JP2012004053A - Vehicular sodium-sulfur battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable sodium-sulfur battery capable of being mounted on a vehicle and having high current density.SOLUTION: A sodium-sulfur battery can be charged/discharged at heavy current by making a solid electrolyte of the sodium-sulfur battery into a thin film to reduce the electrical resistance of the solid electrolyte, by improving the passage of a positive electrode active material to make supply/discharge of the positive electrode active material more efficient, and by reducing a spacing between the solid electrolyte and a positive electrode to decrease a positive electrode resistance value. Stresses applied on the solid electrolyte and a container are relaxed by operating an inside and outside of the sodium-sulfur battery in a vacuum environment. In collision and breakage of the battery, safety is secured by rapidly cooling the battery with water to stop the function of the battery.

Description

Sodium sulfur battery.

A sodium-sulfur battery that uses sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material uses a beta alumina solid electrolyte that is permeable to sodium ions in the partition walls of the positive and negative electrodes, and the sodium in the negative electrode permeates the solid electrolyte. Then, it moves to the positive electrode and combines with sulfur to form sodium sulfide, thereby discharging. The sodium is separated from the sodium sulfide of the positive electrode, permeates the solid electrolyte, and moves to the negative electrode to be charged.
The sodium-sulfur battery is operated at around 300 ° C. where the active material of both electrodes is liquefied.
The voltage of the sodium-sulfur cell is about 2V, and the county cell obtains the necessary voltage by connecting a plurality of cells in series.

JP 2005-197139 A JP 2008-192622 A

A sodium-sulfur battery has a large electric capacity, but its current density is insufficient for a power source of an automobile or the like. Also, high current density and low electrical resistance are required to charge the battery in a short time.
The beta alumina solid electrolyte used in sodium-sulfur batteries is easily damaged by impacts and the like, and if used in an automobile, it causes battery failure.
When the battery is used with a large current or the battery is damaged, a large amount of heat is generated, and the temperature of the battery rapidly increases.

The beta-alumina solid electrolyte of a sodium-sulfur battery is reduced in thickness to lower the electrical resistance of the electrolyte, and the flow path of sulfur and the flow path of sodium sulfide are alternately arranged to facilitate the convection of the positive electrode active material. Reduce electrical resistance between solid electrolytes.
The solid electrolyte is thinned to obtain the impact resistance of the solid electrolyte, and the thinned solid electrolyte is fixed to the positive electrode current collector, the negative electrode current collector, or the battery container, and the positive electrode current collector, negative electrode current collector, or battery container is fixed. The lack of rigidity of the solid electrolyte made into a thin film with the rigidity of.
In a group battery connected with multiple sodium-sulfur cells, the unit cell is housed in a vacuum environment and the inside of the unit cell is also operated in a vacuum, and the unit cell is wrapped in multiple layers with a thin-film insulation to improve the insulation of the group battery. The temperature distribution between the single cells is leveled with a heat pipe, and a heater and a variable heat dissipation mechanism are added to the heat pipe to control the temperature of the single cell within a certain range.
When the county battery is subjected to a strong impact or the unit cell breaks down and generates heat, water is poured into the cooler and the unit cell is rapidly cooled by the heat of vaporization of the water to stop the function of the county battery.
The positive and negative electrodes of the sodium-sulfur unit cell are provided with an unevenness that engages with each other, the plurality of unit cells are accommodated in a highly rigid buffer box, and the plurality of buffer boxes are connected to form a group battery.

The internal electrical resistance of the sodium-sulfur battery is reduced, the convection of the positive electrode active material is made efficient, a battery with a high current density is obtained, and the impact resistance of the battery is also improved.
By operating the sodium-sulfur battery inside and outside in a vacuum environment, the pressure applied to the solid electrolyte is reduced, the solid electrolyte of the thin film satisfies the strength as a partition, and the battery sealing structure is simplified. Further, since the internal pressure of the battery is low, the battery can be square, and the electric capacity of the battery can be increased as compared with the round type.
The temperature of the sodium-sulfur unit cell in the county battery can be leveled and maintained within a certain range, and the power required for maintaining the temperature of the county battery can be reduced by improving the heat insulation.
When the battery is subjected to a strong impact or the unit battery breaks down and heats up, the group battery stops functioning to ensure safety and prevent chain damage of the cells.
The strength of the cell can be kept to the minimum necessary, and the battery can be easily assembled.

Sectional drawing of a square battery. Example 1 Current collecting structure of prismatic battery. Example 1 Sectional drawing of a flat battery. (Example 2) The internal structure of a flat battery. (Example 2) Current collecting structure of flat battery. (Example 2) County battery structure. (Example 3) County battery heat pipe. (Example 3) Radiator and cooler. (Example 3) Another convection layer. Example 4 Another current collector. (Example 5) Another flow path. (Example 6) Cooling pipe. (Example 7)

The structure, configuration and effectiveness of the battery of the present invention will be described together with examples.

