Electrolytic device based on solid electrolyte diaphragm material and method for preparing sodium by using electrolytic device
Technical Field
The invention relates to a device for preparing sodium by electrolyzing a solid electrolyte diaphragm material.
Background
Sodium is an alkali metal element which is widely applied, has a plentiful reserve in the earth crust, occupies an extremely important position in the fields of energy, chemical engineering, medicine, dye, national defense, military industry and the like, and has very high industrial value. In recent years, the rapid development of solid-state lithium batteries has led to the research of derivative solid-state sodium batteries, and as an indispensable electrode material of a negative electrode part of the solid-state batteries, metal sodium has the advantages that other electrode materials are difficult to compare, and when the negative electrode of the battery uses sodium metal, the theoretical capacity of the battery reaches 1166mAhg-1The capacity of the graphite electrode is nearly three times of the theoretical capacity of the graphite electrode of the lithium ion battery at present. Therefore, the demand for high-purity metallic sodium has been rising year by year in the energy storage field and the photovoltaic field.
At present, the preparation methods of the metal sodium mainly comprise the following steps: salt melt electrolysis, caustic soda melt electrolysis, electrolysis of sodium amalgam and beta-Al2O3And (4) electrolyzing by using a diaphragm. The sodium preparing process by salt melting electrolysis is called as down method, the raw material is refined salt, the product is mainly sodium metal and chlorine, the down electrolysis bath is connected with conductive aluminum row by using electrolysis unit formed by combining a plurality of cathodes, graphite is used as electrode, the collector on the upper part of the electrolysis unit respectively stores the product sodium metal and chlorine, and iron diaphragm for preventing the metal sodium and chlorine from contacting again is arranged between the two electrodes. Because the melting point of sodium chloride is as high as 801 ℃, the energy consumption of the electrolytic reaction is huge, and the requirement on an electrolytic device is high, a binary or ternary eutectic is usually adopted to reduce the temperature of the electrolytic reaction, so as to achieve the purposes of saving energy consumption and meeting the requirement of equipment. But the equipment requirement is reduced, impurities are introduced, so that the subsequent purification of products is also carried out, and the introduction of eutectic substances has a limit (about 570 ℃) for reducing the melting temperature, and the electrolytic efficiency is about 80 percent.
The process of caustic soda fusion electrolysis is called as Castner method, the raw material is sodium hydroxide, the products are mainly sodium metal, oxygen and water, the cathode is generally an iron electrode, the anode is generally a nickel electrode, a nickel net for separating electrolysis products is arranged between the two electrodes, the electrolyte is a binary mixture composed of sodium carbonate and sodium hydroxide, the crude sodium obtained by electrolysis needs to be refined, and the product sodium is obtained after molding. The electrolysis temperature required by the Castner method is about 330 ℃, the requirement on equipment is low, but the electrolysis efficiency is only about 50 percent.
Electrolyzing sodium amalgam to prepare metal sodium, wherein the sodium amalgam is used as an anode, a porous iron sheet is used as a cathode, the electrolyte is NaI, NaOH and NaCN saturated with hydrogen, and the metal sodium is floated on the porous iron sheet during electrolysis. The working temperature required by the sodium amalgam process is about 220 ℃, the requirement on equipment is low, the electrolysis efficiency is as high as 95%, and mercury vapor generated in the working process of the method is harmful to operators and pollutes the environment.
β-Al2O3The diaphragm electrolysis for preparing sodium is divided into two types: beta-Al2O3Diaphragm electrolysis of molten sodium hydroxide and beta-Al2O3The diaphragm electrolyzes molten sodium chloride. beta-Al2O3The diaphragm electrolysis process for melting sodium hydroxide includes anode of nickel, cathode of steel, sodium hydroxide as anode liquid, sodium as cathode liquid, beta-Al2O3The tube is a septum. The method has the advantages of low requirement on equipment, high electrolysis efficiency up to 100%, and power consumption of 5500kWh t-1Left and right. beta-Al2O3A process for electrolyzing and smelting sodium chloride by diaphragm features that graphite as anode and steel as cathode, sodium chloride and zinc chloride as anolyte, sodium as catholyte and beta-Al are used as electrolyte2O3The tube is a septum. The method has the advantages of required working temperature of about 340 ℃, low requirement on equipment, high electrolysis efficiency of 100 percent and electricity consumption of 7800kWh t-1Left and right. beta-Al2O3The core of the diaphragm electrolysis sodium preparation process is beta-Al2O3。β-Al2O3Is an inorganic solid electrolyte with high ionic conductivity of only 2mS cm at maximum at room temperature-1However, the synthesis temperature is as high as 1600 ℃, the production energy consumption is high, and the manufacturing equipment is required to have a complicated heat-resisting partLimited in large-scale application. Other conventional inorganic solid electrolyte materials have a relatively severe sodium deposition phenomenon, which affects the service life of the electrolyte separator material.
