JP5713162B2 - Apparatus and method for producing organic sulfur-based positive electrode material for secondary battery - Google Patents

Description

  The present invention mainly relates to an organic sulfur-based active material manufacturing apparatus and method useful as a positive electrode active material for lithium ion or sodium ion secondary batteries.

Lithium ion secondary batteries are widely used as power sources for portable electronic devices because of their small size and high energy density. As the positive electrode active material, a layered compound such as LiCoO ₂ is mainly used (for example, see Patent Document 1). However, when these compounds are fully charged and exposed to a high temperature, oxygen tends to be desorbed, which tends to cause an oxidative exothermic reaction of the non-aqueous electrolyte. In recent years, demand for electric vehicle applications has increased, and there has been a demand for positive electrode materials that are safer, have a wider required operating temperature range (-30 ° C to 60 ° C), and have a large capacity, output, and durability. Yes.
Examples of such positive electrode active materials include Fe, Mn, Ni in addition to Co, oxide-based positive electrodes to which various additives are added, and olivine phosphate compounds LiMPO ₄ (LiMnPO ₄ , LiFePO ₄ , LiCoPO _4, etc.). Proposed. However, none of these exemplified materials shows a stable capacity of 250 mAh / g or more, and a battery having a usable temperature range required for automobiles, etc., safety and large capacity, and large output characteristics. No material has ever existed.

On the other hand, sulfur has attracted attention as a positive electrode active material that is inexpensive, has a large amount of resources, has a low environmental load, has a high theoretical charge / discharge capacity of lithium ions, and does not release oxygen at high temperatures. However, sulfur alone has a high electric resistance, and when it was operated as an electrode by adding a conductive auxiliary agent, elution into the electrolytic solution was remarkable and the cycle characteristics were poor.
In recent years, it has been found that a composite obtained by heating this sulfur with an organic substance exhibits high capacity, good cycle characteristics, and rate characteristics.
The present applicants manufactured a battery incorporating these organic sulfur-based positive electrode materials, and this battery has a usable temperature range as a secondary battery used in automobiles, safety and large capacity, and large output characteristics. It is confirmed that it is a real battery.

In Non-Patent Document 1, Wang et al. Of the Chinese Academy of Sciences synthesized a cathode material capable of taking in and out Li by reacting polyacrylonitrile (hereinafter referred to as PAN) with sulfur at 300 ° C., 13C NMR, FTIR, XPS, etc. It is described that characterization was performed. In this document, sulfur is described as being combined with an organic substance.
In Non-Patent Document 2, C. Lai et al. Of Nankai University in China created activated carbon with a surface area of 1473 m ² / g by heat-treating PAN with sodium carbonate in an Ar atmosphere at 750 ° C., and mixing it with sulfur. An organic sulfur composite containing 57% sulfur is produced by heat treatment at ℃, and this material has a capacity of 1155 mAh / g as a cathode material for lithium-ion batteries and has a capacity of 745 mAh / g even after 84 cycles Is described.
In Non-Patent Document 3, B. Zhang et al. Of Nankai University in China made a composite in which a sulfur acetylene black mixture was heated up to 300 ° C for 6 hours at 149 ° C and mixed with a ball mill and SEM, XRD, fine It is described that comparison was made by pore size distribution, CV, impedance method, and that the heat-treated composite showed a capacity of 500 mAh / g after 50 cycles, but the one that was not heat-treated remained at a low capacity. .
Non-Patent Document 4 describes the result of Shahab et al. Of Iraqi Mosul University examining the amount of sulfur at various temperatures for an organic sulfur composite obtained by reacting bitumen and sulfur at 400 ° C.
Non-Patent Document 5 states that Sun et al. Of Beijing Chemical University improve charge / discharge characteristics and cycle characteristics by using gelatin instead of conventional PEO as a sulfur binder, which is a positive electrode material for lithium-sulfur secondary batteries. And that gelatin does not swell in the organic solvent of the electrolyte, and that the effect of suppressing grain graining by SEM observation after the cycle test has been found.
In Non-Patent Document 6, Trofimov of the Siberian branch of the Russian Academy of Sciences reviews polymer sulfuration and charge / discharge. The structures of compounds produced by sulfuration of various polymers including polyethylene are shown, and the number of radicals and CV by ESR are reported.
In Non-Patent Document 7, Wei et al. Of Shanghai Jiao Tong University used 92 wt.% Acrylonitrile and 8 wt.% Methylacrylate (inexpensive commercial product) instead of the conventional PAN, and MWCNT (multi-walled carbon nanotube) Was added as a conductive additive, 1 g of fiber, 0.1 g of MWCNT, and 10 g of sulfur were ball-milled in ethanol, and a composite containing 35 wt% sulfur heat-treated in nitrogen at 300 ° C. for 4 hours was obtained. It is described that the capacity was 560 mAh / g, 96.5% after 0.5C100 cycle, and 387 mAh / g was output at 7C.

As described above, many studies on organic sulfur-based positive electrode materials have been reported in recent years.
As can be seen from this, the organic sulfur-based positive electrode material is inexpensive, has abundant resources, is composed of harmless sulfur and organic matter, has low environmental impact, has high lithium ion charge / discharge capacity, and Since it is a material that is stable at high temperatures and does not release oxygen, it is very promising as a positive electrode material for sodium ion secondary batteries as well as a positive electrode material for next-generation lithium ion secondary batteries.

  While organic sulfur-based positive electrode materials are such attractive materials, there are various difficulties in their synthesis and production. Specifically, unlike the synthesis of oxide-based positive electrode materials that have been performed exclusively by the firing method, hydrothermal synthesis method, etc., a sulfurization reaction step is required in which an organic substance and sulfur are reacted by heating. . Furthermore, in order to give a sufficient capacity to the product by the inventors' many years of study, the treatment is performed in a state where a sufficient amount of sulfur is present in the organic matter at a temperature of 350 ° C. to 400 ° C. at which sulfur is easily evaporated. I found it necessary to do. During this treatment process, highly toxic hydrogen sulfide is generated by the extraction of hydrogen from organic substances by sulfur. Since hydrogen sulfide is a dangerous gas that can be killed instantly if a gas with a concentration of 0.1% is inhaled, strict management is required.

Conventionally, as a method for treating hydrogen sulfide gas generated in a reaction vessel, an aqueous alkali solution in which hydrogen sulfide gas is discharged outside the vessel through a discharge pipe connected to the reaction vessel outlet, and the discharged hydrogen sulfide gas is accommodated in a separate vessel. There is known a method in which a liquid is bubbled and absorbed. However, in this method, when the inside of the reaction vessel accidentally becomes a negative pressure, the alkaline aqueous solution flows backward to the high-temperature reaction vessel through the discharge pipe, and there is a risk of causing damage to the vessel or a steam explosion due to thermal shock. . In addition, the salt produced by the reaction between the alkaline aqueous solution and hydrogen sulfide precipitates as a solid and closes the discharge pipe, the reaction vessel and the discharge pipe are pressurized with hydrogen sulfide, and the discharge pipe is detached. There was a risk of leakage of hydrogen sulfide. Furthermore, when a large amount of hydrogen sulfide gas is generated abruptly, pressure resistance inside the discharge pipe due to bubbling occurs, and there is a risk that the inside of the discharge pipe is pressurized and hydrogen sulfide leaks.
In addition, sulfur may be deposited on the flow of the generated hydrogen sulfide and cooled at the outlet in an attempt to get out of the reaction vessel, and the precipitated sulfur may cause clogging of the gas outlet of the reaction vessel. In this case, pressurized hydrogen sulfide accumulates in the reaction vessel. However, the hydrogen sulfide that has been pressurized and stored is difficult to safely process during the opening of the vessel, and is accidentally ejected all at once. It was very dangerous because it might leak.

  In addition, the organic sulfur-based positive electrode material synthesized in the reaction vessel contains unreacted sulfur that dissolves in the electrolyte inside the battery and reduces the life of the battery. Treatment is required, and hydrogen sulfide may be generated during sulfur removal. As described above, since it is difficult to obtain an organic sulfur-based positive electrode material in both synthesis and purification, there is an apparatus and method that can perform a series of these synthesis and purification operations quickly and in large quantities in consideration of safety and the environment. Although required, heretofore no such apparatus and method existed.

JP 2009-252630 A

J. Wang, J. Yang, C. Wan, K. Du, J. Xie, and N. Xu, Adv. Funct. Mater., 13, 487-492 (2003). C. Lai, X. P. Gao, B. Zhang, T. Y. Yan and Z. Zhou, J. Phys. Chem. C 113, 4712-4716 (2009). B. Zhang, C. Lai, Z. Zhou, and X.P. Gao, Electrochim. Acta, 54, 3708-3713 (2009). Y. A. Shahab, A. A. Siddiq, and K. S. Tawfiq, Carbon, 26, 801-802 (1988). J. Sun, Y. Huang, W. Wang, Z. Yu, A. Wang, K. Yuan, Electrochim. Acta, 53, 7084-7088 (2008). B. A. Trofimov, Sulfur Reports, 24, 283-305 (2003). W. Wei, J. Wang, L. Zhou, J. Yang, B. Schumann, Y. NuLi, Electrochem. Comm., 13, 399-402 (2011).

  The present invention, in the production of organic sulfur-based positive electrode material, while sufficiently extracting the capacity of the organic sulfur-based positive electrode material, reliably capture the highly toxic hydrogen sulfide gas, prevent its leakage, clogging by the sulfur of the reaction system, An object of the present invention is to provide an apparatus and method capable of removing unreacted sulfur from a product and capable of producing a large amount of an organic sulfur-based positive electrode material in a safe and environmentally friendly manner in a rapid and large amount. And

The present invention provides the following means in order to solve the above problems.
In the invention according to claim 1,
A reaction vessel containing a raw material containing sulfur and organic matter;
A heating source for heating the reaction vessel;
A discharge pipe for taking out hydrogen sulfide generated in the reaction vessel to the outside;
An undulation mechanism for integrally raising and lowering the reaction vessel and the heating source;
The reaction vessel has a heating part in which the raw material is heated by the heating source, and a non-heating part for condensing sulfur vapor generated by heating in the heating part,
The undulation mechanism is capable of switching between a standing state where the heating part is lower than the non-heating part and an inclined state where the non-heating part is lower than the heating part.
An organic sulfur positive electrode material manufacturing apparatus for a secondary battery is provided.

