CN103178246A - Selenium-mesoporous carrier compound, as well as preparation method and application thereof - Google Patents

Abstract

The invention discloses a lithium-selenium battery and a preparation method thereof. The lithium-selenium battery comprises a metal lithium negative electrode, a selenium-mesoporous carrier composite positive electrode and an organic electrolyte. The positive electrode of the selenium-mesoporous carrier composite is made by mixing selenium and the mesoporous carrier in a certain proportion and then heating, and the selenium is evenly dispersed in the mesoporous cells of the mesoporous carrier in the form of ring selenium molecules and/or amorphous chain selenium molecules Inside the tunnel. The mesoporous supports include carbon mesoporous supports, non-carbon mesoporous supports and combinations thereof. The lithium-selenium battery provided by the invention has the advantages of small volume, large capacity, long life, high efficiency, single reaction platform, etc., and is a new type of secondary energy storage battery with high volumetric energy density. The preparation method of the main component of the selenium-mesoporous carrier composite positive electrode is simple, the raw materials are easy to obtain, suitable for large-scale production, and has high practicability.

Description

A kind of selenium-mesoporous carrier complex and its preparation method and application

technical field

The invention belongs to the field of electrochemical power sources, and specifically relates to a selenium-mesoporous carrier composite, a preparation method thereof, a selenium-mesoporous carrier composite positive electrode material and a preparation method thereof, a method for preparing a positive electrode containing the composite, and using the positive electrode The new lithium-selenium battery and its application in high volume energy density energy storage devices.

Background technique

Lithium-selenium battery refers to a type of metal lithium secondary battery that uses elemental selenium or selenium-containing compounds as the positive electrode and metallic lithium as the negative electrode, and realizes the mutual conversion between chemical energy and electrical energy through the chemical reaction between selenium and lithium. Elemental selenium, because of its two-electron reaction mechanism and high density in the electrochemical reaction process, has a high theoretical volume specific capacity, which is suitable for the current development trend of mobile devices with strict volume restrictions. In addition, compared with most positive electrode materials, selenium has high conductivity as a semiconductor, so the positive electrode activity is good, and the utilization rate can be close to 100%, and the selenium formed during the charge and discharge process basically does not form polyselenium ions dissolved in the electrolyte, so The cycle performance is stable and the capacity fading is small. It can be seen that lithium-selenium battery, as a new metal lithium secondary battery, has very important scientific research value and application potential that cannot be underestimated.

Although this new lithium-selenium battery has the advantages of small size, large capacity, long life, and high efficiency, it is a new type of secondary energy storage battery with high volumetric energy density, but the current research on lithium-selenium batteries is very rare. However, the reaction mechanism of selenium as an active substance in the electrode material during charge and discharge is still unclear. Therefore, the development of simple and stable lithium-selenium battery electrode materials and battery assembly methods is of great significance for the in-depth study of the electrochemical reaction performance and reaction mechanism of selenium electrodes, and will also play a huge role in the development of the entire field of mobile energy storage. . Not long ago, Amine et al. (J.Am.Chem.Soc.2012, 134, 4505-4508) made a pioneering work on lithium-selenium batteries and explored the reaction mechanism of selenium, but due to its Using carbon nanotubes as the conductive substrate, the prepared selenium-carbon mixture is used as the positive electrode. Selenium exists in the form of blocks, and the substrate has a weak limiting effect on selenium. Therefore, the electrochemical activity of selenium cannot be effectively exerted, and the reaction is unstable. The cycle capacity of lithium-selenium batteries is low, the discharge capacity decays quickly, and the battery life is limited. Patent CN101794877A discloses a copper fluoride-selenium nanocomposite negative electrode material for lithium ion batteries and its preparation method, in which copper fluoride and elemental selenium are formed into a nanocomposite material by laser sputtering, and the nanocomposite material is used to As the negative electrode material of lithium-ion thin-film battery, however, the preparation method here is complicated, is only suitable for special purposes and is not suitable for large-scale application, and the battery capacity of the battery that obtains like this is on the low side, only has 310mAh/g. Patent CN102623678A discloses a preparation method of Li-Se batteries and lithium battery electrode materials, which discloses the use of thermal evaporation to grow selenium microspheres on substrates and grow selenium nanowires or selenium nanowires on substrates loaded with gold catalysts Nanobelts are used as lithium battery materials, but because the noble metal gold needs to be used in this invention, and the selenium vapor reacts in a fluid atmosphere, it will cause a great waste of selenium. In addition, selenium is deposited on the surface of the substrate, and the effect is unstable. It is easy to fall off. The most important thing is that in this invention, the discharge voltage of selenium as a positive electrode material is too low (about 0.25V), while for lithium battery electrode materials, the voltage platform is below 1V and can only be used as a negative electrode material. Therefore, select a suitable conductive substrate, effectively combine selenium with the conductive substrate, and at the same time confine selenium in the substrate in the form of molecules, so as to prepare lithium-selenium battery electrode materials with high volumetric energy density and cycle stability. Lithium-selenium batteries with high capacity and stable cycle performance are also of great significance to the development of the entire energy storage field.