In the future, the means for industrially preparing the metal sodium is mainly the Downs method for preparing the sodium by melting and electrolyzing the salt, and beta-Al is mainly used2O3The diaphragm electrolysis sodium making process is only occasionally used when making metallic sodium on a small scale in some specific occasions. Therefore, the key to solve the problems is to find an electrolyte material with high ionic conductivity, long service life and simple and convenient synthesis process.
Disclosure of Invention
The invention aims to solve the problems of low electrolysis efficiency, high impurity content and environmental pollution of the traditional sodium preparation method, namely beta-Al2O3The diaphragm electrolysis method adopts the electrolyte material with low ionic conductivity, high energy consumption and high requirements on synthesis equipment, and the conventional electrolyte material has the problem of serious sodium deposition, so that the electrolytic device based on the solid electrolyte diaphragm material and the method for preparing sodium by using the electrolytic device are provided.
An electrolysis device based on a solid electrolyte membrane material, comprising an electrolysis cell, an NASICON type inorganic solid electrolyte membrane cell, a cathode, a chlorine storage, an anode and a metallic sodium collector, the anode consisting of a first anode and a second anode;
the electrolytic tank is sealed, the NASICON type inorganic solid electrolyte diaphragm tank is arranged in the electrolytic tank, a cathode electrolyte cavity is arranged in the NASICON type inorganic solid electrolyte diaphragm tank, and an anode electrolyte cavity is arranged outside the NASICON type inorganic solid electrolyte diaphragm tank; the device comprises a metal sodium collector, an NASICON type inorganic solid electrolyte diaphragm tank, a sodium guide pipe, a protective gas inlet and outlet pipe and a protective gas inlet and outlet pipe valve, wherein the metal sodium collector is arranged outside an electrolytic tank, the top of the NASICON type inorganic solid electrolyte diaphragm tank is hermetically connected with the top of the electrolytic tank, the bottom of the NASICON type inorganic solid electrolyte diaphragm tank is communicated with a feed inlet of the metal sodium collector through the sodium guide pipe, the sodium guide pipe is provided with the sodium guide pipe valve, the side wall of the metal sodium collector is provided with the protective gas inlet and outlet; the top of the NASICON type inorganic solid electrolyte diaphragm tank is provided with a cathode electrolyte feeding pipe and a cathode end protective gas inlet pipe, the cathode electrolyte feeding pipe is provided with a cathode electrolyte feeding pipe valve, the cathode end protective gas inlet pipe is provided with a cathode end protective gas inlet pipe valve, and the NASICON type inorganic solid electrolyte diaphragm tank is provided with a cathode; the chlorine storage device is characterized in that a first anode and a second anode are arranged on the anode electrolyte cavity, an anode electrolyte feeding pipe is arranged at the top of the anode electrolyte cavity, an anode electrolyte feeding pipe valve is arranged on the anode electrolyte feeding pipe, one end of a chlorine guide pipe is arranged at the top of the anode electrolyte cavity, the other end of the chlorine guide pipe is communicated with an air inlet of the chlorine storage device, and a chlorine guide pipe valve is arranged on the chlorine guide pipe.
The method for preparing sodium by using the electrolysis device based on the solid electrolyte diaphragm material comprises the following steps:
firstly, adding anolyte and anolyte into an anolyte cavity through a feed inlet of an anolyte feed pipe, adding catholyte into a catholyte cavity through a feed inlet of a catholyte feed pipe, introducing protective gas into the catholyte cavity through a gas inlet of a cathode-end protective gas inlet pipe, then communicating direct-current voltage between a cathode and a first anode and a second anode, and starting heating equipment; the anolyte is eZnCl2+fBaCl2The ternary eutectic system consists of + gNaCl, wherein e, f and g are the contents of corresponding eutectic substances, e is more than or equal to 0 and less than or equal to 1, f is more than or equal to 0 and less than or equal to 1, g is more than or equal to 0 and less than or equal to 1, and e, f and g are not 0 or 1 at the same time;
secondly, starting a metal sodium cooler, feeding chlorine generated by electrolytic reaction into a chlorine storage device through a chlorine guide pipe, feeding molten metal sodium generated by electrolytic reaction into a metal sodium collector through a sodium guide pipe, and cooling the molten metal sodium into solid metal sodium through the metal sodium cooler; when the metal sodium collector is filled with solid metal sodium, closing a sodium guide pipe valve, simultaneously opening a protective gas inlet and outlet pipe valve, introducing protective gas into the metal sodium collector, and collecting the solid metal sodium; NASICOThe N-type inorganic solid electrolyte diaphragm tank is made of electrolyte material Na1+x+yInxZr2-xSiyP3-yO12The prepared material has x and y in molar percentage of corresponding elements, x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 1 and less than or equal to 2.2.