FIG. 1 is a cross-sectional view of a rectangular sodium-sulfur battery.
The negative electrode plate 1 is a container having a rectangular bottom, and the opening of the negative electrode plate 1 is electrically insulated by a sealing material 12 with a positive electrode plate 2 and a current collector plate 3 as a lid, and the inside is sealed. A square cylindrical current collecting plate 3 is connected to the positive electrode plate 2, and an opening on the opposite side of the current collecting plate 3 is closed by a partition wall 8. There is.
The bottom of the negative electrode plate 1 has a convex portion protruding to the outside, and the battery 9 can be connected in series by the occlusal portion that meshes with the concave portion of the positive electrode plate 2. There is room in the occlusal portion, the connection is maintained even if the battery is shaken by vibration, and a more reliable connection can be made by plating a metal or alloy that liquefies at a high temperature on the contact portion of the electrode.
On the outer periphery of the current collector plate 3, the convection layer 6, the electrolyte 5 and the buffer material 7 are laminated in this order. The inside of the battery 9 is separated into a positive electrode chamber 10 and a negative electrode chamber 11 by a sealing material 12, an electrolyte 5, and a partition wall 8.
The electrolyte 5 is a beta-alumina thin film and is weak against stress by itself. Therefore, the convection layer 6 and the electrolyte 5 are bonded and fixed to the current collector plate 3 with a graphite-based adhesive or an alumina-based adhesive. Withstands stress with a stiffness of 6. When the corners of the current collecting plate 3 are closed with another insulator, the electrolyte 5 and the convection layer 6 can be formed into a thin plate, and the manufacture of the electrolyte 5 and the convection layer 6 is facilitated.

Sodium 23 is accommodated in the negative electrode chamber 11, and the space 27 is expanded when the sodium 23 is consumed by the discharge of the battery 9. In the positive electrode chamber 10, sulfur 24 is accommodated, and as the battery 9 discharges, sodium permeates the electrolyte 5 and is combined with the sulfur 24 to change to sodium sulfide 25. As the discharge of the battery 9 proceeds, the space 26 narrows. The spaces 26 and 27 are evacuated, and vapors of sodium 23, sulfur 24, and sodium sulfide 25 fill the spaces 26 and 27, respectively.
When the battery 9 is charged, sodium is separated from the sodium sulfide 25, and the separated sodium passes through the electrolyte 5 and moves to the negative electrode chamber 11. The separated and generated sulfur cannot pass through the electrolyte 5, and therefore remains in the positive electrode chamber 10.
The negative electrode plate 1, the positive electrode plate 2, and the current collector plate 3 are made of a material having high conductivity such as copper or aluminum. The positive electrode plate 2 and the current collector plate 3 are covered with chromium iron alloy or graphite to protect the material from highly corrosive sulfur 24 and sodium sulfide 25.

The partition wall 8 is made of aluminum or the like and the surface is covered with glass or alumina to ensure insulation, or insulating alumina or the like is used. In order to make the outer shape of the battery 9 in FIG. 1 close to a regular hexahedron, to increase the electric capacity per volume and to ensure the maximum area of the electrolyte 5, the partition wall 8 extends from the vicinity of the negative electrode plate 1 toward the positive electrode plate 2. The negative electrode chamber 11 is secured by protruding greatly.
In order to connect the flow path 4 engraved around the current collecting plate 3 and the positive electrode chamber 10, a large number of flow ports 21 are opened in the current collecting plate 3, and sulfur and sodium sulfide generated and consumed around the electrolyte 5. It becomes the passage.

For the entire sealing, glass or the like is melted to close the space between the partition wall 8, the current collector plate 3, the electrolyte 5, the sealing material 12, and the negative electrode plate 1. When the battery 9 is operated in a vacuum environment both inside and outside, since a large pressure is not applied to the sealing portion, sealing with glass or the like is possible.
The buffer material 7 is packed in the gap between the electrolyte 5 and the negative electrode plate 1, and a material having a high affinity for sodium is selected. The buffer material 7 increases the gap and carries the sodium 23 to the electrolyte 5 by capillary action. The electrolyte 5 is sandwiched between the buffer material 7 and the convection layer 6, and when the electrolyte 5 is damaged, the electrolyte 5 is prevented from being dispersed to prevent the spread of accidents.