Contents of the invention

The present invention provides a selenium-mesoporous carrier complex, which is prepared from selenium and a mesoporous carrier, and the selenium is uniformly dispersed in the form of a single ring selenium molecule and/or an amorphous chain selenium molecule In the mesoporous channels of the mesoporous carrier; the mass percentage of the selenium in the mesoporous carrier is 10-90%. In the composite material obtained by this method, selenium can exist in the pores of the carrier with a stable molecular size, and the inventors of the present invention have unexpectedly found that the composite material obtained by this method can be used as a positive electrode material for lithium ion batteries. Maintain high cycle capacity, excellent stable cycle performance, single and stable discharge platform, the main component of the selenium-mesoporous carrier composite positive electrode has a simple preparation method, easy to obtain raw materials, suitable for large-scale production, and has high practicability .

The present invention also provides a selenium-mesoporous carrier composite anode material, the anode material is prepared from selenium and a mesoporous carrier, and the selenium is homogeneous in the form of a single ring selenium molecule and/or an amorphous chain selenium molecule Dispersed in the mesoporous channels of the mesoporous carrier; the mass percentage of the selenium in the mesoporous carrier is 10-90%.

Preferably, the mesoporous carrier material mentioned in the present invention refers to a carrier material with a pore diameter of 2-50 nm, preferably 2-10 nm, more preferably 2-5 nm.

In the above positive electrode material, the mesoporous support is selected from one or more of carbon mesoporous supports and non-carbon mesoporous supports;

The carbon mesoporous support is a carbon support or a composition thereof with certain electrical conductivity and mesoporous structure;

The non-carbon mesoporous carrier is specifically selected from one or more of mesoporous metals, mesoporous metal oxides, mesoporous semiconductor ceramics, mesoporous molecular sieves and mesoporous phosphate materials;

Wherein, the mesoporous metal is selected from one or more of mesoporous gold, mesoporous platinum, mesoporous aluminum, mesoporous nickel and mesoporous titanium;

The mesoporous metal oxide is selected from one or more of mesoporous ferric oxide, mesoporous ferric oxide, mesoporous titanium dioxide and mesoporous ruthenium oxide;

The mesoporous semiconductor ceramic is selected from one or more of mesoporous silicon carbide and mesoporous zinc oxide;

The mesoporous molecular sieve is one or more of the MCM series and SBA series mesoporous molecular sieves.

The mesoporous phosphate material is selected from one or more of mesoporous aluminum phosphate, mesoporous titanium phosphate, mesoporous vanadium phosphate, mesoporous iron phosphate, and mesoporous zinc phosphate.