When the electrolysis sodium preparation works, the cathode is used as a negative potential, the anode is used as a positive potential, the inert gas atmosphere is adopted, a direct current voltage is added between the cathode and the anode, sodium ions penetrate through the NASICON type inorganic solid electrolyte membrane from the anode area under the driving of an electric field, and are reduced into metallic sodium on a cathode material, and the reaction formula is as follows:
anode: NaCl-e-→Na++1/2Cl2
Cathode: na (Na)++e-→Na
And (3) total reaction: NaCl → Na +1/2Cl2
The principle of the invention is as follows:
conventional inorganic solid electrolyte material, Na in NASICON lattice during electrolytic operation+Needs to pass through the crystal boundary, and moves to the cathode interface to obtain electrons, so as to be converted into sodium atoms; when the electrolyte material has the influences of coarse crystal grains, large grain boundary resistance, low density and the like, a tiny sodium electrode is formed at the grain boundary, air hole, micro-crack and the like in the material, and Na is used for removing the electrolyte+Electrons are obtained on the microelectrodes to undergo redox reactions, so that sodium deposition occurs. The NASICON type inorganic solid electrolyte diaphragm tank adopted by the patent contains inorganic solid electrolyte Na1+x+yInxZr2-xSiyP3-yO12(x and y are respectively the mole percentage of the corresponding elements, x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 1 and less than or equal to 2.2) has the advantages of high density, low grain boundary concentration and the like, and can effectively prevent the sodium deposition phenomenon.
The invention has the beneficial effects that:
(1) the invention adopts the NASICON type inorganic solid electrolyte membrane to prepare the metallic sodium, the solid electrolyte has high ionic conductivity under the working condition, long working life and simple and convenient synthesis process, and avoids the serious sodium deposition existing in other conventional inorganic solid electrolyte materialsLike and beta-Al2O3The high synthesis temperature and high equipment requirement and other harsh conditions required by the diaphragm electrolyte are favorable for the popularization and the application of the diaphragm electrolysis sodium preparation process. In addition, the top of the anode electrolyte cavity is provided with a chlorine guide pipe, so that chlorine generated by electrolytic reaction can be collected into a chlorine storage device, and the chlorine is an important chemical raw material, so that the economic benefit of the process is increased; in addition, the cooler is arranged at the bottom of the metallic sodium collector, so that molten sodium metal prepared by electrolytic reaction can be quickly cooled and collected, and the production speed of the metallic sodium prepared by the process is increased.
(2) The invention provides a process for applying an NASICON type solid electrolyte material to sodium electrolysis, which utilizes the advantages of high ion conductivity and simple and convenient synthesis process of the NASICON type solid electrolyte material, avoids the defects of low electrolysis efficiency, high impurity content, environmental pollution and the like of the traditional salt melting electrolysis, caustic soda melting electrolysis and electrolytic sodium amalgam method, and avoids the serious sodium deposition phenomenon and beta-Al deposition phenomenon of other conventional inorganic solid electrolyte materials2O3The electrolyte material adopted by the diaphragm electrolysis method has the problems of low ionic conductivity, high energy consumption, high synthesis equipment requirement and the like, and is beneficial to popularization and application of the diaphragm electrolysis sodium preparation process.
The invention can obtain an electrolysis device based on a solid electrolyte diaphragm material and a method for preparing sodium by using the electrolysis device.