When a part of the electrolyte 5 is broken, sodium and sulfur react directly to produce sodium disulfide having a high melting temperature and poor conductivity. When the battery 9 is operated in a vacuum environment, the reaction is limited because the pressure is low, and when the reaction is stopped, the generated sodium disulfide or the like closes the damaged portion and is self-repaired.
Since the gas is not sealed inside the battery 9, the pressure inside the battery 9 is low, and high stress is not applied to the container, so that a rectangular container having a large electric capacity per weight can be adopted.
The specific gravity of sodium sulfide 25 is heavier than that of sulfur 24, so that sodium sulfide 25 accumulates at the bottom and sulfur 24 separates and floats on the bottom. The battery 9 in FIG. 1 is assumed to be laid horizontally and used, and therefore the flow path 4 is engraved in parallel with the positive electrode plate 2. When the battery 9 is used upright, the flow path 4 needs to be cut vertically with the positive electrode plate 2.

A large number of thin grooves can be formed in the negative electrode plate 1 instead of the buffer material 7, and the sodium 23 can be carried to the electrolyte 5 by capillary action of the grooves.
The electrolyte 5 can be bonded and fixed to the negative electrode plate 1 through the buffer material 7, or a large number of fine grooves can be cut into the negative electrode plate 1 and directly bonded to the negative electrode plate 1 without the buffer material 7.

FIG. 2 is a cross-sectional view of the current collecting structure of the battery 9 of FIG.
The upper part of the electrolyte 5 in FIG. 2 becomes the positive electrode chamber 10 and is in contact with sulfur or sodium sulfide, and the lower part of the electrolyte 5 becomes the negative electrode chamber 11 and is in contact with sodium.
The channel 4 of the groove cut into the current collector plate 3 is provided with a glass coating 44 every other, and the channel 4 coated with the glass coating 44 has a high affinity for sodium sulfide and becomes a sodium sulfide channel 48. The flow path 4 not provided with the glass coating 44 has a high affinity for sulfur and becomes a sulfur flow path 47. The glass coating 44 is formed by pouring a solution containing glass particles into the groove, drying the solvent, and dissolving the remaining glass particles at a high temperature. The same effect can be obtained by coating alumina or the like instead of the glass coating 44.
The current collecting plate 3 can create the flow path 4 by a method of cutting a groove in a hollow extruded material by machining. Alternatively, a hollow current collector plate 3 can be obtained by cutting a flat extruded material having a groove or forming a groove on a flat plate by rolling, bending it into a square shape, and welding the cut portion. When the battery 9 is used upright, the current collecting plate 3 can employ a hollow grooved extruded material.

Beyond the boundary surface between sulfur 24 and sodium sulfide 25 in the positive electrode chamber 10, the flow path 4 can hold sulfur and sodium sulfide, and the width and depth of the flow path 4 are set to appropriate values according to the size of the battery 9. Thus, each of sulfur and sodium sulfide can be efficiently supplied to or discharged from the convection layer 6.
The convection layer 6 includes an insulating layer 43 in contact with the electrolyte 5 and a separation layer 42 in contact with the current collector plate 3. The insulating layer 43 is a layer of alumina particles 41, and the separation layer 42 is a mixed layer of alumina particles 41 and graphite particles 40. When the alumina particles 41 and the graphite particles 40 are mixed at the same ratio, and a sacrificial metal or the like is mixed and sintered so that many voids remain, a separation layer 42 having a low flow resistance is obtained.
The insulating layer 43 is provided to insulate the electrolyte 5 from the graphite particles 40 of the separation layer 42. If the insulation is maintained, the thinner the insulating layer 43, the better. When the surface of the electrolyte 5 is polished and the convection layer 6 is also polished and faced and sintered, the two can be strongly bonded and integrated together. When not polished, an aluminum adhesive or the like is used for sintering and bonding. The convection layer 6 and the current collector 3 are joined by sintering using a graphite-based adhesive or the like so as to have a low electric resistance.