The method for preparing the selenium-mesoporous carrier composite cathode material provided by the present invention comprises the following steps: after mixing the selenium with the mesoporous carrier, the temperature is raised to 220-300° in a constant-capacity reactor filled with an inert atmosphere C for insulation, then stop heating and cool to room temperature to obtain the selenium-mesoporous carrier complex.

In the above method, the specific surface of the mesoporous support is 200-3000m ² g ^-1 , the pore volume is 0.2-10.0cm ³ g ^-1 , the average pore diameter is 2-50nm, preferably, the pore volume is 0.5- 5.0 cm ³ g ^-1 , more preferably, the pore volume is 0.8-3.0 cm ³ g ^-1 ; also preferably, the average pore diameter is 2-10 nm, more preferably 2-5 nm.

Preferably, the mass ratio of the selenium to the mesoporous support is 0.1:1-9:1, preferably 0.25:1-4:1, and more preferably 1:1-3:1.

Preferably, the inert atmosphere is one or more inert gas atmospheres such as nitrogen and argon.

Preferably, in the heating step, the heating rate is 1-10°C min ^-1 ;

Preferably, in the step of incubating, the time is 10-24 hours.

The invention also provides a selenium-mesoporous carrier composite electrode and a preparation method thereof. The selenium-mesoporous carrier composite electrode contains the selenium-mesoporous carrier composite positive electrode material, a binder and a conductive additive. The preparation of the selenium-mesoporous carrier composite electrode specifically includes the following steps: mixing the selenium-mesoporous carrier composite with a conductive additive, a binder, and a solvent in a certain proportion, and performing pulping, smearing, drying, etc. The procedure is to obtain the positive electrode of the selenium-mesoporous carrier composite.

In the above method, the conductive additive is one or more of carbon black, Super-P, Ketjen black;

In the above method, the binder and solvent are polyvinylidene fluoride (PVDF) (with N-methylpyrrolidone (NMP) as solvent) or polyacrylic acid (PAA), sodium carboxymethylcellulose (CMC), seaweed One or more of sodium bicarbonate (SA), gelatin (both with water as solvent).

The lithium-selenium battery provided by the invention comprises metallic lithium as the negative electrode, the above-mentioned selenium-mesoporous carrier composite electrode as the positive electrode and an organic electrolyte.

In the above battery, the organic electrolyte is carbonate electrolyte or ether electrolyte, the concentration is 0.1-2M, preferably 0.5-1.5M.

In the carbonate electrolyte, the solvent is selected from dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC) and propylene carbonate (PC). One or more, the solute is selected from one or more of lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI).

In the ether electrolyte, the solvent is selected from one or more of 1,3-dioxolane (DOL), ethylene glycol dimethyl ether (DME) and triethylene glycol dimethyl ether (TEGDME), The solute is selected from one or more of lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI).

In addition, the application of the lithium-selenium battery provided by the present invention in the preparation of high volume energy density energy storage devices also belongs to the protection scope of the present invention.

Description of drawings

FIG. 1 is a 48,000-fold magnified transmission electron micrograph of the selenium-mesoporous carbon support composite of Example 1.

Fig. 2 is the charge-discharge curve of the lithium-selenium battery of Example 1 in a carbonate electrolyte solution at a rate of 0.1C.

Fig. 3 is the cycle performance of the lithium-selenium battery of Example 1 in the carbonate electrolyte solution at a rate of 0.1C.

Fig. 4 is the Raman spectrum of the selenium-mesoporous carbon support composite of Example 1 before and after cycling and bulk selenium.

Fig. 5 is the charge-discharge curve of the lithium-selenium battery of Example 2 in the carbonate electrolyte solution at a rate of 0.1C.

Fig. 6 is the charge-discharge curve of the lithium-selenium battery of Example 3 in the carbonate electrolyte solution at a rate of 0.1C.

Fig. 7 is the cycle performance of the lithium-selenium battery of Example 3 in the carbonate electrolyte solution at a rate of 0.1C.

