JP3349491B2 - Operating method of sodium secondary battery at start of operation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a sodium secondary battery at the start of operation .

[0002]

BACKGROUND OF THE INVENTION Power demand is usually greater during the day than during the night, and these fluctuations
In recent years, it is expanding further. As shown in FIG. 6, the power plant is operated corresponding to the maximum peak time during the day (reference numeral a in FIG. 6). It was causing trouble to do it frequently. Therefore, by using a power generation system that combines a high-efficiency power generation device and a power storage device that can store large amounts of power, the power generated at night is stored, and such power is released during the day. Attempts have been made to reduce the load factor (reference numeral b in FIG. 6).

As a secondary battery capable of storing such a large amount of power, a sodium battery (hereinafter, referred to as a "Na battery") has been receiving attention. This Na battery is a secondary battery that uses sodium for one electrode and does not mix the bipolar active material in a molten state with a solid electrolyte, and operates at a high temperature of 300 to 400 ° C, usually around 350 ° C. is there. Β-alumina or the like is used as the solid electrolyte. The Na battery has advantages such as no self-discharge, high performance because the electrode active material is liquid, long life because the electrolyte is solid, and maintenance-free because it is a completely sealed type. Therefore, it is expected to be the most promising as a next-generation large power storage battery.

However, when operating a sodium secondary battery, it is necessary to maintain the temperature at around 300 ° C. and to reduce the temperature difference in the vertical axis direction to zero, but a good heat insulating structure has not been obtained. Was. Although filling the sand is sodium and common fire extinguishing agent of sulfur therein, the sand is a problem that it takes time to heat conduction becomes lower since a uniform temperature.

SUMMARY OF THE INVENTION In view of the above problems, the present invention makes it possible to reduce the temperature difference in the vertical axis direction to zero, and at the same time to start operation of a sodium secondary battery in which the internal temperature distribution is made uniform quickly .
The purpose of the present invention is to provide a driving method that can be used.

[0006]

Means for Solving the Problems The invention of claim 1 for solving the above-mentioned problems is provided inside an outer cylindrical container,
A cylindrical solid electrolyte having a bag-shaped portion, and
A negative electrode chamber filled with sodium in a portion thereof, and an outside of the solid electrolyte.
Side, and impregnated with sulfur to form a positive electrode chamber
The pole and the outer cylinder container opening are interposed with insulating material and bolts are used.
From the fastened upper lid and the lower part of the upper lid,
Are suspended, a tubular lower portion having a sodium outlet holes in the bag-like
Sodium secondary battery body comprising a safety tube of
The outside of the thorium rechargeable battery body is
Operation method of sodium secondary battery consisting of joule body
A is, at least 2 or more insulation means in the vertical direction
Vacuum insulation part divided above and at least in the vertical axis direction
Temperature measuring means for measuring two or more temperature distributions;
The degree of vacuum divided from the temperature distribution
At least two or more vacuum adjusting means,
Based on the temperature distribution in the vertical axis direction of the sodium secondary battery body
By adjusting the degree of vacuum, the temperature inside the module
It is characterized by making the distribution uniform .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

[First Embodiment] A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram of a sodium secondary battery. As shown in FIG. 1, the sodium secondary battery according to the present embodiment includes a plurality of sodium secondary battery bodies 11 containing sodium as an electrode material, and a heating unit 12 for heating the sodium secondary battery body 11. And a module main body 13 whose outer periphery is surrounded by a heat insulating means, wherein the heat insulating means is divided into at least two parts in the vertical axis direction.
A vacuum heat insulating unit 14 made of: a temperature measuring unit 22 for measuring a temperature distribution of the sodium secondary battery 11 in the vertical axis direction;
And a vacuum degree adjusting means 23 for adjusting individual degrees of vacuum divided from the measured temperature distribution. Based on the temperature distribution in the vertical axis direction of the sodium secondary battery main body 11, The module body 13 can be adjusted by adjusting the degree.
The internal temperature distribution is made uniform.