In the region where sulfur penetrates into the insulating layer 43, sulfur is present around the electrolyte 5, and when the battery 9 is discharged, sodium ions that have permeated the electrolyte 5 react with sulfur around the electrolyte 5 to become sodium sulfide. The generated sodium sulfide flows out into the sodium sulfide flow path 48 via the alumina particles 41 having a high affinity for the nearby sodium sulfide, and accumulates in the positive electrode chamber 10 through the flow port 21. As for the consumed sulfur, sulfur 24 accumulated in the positive electrode chamber 10 is replenished through the flow passage 21 and from the sulfur flow path 47 via the graphite particles 40.
When the battery 9 is charged, sodium is separated from sodium sulfide in the vicinity of the electrolyte 5, and sodium ions move to the negative electrode chamber 11 through the electrolyte 5. Sulfur generated by losing sodium accumulates around the electrolyte 5, and when the accumulated sulfur passes through the insulating layer 43, it is discharged to the sulfur flow path 47 via the graphite particles 40 having a high affinity for sulfur, and is passed through the circulation port 21. It passes through and accumulates in the positive electrode chamber 10.
Sodium sulfide 25 consumed by charging the battery 9 is supplied to the vicinity of the electrolyte 5 from the positive electrode chamber 10 through the flow port 21 and from the sodium sulfide channel 48 via the alumina particles 41.
The current path for charging / discharging of the battery 9 bypasses sulfur because of its high electric resistance, and leads to the surrounding sodium sulfide starting from the electrolyte 5, and in the vicinity of the contact point between the alumina particles 41 and the graphite particles 40 immediately adjacent to the sodium sulfide. To the current collector plate 3 through the conductive graphite particles 40. The electric resistance of the insulating layer 43 is proportional to the resistance value of sodium sulfide and the distance between the graphite particles 40 and the electrolyte 5, and if the insulating layer 43 is thinned or eliminated and the graphite particles 40 and the alumina particles 41 are made fine, the electric resistance is suppressed to a low level. It is done.

When the alumina particles 41 and graphite particles 40 on the surface of the insulating layer 43 and the separation layer 42 of the convection layer 6 are fine particles, and the alumina particles 41 and graphite particles 40 inside the separation layer 42 are large particles, The electric resistance between the electrolyte 5 and the current collector plate 3 is reduced, and the flow resistance of sulfur and sodium sulfide in the separation layer 42 is reduced.
Theoretically, the thickness of the electrolyte 5 functions even with a thickness of several nanometers. In reality, the thickness of the electrolyte 5 is determined by durability, strength, and manufacturability. By ensuring that the current collector 3 and the convection layer 6 have the rigidity necessary for the electrolyte 5, the thickness of the conventional electrolyte 5 can be greatly reduced, and the sodium ion conduction resistance of the electrolyte 5 proportional to the thickness can be greatly increased. Decrease.

In the convection layer 6, sodium sulfide flows along the alumina particles 41 between the sodium sulfide flow path 48 and the electrolyte 5 in a direction perpendicular to the electrolyte 5, and the moving distance of sodium sulfide in the convection layer 6 is shortened. Sodium sulfide flows in parallel with the electrolyte 5 in the sodium sulfide flow path 48, and there is no obstruction in the flow direction in the flow path 4, so that sodium sulfide efficiently flows with low viscosity.
In the convection layer 6, sulfur flows along the graphite particles 40 between the sulfur flow path 47 and the electrolyte 5 in the direction perpendicular to the electrolyte 5, and the sulfur moving distance in the convection layer 6 is shortened. Sulfur flows in the sulfur flow path 47 in parallel with the electrolyte 5, and since there is no obstacle in the flow direction in the flow path 4, sulfur flows efficiently with low viscosity.
The insulating layer 43 can be made thin because its function is limited to pure insulation, and the graphite particles 40 of the separation layer 42 become a substantial positive electrode, and the distance between the electrolyte 5 and the separation layer 42 is short, and the distance between the electrolyte 5 and the positive electrode is short. The electrical resistance of is reduced.

By efficient flow of the positive electrode active material, reduction of electric resistance of the positive electrode, and reduction of sodium ion conduction resistance of the electrolyte 5, a sodium sulfur battery capable of flowing a large current with a low voltage drop can be obtained.
By combining the negative electrode plate 1 and the current collector plate 3 together, a battery 9 that can be used even in an environment where strong vibrations such as an automobile continue is obtained.

FIG. 3 is a cross-sectional view of a flat sodium-sulfur battery.
FIG. 4 is a diagram of the internal structure of the flat sodium-sulfur battery of FIG. 3 with the positive electrode plate 2 removed.
The negative electrode plate 1 serves as a lid on the positive electrode plate 2 of the shallow square container, and both are sealed with glass or the like through a thin insulating layer. There is a current collector plate 3 in which a large number of thin plates are arranged at equal intervals in parallel with the negative electrode plate 1, and the current collector plate 3 is connected to the positive electrode plate 2 by a plurality of connection plates 28.
The recess of the negative electrode plate 1 is engaged with the bottom of the positive electrode plate 2, and the batteries 9 can be connected in series.
The negative electrode plate 1, the buffer material 7, the electrolyte 5, the convection layer 6, and the current collector plate 3 are stacked in this order, and the inside of the battery 9 is separated into the positive electrode chamber 10 and the negative electrode chamber 11 by the electrolyte 5 and the partition walls 8.
The negative electrode plate 1, the positive electrode plate 2, the current collector plate 3, and the connection plate 28 are made of a material having high conductivity such as copper or aluminum. The positive electrode plate 2, current collector plate 3, and connection plate 28 are covered with a chromium iron alloy or graphite to protect the material from highly corrosive sulfur 24 and sodium sulfide 25.

