process to care.
This configuration has the following effects.
(1) When the upper container is manufactured, water molecules and hydrogen molecules adsorbed on the outer and inner wall surfaces of the upper container by heating the upper container to a temperature higher than the operating temperature of the secondary battery in the heating process, Alternatively, hydrogen molecules and the like inside the metal forming the outer wall and inner wall can be desorbed, and the gas desorbed in the vacuum degassing process can be removed, so that the vacuum of the hollow portion of the upper container at the operating temperature The degree can be made extremely large and the heat insulation can be improved.

  Here, as the heating temperature in the heating step, when the secondary battery is a sodium-sulfur battery, the operating temperature is 290 ° C. to 350 ° C., and therefore a temperature higher than the operating temperature is used.

Invention of Claim 2 of this invention is the heat insulation container of Claim 1 , Comprising: The outer wall which is formed in the said outer wall part of the said upper container, fuse | melts at predetermined temperature, and forms a hole in the said outer wall part It has a configuration with a melting part.
With this configuration, in addition to the operation of the first aspect , the following operation is provided.
(1) When the high temperature inside the heat insulation container cannot be allowed only by the increase in heat radiation due to the decrease in the vacuum degree of the hollow part of the upper container, the outer wall melting part melts and the high temperature inside the heat insulation container or the hollow part Since the gas can be discharged to the outside of the heat insulating container, an extremely high temperature inside the heat insulating container can be prevented.

Here, as the outer wall melting portion, one formed of an aluminum alloy or the like is used. In addition, when using a material with low bonding property with the outer wall as the outer wall melting portion when forming the outer wall melting portion, it is preferable to perform plating of nickel or aluminum on the hole portion of the outer wall to which the outer wall melting portion is bonded. Moreover, it is preferable that the outer wall melting portion is formed on the top plate portion, particularly on the inner wall of the top of the curved top plate portion, like the inner wall melting portion.
The outer wall melting portion is made of a material having a melting point equal to or higher than the melting point of the inner wall melting portion.

Invention of Claim 3 of this invention is the heat insulation container of Claim 1 or 2, Comprising: The said inner wall melting | dissolving part and / or the said outer wall melting | fusing part are formed in the said top-plate part of the said upper container. It has a configuration.
With this configuration, in addition to the operation of the first or second aspect, the following operation can be obtained.
(1) The temperature of the vicinity of the top plate inside the heat insulating container increases due to convection of heat generated by Joule heat generation or reaction heat of the contained secondary battery or a module in which the secondary battery is assembled. Can be detected early.

The assembled battery according to claim 4 of the present invention is an assembled battery in which unit cells of secondary batteries that operate at a high temperature such as a sodium-sulfur battery are assembled, and any one of claims 1 to 3. And a plurality of unit cells housed in the unit cell housing box, and a plurality of the unit cells housed in the unit cell housing box. .
This configuration has the following effects.
(1) Since the upper container of the heat insulating container is formed in a double wall structure and the inside of the double wall is formed in a vacuum state, heat radiation to the outside can be suppressed and accommodated inside the upper container. Even when the efficiency of the secondary battery is high, that is, when the internal resistance is small and the amount of Joule heat generated by discharging and charging is small, heating by a heater or the like is unnecessary and a thermally independent operation is possible.
(2) Since the upper container of the heat insulating container includes a cylindrical body portion and a curved surface top plate portion, the structural strength is high, and the reinforcing member is provided in the hollow portion of the double wall structure. It is not necessary to provide a filler or a filler for maintaining the strength, so that heat is not radiated to the outside through the reinforcing member or the filler, and the thermal conductivity of the upper container can be extremely reduced.
(3) In the vicinity of the top plate inside the heat insulating container, the temperature rises due to convection of heat generated by Joule heat generation, reaction heat, or the like of the housed secondary battery or a module in which the secondary batteries are assembled. Since the lower opening is formed in the lower part of the upper container of the heat insulating container and the opening is not formed on the top plate part side of the upper container where the temperature becomes high, heat radiation to the outside can be suppressed.
( 4 ) When an inner wall melting part or an outer wall melting part is formed on the inner wall or outer wall of the upper container of the heat insulating container and melts at a predetermined temperature to form a hole, the heat insulating container contains the active material of the secondary battery. When the temperature becomes higher than a predetermined temperature due to leakage or the like, the inner wall melting portion and the outer wall melting portion are melted, and the gas inside the heat insulating container can be gradually released to the outside, and the temperature rise can be prevented.
( 5 ) Since one to a plurality of unit cell housing boxes are provided, the plurality of unit cells can be housed in the unit cell housing box in various arrangements or in an arrangement.

Here, a heater or the like for raising the operating temperature at the time of activation of the unit cell can be provided in the upper and lower portions of the unit cell housing box or in the vicinity thereof.
Further, the unit cell housing box is formed in a circular shape or a polygonal shape such as a quadrangle, a hexagon, an octagon, etc. in a plan view, and a plurality of unit cell housing boxes can be provided by being stacked inside the heat insulating container. Thereby, a high voltage can be obtained by stacking and connecting a predetermined number of unit cell housing boxes in series, and the installation area does not change, so that space saving is excellent.

The invention according to claim 5 of the present invention is the assembled battery according to claim 4 , wherein a plurality of the single cells are housed in a staggered arrangement in the single cell housing box. Yes.
With this configuration, in addition to the operation of the fourth aspect , the following operation is provided.
(1) Since the cells are housed in the cell housing box in a staggered arrangement, the cells can be arranged densely and without waste, and can accommodate a large number of cells and improve the energy density of the assembled battery. Can do.
(2) The cells can be arranged and arranged, and when the cells are electrically connected, they are easily connected in series for each column.

The invention according to claim 6 of the present invention is the assembled battery according to claim 4 or 5 , wherein the unit cell housing is formed in a regular hexagonal shape, a circular shape or an elliptical shape in plan view. have.
With this configuration, in addition to the operation of the fourth or fifth aspect , the following operation is provided.
(1) By forming the unit cell housing box into a regular hexagonal shape, a circular shape, or an elliptical shape in plan view, the space inside the upper container can be used effectively, and the assembled battery can be miniaturized. Further, since the heat insulating container can be reduced in size, the heat radiation area can be reduced, and heat radiation to the outside can be minimized.