In this embodiment, the module main body 12 is filled with sand 31 and a heat transfer member 32 having a high thermal conductivity is provided between the sodium secondary batteries 11.
Is provided, so that the heat of the heater as the heating means is efficiently transmitted, and the internal temperature distribution is made uniform. In the present embodiment, the heat transfer members 32 are arranged in a grid pattern, but the arrangement ratio may be changed as appropriate according to the filling ratio of the sodium secondary battery.

As shown in FIG. 3 showing an example of the structure of the sodium secondary battery 11, sodium 3 is added to a cylindrical solid electrolyte 2 having a bag-like lower part provided inside an outer cylindrical container 1. The positive electrode chamber is formed by placing a porous electrode 4 outside the solid electrolyte 2 and impregnating sulfur 5 which is a positive electrode active material. In addition, an upper lid 22 for closing the outer tube container fitting 21 is provided at an opening of the outer tube container 1, and an insulating material 23 is interposed therebetween and fastened using bolts 24. The upper lid 22 is provided with a safety tube / wick 10 having a sodium outlet hole 10a at the lower part.

In the above configuration, at the time of discharging, as shown in FIG.
a ⁺⁾ and electrons (e ^- separated into), sodium ions (N
a ⁺ ) passes through the solid electrolyte (β-alumina or the like) 2 and enters the cathode chamber outside the solid electrolyte, and combines with the sulfur 5 and the electrons (e ⁻ ) that have circulated outside the cell to form sodium polysulfide (Na). ₂ Sx). On the other hand, during charging, sodium polysulfide (Na ₂ Sx) in the positive electrode chamber separates into sodium ions (Na ⁺ ), electrons (e ⁻ ) and sulfur (S), and the sodium ions (Na ⁺ ) separate the solid electrolyte 2. After passing through the negative electrode chamber inside the tube, it combines with the electrons (e ⁻ ) that have circulated outside the cell to become sodium (Na).

According to the present embodiment, the vacuum heat insulation structure is divided into two upper and lower chambers in the axial direction, and the vacuum degree adjusting means P ₁ and P ₂ for adjusting the degree of vacuum in each of the divided vacuum sections are provided with sodium and sodium. By providing temperature measuring means T ₁ and T ₂ for measuring the temperature distribution in the axial direction of the secondary battery, the degree of vacuum can be adjusted even when there is a temperature distribution in the vertical axis direction inside the module. The heat distribution in the direction can be made uniform. That is, when one of the upper and lower sides of the temperature distribution of the sodium secondary battery is high, the degree of vacuum is reduced in a portion where the temperature is high, the thermal conductivity is improved (see FIG. 5 ), and the temperature is lowered. By doing so, the temperature distribution can be made uniform.

According to the sodium secondary battery of the embodiment, the following effects are obtained. When operating a sodium secondary battery, it is necessary to maintain the temperature at around 300 ° C and make the temperature difference in the vertical axis zero, but it is easy to make it uniform by adjusting the degree of vacuum. Can be. The sand filled therein is a common fire extinguishing agent for sodium and sulfur. However, since the heat conduction is low, the heat transfer member 32 having a high heat conductivity is provided so that the heat of the heating means can be efficiently discharged. The temperature can be transmitted and uniform temperature can be maintained. Further, since the heat transfer member 32 is made of copper, the material of the parallel booth can also be used, and the booth is excellent because there is no heat loss. Note that FIG.
Reference numeral 33 denotes a connection means.

[Second Embodiment] In a second embodiment, a sublimation substance is hermetically sealed in the vacuum portions 14a and 14b of the above-described first embodiment. This sublimation substance is not particularly limited,
Sublimation occurs when the temperature rises, such as paraffin or solder, and the degree of vacuum is reduced by increasing the air pressure. And FIG.
As shown in (2), when the degree of vacuum is lowered, λ can be lowered to release heat and lower the temperature. Here, the sublimation substance is not limited to paraffin, solder, or the like, and may be any substance as long as vaporization and condensation are instantaneous.