Drawings
Fig. 1 is a schematic structural diagram of an electrolytic device based on a solid electrolyte membrane material in example 1, where 1 is an electrolytic cell, 2 is a heating device, 3 is an NASICON-type inorganic solid electrolyte membrane cell, 4 is a cathode, 5 is a cathode electrolyte feeding tube, 6 is an anode electrolyte feeding tube, 7 is a cathode-end shielding gas inlet tube, 8 is a chlorine storage device, 9 is a sodium guide tube, 10 is an anode electrolyte chamber, 11 is a first anode, 12 is a second anode, 13 is a cathode electrolyte chamber, 14 is a metallic sodium collector, 15 is a sodium guide tube valve, 16 is a chlorine guide tube, 17 is a chlorine guide tube valve, 18 is a metallic sodium cooler, 19 is a cathode-end shielding gas inlet tube valve, 20 is an anode electrolyte feeding tube valve, 21 is a cathode electrolyte feeding tube valve, 22 is a shielding gas inlet/outlet tube, and 23 is a shielding gas inlet/outlet tube valve.
Detailed Description
The first embodiment is as follows: the embodiment relates to an electrolytic device based on a solid electrolyte diaphragm material, which comprises an electrolytic cell 1, an NASICON type inorganic solid electrolyte diaphragm cell 3, a cathode 4, a chlorine storage device 8, an anode and a metallic sodium collector 14, wherein the anode consists of a first anode 11 and a second anode 12;
the electrolytic tank 1 is sealed, the NASICON type inorganic solid electrolyte diaphragm tank 3 is arranged in the electrolytic tank 1, a cathode electrolyte cavity 13 is arranged in the NASICON type inorganic solid electrolyte diaphragm tank 3, and an anode electrolyte cavity 10 is arranged outside the NASICON type inorganic solid electrolyte diaphragm tank 3; the sodium metal collector 14 is arranged outside the electrolytic cell 1, the top of the NASICON type inorganic solid electrolyte diaphragm tank 3 is hermetically connected with the top of the electrolytic cell 1, the bottom of the NASICON type inorganic solid electrolyte diaphragm tank 3 is communicated with a feed inlet of the sodium metal collector 14 through a sodium guide pipe 9, a sodium guide pipe valve 15 is arranged on the sodium guide pipe 9, a protective gas inlet and outlet pipe 22 is arranged on the side wall of the sodium metal collector 14, and a protective gas inlet and outlet pipe valve 23 is arranged on the protective gas inlet and outlet pipe 22; the top of the NASICON type inorganic solid electrolyte diaphragm tank 3 is provided with a cathode electrolyte feeding pipe 5 and a cathode end protective gas inlet pipe 7, the cathode electrolyte feeding pipe 5 is provided with a cathode electrolyte feeding pipe valve 21, the cathode end protective gas inlet pipe 7 is provided with a cathode end protective gas inlet pipe valve 19, and the NASICON type inorganic solid electrolyte diaphragm tank 3 is provided with a cathode 4; the chlorine storage device is characterized in that a first anode 11 and a second anode 12 are arranged on the anolyte cavity 10, an anolyte feeding pipe 6 is arranged at the top of the anolyte cavity 10, an anolyte feeding pipe valve 20 is arranged on the anolyte feeding pipe 6, one end of a chlorine guide pipe 16 is arranged at the top of the anolyte cavity 10, the other end of the chlorine guide pipe 16 is communicated with an air inlet of a chlorine storage device 8, and a chlorine guide pipe valve 17 is arranged on the chlorine guide pipe 16.
The second embodiment is as follows: the present embodiment differs from the present embodiment in that: the electrolysis device also comprises a heating device 2, and the heating device 2 is arranged on the outer surface of the electrolysis bath 1.
Other steps are the same as those in the first embodiment.
The third concrete implementation mode: the first or second differences from the present embodiment are as follows: the electrolysis apparatus further comprises a sodium metal cooler 18, the sodium metal cooler 18 being disposed at the bottom end of the sodium metal collector 14.
The other steps are the same as those in the first or second embodiment.
The fourth concrete implementation mode: the difference between this embodiment and one of the first to third embodiments is as follows: the NASICON type inorganic solid electrolyte diaphragm tank 3 is made of an electrolyte material Na1+x+yInxZr2-xSiyP3-yO12The prepared material has x and y in molar percentage of corresponding elements, x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 1 and less than or equal to 2.2.
The other steps are the same as those in the first to third embodiments.