The invention according to claim 7 of the present invention is the assembled battery according to any one of claims 4 to 6 , wherein one or a plurality of the single cells containing a regular hexagonal shape in plan view are accommodated. A box, a rhombus accommodating portion formed by equally dividing the inside of the unit cell accommodating box into three rhombus shapes in plan view, and a staggered arrangement in each rhombus accommodating portion A plurality of unit cells.
With this configuration, in addition to the operation of any one of claims 4 to 6 , the following operation is provided.
(1) By forming the unit cell housing box in a regular hexagonal shape in plan view, the space can be effectively used without forming a useless space inside the upper container, and the assembled battery can be reduced in size. Further, since the heat insulating container can be reduced in size, the heat radiation area can be reduced, and heat radiation to the outside can be minimized.
(2) Since the single cell housing box is provided with three rhombus accommodating portions having a rhombus shape in plan view, and the cells are arranged in a staggered arrangement in each rhombus accommodating portion, the cells are densely packed. Can be disposed without waste, can accommodate a large number of single cells, and can improve the energy density of the assembled battery.
(3) Since the cells are arranged in a staggered arrangement in the rhombus accommodating portion having a rhombus shape in plan view, the cells can be arranged in alignment with the rhombus accommodating portion, and each cell is electrically connected It is easy to connect in series for each column when connecting to each other, and it is easy to connect each cell group connected in series in parallel, and the number of series and the number of parallels can be easily designed as necessary.

  Here, the rhombus accommodating portion is formed by dividing the inside of the unit cell accommodating box by providing a partition plate or the like. The staggered arrangement is an arrangement in which the central axis of each of the three adjacent unit cells is located at the corner of a regular triangle. By arranging the unit cells in a staggered arrangement, the unit cell is the highest. Can be arranged in density. In addition, the contact portions of adjacent unit cells are disposed in an insulated state with an insulating material such as a mica sheet interposed therebetween.

この構成によって、請求項７の作用に加え、以下のような作用を有する。
（１）集合電池全体の直流電圧値が、交流に変換した際の交流２００（Ｖ）の交流電圧適正値以上、且つ交流２００（Ｖ）に接続する場合のインバータ変換素子の耐電圧にスイッチング過電圧を考慮した電圧値以下となるので、集合電池を変圧器を介すことなく交流２００（Ｖ）に接続することができ、変圧器における電力損失をなくし、またその設置コストを削減できる。 The invention according to claim 8 of the present invention is the assembled battery according to claim 7 , wherein the plurality of single cells disposed in each of the rhombus accommodating portions are parallel to a side wall of the rhombus accommodating portion. Each row is connected in series and each row is connected in parallel, and the cell groups of each of the rhombus accommodating portions are connected in series, and the number m of the cells in one row in the rhombus accommodating portion is The number n of the unit cell storage boxes disposed inside the heat insulating container is determined to satisfy (Equation 1).

With this configuration, in addition to the operation of the seventh aspect , the following operation is provided.
(1) The DC voltage value of the entire assembled battery is not less than the appropriate value of the AC voltage of 200 (V) when converted to AC, and the switching overvoltage is equivalent to the withstand voltage of the inverter conversion element when connected to the AC 200 (V). Therefore, the assembled battery can be connected to AC 200 (V) without passing through a transformer, power loss in the transformer can be eliminated, and the installation cost can be reduced.

Here, it is preferable that the outer diameter and height of the heat insulating container are appropriately determined depending on the size of the unit cells, the number m of rows in the rhombus housing unit, the number n of unit cell storage boxes, and the like. In the case of m = 10 and n = 6, if the outer diameter of the unit cell is 20 to 100 mm and the height is 120 to 600 mm, the outer diameter Rd of the heat insulating container is formed to 500 to 2500 mm, and the height Ld is It is preferable to be formed at 1990 to 5450 mm.
In addition, the outer diameter and height of the heat insulation container are appropriately set according to the number m of the row in the rhombus accommodating portion and the number n of the cell storage boxes, but in order to accommodate 3 mn cells in the heat insulation container, The volume needs to be the same as the volume in the case of the outer diameter Rd and the height Ld. Therefore, the outer diameter of the heat insulating container is preferably formed to 0.5 Rd to 2 Rd, and the height is preferably formed to 0.25 Ld to 4 Ld. As the height of the heat insulation container becomes smaller than 0.25 Ld, the outer diameter becomes larger than 2 Rd because the volume is constant, which is not preferable. As the height of the heat insulation container becomes larger than 4 Ld, a temperature difference is caused in the height direction of the heat insulation container, and it is not preferable because the voltage of the battery cell varies or the active material is solidified and it becomes difficult to control the battery cell. .

As described above, according to the present invention, the following advantageous effects can be obtained.
According to the invention of claim 1,
(1) The thermal conductivity of the upper container can be 0.001 W / mK to 0.02 W / mK, heat dissipation to the outside can be suppressed, and the efficiency of the secondary battery accommodated in the upper container Provide a heat insulating container with excellent heat insulating properties that does not require heating with a heater or the like and is capable of thermally independent operation even when the internal resistance is low, that is, even when the internal resistance is small and the amount of Joule heat generated by discharging and charging is small be able to.
(2) Since the structural strength is high and there is no need to provide a reinforcing member in the hollow part of the double-walled structure or to fill with a filler for maintaining the strength, the outer part is provided via the reinforcing member or the filler. Therefore, it is possible to provide a heat insulating container excellent in heat insulating properties that can reduce the thermal conductivity of the upper container extremely without heat dissipation.
(3) It is possible to provide a heat insulating container capable of suppressing heat radiation from the top plate portion of the upper container where the temperature becomes high to the outside.
(4) Heat dissipation from the lower opening side of the upper container can be suppressed, and heat transfer from the joint between the outer wall and the inner wall connected to the lower container is prevented by the heat insulating part. It is possible to provide a heat insulating container having excellent heat insulating properties that can be suppressed.
(5) It is possible to provide an insulated container excellent in productivity that can be easily manufactured without the need for providing a hole or opening for taking out a power line or a measurement line in the upper container, as well as easy installation work. .
(6) Since a double wall structure is not provided with holes or openings, it is possible to provide a heat insulating container that does not conduct heat from the holes or openings and can prevent a decrease in heat insulation of the upper container.
(7) It is possible to provide a heat-insulating container that can hermetically seal the heat-insulating container by joining the upper container and the lower container in an air-tight manner, and can keep the air-tightness in the heat-insulating container and improve the heat-insulating property.
(8) When the inside of the heat insulation container becomes a high temperature of a predetermined temperature or more due to leakage of the active material of the secondary battery, the inner wall melting part melts and the gas inside the heat insulation container flows into the hollow part, and the vacuum of the hollow part Since the temperature decreases and the thermal conductivity of the upper container increases, it is possible to provide an insulated container excellent in safety that can promote heat dissipation to the outside and prevent high temperature.