  According to this apparatus, sulfur and an organic substance can be reacted in a standing reaction vessel to produce a crude product (crude organic sulfur-based positive electrode material), and the reaction vessel can be produced after the production of the crude product. Further, by heating the crude product with the heating source in an inclined state, unreacted sulfur contained in the crude product can be removed. Moreover, the operation | work which makes a reaction container and a heat source into an inclined state can be performed rapidly, easily and safely using a raising / lowering mechanism. Therefore, an apparatus is provided that can synthesize and purify organic sulfur-based positive electrode materials quickly and in large quantities in consideration of safety and the environment. In addition, since it is possible to remove the unreacted sulfur by transferring the crude product to another container without making the reaction vessel inclined after the production of the crude product, if necessary, versatility and It is highly convenient and can be carried out by changing the scale of the apparatus, from the trial production of several grams on the laboratory scale to the industrial scale production.

In the present invention,
The reaction vessel and the heating source also serve as an unreacted sulfur removal device for removing unreacted sulfur contained in the crude product produced in the reaction vessel,
Wherein after formation of the crude product, wherein the reaction vessel by utilizing the relief mechanism and the heating source an inclined state with unreacted sulfur removal is Ru secondary battery organosulfur positive electrode material production apparatus is used as a device by ,I will provide a.

  According to this apparatus, since the reaction vessel and the heating source also serve as an unreacted sulfur removing device, there is no need to prepare the unreacted sulfur removing device as a separate device, and the device can be downsized and the equipment cost can be reduced. Can do. In addition, since there is no need to transfer the crude product produced in the reaction vessel to another vessel and remove unreacted sulfur, the synthesis and purification operations for organic sulfur-based positive electrode materials can be efficiently performed as a series of operations. In addition, it can be performed safely, and high-capacity organic sulfur-based positive electrode materials can be mass-produced.

In the invention according to claim 1 ,
An unreacted sulfur removing device for removing unreacted sulfur contained in the crude product produced in the reaction vessel,
The unreacted sulfur removing device includes a processing container for storing the crude product,
A heating source for heating the processing vessel;
An inert gas supply means for supplying an inert gas into the processing vessel;
The processing container includes a heating unit in which the crude product is heated by the heating source, and a non-heating unit that condenses sulfur vapor generated by heating in the heating unit, and the non-heating unit is more than the heating unit. Is also inclined to be at a low position,
The inert gas supply means, the organosulfur positive electrode material manufacturing equipment for a secondary battery that to supply inert gas into the processing chamber as inert gas flows toward the non-heated part from the heating unit provide.

According to this apparatus, the crude product is accommodated in the processing container of the unreacted sulfur removal apparatus, and the processing container is heated while being inclined so that the non-heating part is positioned lower than the heating part. By supplying the inert gas into the processing vessel so that the inert gas flows from the heating part toward the non-heating part, unreacted sulfur contained in the crude product becomes vapor, and this sulfur vapor becomes the inert gas. It is carried on the flow of the water and condenses in the non-heated part. Therefore, unreacted sulfur is removed from the crude organic sulfur-based positive electrode material in the processing container, and the purified organic sulfur-based positive electrode material can be reliably recovered.
In addition, when an organic substance such as rubber is used as a raw material, the crude product produced by the sulfurization reaction becomes hard, so if unnecessary sulfur (unreacted sulfur) is trapped inside, the synthesis reaction in the reaction vessel Immediately after that, even if this sulfur is removed, it may not be sufficiently removed. Even in such a case, according to this apparatus, the crude product can be crushed and then transferred to another container (processing container) to perform the removal operation.

The invention according to claim 2
Comprising a collecting device for collecting hydrogen sulfide taken out from the discharge pipe;
The collection device includes a plurality of collection containers containing a liquid capable of absorbing hydrogen sulfide,
The collection container has a front container in which an end of the discharge pipe is disposed inside, and a rear container for collecting hydrogen sulfide not collected in the front container,
The end of the discharge pipe is not in contact with the liquid accommodated in the preceding container,
An organic sulfur-based positive electrode material manufacturing apparatus for a secondary battery according to claim 1 is provided.

  According to this apparatus, the hydrogen sulfide taken out from the reaction vessel through the discharge pipe is first sent to the upstream vessel and collected, and then sent to the downstream vessel and collected. Here, even if the end of the discharge pipe is not in contact with the liquid contained in the preceding container, and the inside of the reaction container accidentally becomes a negative pressure, the liquid (alkaline aqueous solution) in the preceding container through the discharge pipe. ) Is prevented from flowing back into the hot reaction vessel. Further, it is possible to prevent the salt produced by the reaction between the liquid and hydrogen sulfide from becoming a solid and blocking the discharge pipe. Moreover, when a large amount of hydrogen sulfide gas is generated abruptly, pressure resistance inside the exhaust pipe due to bubbling occurs, and pressurization inside the exhaust pipe is prevented. As a result, the risk of leakage of hydrogen sulfide can be greatly reduced, and the device is a safe device that is environmentally friendly.

The invention according to claim 3
The front-stage container and the rear-stage container are connected by a connecting pipe that guides hydrogen sulfide that has not been collected in the front-stage container to the rear-stage container,
One end of the connecting pipe is not in contact with the liquid stored in the front container,
The other end of the connecting pipe is in contact with the liquid stored in the rear container,
An organic sulfur-based positive electrode material manufacturing apparatus for a secondary battery according to claim 2 is provided.

  According to this apparatus, most of the hydrogen sulfide taken out from the reaction vessel through the discharge pipe is first safely collected without bubbling in the former vessel, and the hydrogen sulfide that could not be collected in the former vessel is collected in the latter vessel. It can be reliably collected by bubbling.

According to the invention of claim 4 ,
The organic sulfur type positive electrode material manufacturing apparatus for secondary batteries of Claim 2 or 3 provided with the stirring apparatus for stirring the liquid accommodated in the said front stage container.

  According to this apparatus, by stirring the liquid stored in the former container, the hydrogen sulfide contacted with the hydrogen sulfide introduced into the former container through the discharge pipe comes into contact with the liquid in the former container. Will always be in contact with the hydrogen sulfide. Therefore, a large amount of hydrogen sulfide can be absorbed quickly.

The invention according to claim 5
The said exhaust pipe provides the organic sulfur type positive electrode material manufacturing apparatus for secondary batteries in any one of the Claims 1 thru | or 4 whose internal diameter of the edge part connected to the said reaction container is 10 mm or more.

  According to this apparatus, when sulfur is evaporated from the reaction mixture on the flow of hydrogen sulfide generated in the reaction vessel, the gas outlet of the reaction vessel (the end connected to the reaction vessel of the discharge pipe) is blocked by sulfur. This prevents the risk of leakage of hydrogen sulfide.

The invention according to claim 6
The reaction vessel has the heating part below and the non-heating part above,
The obstacle according to any one of claims 1 to 5 , wherein an obstacle for contacting and condensing sulfur vapor generated by heating the raw material is disposed below the discharge pipe in the non-heating portion. An apparatus for producing an organic sulfur positive electrode material for a secondary battery is provided.

  According to this apparatus, the sulfur vapor generated by heating the raw material condenses by contacting an obstacle before reaching the discharge pipe, so that the gas outlet (discharge pipe) of the reaction vessel is blocked by sulfur. Can be prevented, and the risk of leakage of hydrogen sulfide can be further reduced.

The invention according to claim 7 provides:
A raw material containing sulfur and organic matter is contained in the lower part of the reaction vessel, and the lower part is heated to cause a sulfurization reaction between sulfur and organic matter in the reaction vessel to produce a crude product. A sulfurization heat treatment step;
A purification step of removing unreacted sulfur contained in the generated crude product,
The purification step includes
Inclining the reaction vessel containing the generated crude product so that the upper part is lower than the lower part;
Heating the lower part at a high position of the inclined reaction vessel to extract unreacted sulfur from the crude product as sulfur vapor, and condensing the extracted sulfur vapor at the upper part at a low position Including,
An organic sulfur-based positive electrode material manufacturing method for a secondary battery is provided.

  According to this method, after producing the crude product in the reaction vessel, the reaction vessel is tilted as it is to perform the unreacted sulfur removal treatment. Therefore, the crude product in the reaction vessel is transferred to another vessel and unreacted. There is no need for sulfur removal treatment, organic sulfur-based cathode materials can be synthesized and refined efficiently and safely as a series of operations, and high-capacity organic sulfur-based cathode materials can be mass-produced. It becomes. In addition, it is not necessary to prepare an unreacted sulfur removing device as a separate device, and it is possible to realize downsizing of the device and reduction in equipment cost.

  According to the organic sulfur positive electrode material manufacturing apparatus and the manufacturing method for a secondary battery according to the present invention, it is possible to prevent leakage of dangerous hydrogen sulfide generated during the production of the organic sulfur positive electrode material, and a high capacity organic sulfur system. A large amount of the positive electrode material can be synthesized and unreacted sulfur can be desorbed and purified reliably and easily.

It is the schematic which shows the whole structure of the manufacturing apparatus which concerns on this invention. It is a figure which expands and shows the reaction container shown by FIG. It is a figure which shows the state which has made the reaction container into the inclination state and has removed unreacted sulfur from a crude product. It is a figure which shows the state which is removing the unreacted sulfur from a crude product using the unreacted sulfur removal apparatus provided as a separate apparatus with the reaction container and the heat source. It is a side view which shows the structure and effect | action of a raising / lowering mechanism. It is a partial cross section side view which shows a mode that the reaction container is set to the upright state. It is a top view of a container fixing band.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an apparatus for producing an organic sulfur positive electrode material for a secondary battery and a production method according to the invention will be described with reference to the drawings as appropriate.
FIG. 1 is a schematic view showing the overall configuration of the production apparatus according to the present invention, and FIG. 2 is an enlarged view of the reaction vessel shown in FIG.

  The production apparatus according to the present invention includes a reaction vessel (1) containing a raw material (M) containing sulfur and organic matter, a heating source (5) for heating the reaction vessel (1), and a reaction vessel (1). A discharge pipe (2) for taking out hydrogen sulfide generated by heating to the outside, a collection device (3) for collecting hydrogen sulfide taken out from the discharge pipe (2), and a reaction vessel (1) An unreacted sulfur removing device (4) for removing unreacted sulfur contained in the crude organic sulfur-based positive electrode material is provided.

In the present invention, the unreacted sulfur removing device (4) can be used as the reaction vessel (1) and the heating source (5) shown in FIG. 1 (see FIG. 3), or the reaction vessel (1) and the heating source. It can also be provided as a separate device from (5) (see FIG. 4).
In addition, although the kind of heating source (5) is not specifically limited, since an electric furnace is used suitably like the example of illustration, in the following description, a heating source may be demonstrated as an electric furnace (5).

  The reaction vessel (1) has a vertically long bottomed cylindrical shape, and has a heating part (6) heated by an electric furnace (5) serving as a heating source for the raw material, and in the heating part (6). The non-heating part (7) which condenses the sulfur vapor | steam produced by heating is provided upwards. The ratio of the length of the reaction vessel (1) to the diameter (inner diameter) is preferably 7: 1 to 3: 1 and more preferably 6: 1 to 4: 1.