The partition wall 8 is made of aluminum or the like, and the surface is covered with glass or alumina to ensure insulation, or insulating alumina or the like is used. The partition wall 8 has a concave shape and penetrates a hole formed in the convection layer 6 and the electrolyte 5. The partition wall 8 is provided with an angle portion facing inward at the opening, and the angle portion of the partition wall 8 is fixed to the negative electrode plate 1 with glass or the like as an adhesive.
The buffer material 7 is packed in the gap between the electrolyte 5 and the partition wall 8 and the negative electrode plate 1, and a material having a high affinity for sodium is selected to increase the gap and carry the sodium 23 in the negative electrode chamber 11 to the electrolyte 5 by capillary action.
A large number of thin grooves can be formed in the negative electrode plate 1 instead of the buffer material 7, and the sodium 23 in the negative electrode chamber 11 can be conveyed to the electrolyte 5 by capillary action of the grooves.
Since the electrolyte 5 is a beta-alumina thin film alone and is weak against stress, the convection layer 6 and the electrolyte 5 are fixed to the current collector plate 3 and the stress is resisted by the rigidity of the current collector plate 3 and convection layer 6. The current collector plate 3 and the convection layer 6 are electrically connected by being bonded with a graphite-based adhesive or the like. It is also possible to withstand the stress by fixing the electrolyte 5 to the buffer material 7 and fixing the buffer material 7 to the negative electrode plate 1. It is also possible to withstand stress by cutting grooves in the negative electrode plate 1, eliminating the buffer material 7, and directly bonding the electrolyte 5 to the negative electrode plate 1.

The entire sealing is performed by melting glass or the like to block between the partition wall 8, the electrolyte 5, the negative electrode plate 1, and the positive electrode plate 2. When the battery 9 is operated in a vacuum environment both inside and outside, since a large pressure is not applied to the sealing portion, sealing with glass or the like is possible.
In FIG. 3, the partition wall 8 is covered with the positive electrode plate 2, but a structure in which both the positive electrode plate 2 and the partition wall 8 are juxtaposed is also possible.

FIG. 5 is a cross-sectional view of the current collecting structure of the flat battery of FIG.
The current collecting plate 3 is a thin plate and is arranged at equal intervals to form a flow path 4. A connection plate 28 is connected to the current collector plate 3. One surface of the current collector plate 3 is covered with a glass coating 44 having a high affinity for sodium sulfide, and the glass coating 44 is opposed to the adjacent plate to form a sodium sulfide flow path 48. The current collector plate 3 without the glass coating 44. The opposite surface has a high affinity for sulfur and forms a sulfur flow path 47.
The insulating layer 43 is eliminated from the convection layer 6 so that only the separation layer 42 is obtained, and the electrolyte 5 and the separation layer 42 are polished or manufactured with high flatness, and the graphite particles 40 of the separation layer 42 in contact with the electrolyte 5 are subjected to electrolytic etching or the like. It is recessed from the surface to ensure insulation between the electrolyte 5 and the graphite particles 40. By eliminating the insulating layer 43, the distance between the electrolyte 5 and the separation layer 42 is reduced, and the electrical resistance of the convection layer 6 is reduced. Even in the region where the electrolyte 5 is immersed in sodium sulfide, sulfur is supplied from the sulfur flow path 47 along the graphite particles 40 to the vicinity of the electrolyte 5, and the active region during discharge of the electrolyte 5 increases and the electric resistance of the battery 9 decreases. .

FIG. 6 is a diagram of a group battery 65 in which a large number of sodium-sulfur single cells 61 are accommodated in a vacuum vessel 60.
FIG. 6 shows a group battery 65 in which the cells 61 are accommodated in a four-row configuration, and the cells 61 are packed in a buffer box 64. The periphery of the buffer box 64 is wrapped in a heat insulating material 62 and stored in a vacuum container 60. The space in the vacuum vessel 60 is evacuated to enhance the heat insulation effect. The inside of the unit cell 61 accommodated in the vacuum vessel 60 is also operated in a vacuum state.
A heat radiating plate 68 is attached to the outside of the vacuum vessel 60 to reduce the thermal resistance to the outside air.
The heat insulating material 62 has a high heat insulating effect by stacking aluminum foil and glass fiber or the like in multiple layers.