According to invention of Claim 2 , in addition to the effect of Claim 1 ,
(1) When the high temperature inside the heat insulating container cannot be allowed by the increase in heat dissipation due to the decrease in the vacuum degree of the hollow part of the upper container due to the melting of the inner wall melting part, the outer wall melting part melts and the heat insulating container or Since the high-temperature gas inside the hollow portion can be discharged to the outside of the heat insulation container, it is possible to provide a heat insulation container excellent in safety that can prevent an extremely high temperature inside the heat insulation container.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2,
(1) The temperature of the vicinity of the top plate inside the heat insulating container increases due to convection of heat generated by Joule heat generation or reaction heat of the contained secondary battery or a module in which the secondary battery is assembled. Can be provided.

According to invention of Claim 4 ,
(1) The thermal conductivity of the upper container can be 0.001 W / mK to 0.02 W / mK, heat dissipation to the outside can be suppressed, and the efficiency of the secondary battery accommodated in the upper container Provides a battery with excellent thermal insulation that does not require heating by a heater or the like and is capable of thermally independent operation even when the internal resistance is low, that is, even when the internal resistance is small and the amount of Joule heat generated by discharging and charging is small. be able to.
(2) Since the structural strength of the heat insulation container is high and there is no need to provide a reinforcing member in the hollow part of the double wall structure or to fill the filler for maintaining the strength, Therefore, it is possible to provide an assembled battery excellent in heat insulating property that does not radiate heat to the outside and can extremely reduce the thermal conductivity of the upper container.
(3) It is possible to provide an assembled battery that can suppress heat radiation from the top plate portion of the upper container where the temperature becomes high.
(4) Heat dissipation from the lower opening side of the upper container can be suppressed, and heat transfer from the joint between the outer wall and the inner wall connected to the lower container is prevented by the heat insulating part. An assembled battery that can be suppressed can be provided.
(5) It is easy to install, and it is not necessary to provide a hole or opening for taking out the power line or the measurement line in the upper container, so that it is possible to provide an assembled battery excellent in productivity that can easily manufacture the upper container. .
(6) Since no hole or opening is provided in the double wall structure, there is no heat conduction from the hole or opening, and it is possible to provide an assembled battery that can prevent the heat insulation of the upper container from deteriorating.
( 7 ) When the inside of the heat insulation container becomes a high temperature of a predetermined temperature or more due to leakage of the active material of the secondary battery, the inner wall melting part melts and the gas inside the heat insulation container flows into the hollow part, and the vacuum of the hollow part As the temperature decreases and the thermal conductivity of the upper container increases, it is possible to provide an assembled battery excellent in safety that can promote heat dissipation to the outside and prevent high temperature.
( 8 ) When the high temperature inside the heat insulation container cannot be allowed only by the increase in heat dissipation due to the decrease in the vacuum degree of the hollow part of the upper container due to the melting of the inner wall melting part, the outer wall melting part melts and the heat insulation container or Since the high-temperature gas inside the hollow portion can be released to the outside of the heat insulating container, it is possible to provide an assembled battery with excellent safety that can prevent an extremely high temperature inside the heat insulating container.
( 9 ) Since one to a plurality of unit cell housing boxes are provided, the plurality of unit cells can be housed in the unit cell housing box in various arrangements or arranged. It is possible to provide an assembled battery that is excellent and can be easily arranged.

According to invention of Claim 5 , in addition to the effect of Claim 4 ,
(1) Since the cells are housed in the cell housing box in a staggered arrangement, the cells can be arranged densely and without waste, and can accommodate a large number of cells and improve the energy density of the assembled battery. It is possible to provide an assembled battery that can
(2) A battery cell in which the cells can be arranged and arranged, and when the cells are electrically connected, it is easy to connect in series for each column, and the battery has excellent workability in electrical connection of the cells. Can be provided.

According to invention of Claim 6 , in addition to the effect of Claim 4 or 5 ,
(1) By forming the unit cell housing box into a regular hexagonal shape, a circular shape or an elliptical shape in plan view, the space inside the upper container can be used effectively, the assembled battery can be miniaturized, and the heat insulating container can be miniaturized. Therefore, it is possible to provide an assembled battery that can reduce the heat dissipating area and minimize heat dissipating to the outside.

According to the invention of claim 7 , in addition to the effect of any one of claims 4 to 6 ,
(1) By forming the unit cell housing box in a regular hexagonal shape in plan view, a compact assembled battery that can effectively use the space without forming a useless space inside the upper container and can reduce the size of the assembled battery. Can be provided.
(2) Since the heat insulating container can be reduced in size, it is possible to provide an assembled battery that can reduce the heat radiation area and minimize heat radiation to the outside.
(3) Three rhombus accommodating portions having a rhombus shape in plan view are provided inside the cell housing box, and the cells are arranged in a staggered arrangement in each rhombus accommodating portion. Therefore, it is possible to provide an assembled battery that can be disposed without waste, can accommodate a large number of single cells, and can improve the energy density of the assembled battery.
(4) Since the cells are arranged in a staggered arrangement in the rhombus accommodating portion having a rhombus shape in plan view, the cells can be arranged in alignment with the rhombus accommodating portion, and each cell is electrically connected. It is easy to connect in series for each column when connecting to each other, and it is easy to connect each group of cells connected in series in parallel, and the freedom of design that can easily design the number of series and the number of parallel as needed It is possible to provide an assembled battery excellent in degree and ease.