The heating section (6) is provided in the lower part of the reaction vessel (1) (in the range from the lower half to the second third of the entire height), and the raw material is accommodated in the electric furnace (5). This is the part heated by the heater (5a). The heating temperature is set to a temperature (preferably 300 to 450 ° C., more preferably 350 to 420 ° C.) sufficient to cause sulfur reaction between the sulfur contained in the raw material and the organic substance. The temperature increase rate of the heating section (6) is preferably about 40 minutes if the time required for raising the temperature to 450 ° C. is up to 50 g, and about 3 hours if the raw material is 50 g or more.
A non-heating part (7) is provided in the upper part (the range except heating part (6) among the whole height) of reaction container (1), and touches the heat insulating material (5b) or external air of an electric furnace (5). It is desirable to be in a coolable place. The temperature of the non-heating part (7) is a temperature at which sulfur vapor generated and raised by heating in the heating part (6) can condense and fall (preferably 100 ° C. or less, more preferably 50 ° C. or less). The
The temperature in the reaction vessel (1) is measured by the thermocouple (20), and is adjusted by controlling the electric furnace (5) with the temperature controller (21) based on the measured value.

  As the material of the reaction vessel (1), it is preferable to use mullite, alumina, quartz, or aluminum for the part that comes into contact with the raw material in which liquid sulfur is present. Rough mullite or aluminum is more preferred. Ceramic containers and quartz containers are vulnerable to mechanical shock, so when creating large containers, a stainless steel airtight container (1a) is placed on the outside from the viewpoint of airtightness and breakage resistance, and the interior is made of mullite. Or it is preferable to accommodate the reaction container (1) made from aluminum (refer FIG. 2).

The raw material contained in the reaction vessel (1) is sulfur with respect to 100 parts by mass of organic substances such as polyacrylonitrile (PAN), coal pitch, rubber, paraffins, activated carbon, acetylene black, bitumen, gelatin, polyethylene resin, acrylic resin and the like. 120 to 600 parts by mass (preferably 140 to 400 parts by mass) are mixed. Although the mixing method is not particularly limited, for example, mixing can be performed using a general mixing device such as a mortar or a ball mill. Moreover, you may mix | blend the general material (conductive auxiliary agent etc.) which can be mix | blended with the positive electrode active material of a secondary battery as needed. The form of the raw material may be powdery or may be formed into a pellet or the like, and is not particularly limited.
This raw material is accommodated in a heating part (6) and heated at 250 to 500 ° C., preferably 300 to 450 ° C., more preferably 350 to 420 ° C., thereby causing a sulfurization reaction between sulfur and organic matter. When this sulfidation reaction (sulfurization heat treatment step) is performed in a non-oxidizing atmosphere, when the organic substance is PAN, simultaneously with the PAN ring-closing reaction, the vapor form sulfur reacts with PAN and is modified by sulfur. Is obtained. Here, the non-oxidizing atmosphere includes a depressurized state having a low oxygen concentration such that the oxidation reaction does not proceed, an inert gas atmosphere such as nitrogen or argon, a sulfur gas atmosphere, and the like.

During the sulfurization reaction between sulfur and organic matter, a large amount of sulfur vapor is generated because the reaction temperature is sufficiently higher than the temperature at which sulfur evaporates.
In a moving bed reaction apparatus used industrially or in a normal heating reaction vessel such as a rotary kiln, sulfur quickly escapes from the reaction system and cannot sufficiently react with organic matter. In addition, even when mixed raw materials are placed in a crucible or the like having a length to diameter ratio of 3: 1 or less and reacted in an atmospheric furnace, the evaporated sulfur does not return to the reaction system, so that sulfur is insufficient and organic sulfur has good characteristics. It is difficult to reliably obtain a positive electrode material.
On the other hand, according to the production apparatus according to the present invention, since the non-heating part (7) having a low temperature is provided on the upper part of the reaction vessel (1), it is generated and raised by heating in the heating part (6). The sulfur vapor condensed in the non-heated part (7), falls to the heated part (6), and is again subjected to a sulfidation reaction as a raw material (that is, the evaporated sulfur is returned to the raw material as a liquid). Therefore, the problem of lack of sulfur does not occur.

  A flange is formed on the upper part of the airtight container (1a) for accommodating the reaction container (1), and a lid (12) for sealing the reaction container (1) is fixed to the flange with a bolt. One end of a discharge pipe (2) for taking out hydrogen sulfide generated by heating in the reaction vessel (1) is hermetically inserted and fixed to the lid (12). A water-cooled pipe (15) is disposed below the flange.

Although the number of the discharge pipes (2) may be one, it is preferable to provide a plurality (two in the illustrated example). This is because even if one discharge pipe (2) is blocked by solidification of sulfur vapor, hydrogen sulfide can be discharged out of the container through the remaining discharge pipe (2). The plurality of discharge pipes are all connected to the collection device (3), and hydrogen sulfide that has flowed out of the reaction vessel through each discharge pipe is collected by the collection device (3).
As the discharge pipe (2), a pipe in which a plurality of pipes are connected in the length direction is usually used. For example, a pipe in which a glass pipe, a polyethylene tube and a fluororesin pipe are connected in the length direction is used. The same applies to connecting pipes (32) and (33) described later.
A pressure gauge (10) for measuring the pressure inside the reaction vessel is attached to the upper portion of the reaction vessel (1) in order to detect the blockage of the discharge pipe (2).

Another method for preventing clogging of the discharge pipe (2) due to solidification of sulfur is to increase the inner diameter of the discharge pipe (2). The present inventors have confirmed that the inner diameter of the discharge pipe (2) (the inner diameter of the end of the discharge pipe (2) connected to the reaction vessel (1)) should be 10 mm or more. However, even if the inner diameter of the discharge pipe (2) is less than 10 mm, a mechanism for scraping the solidified sulfur inside the discharge pipe (2) or a heating mechanism for melting the solidified sulfur inside the discharge pipe (2) By providing this, blockage of the discharge pipe (2) due to solidification of sulfur can be prevented.
Further, as another method, a tube (8) different from the discharge pipe (2) is connected to the reaction vessel (1), and an inert gas having a low molecular weight such as nitrogen is supplied from the tube (8) to the reaction vessel. The density of the gas in the upper part of the reaction vessel (1) (non-heated part (7)) is lowered by flowing at a flow rate of 50 to 200 ml / min, more preferably 75 to 150 ml / min per 200 cm ² of the lid area of (1). A method in which sulfur vapor having a high molecular weight and a large molecular weight (S ₈ , molecular weight 256) sinks downward, or the upper part of the reaction vessel (1) is actively cooled by air cooling or water cooling to discharge pipe (2) Of reducing sulfur vapor reaching the surface, and a method of providing an obstacle (9) such as aluminum foil in front (downward) of the discharge pipe (2) in the non-heated part (7) to condense and adhere sulfur on the obstacle surface , Sulfur collection cooling inside the reaction vessel (1) A method of removing sulfur vapor from exhaust gas by providing a vessel can be exemplified.

The production apparatus according to the present invention includes an undulation mechanism (11) that integrally undulates the reaction vessel (1) and the heating source (electric furnace (5)). The undulation mechanism (11) is omitted in FIG.
FIG. 5 is a diagram showing the configuration and action of the undulation mechanism (11).
The undulation mechanism (11) includes an upright state (see FIG. 1) in which the heating part (6) of the reaction vessel (1) housed in the electric furnace (5) is positioned lower than the non-heating part (7), and non-heating. The undulation mechanism (11) which can switch the inclination state (refer FIG. 3) which a part (7) becomes a lower position than a heating part (6) has. In FIG. 5, the solid line indicates the standing state, and the two-dot chain line indicates the inclined state.

As shown in FIG. 5, the undulation mechanism (11) includes a hinge (12) fixed to both sides of the electric furnace (5) containing the reaction container (1), the reaction container (1) and the electric furnace (5 ) Is attached to the base (13), the hinge (14) fixed to the base (13), and the rotary stay (16) connecting the hinge (12) and the hinge (14). . The hinge (12) is slidable in the vertical direction of the electric furnace (5), and is located above the electric furnace (5) in a standing state and below the electric furnace (5) in an inclined state.
By providing such an undulation mechanism (11), the operator can stand up the reaction vessel (1) and the electric furnace (5) (solid line position in FIG. 5) and inclined position (two-dot chain line in FIG. 5). Position) can be easily switched. Further, the positions of the reaction vessel (1) and the electric furnace (5) can be fixed using a fixing tool (not shown) such as a hook in each of the standing state and the inclined state.

  The angle formed between the central axis of the reaction vessel (1) and the horizontal axis is 90 ° in the standing state, and is 5 ° or less, preferably 2 to 3 ° downward from the horizontal axis in the inclined state. If the tilt angle is too small (less than 2 °), there is a possibility that droplets of simple sulfur aggregated in the removal operation of unreacted sulfur (single sulfur) described later flow down toward the crude product, which is too large (5 ° Ultra)) and a large amount of sulfur vapor may reach the discharge pipe (2) and solidify, which is not preferable in either case. The inclination angle can be set by adjusting the length of the rotary stay (16).

The undulation mechanism (11) includes a container fixing band (17) for preventing the reaction container (1) from being detached from the electric furnace (5) when the reaction container (1) is inclined.
FIG. 7 is a plan view of the container fixing band (17).
The container fixing band (17) is formed in an annular shape in plan view as a whole by connecting two semi-annular members with bolts (17a) and nuts (17b).
Each of the two semi-annular members has a semicircular arcuate portion (17e) and a rising portion (17f) that rises vertically upward on the inner peripheral side of the flange portion (17e). A notch (17c) is formed in the bowl-shaped portion (17e).
The container fixing band (17) sandwiches the side surface of the upper part of the reaction container (1) protruding upward from the electric furnace (5) between the opposed rising parts (17f) of the two semi-annular members, The nut (17b) is fastened to the bolt (17a) to be fixed to the reaction vessel (1). In this state, the bolt (17d) is inserted into the notch (17c) of the bowl-shaped portion (17e) and the bolt is fixed to the upper surface of the electric furnace (5), whereby the reaction vessel (1) is Fixed to the electric furnace (5). (See Figure 6)
The container fixing band (17) is formed of a metal material having a spring property, which makes it possible to reliably fix the reaction containers (1) made of various different materials having different thermal expansion coefficients.

The collection device (3) is provided for collecting hydrogen sulfide taken out from the reaction vessel (1) through the discharge pipe (2) and contains a plurality of liquids (L) capable of absorbing hydrogen sulfide. Equipped with a collection container.
A plurality of collection containers were not collected in the former container (30) in which the end of the discharge pipe (2) connected to the reaction container (1) is disposed, and the former container (30). It is comprised from the back | latter stage container (31) which collects hydrogen sulfide.