The fifth concrete implementation mode: the embodiment utilizes an electrolysis device based on a solid electrolyte diaphragm material to prepare sodium, and comprises the following steps:
firstly, adding anolyte and anolyte into an anolyte cavity 10 through a feed inlet of an anolyte feed pipe 6, adding catholyte into a catholyte cavity 13 through a feed inlet of a catholyte feed pipe 5, introducing protective gas into the catholyte cavity 13 through a gas inlet of a cathode end protective gas inlet pipe 7, then communicating direct-current voltage between a cathode 4 and a first anode 11 and a second anode 12, and starting a heating device 2; the anolyte is eZnCl2+fBaCl2The ternary eutectic system consists of + gNaCl, wherein e, f and g are the contents of corresponding eutectic substances, e is more than or equal to 0 and less than or equal to 1, f is more than or equal to 0 and less than or equal to 1, g is more than or equal to 0 and less than or equal to 1, and e, f and g are not 0 or 1 at the same time;
secondly, a metal sodium cooler 18 is started, chlorine generated by electrolytic reaction enters a chlorine storage 8 through a chlorine guide pipe 16, and molten metal sodium generated by electrolytic reaction passes through the sodium guide pipe9, the molten metal sodium enters a metal sodium collector 14, and the molten metal sodium is cooled into solid metal sodium by a metal sodium cooler 18; after the metallic sodium collector 14 is filled with solid metallic sodium, closing the sodium guide pipe valve 15, simultaneously opening the protective gas inlet and outlet pipe valve 23, introducing protective gas into the metallic sodium collector 14, and collecting the solid metallic sodium; the NASICON type inorganic solid electrolyte diaphragm tank 3 is made of an electrolyte material Na1+x+yInxZr2-xSiyP3-yO12The prepared material has x and y in molar percentage of corresponding elements, x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 1 and less than or equal to 2.2.
The beneficial effects of the embodiment are as follows:
(1) the embodiment adopts the NASICON type inorganic solid electrolyte membrane to prepare the metallic sodium, the solid electrolyte has high ionic conductivity under the working condition, long working life and simple and convenient synthesis process, and avoids the serious sodium deposition phenomenon and beta-Al deposition phenomenon of other conventional inorganic solid electrolyte materials2O3The high synthesis temperature and high equipment requirement and other harsh conditions required by the diaphragm electrolyte are favorable for the popularization and the application of the diaphragm electrolysis sodium preparation process. In addition, the top of the anode electrolyte cavity is provided with a chlorine guide pipe, so that chlorine generated by electrolytic reaction can be collected into a chlorine storage device, and the chlorine is an important chemical raw material, so that the economic benefit of the process is increased; in addition, the cooler is arranged at the bottom of the metallic sodium collector, so that molten sodium metal prepared by electrolytic reaction can be quickly cooled and collected, and the production speed of the metallic sodium prepared by the process is increased.
(2) The embodiment provides a process for applying the NASICON type solid electrolyte material to the electrolytic sodium production, and the advantages of high ion conductivity and simple and convenient synthesis process of the NASICON type solid electrolyte material are utilized, so that the defects of low electrolytic efficiency, high impurity content, environmental pollution and the like of the traditional salt melt electrolysis, caustic soda melt electrolysis and electrolytic sodium amalgam method are avoided, and the relatively serious sodium deposition phenomenon and beta-Al existing in other conventional inorganic solid electrolyte materials are avoided2O3The electrolyte material adopted by the diaphragm electrolysis method has the problems of low ionic conductivity, high energy consumption, high requirements on synthesis equipment and the like, and is favorable for diaphragm electrolysisThe popularization and the application of the sodium decomposing process.