According to the invention described in claim 8 , in addition to the effect of claim 7 ,
(1) The DC voltage value of the entire assembled battery is not less than the appropriate value of the AC voltage of 200 (V) when converted to AC, and the switching overvoltage is equivalent to the withstand voltage of the inverter conversion element when connected to the AC 200 (V). Therefore, it can be connected to AC 200 (V) without going through a transformer, eliminates power loss in the transformer, and is excellent in cost saving that can reduce the installation cost. An assembled battery can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a perspective view of a partially broken main part of the assembled battery according to the first embodiment. FIG. 2A is a side sectional view of the essential part of the assembled battery according to the first embodiment. Fig. 3 is a side cross-sectional view of the main part showing another example of the heat insulating portion, Fig. 3 (a) is a cross-sectional view taken along the line AA in Fig. 2, and Fig. 3 (b) is a cross-sectional view of Fig. 3 (a). It is a principal part enlarged view.
In the figure, 1 is an assembled battery, 2 is a bell-shaped upper container with an open bottom, 3 is a lower container in which the lower opening of the upper container 2 is inserted, and 4 is composed of an upper container 2 and a lower container 3. The heat insulating container 5 is a cylindrical body part of the upper container 2, 6 is a curved top plate part integrally formed on the upper part of the body part 5, and 7 is an outer wall part of the body part 5 and the top plate part 6. , 8 is an inner wall portion disposed inside the outer wall portion 7, 9 is a hollow portion formed between the outer wall portion 7 and the inner wall portion 8, and the outer wall portion 7 and the inner wall portion 8 are the lower end portion of the upper container 2. The hollow portion 9 is sealed by the sealing portion 9a. The cross-sectional shape of the lower end sealing portion 9a is not limited to a linear shape in which the lower end portion of the inner wall portion 8 and the lower end portion of the outer wall portion 7 are connected at the shortest distance, and a mountain shape, a curved shape, or the like is used. You can also. By setting the lower end sealing portion 9a to have a cross-sectional mountain shape or a curved shape, the heat transfer distance from the inner wall portion 8 to the outer wall portion 7 can be increased, and heat radiation by the lower end sealing portion 9a can be reduced. 10 is an upper flange portion provided around the outer wall portion 7 of the body portion 5, 11 is a pedestal portion of the lower container 3, 12 is a cylindrical peripheral wall portion erected from the pedestal portion 11, and 13 is an upper end of the lower container 3. A lower flange portion provided around the edge, 14 is a bolt and nut that joins the upper flange portion 10 and the lower flange portion 13, 15 is a single cell of a secondary battery that operates at a high temperature such as a sodium-sulfur battery, and 16 is A unit cell housing box having a regular hexagonal shape in plan view in which a plurality of unit cells 15 are housed, and 16a is erected in the unit cell housing box 16, and the cell unit housing box 16 is equally divided into three rhombus regions. A partition plate 16b, three rhombus accommodating portions formed inside the single cell housing box 16, and 17 a plurality of unit cell housing boxes 16 each housing a plurality of single cells 15 stacked in an electrically connected manner. The module 18 is formed as a gantry 11 A power line 19, which is disposed to penetrate the pedestal 11 and supplies power for taking out and charging power discharged from the module 17, is used to control the total voltage and temperature of the module 17. It is a measurement line connected to an external measuring instrument or the like for measurement.

In FIG. 2A, 21 is a protective container disposed around the module 17, 22 and 23 are upper and lower heaters for starting disposed at the upper and lower portions of the module 17, and 24a and 24b are lower portions. It is the fitting heat insulating material (fitting heat insulation part) laminated | stacked on the upper part of the heat insulating material (heat insulation part) 24c laid in the bottom part of the container 3. FIG. The lower opening of the upper container 2 is in contact with the lowermost lower heat insulating material 24c. The fitting heat insulating materials 24a and 24b are formed in a cylindrical shape having the same shape as the lower opening of the upper container 2 and are fitted in the lower opening. The protective container 21, the upper heater 22, and the lower heater 23 shown in FIG. 2A are not shown in FIG. 1 for easy understanding. In FIG. 2B, 25 is a heat insulating material laid on the bottom of the lower container 3, and 26 is a vacuum heat insulating plate laid on the upper surface of the heat insulating material 25 and fitted into the lower opening of the upper container 2. In the first embodiment, as shown in FIG. 2A, the heat insulating materials 24a, 24b, and 24c are used as the heat insulating portions. However, as shown in FIG. 2B, the heat insulating materials 25 are used as the heat insulating portions. And the vacuum heat insulating plate 26 can be used in combination. In addition, it is not restricted to what is shown in FIG.2 (b), The heat insulating material 25 can also be used as a vacuum heat insulation plate. The vacuum heat insulating plate 26 has a vacuum heat insulating layer formed in an internal hollow portion.
Moreover, in Fig.3 (a), 31 is a parallel connection terminal for connecting the group of the cell 15 connected in series in parallel. In FIG. 3B, 15a, 15b and 15c are single cells, 33 is a positive terminal, 34 is a negative terminal, and 35 is an mica sheet which is an insulating material wound around each single cell 15, 15a, 15b and 15c. It is.

Here, the outer diameter and height of the heat insulating container 4 are preferably set as appropriate depending on the size, number, and arrangement of the cells 15 accommodated. In the first embodiment, as shown in FIGS. 1 to 3, a plurality of unit cells 15 are arranged in a staggered arrangement in three rhombus accommodating units 16 b in the unit cell housing 16, and the unit cells are arranged. A plurality of storage boxes 16 are stacked, and a predetermined number of single cells 15 are stored in the heat insulating container 4. In the first embodiment, the cell 15 has an outer diameter of 20 to 100 mm and a height of 120 to 600 mm, and the heat insulating container 4 has an outer diameter of 500 to 2500 mm and a height of 1090 to 5450 mm. A thing was used.
In addition, since the arrangement of the unit cells 15 accommodated in the heat insulating container 4 is not limited to the above, the outer diameter and height of the heat insulating container 4 are appropriately determined depending on the arrangement of the unit cells 15.
As the material of the unit cell housing 16, stainless steel, carbon steel, or the like is used. In particular, when carbon steel is used, the heat storage property is improved and heat dissipation can be suppressed. Also, carbon fiber lining can be applied, and similar effects can be obtained.
In the first embodiment, heat-resistant and electrically insulating sand (not shown) is provided between the protective container 21 and the module 17 or inside the unit cell housing 16 of the module 17 to prevent fire. ). Thereby, even if it is a case where the inside of the heat insulation container 4 becomes high temperature by the leakage of the active material of the cell 15, etc., generation | occurrence | production of a fire can be suppressed.

With respect to the assembled battery 1 according to the first embodiment configured as described above, a method for manufacturing the upper container 2 of the heat insulating container 4 will be described below.
First, the upper container 2 is put into a heating furnace heated to a temperature equal to or higher than the operating temperature of the module 17 of the secondary battery and heated (heating process). Next, a vacuum pump or the like is connected to a deaeration port (not shown) provided in the hollow portion 9 in a heated state to perform vacuum deaeration (vacuum deaeration step). In addition, after a vacuum deaeration process, a deaeration port is sealed and the hollow part 9 is sealed. As a result, water molecules and hydrogen molecules adsorbed on the inner surface of the outer wall 7 of the upper container 2 and the outer surface of the inner wall 8, or hydrogen molecules inside the metal forming the inner surface of the outer wall 7 and the inner wall 8, etc. Since it can be desorbed and removed, and generation of water vapor and hydrogen can be suppressed during operation, the degree of vacuum of the hollow portion 9 can be made extremely low. In the first embodiment, when the unit cell 15 of the secondary battery to be accommodated is a sodium-sulfur battery, it is heated to its operating temperature of 290 ° C. to 350 ° C. or higher, for example, 500 ° C.