  As the liquid (L) capable of absorbing hydrogen sulfide, an aqueous solution in which an alkaline substance such as sodium hydroxide or potassium hydroxide is dissolved in water is preferably used. Sodium carbonate or potassium carbonate generates a poorly soluble salt such as bicarbonate by absorbing hydrogen sulfide, which not only reduces the ability to absorb hydrogen sulfide, but also clogs the tube (bubbling tube) that introduces gas into the liquid. Therefore, use as a hydrogen sulfide absorbent must be avoided. Therefore, these carbonates cannot be used in the latter vessel (31) for bubbling a gas containing hydrogen sulfide, as described later, but can be used in the former vessel (30) that does not bubble the gas. it can.

  As a specific example of the liquid (L) capable of absorbing hydrogen sulfide, in the case of sodium hydroxide, 90 parts by mass or more and less than 120 parts by mass, more preferably 100 parts by mass or more with respect to 100 parts by mass of the organic substance used in the sulfurization reaction. Less than 110 parts by weight, in the case of potassium hydroxide, 120 parts by weight or more and less than 170 parts by weight, preferably 130 parts by weight or more and less than 150 parts by weight, 300 parts by weight or more and less than 10,000 parts by weight, more preferably 400 parts by weight or more and 5000 parts by weight. An aqueous solution dissolved in less than 1 part can be used.

As shown in FIG. 1, the end of the discharge pipe (2) connected to the reaction vessel (1) is not in contact with the liquid (L) contained in the preceding vessel (30), and the liquid (L) It is located above the liquid level.
As a result, even if the inside of the reaction vessel accidentally becomes a negative pressure, the alkaline aqueous solution does not flow back to the high temperature reaction vessel through the discharge pipe. Can be prevented. In addition, since the salt produced by the reaction between the alkaline aqueous solution and hydrogen sulfide does not precipitate as a solid and clogs the discharge pipe, the reaction vessel and the discharge pipe are pressurized with hydrogen sulfide, causing leakage of hydrogen sulfide. Can also be prevented. Furthermore, even when a large amount of hydrogen sulfide gas is generated abruptly, pressure resistance inside the discharge pipe due to bubbling does not occur, so that the inside of the discharge pipe is pressurized and leakage of hydrogen sulfide can be prevented.

  The liquid (L) accommodated in the front vessel (30) is stirred by a stirring device (34) made of a magnetic stirrer or the like. As a result, when the gas containing hydrogen sulfide introduced into the front vessel (30) through the discharge pipe (2) comes into contact with the liquid (L), the liquid level in contact with the gas always moves and changes. Become. Therefore, apparently, the contact area between the gas and the liquid surface increases, and hydrogen sulfide can be absorbed rapidly.

The former container (30) and the latter container (31) are connected by a connecting pipe (32) that guides hydrogen sulfide that has not been collected in the former container (30) to the latter container (31).
At least one or more post-stage containers (31) may be provided, but a plurality of, preferably three or more, are preferably provided in order to reliably absorb all of the hydrogen sulfide. In the illustrated example, three are provided. When providing a plurality of rear containers (31), as shown in the figure, a plurality of rear containers (31) are connected in series with each other via a connecting pipe (33), and one of the rear containers (31) is connected to the front It connects with a container (30) and a connection pipe (32).

One end of the connecting pipe (32) connecting the front container (30) and the rear container (31) is not in contact with the liquid (L) contained in the front container (30) as described above. The other end is in contact with the liquid (L) contained in the rear container (31).
The gas containing hydrogen sulfide that has not been absorbed by the liquid in the front vessel (30) is introduced into the first rear vessel (31) through the connecting pipe (32), and then into the rear vessel (31). By bubbling the contained liquid (L), hydrogen sulfide is absorbed into the liquid.
The reason why the gas containing hydrogen sulfide is bubbled with respect to the liquid in the latter container (31) is that most of the hydrogen sulfide (about 90%) is absorbed by the liquid in the former container (30). This is because the above-described bubbling does not cause any adverse effects.
Since most of the hydrogen sulfide is absorbed by the liquid in the front vessel (30), the front vessel (30) contains a liquid corresponding to the expected amount of generated hydrogen sulfide, and the rear vessel (31). It is sufficient to store about 10% to 20% of the liquid in the front container (30).

  The gas containing hydrogen sulfide introduced into the first latter container (31) is sequentially introduced into the second latter container and the third latter container through the connecting pipe (33). Hydrogen sulfide that could not be absorbed by the liquid in the first latter container (31) is absorbed by being bubbled by the liquid in the second and subsequent latter containers.

The raw material containing sulfur and organic matter contained in the reaction vessel (1) undergoes a sulfurization reaction when heated, and a crude product is produced (synthesized).
This crude product contains about 50 to 200 parts of sulfur with respect to 100 parts by weight of the organic substance-derived substance. Among these, sulfur trapped inside the structure of organic matter does not dissolve into the electrolyte solution by charge and discharge when used in a battery as an electrode, but sulfur that gives a reflection peak peculiar to sulfur crystals by powder X diffraction (hereinafter referred to as “sulfur”). In the presence of elemental sulfur), it dissolves in the electrolyte and causes deterioration of the battery. Therefore, such elemental sulfur must be removed from the produced crude product.
Sulfur has the property of becoming steam when heated. In addition, when heated in air, it ignites with a blue flame at about 300 ° C. and burns slowly. In order to remove unnecessary sulfur (elemental sulfur) as an electrode from the synthesized crude product containing excess sulfur, it is volatilized as molecular sulfur by heating in an inert gas stream or under vacuum, and then from the crude product. It is desirable to remove.

Hereinafter, the unreacted sulfur removing device (4) for removing unreacted sulfur (single sulfur) contained in the crude product generated in the reaction vessel (1) will be described.
As described above, the unreacted sulfur removing device (4) can be used as the reaction vessel (1) and the heating source (5) (see FIG. 3), or the reaction vessel (1) and the heating source (5). Can also be provided as a separate device (see FIG. 4).

First, the case where the reaction vessel (1) and the heating source (5) are also used as the unreacted sulfur removing device (4) will be described.
In this case, after a crude product is generated in the reaction vessel (1), the unheated portion (7) is heated to the heated portion (6) by using the undulation mechanism (11) and the reaction vessel (1) and the heating source (5). ) Inclined state that is lower (see FIG. 3). Thereby, it becomes possible to use the reaction vessel (1) and the heating source (5) as the unreacted sulfur removing device (4).

After the reaction vessel (1) and the heating source (5) are inclined as shown in FIG. 3, the crude product (C) accommodated in the heating section (6) of the reaction vessel (1) is further heated. . The heating temperature is preferably 200 to 450 ° C, and more preferably 250 to 400 ° C. When the heating temperature is less than 200 ° C., the transpiration of sulfur is extremely slow, and industrial utility is poor. When it exceeds 450 ° C. (or when it is heated for a long time at 300 ° C. or higher), sulfur involved in charge / discharge may be removed from the crude product, which is not desirable.
Specifically, after completion of the sulfidation reaction with the reaction vessel (1) in the standing state (see FIG. 1), the reaction vessel (1) and the heating source (5) are set in an inclined state to a temperature of 350 to 400 ° C. It is good to carry out removal of sulfur using residual heat, keeping for minutes-2 hours, more preferably 45 minutes-90 minutes, and letting it cool naturally after that.

By heating the crude product at 200 to 450 ° C. with the reaction vessel (1) and the heating source (5) in an inclined state, the elemental sulfur (unreacted sulfur) contained in the crude product becomes steam and the crude product Taken from. Since sulfur vapor is heavier than air, it flows obliquely downward in the inclined reaction vessel (1) (see the one-dot chain line arrow in FIG. 3) and agglomerates in the non-heating part (7) where the temperature is low to form liquid or solid It becomes sulfur (S).
Here, since the reaction vessel (1) is in an inclined state in which the non-heating part (7) is positioned lower than the heating part (6), the reaction container (1) is removed from the crude product by the heating part (6). The single sulfur droplets aggregated in the heating section (7) are prevented from flowing down toward the crude product (C).
Hydrogen sulfide generated by heating is guided to the collection device (3) through the discharge pipe (2) and collected by the front vessel (30) and the rear vessel (31).

  At the time of heating, an inert gas having a low molecular weight such as nitrogen is allowed to flow from the tube (8) connected to the reaction vessel (1) to lower the density of the gas at the top of the inclined reaction vessel (1). It is preferable that sulfur vapor having a large density and a large molecular weight flow down from the sample.

Next, the case where the unreacted sulfur removing device (4) is provided as a separate device from the reaction vessel (1) and the heating source (5) will be described.
When organic materials such as rubber are used as raw materials, if the product (crude product) becomes hard and unnecessary sulfur (unreacted sulfur) is trapped inside, the synthesis reaction in the reaction vessel (1) Immediately after that, if the reaction vessel (1) is inclined to remove this sulfur, it may not be sufficiently removed. In such a case, it is necessary to pulverize the product (crude product) and then transfer it to a separate container for removal.
By providing the unreacted sulfur removal device (4) as a separate device from the reaction vessel (1) and the heating source (5), the crude product synthesized in the reaction vessel (1) is once taken out and pulverized. Then, it can be transferred to the unreacted sulfur removal device (4) to perform the sulfur removal work.

FIG. 4 is a schematic view showing an entire configuration of an unreacted sulfur removing device (4) provided as a separate device from the reaction vessel (1) and the heating source (5).
The unreacted sulfur removal device (4) includes a cylindrical processing container (40) for containing and heating the crude product,
A heat source (45) for heating the processing container (40) and an inert gas supply means (41) for supplying an inert gas into the processing container (40) are provided.
The type of the heat source (45) is not particularly limited, but an electric furnace is preferably used as shown in the illustrated example. Therefore, in the following description, the heat source may be described as the electric furnace (45).

  The material of the processing vessel (40) is preferably mullite, alumina, quartz, aluminum, or stainless steel, and mullite, alumina, or quartz having a rough surface is more preferable in terms of air permeability of sulfur vapor and ease of peeling from raw materials. preferable.

Both ends of the processing container (40) are closed by lids (48) (49).
A lid (48) provided on one end side (low inclination side) of the processing vessel (40) is provided with a discharge pipe for discharging gas containing hydrogen sulfide generated in the processing vessel (40) to the outside ( 46) is connected to one end, and the other end of the discharge pipe (46) is connected to a collection container (47) containing a liquid capable of absorbing hydrogen sulfide.
A lid (49) provided on the other end side (highly inclined side) of the processing vessel (40) is provided with a supply pipe (50) for supplying an inert gas such as nitrogen into the processing vessel (40). One end is connected, and the other end of the supply pipe (50) is connected to a gas container (51) storing an inert gas. The supply pipe (50) and the gas container (51) constitute an inert gas supply means (41).