The following examples were used to demonstrate the beneficial effects of the present invention:
example 1: an electrolysis apparatus based on a solid electrolyte membrane material, comprising an electrolysis cell 1, a heating device 2, an NASICON type inorganic solid electrolyte membrane cell 3, a cathode 4, a chlorine storage 8, an anode consisting of a first anode 11 and a second anode 12, a metallic sodium collector 14 and a metallic sodium cooler 18; the NASICON type inorganic solid electrolyte diaphragm tank 3 is made of an electrolyte material Na1+x+yInxZr2-xSiyP3-yO12The preparation is carried out, wherein x and y are respectively the mole percentage of the corresponding elements, x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 1 and less than or equal to 2.2;
the electrolytic tank 1 is arranged in a closed manner, the heating device 2 is arranged on the outer surface of the electrolytic tank 1, the NASICON type inorganic solid electrolyte diaphragm tank 3 is arranged in the electrolytic tank 1, the inside of the NASICON type inorganic solid electrolyte diaphragm tank 3 is a cathode electrolyte cavity 13, and the outside of the NASICON type inorganic solid electrolyte diaphragm tank 3 is an anode electrolyte cavity 10; the sodium metal collector 14 is arranged outside the electrolytic cell 1, the top of the NASICON type inorganic solid electrolyte diaphragm tank 3 is hermetically connected with the top of the electrolytic cell 1, the bottom of the NASICON type inorganic solid electrolyte diaphragm tank 3 is communicated with a feed inlet of the sodium metal collector 14 through a sodium guide pipe 9, a sodium guide pipe valve 15 is arranged on the sodium guide pipe 9, a protective gas inlet and outlet pipe 22 is arranged on the side wall of the sodium metal collector 14, a protective gas inlet and outlet pipe valve 23 is arranged on the protective gas inlet and outlet pipe 22, and a sodium metal cooler 18 is arranged at the bottom end of the sodium metal collector 14; the NASICON type inorganic solid electrolyte diaphragm tank 3 is characterized in that a cathode electrolyte feeding pipe 5 and a cathode end protective gas inlet pipe 7 are arranged at the top of the NASICON type inorganic solid electrolyte diaphragm tank 3, a cathode electrolyte feeding pipe valve 21 is arranged on the cathode electrolyte feeding pipe 5, a cathode end protective gas inlet pipe valve 19 is arranged on the cathode end protective gas inlet pipe 7, a cathode 4 is arranged on the NASICON type inorganic solid electrolyte diaphragm tank 3, and one end of the cathode 4 is arranged outside the electrolytic tank 1; a first anode 11 and a second anode 12 are arranged on the anode electrolyte cavity 10, and one ends of the first anode 11 and the second anode 12 are both arranged outside the electrolytic tank 1; the top of the anode electrolyte cavity 10 is provided with an anode electrolyte feeding pipe 6, the anode electrolyte feeding pipe 6 is provided with an anode electrolyte feeding pipe valve 20, one end of a chlorine guide pipe 16 is arranged at the top of the anode electrolyte cavity 10, the other end of the chlorine guide pipe 16 is communicated with an air inlet of a chlorine storage device 8, and the chlorine guide pipe 16 is provided with a chlorine guide pipe valve 17.
Example 2: the method for preparing sodium by using the electrolytic device based on the solid electrolyte membrane material as described in the embodiment 1 comprises the following steps:
firstly, adding anolyte and anolyte into an anolyte cavity 10 through a feed inlet of an anolyte feeding pipe 6, adding catholyte into a catholyte cavity 13 through a feed inlet of a catholyte feeding pipe 5, and introducing protective gas into the catholyte cavity 13 through a gas inlet of a cathode end protective gas inlet pipe 7 to protect a product molten sodium metal from side reaction; then, connecting direct current voltage between the cathode 4 and the first anode 11 and the second anode 12, and starting the heating device 2; the anolyte is eZnCl2+fBaCl2The ternary eutectic system consists of + gNaCl, wherein e, f and g are the contents of corresponding eutectic, e is more than or equal to 0 and less than or equal to 1, f is more than or equal to 0 and less than or equal to 1, g is more than or equal to 0 and less than or equal to 1, and e, f and g are not 0 or 1 at the same time, the cathode electrolyte is high-purity metal sodium, and the purity of the cathode electrolyte is 99.9-99.99%; the anode electrolyte is a mixture consisting of sodium chloride and zinc chloride;
secondly, a metal sodium cooler 18 is started, chlorine generated by electrolytic reaction enters a chlorine storage 8 through a chlorine guide pipe 16, so that side reaction is prevented from occurring and the economic benefit of the process is further improved; molten metal sodium generated by the electrolysis reaction enters a metal sodium collector 14 through a sodium guide pipe 9, the molten metal sodium is cooled into solid metal sodium through a metal sodium cooler 18, and the molten metal sodium is rapidly cooled to increase the production benefit; after the metallic sodium collector 14 is filled with solid metallic sodium, closing the sodium guide pipe valve 15, simultaneously opening the protective gas inlet and outlet pipe valve 23, introducing protective gas into the metallic sodium collector 14, and collecting the solid metallic sodium; NASICON type inorganic solid electrolyte diaphragm tank 3 is composed of electrolyteMaterial Na1+x+yInxZr2-xSiyP3-yO12The prepared material has x and y in molar percentage of corresponding elements, x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 1 and less than or equal to 2.2.
After the solid sodium metal is collected, the electrolysis for producing sodium can be continued according to the first step and the second step.
The purity of the chlorine and the solid sodium metal collected in the present example was measured, and the measurement results show that: the purity of the chlorine gas and the solid sodium metal collected in the embodiment is extremely high, the purity of the solid sodium metal is 99.9-99.99%, and the purity of the chlorine gas is 99.8-99.99%.