ここで、菱形収容部１６ｂ内の一列（ｍ本）の単電池１５は直列に接続され、各列は並列に接続され、各々の菱形収容部１６ｂ（３つ）は直列に接続され、各々の単電池収容箱体１６（ｎ個）は直列に接続されているので、（数２）の３ｍｎはモジュール１７内の単電池１５の内、直列に接続されたものの本数となる。Ｅ_ｃは単電池１５の充電終止電圧、Ｅ_ｄは単電池１５の放電終止電圧であるので、３ｍｎＥ_ｃは集合電池１の充電終止電圧Ｅ_ｃとなり、３ｍｎＥ_ｄは集合電池１の放電終止電圧となる。ここで、放電開始から放電終了までの集合電池１が出力する直流電圧値をＥとすると、３ｍｎＥ_ｄ≦Ｅ≦３ｍｎＥ_ｃである。
集合電池１を変圧器を介すことなく交流２００（Ｖ）に接続するためには、集合電池全体の直流電圧値Ｅを交流に変換した際の交流電圧値Ｅ／√２が、交流２００（Ｖ）の交流電圧適正値以上でなければならない。交流電圧適正値を２０２±２０（Ｖ）とすると、Ｅ≧（２０２±２０）√２となる。また、集合電池１を変圧器を介すことなく交流２００（Ｖ）に接続するためには、集合電池全体の直流電圧値Ｅが、交流２００（Ｖ）に接続する場合のインバータ変換素子の耐電圧にスイッチング過電圧を考慮した電圧値以下でなければならない。この電圧値を４２５（Ｖ）とすると、Ｅ≦４２５なる。
Ｅが常にＥ≧（２０２±２０）√２、及び、Ｅ≦４２５を満たすためには、３ｍｎＥ_ｃ≦４２５、及び、３ｍｎＥ_ｄ≧２２２√２を満たせばよい。
本実施の形態１においては、１０本の単電池１５を直列に接続しそれを１０列並列に接続し、これらが一つの単電池収容箱体１６の３つの菱形収容部１６ｂに各々収容され、この単電池収容箱体１６を６個積み重ねて、モジュール１７を形成している。また、一つの単電池１５の充電終止電圧Ｅ_ｃが２．３５（Ｖ）、放電終止電圧Ｅ_ｄが１．８０（Ｖ）である。これにより、上記（数１）を満たし、集合電池１を変圧器を介さずに交流２００（Ｖ）に接続することができる。 Next, the arrangement and electrical connection of the single cells 15 in the module 17 will be described with reference to FIG.
As shown in FIG. 3A, the unit cells 15 are formed in a columnar shape, and the plurality of unit cells 15 are erected in a unit cell housing box 16 having a regular hexagonal shape in plan view. The unit cell housing 16 is equally divided into three rhombus accommodating portions 16b having a rhombic shape in plan view by a partition plate 16a. The rhombus accommodating portion 16b is formed to have the same length as one side of the regular hexagonal unit cell housing box 16, and the corners are formed with an acute angle of approximately 60 ° and an obtuse angle of approximately 120 °. . As shown in FIG. 3 (b), each rhombus accommodating portion 16b is arranged in a staggered arrangement with the cells 15 standing up. That is, the three adjacent unit cells 15a, 15b, and 15c are in contact with each other through the mica sheet 35, and the centers of the unit cells 15a, 15b, and 15c are arranged at the corners of an equilateral triangle. Yes. Thereby, the single cells 15a, 15b, and 15c can be densely arranged without useless space.
Moreover, as shown to Fig.3 (a), ten cells 15 are connected in series for every row | line | column parallel to the side wall of the rhombus accommodating part 16b in the cell accommodating box 16, and it is connected in series. 10 cells are arranged in parallel, the positive terminal 33 of the first cell 15 in each column and the negative terminal 34 of the last cell 15 in each column are connected by a parallel connection terminal 31, and each column is Connected in parallel. Further, each rhombus accommodating portion 16b in one unit cell housing box 16 is connected in series, and a positive terminal and a negative terminal for the unit cell housing box 16 provided on a side wall of the unit cell housing box 16 or the like. (Not shown). Further, the unit cell housing box 16 in which the unit cells 15 are accommodated in each rhombus accommodating unit 16b is filled with a predetermined amount of fire-proof sand between the adjacent unit cells 15, and an insulating plate is mounted thereon. 6 modules are stacked and connected in series in the vertical direction by a positive electrode terminal and a negative electrode terminal (not shown) provided on the side wall of the unit cell housing box 16 or the like to form a module 17. Here, the number m of the cells 15 in a row in the rhombus accommodating portion 16b and the number n of the cell storage boxes 16 disposed in the heat insulating container 4 are determined so as to satisfy (Equation 2). As a result, the DC voltage value of the entire assembled battery 1 is not less than the appropriate value of the AC voltage of 200V AC when converted to AC, and the switching overvoltage is considered in the withstand voltage of the inverter conversion element when connected to the AC voltage of 200V. Since it becomes below a voltage value, it can connect to AC200V without going through a transformer.

Here, one row (m pieces) of cells 15 in the rhombus accommodating portion 16b are connected in series, each row is connected in parallel, and each rhombus accommodating portion 16b (three) is connected in series, Since the unit cell housing boxes 16 (n pieces) are connected in series, 3 mn in (Equation 2) is the number of the unit cells 15 in the module 17 connected in series. Since E _c is the end-of-charge voltage of the unit cell 15 and E _d is the end-of-discharge voltage of the unit cell 15, 3 mnE _c is the end-of-charge voltage E _c of the assembled battery 1, and 3 mnE _d is the end-of-discharge voltage of the assembled battery 1. Become. Here, when the DC voltage value output from the assembled battery 1 from the start of discharge to the end of discharge is E, 3 mnE _d ≦ E ≦ 3 mnE _c .
In order to connect the assembled battery 1 to the alternating current 200 (V) without using a transformer, the alternating voltage value E / √2 when the direct current voltage value E of the entire assembled battery is converted into alternating current is set to the alternating current 200 ( V) must be greater than the appropriate AC voltage. When the AC voltage appropriate value is 202 ± 20 (V), E ≧ (202 ± 20) √2. Further, in order to connect the assembled battery 1 to the AC 200 (V) without passing through a transformer, the DC voltage value E of the entire assembled battery is the resistance of the inverter conversion element when connected to the AC 200 (V). The voltage must be less than the voltage value considering the switching overvoltage. When this voltage value is 425 (V), E ≦ 425.
In order for E to always satisfy E ≧ (202 ± 20) √2 and E ≦ 425, it is only necessary to satisfy 3mnE _c ≦ 425 and 3mnE _d ≧ 222√2.
In the first embodiment, ten unit cells 15 are connected in series and connected in 10 rows in parallel, and these are accommodated in the three rhombus accommodating portions 16b of one unit cell housing box 16, respectively. Six unit cell housing boxes 16 are stacked to form a module 17. The charging termination voltage _{E c} of one unit cell 15 is 2.35 (V), discharge end voltage _{E d} is 1.80 (V). Thereby, said (Formula 1) is satisfy | filled and the assembled battery 1 can be connected to alternating current 200 (V) without passing through a transformer.