The processing container (40) is generated by heating in the heating unit (42), in which the crude product (C) accommodated therein is heated by the heater (45a) of the electric furnace (45), and in the heating unit (42). While having the non-heating part (43) which condenses sulfur vapor | steam, it arrange | positions so that a non-heating part (43) may become a lower position than a heating part (42).
The angle of inclination is set to 5 ° or less, preferably 2 to 3 ° with respect to the horizontal axis. If the tilt angle is too small (less than 2 °), there is a possibility that droplets of simple sulfur aggregated in the removal operation of unreacted sulfur (single sulfur) described later flow down toward the crude product, which is too large (5 ° And a large amount of sulfur vapor reaches the discharge pipe (46) and is solidified, which may block the discharge pipe.

  The temperature in the heating unit (42) is measured by the thermocouple (52), and is adjusted by controlling the electric furnace (45) with the temperature controller (53) based on the measured value.

On one end side of the processing vessel (40), a non-heating part (43) between the heating part (42) and the lid (48) is provided with a collection paper (54) for collecting sulfur vapor. ing.
On the other end side of the processing vessel (40), a cylindrical backflow prevention member (55) for preventing the backflow of sulfur vapor is disposed between the heating unit (42) and the lid (49). . There is a gap through which the inert gas can flow between the backflow prevention member (55) and the processing container (40), and the portion where the backflow prevention member (55) is disposed is not heated. .

Hereinafter, a method for removing unreacted sulfur (single sulfur) contained in the crude product using the unreacted sulfur removing device (4) shown in FIG. 4 will be described.
When the crude product (C) accommodated in the processing vessel (40) is heated by an electric furnace (45) at 200 to 450 ° C., preferably 250 to 400 ° C., unreacted sulfur contained in the crude product is obtained. It becomes steam.
Then, while heating the crude product, the inert gas supply means (41) causes the inert gas to flow from the high position heating section (42) toward the low position non-heating section (43). By supplying the inert gas into the inside, the generated sulfur vapor is carried on the flow of the inert gas and aggregates in the non-heated part (43) having a low temperature to become liquid or solid sulfur (S). .
In FIG. 4, the flow of the inert gas is indicated by a dotted arrow, the flow of sulfur vapor is indicated by a one-dot chain arrow, and the flow (dropping) of the aggregated sulfur is indicated by a solid arrow.

Here, since the processing container (40) is disposed so that the non-heating part (43) is positioned lower than the heating part (42), the crude product (C) in the heating part (42). The single sulfur droplets removed from the water and agglomerated in the non-heated part (43) are prevented from flowing down toward the crude product.
The hydrogen sulfide generated by heating is guided to the collection container (47) through the discharge pipe (46) and collected. In FIG. 4, the flow of gas containing hydrogen sulfide is indicated by a two-dot chain line arrow.

  Hereinafter, the effect of the present invention will be clarified by showing examples and comparative examples of the present invention. However, the present invention is not limited to the following examples.

<Example 1>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries)
1. Preparation of raw material 2 g of polyacrylonitrile powder and 7 g of sulfur (manufactured by Kishida Chemical Co., 99%) were mixed to obtain a raw material.

2. An apparatus alumina tanman tube (SSA-S, manufactured by Nikkato, inner diameter 50 mmφ, outer diameter 60 mmφ, length 180 mm) was used as a reaction vessel. The raw material was put into the bottom of the Tamman tube, and connected to a stainless steel flange having a water cooling function by using an O-ring to maintain airtightness. This flange has an opening that allows three alumina pipes to be tightly held with an O-ring and kept airtight, and has two Swagelok standard openings (swagelok ports) that can be used to introduce and exhaust gas separately. Have. A tube for feeding nitrogen gas was connected to the swagelok port, and a pressure gauge was attached to the other swagelok port. Alumina pipes (SSA-S, made by Nikkato, outer diameter 6.3 mmφ, inner diameter 4 mmφ, length 80 mm) are attached to two of the alumina pipe ports, and separately closed alumina pipes (SSA-S, made by Nikkato, outer A thermocouple (type K) was inserted into a diameter of 6.3 mmφ, an inner diameter of 4 mmφ, and a length of 200 mm, and contacted with the raw material.
Two fluororesin tubes (outer diameter: 6.3mm, inner diameter: 3mm, length: 150mm) are attached by drilling two holes in the silicone rubber stopper, and three sets of them are attached to three Erlenmeyer flasks (each volume 250ml). Attached. About 70 ml of an alkaline aqueous solution prepared by dissolving 3 g of sodium hydroxide in 280 ml of water was poured into each Erlenmeyer flask. Polyethylene pipes (outer diameter 8 mm, inner diameter 6 mm, length 500 mm) were connected to two alumina pipes connected to the reaction vessel, and two polyethylene pipes were joined using a Y-shaped pipe. Extend the polyethylene tube 1m from the Y-shaped tube, connect it to one of the two fluororesin tubes attached to the Erlenmeyer flask, connect the polyethylene tube from the other fluororesin tube to another Erlenmeyer flask, and connect the three Erlenmeyer flasks. A polyethylene pipe was piped so that the gas passed in series. The first of the three Erlenmeyer flasks does not immerse the fluororesin tube in the alkaline aqueous solution. In the remaining two Erlenmeyer flasks, the tube containing the gas is immersed in the alkaline aqueous solution, and the exhaust gas is bubbled to sulfidize. Hydrogen was able to be collected.

3. A reaction vessel in which 100 ml / min of nitrogen gas was sent into the sulfurization heat treatment process was set in an electric furnace, and a portion from the bottom of the reaction vessel up to 100 mm was heated.
Nitrogen gas was bubbled in the last row of the triple Erlenmeyer flasks, that is, after the airtightness of the entire system was confirmed, the temperature increase by the electric furnace was started. On the way, it can be seen from the frequency of bubble generation in the second Erlenmeyer flask that the generation of gas became intense when the raw material temperature exceeded 200 ° C. Throughout the experiment, the display of the hydrogen sulfide detector remained at 0 ppm.
After heating to a raw material temperature of 380 ° C. over 40 minutes and stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise above 420 ° C.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was kept at 300 ° C. for 3 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 3.2 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 2>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries)
1. Preparation of raw material 20g of polyacrylonitrile powder and 70g of sulfur (Hosoi Chemical Industry 200 mesh, 99.9%) were weighed into a plastic bag, mixed by hand and used as a raw material.

2. A quartz tube (inner diameter: 180 mmφ, length: 380 mm) with the lower part of the apparatus closed in a hemisphere was used as a reaction vessel, and the raw material was placed in the bottom of the quartz tube. A lid capable of holding four glass tubes (made of Pyrex (registered trademark), outer diameter 6 mmφ, inner diameter 4 mmφ) hermetically using an O-ring was attached to the quartz tube opening with the O-ring. One of the glass tubes was used as a nitrogen gas introduction tube. Two of the glass tube ports are exhaust gas ports, and a thermocouple (K type) is put into a closed alumina tube (SSA-S, manufactured by Nikkato, outer diameter 8 mmφ, inner diameter 4 mmφ, length 200 mm). Contact.
Two fluororesin tubes (outer diameter: 6.3mmφ, inner diameter: 3mmφ, length: 150mm) are attached by drilling two holes in a silicone rubber stopper, and three sets of them are attached to three Erlenmeyer flasks (each volume 500ml) It was. About 100 ml of an alkaline aqueous solution in which 40 g of sodium hydroxide was dissolved in 300 ml of water was poured into each Erlenmeyer flask. Two polyethylene pipes (outer diameter 8 mmφ, inner diameter 6 mmφ, length 500 mm) were connected to two of the exhaust gas ports protruding from the reaction vessel, and two polyethylene tubes were joined using a Y-shaped tube. Extend the polyethylene tube 1m from the Y tube, connect it to one of the two fluororesin tubes of the Erlenmeyer flask, connect the polyethylene tube from the other fluororesin tube to the other Erlenmeyer flask, and gas from the three Erlenmeyer flasks. A polyethylene pipe was piped so as to pass in series. The first of the three Erlenmeyer flasks does not immerse the fluororesin tube in the alkaline aqueous solution. In the two remaining Erlenmeyer flasks, the exhaust gas is bubbled by immersing the tube containing the gas in the alkaline aqueous solution. Hydrogen sulfide can be collected.

3. Sulfurization heat treatment process Nitrogen gas 100 ml / min was sent into the reaction vessel and set in an electric furnace, and the part from the bottom of the reaction vessel up to 350 mm was heated.
After heating to a raw material temperature of 380 ° C. over 40 minutes and stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise above 420 ° C.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 300 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 32 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 3>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries)
1. Preparation of raw materials 100 g of polyacrylonitrile powder and 350 g of sulfur (Hosoi Chemical Industry 200 mesh, 99.9%) were weighed into a plastic bag, mixed by hand and used as a raw material.

2. Apparatus An apparatus having the configuration shown in FIGS. 1 to 3 and FIGS. 5 to 7 was used (the following symbols correspond to the drawings). However, there were two Erlenmeyer flasks corresponding to the latter container (41).
A mullite reaction vessel (inner diameter: 113 mmφ, length: 410 mm) was used as the reaction vessel (1), and the raw material was placed in the bottom of the reaction vessel. The mullite reaction vessel (1) was placed in a stainless steel vessel (inner diameter: 120 mmφ, length: 450 mm) (1a) having a water-cooled flange that provides an airtight atmosphere (see FIG. 2).
A stainless steel lid (outer diameter 6 mmφ, thickness 10 mmt) (12) with four swagelok ports and a 10 mmφ port to which a thermocouple is attached was attached to the stainless steel container with eight bolts. A thermocouple (K type) (20) is placed in an alumina tube (SSA-S, manufactured by Nikkato Co., Ltd., outer diameter 10 mmφ, inner diameter 6 mmφ, length 750 mm) that can store the thermocouple, and brought into contact with the raw material (M). The alumina tube was fixed to the stainless steel lid with an O-ring and a stainless steel ring. A nitrogen gas inlet pipe (8) was attached to one of the four swage lock ports. A vacuum exhaust line and a pressure gauge (10) were attached to another port. The remaining two ports were exhaust gas outlets (inner diameter: 4.5 mmφ) (discharge pipe (2)). Stop cocks were provided in each of the four mouths.
Two fluororesin tubes (outer diameter: 6.3mmφ, inner diameter: 3mmφ, length: 150mm) are attached by drilling two holes in a silicone rubber stopper, and three sets of these, three Erlenmeyer flasks (collecting each) (Capacity 1000ml). About 300 ml of an alkaline aqueous solution in which 200 g of sodium hydroxide was dissolved in 1200 ml of water was poured into each Erlenmeyer flask.
Connect polyethylene pipes (outer diameter 8 mm, inner diameter 6 mm, length 500 mm) (exhaust pipe (2)) to the two exhaust gas ports protruding from the reaction vessel, and join the two polyethylene pipes using a Y-shaped pipe. It was. Extend the polyethylene tube by 1m from the Y tube, connect it to one of the two fluororesin tubes attached to one Erlenmeyer flask (front vessel (30)), and connect the other fluororesin tube to the other Erlenmeyer flask (rear stage) A polyethylene pipe (connecting pipe (32) (33)) was connected to the container (31)), and a polyethylene pipe was piped so that the gas passed through the three Erlenmeyer flasks in series. The first of the three Erlenmeyer flasks (front vessel (30)) does not immerse the fluororesin tube (discharge tube (2)) in an aqueous alkaline solution, and the remaining two Erlenmeyer flasks (rear vessel (31)) The pipes (connecting pipes (32) and (33)) into which the gas enters are immersed in an alkaline aqueous solution, and the exhaust gas is bubbled so that hydrogen sulfide can be collected.