FIG. 7 is a view of the row heat pipe 70 of the county battery 65 of FIG. 6 and its surroundings.
The row heat pipe 70 is electrically insulated from the unit cells 61 and is thermally connected. The county heat pipe 71 is connected to the row heat pipe 70 for each row of the cells 61 to equalize the temperature of all the batteries. The county heat pipe 71 is equipped with a thermometer 75, a heater 73, a radiator 74 and a cooler 80. When the temperature of the unit cell 61 decreases, the current is passed through the heater 73 to warm the group heat pipe 71, the heat is distributed to the column heat pipe 70, and the unit cell 61 connected to the column heat pipe 70 is warmed.
A plurality of buffer boxes 64 containing three unit cells 61 are connected in each row to form a group battery 65. By storing the unit cells 61 in a highly rigid buffer box 64, the strength of the unit cells 61 is minimized. The positive and negative electrodes of the unit cell 61 are occluded so that the unit cells 61 are connected in series, and the assembly of the group cell 65 is facilitated.
A group battery with a voltage of 600 V requires 300 sodium-sulfur single cells. If a single cell is accommodated in 3 rows, 2 columns, and 2 rows in a buffer box, the county battery can be configured with 25 buffer boxes in 5 rows and 5 columns. .

FIG. 8 is a diagram of the radiator 74 and the cooler 80 of FIG.
The heat dissipating bellows 72 of the heat dissipator 74 is connected to the group heat pipe 71, and an evaporating material such as hydrocarbon is sealed inside the heat dissipating bellows 72. When the temperature of the unit cell 61 rises and the county heat pipe 71 warms and the evaporation material in the heat dissipation bellows 72 evaporates, the internal pressure of the heat dissipation bellows 72 increases and the heat dissipation bellows 72 extends.
When the heat dissipating bellows 72 is extended, the heat dissipating bellows 72 is attached to the tip of the heat dissipating bellows 72 between the container heat pipe 77 attached to the vacuum container 60 and the heat dissipating heat pipe 76 connected to the county heat pipe 71. The tapered contact piece 78 is sandwiched between the tapered group heat pipe 71 and the container heat pipe 77 to release the heat. The released heat is radiated to the outside air through the vacuum container 60, and the temperature of the unit cell 61 reaches the upper temperature limit. Control not to exceed.
The heat radiating bellows 72 and the contact piece 78 are thermally insulated by an insulating material 79, and the heat is blocked so that the temperature change of the contact piece 78 does not affect the heat radiating bellows 72.
Since the upper limit temperature of the unit cell 61 is controlled by the heat radiating bellows 72, the unit cell 61 is not overheated, a structure with high heat insulation can be adopted for the group cell 65, and the temperature of the unit cell 61 can be maintained with less power. Bimetal or the like can be used instead of the heat dissipation bellows 72.

When receiving a strong impact or when the unit cell 61 breaks down and generates heat, the emergency valve 81 is opened, the water in the water container 85 is caused to flow through the hose 84 to the emergency valve 81, and the introduction pipe 82 connected to the emergency valve 81 is used. Water flows into the cooler 80, the water evaporates in the cooler 80, takes heat from the county heat pipe 71, and the steam generated in the cooler 80 is discharged outside the county battery 65 through the discharge pipe 83, A vacuum of 65 is maintained. The water in the water container 85 is pressurized so that water flows to the cooler 80 when the emergency valve 81 is opened.
In an emergency, the unit cell 61 connected to the heat pipe is cooled by the cooler 80, and the unit cell 61 stops the function of the cell and ensures safety. The unit cell 61 is protected by protecting the normal unit cell 61 in the event of an accident. Can prevent chain damage. The introduction pipe 82 and the discharge pipe 83 are made of a material having low thermal conductivity, bent and meandered to maintain high heat insulation.

FIG. 9 is a diagram of another convection layer of a sodium sulfur battery.
In the convection layer 6b of FIG. 9, a woven fabric using long fibers is used. In the convection layer 6c in FIG. 9, a non-woven fabric using short fibers is used. The convection layer 6 of Example 1 or Example 2 can be replaced with the convection layer 6b or the convection layer 6c.
In Example 1, Example 2, and this example, alumina and graphite are used as the material of the convection layer 6, but they have a high affinity for sulfur such as chromium iron alloy and the like, and are compatible with conductive materials and sodium sulfide such as silica. It is also possible to use high-quality materials.

FIG. 10 is a diagram of another current collector plate of the sodium-sulfur battery.
In the current collector plate 3b of FIG. 10, thin plates are arranged at equal intervals to form a flow path 4, and a plurality of current collectors 46 penetrating the thin plate are connected to collect current. In the current collector plate 3c of FIG. 10, holes are formed in one thin plate to become the flow ports 21, and the thin plates are alternately bent to form the flow path 4, and a plurality of current collectors 46 are connected to the current collector plate 3c to collect current. ing. Although the sealing structure and the electrode structure of the current collecting plate 3 of Example 1 are changed, the current collecting plate 3 can be replaced with the current collecting plate 3b or the current collecting plate 3c of FIG. The current collector plate 3 of Embodiment 2 can be replaced with the current collector plate 3c of FIG.