Next, the relationship between the thermal conductivity of the vacuum heat insulating layer formed in the hollow portion 9 of the upper container 2 and the single cell efficiency of the unit cell 15 will be described with reference to FIG.
FIG. 4 is a relational diagram showing the relationship between the thermal conductivity of the vacuum heat insulating layer of the upper container and the single cell efficiency of the single battery. FIG. 4 shows the assembled battery 1 according to the first embodiment, in which the thermal conductivity λ _d of the vacuum heat insulating layer formed in the hollow portion 9 of the upper container 2 and the single cell efficiency η _c of the single battery 15 are appropriately changed. FIG. 5 is a graph showing the thermal conductivity and single cell efficiency of a vacuum heat insulating layer capable of thermal self-sustained operation when an operation of repeatedly charging for 8 hours and discharging for 8 hours is performed.
Here, the single cell efficiency is the ratio of the amount of power discharged to the amount of power charged in one single battery 15 (single cell). As the internal resistance of the single battery 15 decreases, the single cell efficiency is Get higher. On the other hand, as the internal resistance of the unit cell 15 decreases, the amount of Joule heat generated when a current flows through the unit cell 15 decreases.
As shown in FIG. 4, when the thermal conductivity λ _d of the vacuum heat insulating layer formed in the hollow portion 9 of the upper container 2 is 0.001 W / mK to 0.01 W / mK, the single cell efficiency η _c is 0. It was found that even when the highly efficient single battery 15 of 89 to 0.99 was used, the assembled battery 1 can be operated thermally independently. In particular, when the unit cell 15 having a single cell efficiency η _c of 0.90 is used, the thermal conductivity λ _d is set to 0.0086 W / mK, and the unit cell 15 having a unit cell efficiency η _c of 0.93 is used. Has a thermal conductivity λ _d of 0.0059 W / mK, and in the case of using the single battery 15 having a single cell efficiency η _c of 0.96, the thermal conductivity λ _d is 0.0034 W / mK. 1 was found to be able to perform a thermally independent operation. Note that the degree of vacuum of the vacuum heat insulating layer for setting the thermal conductivity λ _d to 0.0086 W / mK was 16 Pa.

Next, the inner wall melting portion and the outer wall melting portion formed in the inner wall portion 8 and the outer wall portion 7 of the upper container 2 will be described with reference to FIG.
FIG. 5 is an enlarged cross-sectional view of a main part of the top plate portion 6 of the upper container 2.
In FIG. 5, reference numeral 41 denotes an inner wall melting portion formed in the inner wall portion 8, 42 denotes a hole portion drilled in the inner wall portion 8 and embedded with the inner wall melting portion 41, and 43 denotes an outer wall melting portion formed in the outer wall portion 7, Reference numeral 44 denotes a hole formed in the outer wall portion 7 and embedded with the outer wall melting portion 43.
An inner wall melting portion 41 formed of an aluminum alloy or the like that melts at a predetermined temperature, for example, 400 ° C. to 800 ° C., preferably 600 ° C. to 800 ° C., is embedded in the hole 42. Thereby, when the inside of the heat insulating container 4 becomes higher than the operating temperature, for example, 600 ° C. or higher due to leakage of the active material of the unit cell 15, the inner wall melting portion 41 is melted and the hole 42 is formed in the inner wall portion 8. The formed and expanded gas inside the heat insulating container 4 flows into the hollow portion 9 and the vacuum degree pressure of the hollow portion 9 can be lowered, so that the thermal conductivity is increased and the heat radiation to the outside is promoted to increase the temperature. Can be prevented.
In addition, an outer wall melting portion 43 formed of an aluminum alloy or the like that melts at a predetermined temperature, for example, 400 ° C. to 1200 ° C., preferably 600 ° C. to 900 ° C., is embedded in the hole 44. In addition, it is preferable to use what has a melting | fusing point similar to or higher than the melting | fusing point of the inner wall melting | fusing part 41 as the outer wall melting | fusing part 43. FIG. As a result, when the inside of the heat insulating container 4 becomes a high temperature of a predetermined temperature or more and the inner wall melting portion 41 is melted, and the heat radiation due to the decrease in the vacuum degree of the hollow portion 9 cannot be allowed, the outer wall melting portion 43 melts. Since the high-temperature gas inside the heat insulating container 4 or the hollow portion 9 can be discharged to the outside of the heat insulating container 4, it is possible to prevent a high temperature.
When the inner peripheral surfaces of the hole 42 and the hole 44 are plated with nickel or aluminum, the materials of the inner wall melting part 41 and the inner wall part 8 or the outer wall melting part 43 and the outer wall part 7 are different. It is possible to prevent a bonding failure due to.

Next, the radiant heat reflecting portion and the getter will be described with reference to FIG.
FIG. 6 is a cross-sectional view of the main part of the body portion 5 of the upper container 2. Reference numeral 51 denotes a radiant heat reflecting portion disposed along the outer surface of the inner wall portion 8, that is, the surface on the hollow portion 9 side, 52 denotes a radiant heat reflecting portion disposed along the inner surface of the inner wall portion 8, and 53 denotes the hollow portion 9. The getter is disposed and fixed on the radiant heat reflecting portion 51.
The radiant heat reflecting portions 51 and 52 can be formed by polishing a predetermined surface of the inner wall portion 8, or one or more reflecting plates can be provided along the inner wall portion 8. As the radiant heat reflecting portions 51 and 52, those formed of aluminum, copper or the like are used. Thereby, the radiant heat which generate | occur | produced from the module 17 grade | etc., Can be reflected, and the thermal radiation to the outside can be suppressed.
A getter 53 that absorbs the remaining gas is disposed and fixed on the radiant heat reflecting portion 51 of the hollow portion 9 of the upper container 2. Thereby, even after sealing the hollow part 9 of the upper container 2, the residual gas inside the hollow part 9 can be removed and the degree of vacuum can be further reduced. As the getter, a lump such as a zirconia alloy or a titanium alloy is used.