3. Sulfurization heat treatment step Reaction vessel (1) was evacuated and replaced with nitrogen gas. Then, nitrogen gas (100 ml / min) was sent in and set in electric furnace (5). 6)) was heated (see FIG. 1).
After heating to a raw material temperature of 400 ° C. over 180 minutes and stopping the heating of the electric furnace (5), when the raw material temperature no longer rises above 420 ° C., an electric furnace (5 ) And the reaction container (1) was brought down.

4). Purification process (single sulfur removal process)
The fallen reaction vessel (1) was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product (C) produced in the vessel could be kept at a high position (see FIG. 3). In this inclined state, the temperature of the crude product was cooled as it decreased from 400 ° C., and then the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 159 g.
While the temperature decreased from 400 ° C., steam was generated from the crude product (C), and the steam flowed down toward the mouth of the reaction vessel and condensed in the non-heated part (7). The condensed product was elemental sulfur (S). Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 4>
(Manufacture of organic sulfur-based cathode materials for secondary batteries (mass synthesis))
In Example 3, when the raw material polyacrylonitrile powder was increased to 150 g and synthesis was performed, a clogging of sulfur occurred at the exhaust gas outlet (exhaust pipe (2)) with an inner diameter of 4.5 mmφ, so the gas outlet was expanded to 10 mmφ. The experiment was conducted by increasing the amount of raw materials.

1. Preparation of raw materials 647.9 g of polyacrylonitrile powder and 925.0 g of sulfur (Hosoi Chemical Industries 200 mesh, 99.9%) were weighed into a plastic bag and mixed by hand mixing to make a raw material.

2. Apparatus An apparatus having the configuration shown in FIGS. 1 to 3 and FIGS. 5 to 7 was used (the following symbols correspond to the drawings). However, there were two Erlenmeyer flasks corresponding to the latter container (41).
A mullite reaction vessel (inner diameter: 113 mmφ, length: 410 mm) was used as the reaction vessel (1), and the raw material (M) was placed at the bottom of the reaction vessel. The mullite reaction vessel was placed in a stainless steel vessel (inner diameter: 120 mmφ, length: 450 mm) equipped with a water-cooled flange that gave an airtight atmosphere (see FIG. 2). A stainless steel lid (outer diameter 6 mmφ, thickness 10 mmt) (12) with four swagelok ports and an exhaust gas outlet (exhaust pipe (2)) with an inner diameter of 10 mmφ was attached to the stainless steel container with eight bolts. . A thermocouple (K type) (20) is placed in an alumina tube (SSA-S, manufactured by Nikkato Co., Ltd., outer diameter 4 mmφ, inner diameter 2 mmφ, length 500 mm) with a closed end that can store a thermocouple, and then brought into contact with the raw material. The tube and a stainless steel ferrule made of Suedilock were fastened and fixed to the mouth 1 of Swedilock. A nitrogen gas introduction pipe (8) was attached to the swage lock port 2. Further, a vacuum exhaust line and a pressure gauge (10) were attached to the swage lock port 3. The remaining swage lock port 4 was used as a spare exhaust gas port. A stopcock was provided at the swede lock opening other than the thermocouple.
A vinyl hose (discharge pipe (2)) reinforced with a fluororesin wire having an inner diameter of 20 mmφ was attached to the exhaust gas outlet, and tightened with a stainless steel hose band. The other end of the hose was attached to an alumina tube (outer diameter 20 mmφ, length 100 mm) by tightening with a stainless steel hose band, and the alumina tube was put into a hole opened in a No. 16 silicone rubber stopper. Two fluororesin tubes (outer diameter 6.3mmφ, inner diameter 3mmφ, length 150mm) were passed through the silicone rubber stopper. This silicone rubber stopper is a 2L Erlenmeyer flask (main flask) containing an alkaline aqueous solution in which 500 g of sodium hydroxide is dissolved in water to 1000 ml and a 40 mm stirrer driven by a stirrer (34) (previous stage) Attached to the container (30)). One of the two fluororesin tubes of the silicone rubber plug was used as a gas outlet, and the other was connected to a spare exhaust port of the swage lock port 4 with a vinyl pipe (outer diameter 8 mmφ, inner diameter 6 mmφ, length 1000 mm).
An alkaline aqueous solution prepared by dissolving 50 g of sodium hydroxide in 300 ml of water was placed in an Erlenmeyer flask (capacity 1000 ml) serving as a collection container. Two fluororesin tubes (outer diameter 6.3mm, inner diameter 2mm, length 150mm) are attached to the flask by drilling two holes in a silicone rubber stopper, one of which is immersed 5mm in the internal aqueous solution for gas introduction. The other tube not immersed in the aqueous solution was used as a gas outlet tube. Three sets of this flask, a rubber stopper, and a fluororesin tube were prepared, and these three flasks were designated as flasks A, B, and C. Connect the exhaust gas outlet (exhaust pipe (2)) protruding from the reaction vessel to the gas introduction pipe of flask A with polyethylene pipe (10mmφ, inner diameter 8mmφ, length 50cm) (exhaust pipe (2)), and the connection part is copper wire Reinforced with tie. Gas outlet pipe of flask A (connecting pipe (32)) and gas inlet pipe of flask B (connecting pipe (33)), and gas outlet pipe of flask B (connecting pipe (33)) and gas inlet pipe of flask C ( The connecting pipe (33)) was connected in the same manner, and the gas outlet pipe of Flask C was connected to the exhaust pipe to the outside.
100 ml / min of nitrogen gas was fed into the reaction vessel (1), and it was confirmed that there was no leak in the exhaust by bubbling flasks A, B, and C.

3. The stainless steel container containing the sulfidation heat treatment step reaction vessel (1) was put in an electric furnace (5), and a portion (heating section (6)) from the bottom to 400 mm was heated (see FIG. 1). After heating up to a raw material temperature of 400 ° C. over 180 minutes and stopping the heating of the electric furnace (5), when the raw material temperature no longer rises above 420 ° C., an electric furnace (5 ) And the reaction container (1) was brought down.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (the upper part of the reaction vessel) was down so that the crude product (C) produced in the vessel could be kept at a high position (see FIG. 3). . The heating of the crude product was continued in this inclined state to keep the temperature of the crude product at 400 ° C. for 2 hours, and then the electric furnace (5) was turned off. After the temperature was lowered in this state, the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 1021.9 g.
During the heating, steam was generated from the crude product (C), and the steam flowed down toward the mouth of the reaction vessel (1) to condense in the low temperature part (non-heated part (7)) that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 5>
(Removal of unreacted sulfur from the crude product (purification))
1. Production of crude product 100.5 g of polyacrylonitrile powder and 350.6 g of sulfur (Hosoi Chemical 200 mesh, 99.9%) were weighed into a plastic bag and mixed by hand, using the same method as in Example 3. After synthesizing the product, the whole was cooled without bringing down the electric furnace and the reaction vessel, and 264.5 g of a crude product containing single sulfur was obtained.

2. As the apparatus unreacted sulfur removal apparatus, an apparatus having the configuration shown in FIG. 4 was used.
Hereinafter, the structure of the used unreacted sulfur removal apparatus will be described (the following symbols correspond to the drawings).
Place an insole by placing three pieces of carbon paper (Toray, TGP-H-030, 250mmL × 25mmW) on the bottom and two sides of a 300mm long boat (ship vessel) (56) made of aluminum foil. On top of that, 104.0 g of the produced crude product (C) was added to a uniform thickness. Place the boat in a quartz tube (outer diameter 50mmφ, inner diameter 45mmφ, length 600mm) (processing vessel (40)) and sample bottle (outer diameter 40mmφ, length 90mm) (backflow) to prevent backflow and condensation of sulfur gas The prevention member (55) was put. A silicone rubber stopper (No. 15) having a nitrogen gas inlet (lid (49)) was fitted on the side where the sample bottle was placed. One port has an alumina protective tube (Nikkato, SSA-S, outer diameter 4 mmφ, inner diameter 2 mmφ, length 400 mm) with a thermocouple (K type) (52) and a fluororesin tube (gas outlet) ( A silicone rubber stopper (lid (48)) containing an outer diameter of 6.3 mm, an inner diameter of 3 mm, and a length of 150 mm (discharge pipe (46)) was attached.

3. Purification process (single sulfur removal process)
By installing the quartz tube (reaction vessel (1)) containing the crude product in a tubular electric furnace (model MTKW540, inclined by 3 degrees) (45), the lid (48) is lower than the lid (49). Tilt to position. Nitrogen gas was supplied from the supply pipe (50) at a rate of 200 ml per minute, the temperature in the heating section (42) was set to 300 ° C., and the temperature was kept for 4 hours. A polyethylene pipe is extended from the gas outlet (exhaust pipe (46)) and connected to the collection container (47). The gas coming out is led to the collection container (47), and 10 g of sodium hydroxide is added to 200 ml of water. Bubbling was carried out in a dissolved alkaline aqueous solution, and hydrogen sulfide incorporated in the crude product was collected.
The quartz tube was taken out of the electric furnace (5), cooled to room temperature, and 68.1 g of finely powdered organic sulfur-based positive electrode material that easily scattered in a black mist was obtained.