FIG. 11 is a diagram of another flow path of the sodium-sulfur battery.
The flow path 4b is sintered using larger graphite particles 40 and alumina particles 41 than the convection layer 6 to form a flow path. Near the contact surface of particles of the same material is a flow path.
The flow path 4c is a woven fabric in which thin graphite long fibers 50 and alumina long fibers 51 are used as warp yarns, and thick graphite long fibers 50 and alumina long fibers 51 are used as weft yarns. Near the contact surface of the book is a flow path. A non-woven fabric using short fibers instead of long fibers can be used as the flow path 4c.
The flow path 4b and the flow path 4c can be adopted to replace the flow path 4 of the first and second embodiments, and since the flow path is not formed in the current collection plate 3, the current collection plate 3 is simplified and the distribution port Just open 21. The flow path 4 b can be manufactured by sintering together with the convection layer 6.
Graphite and alumina are used for the flow path 4b and the flow path 4c, but it is also possible to use a material having high affinity for sulfur such as chromium iron alloy and a material having high affinity for sodium sulfide such as silica.

FIG. 12 is a diagram of a county battery 65 in which a cooling pipe 86 is installed and a large number of sodium sulfur single cells 61 are accommodated.
The unit cell 61 accommodated in the county battery 65 is provided with a cooling pipe 86 that is electrically insulated and thermally connected. Water flows from the water container 85 to the cooling pipe 86 through the hose 84, the emergency valve 81, and the introduction pipe 82, water evaporates in the cooling pipe 86 and cools the unit cell 61, and the steam generated in the cooling pipe 86 is discharged. The tube 83 is discharged out of the county battery, and the vacuum of the county battery 65 is maintained.
The water in the water container 85 is pressurized, a strong impact or overheating of the unit cell 61 is detected, the emergency valve 81 is opened, the unit cell 61 is cooled, and the battery function is stopped urgently.
In FIG. 12, the cooling pipe 86 is juxtaposed to the unit cell 61. However, if the cooling pipe 86 is wound around the unit cell 61 or provided separately for each unit cell 61, more rapid cooling is possible. .

The sodium-sulfur battery of the present invention has a high current density and withstands impact, and is practical as a power source for automobiles and the like.

DESCRIPTION OF SYMBOLS 1 Negative electrode plate, 2 Positive electrode plate, 3 Current collecting plate, 3b Current collecting plate, 3c Current collecting plate 4 Flow path, 4b flow path, 4c flow path, 5 Electrolyte, 6 Convective layer 6b Convective layer, 6c Convective layer, 7 Buffer Material, 8 Partition, 9 Battery 10 Positive electrode chamber, 11 Negative electrode chamber, 12 Sealing material, 21 Flow port 23 Sodium, 24 Sulfur, 25 Sodium sulfide 26 Space, 27 Space, 28 Connection plate, 40 Graphite particles, 41 Alumina particles 42 Separation layer, 43 Insulating layer, 44 Glass coating, 46 Current collector, 47 Sulfur flow path 48 Sodium sulfide flow path, 50 Graphite long fiber, 51 Alumina long fiber 52 Graphite short fiber, 53 Alumina short fiber, 60 Vacuum vessel 61 Single Battery, 62 Heat insulating material, 64 Buffer box, 65 County battery, 68 Heat sink 70 Row heat pipe, 71 County heat pipe, 72 Heat radiation bellows 73 Heater, 74 Heat radiator, 75 Thermometer, 76 Heat radiation Heat pipe 77 Container heat pipe, 78 Contact piece, 79 Insulation material, 80 Cooler 81 Emergency valve, 82 Inlet pipe, 83 Discharge pipe, 84 hose, 85 Water container 86 Cooling pipe

Claims (18)