Next, another example of an array of cells 15 will be described with reference to FIG.
FIG. 7 is a cross-sectional view of the main part showing another example of the arrangement of the unit cells.
In FIG. 7 , 2 is an upper container, 7 is an outer wall part, 8 is an inner wall part, 9 is a hollow part, 15 is a single cell, and these are the same as those described in FIG. A description will be omitted. Reference numeral 16 'denotes a unit cell housing box formed in a circular shape in plan view. In FIG. 7 , the parallel connection terminal 31, the positive electrode terminal 33, and the negative electrode terminal 34 are not shown for easy understanding.
In the first embodiment, as shown in FIG. 3A, the unit cell housing box 16 is formed in a regular hexagonal shape in plan view, and a plurality of unit cells 15 are formed inside the unit cell housing box 16. However, the present invention is not limited to this. As shown in FIG. 7 , the unit cell housing box 16 'is formed in a circular shape in plan view, and the unit cell housing box is circular. A plurality of single cells 15 can be accommodated in a staggered arrangement inside 16 '. By making the unit cell housing box 16 ′ circular, the electrical connection between the unit cells 15 is somewhat complicated, but the number of unit cells 15 can be increased. Or when accommodating the same number, the upper container 2 can be reduced in size compared with a hexagon.

As described above, the assembled battery and the heat insulating container according to the first embodiment are configured, and thus have the following effects.
(1) The upper container 2 of the heat insulating container 4 is formed in a double wall structure in which the hollow portion 9 is formed in a vacuum shape, and the vacuum degree of the hollow portion 9 is 100 Pa or less, preferably 10 Pa or less in absolute pressure. Therefore, the thermal conductivity of the upper container 2 can be set to 0.001 W / mK to 0.02 W / mK, heat dissipation to the outside can be suppressed, and the unit cell accommodated inside the upper container 2 Even when the efficiency of 15 is high, that is, when the internal resistance is small and the amount of Joule heat generated by discharging and charging is small, heating by a heater or the like is unnecessary and a thermally independent operation can be performed.
(2) Since the body portion 5 of the upper container 2 is formed in a cylindrical shape and the top plate portion 6 is formed in a curved surface formed integrally with the body portion 5, the structural strength is high, thereby Since there is no need to provide a reinforcing member in the hollow portion 9 in the double wall structure or to fill with a filler for maintaining the strength, heat is not radiated to the outside via the reinforcing member or the filler. The thermal conductivity of the container 2 can be made extremely small.
(3) In the vicinity of the top plate portion 6 inside the heat insulating container 4, the temperature rises due to convection of heat generated by Joule heat generation, reaction heat, or the like of the accommodated secondary battery unit cell 15 or the module 17 in which the cells are assembled. Since the top plate portion 6 is formed in a curved shape, the structural strength can be maintained without providing a reinforcing member or a filler in the hollow portion 9 of the double wall structure of the top plate portion 6. Since no filler is provided, heat radiation to the outside can be suppressed.
(4) Since the top container 6 is integrally formed on the upper part of the cylindrical body part 5 and the lower opening part is formed on the lower part, the upper container 2 has an inner wall part at the upper part inside the heat insulating container 4 where the temperature rises. Since there is no joint portion between the outer wall and the heat conductivity, the heat conductivity can be reduced and the heat radiation to the outside can be suppressed.
(5) Since the lower container 3 is formed by the gantry part 11 and the peripheral wall part 12, the body part 5 of the upper container 2 is inserted into the lower container 3 and the lower opening is brought into contact with the heat insulating material 24c. Since the fitting insulators 24a and 24b are fitted into the lower opening and the upper container 2 is inserted into the lower container 3, heat radiation from the lower opening side of the upper container 2, particularly the lower end of the upper container 2 The heat radiation from the joint part of the outer wall part 7 and the inner wall part 8 joined by the part can be suppressed. Further, when the vacuum heat insulating plate 26 is used in place of the heat insulating materials 24a and 24b, the heat insulating property can be further improved and the vacuum heat insulating plate 26 is fitted into the lower opening of the upper container 2, so that the vacuum The heat transmitted through the side wall of the heat insulating plate 26 can be blocked by the heat insulating portion 25 laid under the heat insulating plate 26, and the heat insulating property can be remarkably enhanced.
(6) Since the upper container 2 includes the upper flange portion 10 and the lower container 3 includes the lower flange portion 13, the upper flange portion 10 of the upper container 2 is airtightly joined to the lower flange portion 13 of the lower container 3. The heat insulation container 4 can be sealed, the airtightness in the heat insulation container 4 is maintained, and the heat insulation can be improved.
(7) When the upper container 2 is manufactured, the water adsorbed on the surface of the outer wall 7 or the inner wall 8 of the upper container 2 by heating the upper container 2 to a temperature higher than the operating temperature of the secondary battery in the heating step. Molecules, hydrogen molecules, or hydrogen molecules inside the metal that forms the outer wall 7 or inner wall 8 can be desorbed, and the gas desorbed in the vacuum degassing step can be removed. The degree of vacuum of the hollow portion can be made extremely low to 100 Pa or less, preferably 10 Pa or less.
(8) By reflecting the radiant heat generated from the module 17 accommodated inside the heat insulating container 4 by the radiant heat reflecting portions 51 and 52, it is possible to suppress leakage to the outside, and to improve the heat insulation.
(9) By disposing a getter 53 that absorbs gas remaining in the hollow portion 9 of the upper container 2 on the surface of the inner wall portion 8 on the hollow portion 9 side, the degree of vacuum of the hollow portion 9 is 100 Pa or less, preferably 10 Pa. It can reduce to the following and can improve the heat insulation of the upper container 2. FIG.
(10) When the inside of the heat insulating container 4 becomes a high temperature of a predetermined temperature or more due to leakage of the active material of the unit cell 15, the inner wall melting part 41 melts and the gas inside the heat insulating container 4 flows into the hollow part 9, Since the degree of vacuum of the hollow portion 9 is reduced and the thermal conductivity of the upper container 2 is increased, heat dissipation to the outside can be promoted to prevent high temperature and excellent safety. Further, when the high temperature inside the heat insulating container 4 becomes unacceptable only by an increase in heat radiation due to a decrease in the degree of vacuum of the hollow part 9 of the upper container 2 due to melting of the inner wall melting part 41, the outer wall melting part 43 melts. Since the high-temperature gas inside the heat insulating container 4 and the hollow portion 9 can be released to the outside of the heat insulating container 4, extreme temperature rise inside the heat insulating container 4 can be prevented, and the safety is excellent.
(11) Since the unit cell housing box 16 is formed in a regular hexagon, the unit cell housing box 16 is housed in the cylindrical body portion 5 of the upper container 2 without forming a useless space. , Space saving can be improved.
(12) The inside of the cell housing box 16 is partitioned by a partition plate 16a to form three rhombus housing portions 16b having a rhombus shape in plan view, and the cells 15 are arranged in a staggered arrangement in each rhombus housing portion 16b. Since it is disposed, the unit cells 15 can be densely arranged without waste, and a large number of unit cells 15 can be accommodated, and the energy density of the battery assembly 1 can be improved. Moreover, since the cells 15 are arranged in the rhombus accommodating portion 16b in a staggered arrangement, the cells 15 can be arranged in an array, and each column 15 is electrically connected to each other when electrically connected. It is easy to connect in series each time, and it is easy to connect each group of single cells 15 connected in series in parallel, and the number of series and the number of parallels can be easily designed as necessary.
(13) The DC voltage value of the assembled battery 1 as a whole is switched to an AC voltage appropriate value of AC 200 (V) when converted to AC, and to the withstand voltage of the inverter conversion element when connected to AC 200 (V). Since it becomes below the voltage value which considered the overvoltage, it can connect to alternating current 200 (V) without passing through a transformer, the electric power loss in a transformer can be eliminated, and the installation cost can be reduced.