<Example 6>
(Collection of hydrogen sulfide generated during synthesis of crude products)
When the crude product was synthesized from 100.5 g of polyacrylonitrile and 350.6 g of sulfur in the same manner as in Example 3, hydrogen sulfide released outside the reaction vessel (1) was captured using three Erlenmeyer flasks (collection vessels). Gathered. A, B, C in order from the first flask containing the exhaust gas, and 300 ml of water and 86.2 g, 30.1 g, 12.3 g of sodium hydroxide were placed in each Erlenmeyer flask, and the entire flask including the Erlenmeyer flask and the internal solution was added. The mass was recorded. Two holes of 6 mmφ were drilled in the silicone rubber stopper, and fluororesin tubes (exhaust pipe (2)) having a length of 200 mm, an outer diameter of 6.3 mmφ, and an inner diameter of 3 mmφ were passed through each hole. Insert a stirring bar into the Erlenmeyer flask (first vessel (30)) that first guides the exhaust gas from the reaction vessel (1), fit the silicone rubber stopper mentioned above, and fasten it to the Erlenmeyer flask with copper wire so that the stopper does not come off. Wearing. The exhaust gas from the reaction vessel (1) is led to an Erlenmeyer flask (previous vessel (30)) by a polyethylene tube (10mmφ, inner diameter 8mmφ, length 800mm) (discharge tube (2)), and the polyethylene tube is outside the fluororesin tube The connection was tied with copper wire. Adjust the length of the fluororesin tube that passes through the silicone rubber stopper, position the opening above the liquid level of the first Erlenmeyer flask (front vessel (30)), and blow the exhaust gas to the sodium hydroxide aqueous solution. did. Using another fluororesin tube attached to the silicone stopper as the gas outlet, a polyethylene tube (outer diameter 8mmφ, inner diameter 6mmφ, length 400mm) between the second Erlenmeyer flask and the fluororesin tube (connecting pipe ( 33)) and the connection part was tied with a copper wire. The third Erlenmeyer flask was similarly connected from the second Erlenmeyer flask. In the third and second Erlenmeyer flasks (the latter container (31)), the length of the fluororesin tube (connecting pipe (33)) that passes through the silicone rubber stopper is adjusted, and the opening is positioned below the liquid level. Then, the exhaust gas was allowed to pass through (bubbling) the aqueous sodium hydroxide solution.

The composition formula of polyacrylonitrile is C ₃ NH ₃ (formula 53), and it is considered that hydrogen atoms are extracted by sulfur and changed to C ₃ NH. About 60 g of hydrogen sulfide was expected to be generated from about 100 g of polyacrylonitrile.
The weight increase of the first Erlenmeyer flask was 75.4g, the second was 4.2g and the third was 0.5g. Since the total weight increase was larger than expected and ammonia odor was also present, it is considered that sulfur compounds other than ammonia and hydrogen sulfide were exhausted and collected. The expected amount of hydrogen sulfide generated is about 2 moles, and the sodium hydroxide in flask A is also about 2 moles. Considering that most of the hydrogen sulfide was collected in flask A, the following reaction occurred: It is thought that there is.
H ₂ S + NaOH = NaHS + H ₂ O

From the flask A, a large number of transparent columnar crystals thought to be NaHS were precipitated. From this, it was found that 1 mol of sodium hydroxide is the minimum amount required for collection with respect to 1 mol of the expected hydrogen sulfide generation amount. Furthermore, for polyacrylonitrile, it is presumed that the reaction of C ₃ NH ₃ + S = C ₃ NH + H ₂ S has occurred, and from the formula including NaOH, C ₃ NH ₃ + S + NaOH = C ₃ NH + NaHS + H ₂ O, It was found that it was necessary to prepare sodium hydroxide for collecting hydrogen sulfide at a ratio of acrylonitrile: sodium hydroxide = 53: 40.
In addition, since the amount of collection of flask A is large and the amount of collection in the third flask is low, the amount of sodium hydroxide according to the amount of collection is A, and the amount of hydrogen sulfide is as large as the expected amount of hydrogen sulfide. , It was found that C can be adjusted less. When looking at the gas evolution, the second flask at the time of the most intense reaction shows relatively intense bubbles, so the third flask should be used to prevent slight hydrogen sulfide leakage. It is considered preferable to provide it.

<Example 7>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of activated carbon-sulfur composite))
1. Preparation of raw materials 3.0069g of polyacrylonitrile and 9.0819g of sodium carbonate (99% manufactured by Kanto Chemical Co., Inc.) were added and mixed with 40ml of N, N-dimethylformamide (Kishida Chemical), and then the solvent was removed in a dryer at 115 ° C for 13 hours. The resin-like material was crushed. Heat treatment was performed at 750 ° C. for 2 hours through an alumina crucible (P-6, manufactured by Nikkato Corporation) through 100 ml / min of argon. The product was mixed with water and then filtered to obtain activated carbon. A material obtained by adding 5.0596 g of sulfur to 1.1994 g of this activated carbon and mixing it in a mortar was used as a raw material.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 400 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 400 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 1.6051 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 8>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of activated carbon-sulfur composite))
1. Preparation of raw material Sulfur was added to 1.007 g of activated carbon (manufactured by Kansai Thermal Chemical Co., Ltd., Max Soap (mSC-30)) and mixed in a mortar.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 400 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 400 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 4.454 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 9>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of acetylene black-sulfur composite))
1. Preparation of Raw Material A material obtained by adding 5.0103 g of sulfur to 1.0112 g of acetylene black (manufactured by Denki Kagaku) and mixing in a mortar was used.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 411 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 400 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 1.7023 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 10>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of bitumen-sulfur composite))
1. Preparation of raw material The raw material was 10.4630 g of sulfur added to 2.2479 g of bitumen (Osaka Gas Chemical) and mixed in a mortar.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 320 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 367 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 300 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 3.1466 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 11>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of gelatin-sulfur composite))
1. Preparation of raw material 1.5078 g of gelatin (house food industry) added with 5.0063 g of sulfur and mixed in a chuck-type plastic bag was used as the raw material.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise above 412 ° C.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was kept at 300 ° C. for 3 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 1.2309 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 12>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of polyethylene-sulfur composites))
1. Preparation of raw materials 1.0005 g of polyethylene film cut out from a wrap film and 5.0058 g of sulfur were used as raw materials.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 411 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was kept at 300 ° C. for 3 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 1.5522 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 13>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of acrylic-sulfur composites))
1. Preparation of raw materials 1.023 g of finely cut acrylic fibers and 4.93178 g of sulfur were used as raw materials.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, when the raw material temperature did not rise to 415 ° C. or higher, the reaction vessel was brought down together with the electric furnace.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was kept at 300 ° C. for 3 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 0.8499 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 14>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of charcoal-sulfur composites))
1. Preparation of raw materials 0.9896g charcoal and 4.3824g sulfur crushed in a mortar were used as raw materials.

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 416 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 300 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 0.5462 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Example 15>
(Manufacture of organic sulfur-based positive electrode materials for secondary batteries (synthesis and desulfurization of paraffin-sulfur composite))
1. Preparation of raw materials The raw materials were candle candles (1.0022 g) and sulfur (5.004 g).

2. Apparatus The same apparatus as in Example 1 was used.

3. The raw material for the sulfidation heat treatment process was placed in a reaction vessel, and heated to a raw material temperature of 380 ° C. in an electric furnace through nitrogen at 100 ml / min for about 40 minutes. After stopping the heating of the electric furnace, the reaction vessel was brought down together with the electric furnace when the raw material temperature did not rise to 402 ° C. or higher.

4). Purification process (single sulfur removal process)
The fallen reaction vessel was fixed in an inclined state so that the mouth of the reaction vessel (upper part of the reaction vessel) was downward so that the crude product produced in the vessel could be kept at a high position. In this inclined state, the portion containing the crude product was heated, and the temperature of the crude product was maintained at 300 ° C. for 2 hours. Then, the temperature was lowered and the product in the reaction vessel was taken out. The obtained product (organic sulfur-based positive electrode material for secondary battery) was 1.2334 g.
During the heating, steam was generated from the crude product, and the steam flowed down toward the mouth of the reaction vessel and condensed in a low temperature portion that was not heated. The condensed product was elemental sulfur. Since the reaction vessel was inclined so that the crude product was at a high position, the condensed sulfur did not flow down to the crude product produced in the reaction vessel.

<Comparative Example 1>
(Synthesis using quartz tube)
1. Preparation of raw material A mixture of 20 g of polyacrylonitrile powder and 70 g of sulfur (Aldrich, 99.9%) in a mortar was used as a raw material.

2. A quartz tube (inner diameter: 60 mmφ, length: 380 mm) with the lower part of the apparatus closed in a hemispherical shape was used as a reaction vessel, and the raw material was placed in the bottom of the reaction vessel. To the lid of this container, a silicone rubber stopper (No. 15) with two holes of 8 mmφ and one hole of 6 mmφ was attached with a cork borer. Attached to this is an alumina tube with a closed end (made by Nikkato, material SSA-S, outer 6mmφ, inner diameter 4mmφ, length 400mm), a K-type thermocouple is placed inside this alumina tube, the raw material temperature is measured, The furnace was used for temperature control. Separately, two alumina tubes (manufactured by Nikkato, material SSA-S, outer 8 mmφ, inner diameter 5 mmφ, length 80 mm) were pierced into the above-mentioned silicone rubber stoppers to form a nitrogen introduction tube and an exhaust tube, respectively.
Two fluororesin tubes (outer diameter 8 mm, inner diameter 6 mm, length 150 mm) are attached by drilling two holes in a silicone rubber stopper, and three sets of these are attached to three Erlenmeyer flasks (each volume 500 ml) It was. About 100 ml of an alkaline aqueous solution in which 20 g of sodium hydroxide was dissolved in 300 ml of water was poured into each Erlenmeyer flask. Connect the silicone rubber pipe (10mmφ, inner diameter 8mmφ, length 50cm) to the exhaust port protruding from the reaction vessel, connect the other end to two fluororesin tubes of the Erlenmeyer flask, and connect another Erlenmeyer flask from the other fluororesin tube The silicone rubber tube was connected to the tube, and the silicone rubber tube was piped so that the gas passed through the three Erlenmeyer flasks in series. In each of the three Erlenmeyer flasks, the tubes containing the gas were immersed in an alkaline aqueous solution, and the exhaust gas was bubbled so that hydrogen sulfide could be collected.

3. Sulfurizing heat treatment step 100 ml of nitrogen gas was fed into the reaction vessel for 2 hours to perform gas replacement, and the nitrogen inflow pipe was closed by the pinchcock Hoffman method. The reaction vessel was placed in an electric furnace and heated up to 250 mm from the bottom of the reaction vessel.
After 20 minutes from the heating, when the temperature of the raw material reached 180 ° C., a large amount of hydrogen sulfide gas was generated and an odor began to appear. Hydrogen sulfide permeated through the silicone rubber tube, and when the detector was brought close to it, the surface showed 10 ppm. The generation of hydrogen sulfide gas became noticeable at 240 ° C, and a large amount of sulfur adhered to the upper part of the reaction vessel. Immediately after, the sulfur blocked the outlet piping, and the hydrogen sulfide gas accumulated in the reaction vessel caused the silicone rubber stopper to come off the reaction vessel, causing hydrogen sulfide to leak, and the hydrogen sulfide detector sounded an alarm exceeding 20 ppm. A gas mask was used to remove the sulfur in the blocked part, and a silicone rubber stopper was fitted into the reaction vessel to continue the operation. Hydrogen sulfide leaking into the room was sucked through a duct and exhausted outdoors. After stopping the heating of the electric furnace at 380 ° C, when the raw material temperature no longer rises above 420 ° C, take out the reaction vessel from the electric furnace, lie down on quartz cotton and cool it down, and the condensed sulfur is coarse. In order to keep the crude product in a high position so that it does not flow down to the product, it was cooled by tilting the mouth of the reaction vessel downward. The obtained crude product was 60 g of a brittle mass.