  In a sodium-sulfur battery using sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, a solid electrolyte of a thin film permeable to sodium ions is used for the partition walls of the positive electrode and the negative electrode, and the solid electrolyte is directly or intervened. A sodium-sulfur battery characterized by being fixed to a negative electrode current collector, a positive electrode current collector, or a battery container.   In a sodium-sulfur battery that uses sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, a thin-film solid electrolyte that is permeable to sodium ions is used for the partition walls of the positive and negative electrodes, and gas is sealed in both the positive and negative electrode chambers. A sodium-sulfur battery, wherein the remaining space is filled with vapor of the active material without vacuum.   A sodium-sulfur battery characterized in that a beta-alumina thin film is employed for the solid electrolytes of claims 1 and 2.   In a sodium-sulfur battery using sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, the positive electrode current collector is provided with a plurality of grooves and voids, and the positive electrode current collector groove is made of a material having a high affinity for sodium sulfide. Covering the surface of the air gap and the groove and the void as a sodium sulfide flow path, the groove and void of the cathode current collector not covering the surface with the material as a sulfur flow path, the sodium sulfide flow path and the sulfur flow path A sodium-sulfur battery characterized in that the flow paths are alternately arranged on the positive electrode current collector.   In a sodium-sulfur battery that uses sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, a permeable sintered body made of a material with a high affinity for sodium sulfide and a conductive material with a high affinity for sulfur A sodium-sulfur battery characterized in that a cloth and a cloth for sulfur and sodium sulfide are used in the vicinity of the positive electrode current collector.   6. A sodium-sulfur battery according to claim 4 and claim 5, wherein a permeable insulating layer is disposed on the positive electrode side of the solid electrolyte, and a conductive material having a high affinity for sulfur and a material having a high affinity for sodium sulfide are sintered. The permeable separation layer is disposed next to the insulating layer, and the separation layer and the positive electrode current collector and the flow path are electrically and physically connected, so that the convection structure of the positive electrode active material in the vicinity of the solid electrolyte and the solid electrolyte A sodium-sulfur battery characterized by improved electrical connection in the vicinity.   7. A sodium-sulfur battery characterized in that the separation layer according to claim 6 uses a cloth made by blending a conductive fiber having high affinity for sulfur and a fiber having high affinity for sodium sulfide.   The insulating layer of claim 6 is omitted, and instead, the unevenness of the surface of the solid electrolyte and the surface of the separation layer is reduced, the conductor on the surface of the separation layer is recessed, and the solid electrolyte and the separation layer are formed without the insulation layer. A sodium-sulfur battery characterized by ensuring insulation.   In a group battery in which multiple sodium-sulfur single cells using sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material are connected, the container of the group battery is a vacuum vessel, the unit cell is also in a vacuum environment, and the unit cell in the group battery A sodium-sulfur battery that operates in a vacuum environment both inside and outside.   The county battery according to claim 9, characterized in that glass or ceramic fibers and particles are laminated on an aluminum thin film to form a heat insulating curtain, and the heat insulating curtain is laminated in multiple layers to cover the inside of the vacuum vessel, thereby insulating the county battery. Sodium sulfur battery.   In the Gun battery, which connects multiple sodium-sulfur cells that use sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, a heat pipe that is electrically insulated from the single cell and thermally connected is installed, A sodium-sulfur battery characterized in that the unit cells contained in a county battery are thermally connected to each other.   A sodium-sulfur battery, wherein a heater is installed in the heat pipe of the county battery according to claim 11, and when the temperature of the heat pipe falls below a specified temperature, an electric current is passed through the heater to heat the heat pipe.   The heat pipe of variable heat flow is installed in the heat pipe of the county battery of claim 11, and when the temperature of the heat pipe exceeds a specified temperature, heat is released from the heat pipe to the outside of the county battery, and excessive heat in the county battery is Sodium-sulfur battery characterized by dissipating heat.   14. A sodium-sulfur battery characterized in that the variable mechanism of claim 13 uses a bellows that encloses the evaporating material and expands and contracts by changing the vapor pressure of the evaporating material with temperature.   In the Gun battery connected with multiple sodium-sulfur single cells using sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, a cooling pipe that is electrically insulated from the single cell and thermally connected is installed, A strong shock or overheating of the unit cell is detected, the valve is opened and water flows through the cooling pipe, the unit cell is cooled with the heat of vaporization of water, and the cooled water and steam are discharged out of the county cell for emergency. A sodium-sulfur battery characterized by cooling the county battery while sometimes maintaining the vacuum of the county battery.   A cooler is installed in the heat pipe according to claim 11, a strong impact or overheating of the unit cell is detected, a valve is opened, water is allowed to flow through the cooler, the heat pipe is cooled with the heat of vaporization of water, and after cooling Water and steam are discharged outside the county battery, and the county battery is cooled while maintaining the county battery vacuum in an emergency.   In a sodium-sulfur battery using sodium as the negative electrode active material and sulfur and sodium sulfide as the positive electrode active material, the battery positive electrode and negative electrode are provided with irregularities that engage each other, and the battery positive electrode and negative electrode can be directly and flexibly connected. Sodium sulfur battery.   In a group battery in which a plurality of sodium-sulfur single cells using sodium as a negative electrode active material and sulfur and sodium sulfide as a positive electrode active material are connected, a plurality of single cells are connected to a highly rigid buffer box, and the plurality of buffer boxes A sodium-sulfur battery characterized by being connected to a county battery.

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