As described above, the present invention relates to a heat insulating container that accommodates a secondary battery that operates at a high temperature, such as a plurality of sodium-sulfur batteries, and in particular, according to the present invention, the efficiency of the secondary battery accommodated therein is high. In other words, even if the internal resistance is small and the amount of Joule heat generated by discharging and charging is small, it is possible to operate in a thermally independent manner while suppressing heat dissipation . It is possible to provide a heat-insulating container excellent in safety that can promote heat dissipation and prevent high temperature .
In addition, as described above, the present invention relates to an assembled battery in which a plurality of secondary batteries that operate at a high temperature, such as a sodium-sulfur battery, are assembled, and in particular, according to the present invention, a thermally independent operation with reduced heat dissipation. In addition, it is possible to increase the energy density because the cells can be arranged densely and without waste, and the combination of the number of cells in series and the number of cells in parallel can be increased to 200 volts AC without using a transformer. It is possible to provide an assembled battery excellent in safety that can be connected and further promotes heat dissipation to the outside when the temperature becomes higher than a predetermined temperature and prevents high temperature .

FIG. 3 is a partially broken perspective view of the battery assembly according to the first embodiment. (A) Main part side surface sectional drawing of the assembled battery in Embodiment 1 (b) Main part side surface sectional view which shows the other example of a heat insulation part. (A) A sectional view taken along the line AA in FIG. 2 (b) An enlarged view of the main part of FIG. Relationship diagram showing the relationship between the thermal conductivity of the vacuum insulation layer of the upper container and the unit cell efficiency of the unit cell An enlarged cross-sectional view of the main part of the top plate of the heat insulation container Expanded cross-sectional view of the main part of the body of the heat insulation container Cross-sectional view of the main part showing another example of the arrangement of unit cells

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collective battery 2 Upper container 3 Lower container 4 Thermal insulation container 5 Body part 6 Top plate part 7 Outer wall part 8 Inner wall part 9 Hollow part 9a Lower end part sealing part 10 Upper flange part 11 Mounting part 12 Peripheral wall part 13 Lower flange part 14 Bolt Nut 15 Cell 16, 16 ′ Cell housing box 16 a Partition plate 16 b Diamond housing portion 17 Module 18 Power line 19 Measuring line 21 Protective container 22 Upper heater 23 Lower heater 24a, 24b Fitting heat insulating material (fitting heat insulating portion)
24c Heat insulation material (heat insulation part)
25 heat insulating material 26 vacuum heat insulating plate 31 parallel connection terminal 33 positive electrode terminal 34 negative electrode terminal 35 mica sheet 41 inner wall melting part 42, 44 hole part 43 outer wall melting part 45 temperature sensor 51, 52 radiant heat reflection part 53 getter

Claims (8)

A hermetically sealed insulated container containing a secondary battery operating at a high temperature such as a sodium-sulfur battery,
A lower container having a gantry part, a peripheral wall part erected from the gantry part, and a heat insulating part laid on the gantry part;
It has a top plate part, a body part, and a lower opening part in the lower part, and is formed in a double wall structure in which a space between the outer wall part and the inner wall part is formed in a vacuum shape, and the lower opening part is formed in the lower part An upper container that contacts the heat insulating portion of the container and is inserted into the lower container;
An inner wall melting portion that is formed on the inner wall portion of the upper container and melts at a predetermined temperature to form a hole in the inner wall portion;
It is equipped with the heat insulation container characterized by the above-mentioned. The heat insulation container according to claim 1 , further comprising an outer wall melting part that is formed on the outer wall part of the upper container and melts at a predetermined temperature to form a hole in the outer wall part. The heat insulation container according to claim 1, wherein the inner wall melting part and / or the outer wall melting part is formed in the top plate part of the upper container. An assembled battery in which secondary cells operating at a high temperature such as a sodium-sulfur battery are assembled,
And the heat insulating container according to any one of claims 1 to 3,
One or a plurality of single cell housing boxes housed in the heat insulating container;
A plurality of the single cells housed in the single cell housing box;
An assembled battery characterized by comprising: The assembled battery according to claim 4 , wherein the plurality of single cells are accommodated in the single cell accommodation box in a staggered arrangement. The assembled battery according to claim 4 or 5 , wherein the unit cell housing box is formed in a regular hexagonal shape, a circular shape, or an elliptical shape in plan view. One or a plurality of the single cell housing boxes formed in a regular hexagonal shape in plan view, and a rhombus housing formed by equally dividing the inside of the single cell housing box into three diamond shapes in plan view parts and a set cell according to any one of claims 4 to 6, characterized in that it comprises a plurality of said unit cells arranged in a staggered arrangement in the rhombic accommodating portion of each . A plurality of the cells arranged in each rhombus accommodating portion are connected in series for each row parallel to the side wall of the rhombus accommodating portion, and each row is connected in parallel, and each rhombus accommodating portion Are connected in series, and the number m of the single cells in a row in the rhombus accommodating portion and the number n of the single cell storage boxes disposed in the heat insulating container are ( The assembled battery according to claim 7 , wherein the battery is determined so as to satisfy Formula 1).

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