4). Purification process (single sulfur removal process)
Since the obtained crude product did not remove sulfur by heating the reaction vessel and the electric furnace by inclining immediately after synthesis, it contained a large amount of elemental sulfur and cannot be used as it is as a positive electrode material. For this reason, the lump was pulverized, and 2 g each was heated in a vacuum processing vessel under vacuum at 250 ° C. for 2 hours to remove sulfur. About 1 g of organic sulfur-based positive electrode material was obtained from 2 g of the crude product.

<Comparative Example 2>
(Synthesis using rotary kiln)
1. Preparation of raw material A mixture of 5 g of polyacrylonitrile powder and 17.5 g of sulfur (Kishida Chemical, 99%) was used as a raw material.

2. A rotary kiln used in a general synthesis method for firing the apparatus raw material evenly while rotating was used.
A quartz tube container (cylindrical, inner diameter 74 mmφ, outer diameter 80 mmφ, length 180 mm, and a quartz plate with openings of 30 mmφ on each end) was used as a reaction vessel, and raw materials were put into this vessel. This container was placed in a quartz core tube that rotates horizontally once per minute so that two openings are in the same direction as the core tube. A vinyl tube was connected to the gas outlet between the cores, and this tube was immersed in an Erlenmeyer flask containing an alkaline aqueous solution of 40 g of sodium hydroxide dissolved in 300 ml of water so that the exhaust gas was bubbled. The suction port of the activated carbon absorber was installed at the outlet of the Erlenmeyer flask to collect the hydrogen sulfide that could not be collected and send the exhaust to the outdoors.

3. Nitrogen gas was allowed to flow at 100 ml / min into the reaction vessel for the sulfidation heat treatment step , and the temperature was raised to 400 ° C. over 1 hour.
After the temperature reached 400 ° C., the temperature was lowered and the product was removed. The product obtained was 6.4 g. If the positive electrode active material sufficiently contains sulfur, a mass of 8 g can be expected, but the product is deficient in sulfur, the properties are different from the original fine powder, and the particles are aggregated. This is probably because most of the sulfur used had flew away before 350 ° C, the appropriate temperature for the reaction. Furthermore, it was difficult to clean the core tube to which sulfur adhered after the reaction.

<Summary of Examples and Comparative Examples>
As described above, according to the example (the present invention), it was possible to reliably capture dangerous hydrogen sulfide generated during the production of the organic sulfur-based positive electrode material and completely prevent leakage. Moreover, the high capacity | capacitance organic sulfur type positive electrode material from which unreacted sulfur was removed was able to be synthesize | combined efficiently.
On the other hand, in the comparative example, hydrogen sulfide leaked or could not be sufficiently collected by the apparatus system. Moreover, in order to remove unreacted sulfur, a heat treatment under vacuum is separately required, and a high-capacity organic sulfur-based positive electrode material cannot be synthesized efficiently.

  Hereinafter, the test example which confirmed the performance as a positive electrode active material of a lithium ion secondary battery about the organic sulfur type positive electrode material obtained in Examples 1-5 and 7-15 and Comparative Examples 1 and 2 is shown.

<Test example>
1. Electrode fabrication
The resulting organic sulfur-based positive electrode material 3.0mg, PTFE (polytetrafluoroethylene) 2.7mg, and acetylene black 0.3mg are kneaded by hand using an agate mortar to form a sheet, and the disk shape is about 10mm in diameter. The shape was adjusted so that The obtained disc-shaped electrode sheet is placed on an aluminum mesh (# 100 mesh) punched out into a circle with a diameter of 13 mm, and is pressed and integrated with a desktop hand press at a pressure of 20 MPa. As a result, a positive electrode was produced. The aluminum mesh is a current collector that plays a role of increasing the current collecting performance of the electrode. On the other hand, metallic lithium having a diameter of 13 mm and a thickness of 0.5 mm was used for the negative electrode.

2. Battery production
A 2032 type coin battery was assembled as a battery for evaluation. A polypropylene microporous membrane (Celgard 2400, manufactured by Celgard) was used as the separator. The electrolyte used was a mixture of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1 and LiPF ₆ (lithium hexafluorophosphate) dissolved to a concentration of 1 mol / L. .
According to a conventional method, the positive electrode using the above-mentioned organic sulfur-based positive electrode material and the lithium metal negative electrode are opposed to each other, and a separator impregnated with an electrolytic solution is sandwiched therebetween so that the two are not in direct contact with each other. A battery was produced by placing it in a battery can together with a leaf spring, placing a lid, and crimping and sealing the battery can and lid.

3. Charge / discharge test
A charge / discharge test was performed on the manufactured battery. The current density during the charge / discharge test was 60 mA / g. This is because when the organic sulfur-based positive electrode material has an electric capacity of 600 mAh / g, the test is performed at a sufficiently slow charge / discharge rate that is charged or discharged over 10 hours. When the current value is increased, when the resistance is large, the original electric capacity may not be exhibited. Therefore, a test at a slow charge / discharge rate was performed. The voltage range is 1.0 to 3.0V vs. Tests were performed with Li ⁺ / Li. The test temperature was 30 ° C.
The results of the charge / discharge test are shown in Table 1.

4). Battery evaluation results
As shown in Table 1, in most examples using the organic sulfur-based positive electrode material obtained by the apparatus and method of the present invention, the conventional transition metal oxide positive electrode was realized as the positive electrode material of the lithium ion secondary battery. A difficult large electric capacity of 250 mAh / g or more was obtained.
A large electric capacity was also obtained when the organic sulfur-based positive electrode material obtained by the method of Comparative Example 1 was used. However, as described above, the method of Comparative Example 1 generates a large amount of hydrogen sulfide gas. The danger is very high. In addition, the method of Comparative Example 2 is not suitable for synthesizing a large amount of organic sulfur-based positive electrode material because it requires a separate heat treatment under vacuum in order to remove unreacted sulfur.
From this, the apparatus and method of the present invention are capable of synthesizing an organic sulfur-based positive electrode material capable of obtaining a large charge / discharge capacity quickly and in a large amount in consideration of safety and the environment, compared with the prior art. It can be said that this is an excellent method and apparatus.

  The present invention is mainly used for producing an organic sulfur-based active material useful as a positive electrode active material for lithium ion or sodium ion secondary batteries.

1 reaction vessel 2 discharge pipe 3 collection device 4 unreacted sulfur removal device 5 heating source (electric furnace)
6 Heating part 7 Non-heating part 9 Obstacle 11 Elevating mechanism 30 Pre-stage container 31 Rear-stage container 32 Connecting pipe 34 Stirring device 40 Processing container 41 Inert gas supply means 42 Heating part 43 Non-heating part 45 Heat source (electric furnace)
C Crude product L Liquid that can absorb hydrogen sulfide M Raw material S Sulfur (single sulfur)

Claims (7)

A reaction vessel containing a raw material containing sulfur and organic matter;
A heating source for heating the reaction vessel;
A discharge pipe for taking out hydrogen sulfide generated in the reaction vessel to the outside;
An undulation mechanism for integrally raising and lowering the reaction vessel and the heating source;
An unreacted sulfur removing device for removing unreacted sulfur contained in the crude product produced in the reaction vessel,
The reaction vessel has a heating part in which the raw material is heated by the heating source, and a non-heating part for condensing sulfur vapor generated by heating in the heating part,
The undulation mechanism is capable of switching between a standing state where the heating part is lower than the non-heating part and an inclined state where the non-heating part is lower than the heating part,
The unreacted sulfur removing device includes a processing container for storing the crude product,
A heating source for heating the processing vessel;
An inert gas supply means for supplying an inert gas into the processing vessel;
The processing container includes a heating unit in which the crude product is heated by the heating source, and a non-heating unit that condenses sulfur vapor generated by heating in the heating unit, and the non-heating unit is more than the heating unit. Is also inclined to be at a low position,
The inert gas supply means supplies the inert gas into the processing container so that the inert gas flows from the heating unit toward the non-heating unit;
Equipment for producing organic sulfur-based positive electrode materials for secondary batteries. Comprising a collecting device for collecting hydrogen sulfide taken out from the discharge pipe;
The collection device includes a plurality of collection containers containing a liquid capable of absorbing hydrogen sulfide,
The collection container has a front container in which an end of the discharge pipe is disposed inside, and a rear container for collecting hydrogen sulfide not collected in the front container,
The end of the discharge pipe is not in contact with the liquid accommodated in the preceding container,
Claim 1 Symbol placement of organosulfur positive electrode material manufacturing apparatus for a secondary battery. The front-stage container and the rear-stage container are connected by a connecting pipe that guides hydrogen sulfide that has not been collected in the front-stage container to the rear-stage container,
One end of the connecting pipe is not in contact with the liquid stored in the front container,
The other end of the connecting pipe is in contact with the liquid stored in the rear container,
The organic sulfur type positive electrode material manufacturing apparatus for secondary batteries of Claim 2 . The organic sulfur type positive electrode material manufacturing apparatus for secondary batteries of Claim 2 or 3 provided with the stirring apparatus for stirring the liquid accommodated in the said front stage container. The said exhaust pipe is an organic sulfur type positive electrode material manufacturing apparatus for secondary batteries in any one of Claims 1 thru | or 4 whose internal diameter of the edge part connected to the said reaction container is 10 mm or more. The reaction vessel has the heating part below and the non-heating part above,
The obstacle according to any one of claims 1 to 5 , wherein an obstacle for contacting and condensing sulfur vapor generated by heating the raw material is disposed below the discharge pipe in the non-heating portion. Equipment for manufacturing organic sulfur-based positive electrode materials for secondary batteries. A raw material containing sulfur and organic matter is contained in the lower part of the reaction vessel, and the lower part is heated to cause a sulfurization reaction between sulfur and organic matter in the reaction vessel to produce a crude product. A sulfurization heat treatment step;
A purification step of removing unreacted sulfur contained in the generated crude product,
The purification step includes
Inclining the reaction vessel containing the generated crude product so that the upper part is lower than the lower part;
Heating the lower part at a high position of the inclined reaction vessel to extract unreacted sulfur from the crude product as sulfur vapor, and condensing the extracted sulfur vapor at the upper part at a low position Including,
A method for producing an organic sulfur-based positive electrode material for a secondary battery.

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