[Third Embodiment] The third embodiment relates to an operation method at the time of starting operation of the sodium secondary battery of the first embodiment. At the start of operation of the sodium secondary battery, it is necessary to gradually increase the temperature. When the temperature rises, the temperature is increased while measuring the temperature in the vertical axis direction of the sodium secondary battery. As a result, a uniform temperature is always applied to the sodium secondary battery main body, so that sodium flows back and forth through the sodium outflow hole 11a, and damage of the solid electrolyte 2 is prevented.

[0016]

As described above, as described above, the inside of the outer cylindrical container is provided.
And a cylindrical solid electrolyte having a bag-shaped lower part.
Negative electrode chamber filled with sodium inside the body electrolyte, and the solid
Disposed outside the electrolyte and impregnated with sulfur to form the cathode compartment
With a porous electrode and an insulating material
From the upper lid fastened using a
It is drooped inside the denaturation, the lower part has a bag-like shape,
Rechargeable sodium battery with tubular safety tube
The body and the outside of the sodium secondary battery body with heat insulating means.
Sodium secondary battery consisting of enclosed module body
Operating method, wherein the heat insulating means is less in the vertical axis direction.
Vacuum insulation part divided into at least two parts and vertical axis direction
Temperature measuring means for measuring at least two or more temperature distributions
And the individual vacuum degrees divided from the measured temperature distribution
At least two or more vacuum degree adjusting means for adjusting
The temperature of the sodium secondary battery body in the vertical axis direction
By adjusting the degree of vacuum based on the distribution, the module body
Since the internal temperature distribution is made uniform, even if there is a temperature distribution in the vertical axis direction inside the module, the heat distribution in the vertical axis direction can be made uniform by adjusting the degree of vacuum.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a combustion device of a sodium secondary battery according to a first embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a schematic diagram of an internal structure of a sodium secondary battery.

FIG. 4 is an operation principle diagram of a sodium secondary battery.

FIG. 5 is a diagram showing the relationship between the degree of vacuum and the coefficient of thermal expansion (λ).

FIG. 6 is a power demand curve for one day.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Sodium secondary battery main body 12 Heating means 13 Module main body 21a Upper vacuum part 21b Lower vacuum part 21 Vacuum insulation part 22 Temperature measuring means 23 Vacuum degree adjusting means 32 Heat transfer member 33 Connecting means

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsumi Nagata 1-1, Akunouramachi, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) References JP-A-11-185801 (JP, A) JP-A-9-35725 (JP, A) JP-A-8-138761 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 10/39

Claims (1)

(57) [Claims] 1. A bag-shaped lower part provided inside an outer cylindrical container.
And a solid electrolyte inside the solid electrolyte.
A negative electrode chamber filled with lithium and disposed outside the solid electrolyte
And a porous electrode impregnated with sulfur to form a positive electrode chamber.
Insulation material is interposed at the opening of the cylindrical container and fastened with bolts
From the upper lid and the lower part of the upper lid, drooped inside the solid electrolyte
With a bag-shaped lower part and a sodium outlet hole
A sodium secondary battery body comprising a tube;
Module with the outside of the secondary battery body surrounded by heat insulation means
Operating method for a sodium secondary battery
The heat insulating means is divided into at least two in the vertical axis direction.
Vacuum insulation part, and at least two or more in the vertical axis direction.
Temperature measuring means for measuring a temperature distribution, and
At least adjust the degree of vacuum individually divided from the cloth
Two or more vacuum adjusting means,
The degree of vacuum is determined based on the temperature distribution in the vertical axis
By adjusting, the temperature distribution inside the module body becomes uniform
Operation of sodium secondary battery
Driving method at the start.