Fig. 8 is the cycle performance of the lithium-selenium battery of Example 4 in the carbonate electrolyte solution at a rate of 0.1C.

Detailed ways

The present invention will be further described below in conjunction with specific examples.

The experimental methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials can be obtained from commercial sources.

Example 1

(1) Preparation of Se-Mesoporous Carrier Complex

The mesoporous carrier used in the experiment is mesoporous carbon (purchased from Nanjing Xianfeng Nano Material Technology Co., Ltd.), with a specific surface area of 612.3m ² g ^-1 , a pore volume of 0.697cm ³ g ^-1 , and an average pore diameter of 4.3nm. The mass fraction of selenium in the prepared selenium-mesoporous carbon composite was 50%.

The preparation method of selenium-mesoporous carbon composite is as follows:

(1) Weigh selenium and mesoporous carbon according to the mass ratio of 1:1 and mix them evenly;

(2) Heat the mixture of selenium and mesoporous carbon in a constant-capacity reactor filled with argon to 260°C at a heating rate of 5°C min ^-1 and keep heating for 12h to fully disperse selenium into the mesoporous carbon ;

(3) Stop heating and return to room temperature to obtain a selenium-mesoporous carbon composite.

It can be clearly seen from the transmission electron microscope photo of Fig. 1 that selenium exists completely in the mesoporous channel of the mesoporous carrier, and no residue remains on the surface of the mesoporous carrier, so the mesoporous carrier has a good confinement effect on the selenium molecule, and the presence of selenium The form is very stable.

(2) Preparation of selenium-mesoporous carrier composite positive electrode

The selenium-mesoporous carbon composite prepared above is mixed with Super-P, the binder sodium alginate and water in a certain proportion, and the selenium-mesoporous carbon composite positive electrode is obtained through pulping, smearing, drying and other technological processes .

(3) Assemble lithium-selenium battery

The above-prepared selenium-mesoporous carbon composite positive electrode and lithium negative electrode were assembled into a lithium-selenium battery, and the electrolyte was selected from carbonate electrolyte (1M LiPF ₆ PC/EC (1:1 volume ratio) solution).

(4) Lithium-Selenium Battery Test

The lithium-selenium battery was subjected to a constant current charge-discharge test using a charge-discharge instrument, and the cyclic voltammetry test was performed on the lithium-selenium battery using an electrochemical workstation. The test voltage range was 1.0-3.0V, and the test temperature was 25°C. The battery capacity and charge and discharge current are calculated based on the mass of elemental selenium. Fig. 2 is the charge-discharge curve of the lithium-selenium battery at a rate of 0.1C (equivalent to 68mA g ^-1 ) in a carbonate electrolyte. The discharge capacity of the lithium-selenium battery in the above voltage range is 932mA h g ^-1 in the first cycle, the charge capacity in the first cycle is 696mA h g ^-1 , and the capacity gradually stabilizes at about 675mA h g ^-1 from the second cycle, and the cycle curve is stable , Coulombic efficiency is about 100%, the discharge platform is a single platform, and the discharge voltage is close to 2V. Fig. 3 is the cycle performance of the lithium-selenium battery in a carbonate electrolyte solution at a rate of 0.1C. The lithium-selenium battery has a capacity of about 670 mA h g ^-1 after 30 cycles, and has good capacity retention and coulombic efficiency. Fig. 4 is the Raman spectrum of the selenium-mesoporous carbon composite before and after charging and discharging and bulk selenium. It can be seen that selenium exists as a single cyclic selenium molecule before charging and discharging, but after cycling, selenium transforms into an amorphous chain selenium molecule. This is different from the reaction form of bulk bulk selenium reported earlier.

Comparative example 1.1

Other conditions are the same as in Example 1, except that the carrier in the selenium mesoporous carrier material adopts a porous carbon material with an average pore diameter of about 2 microns, and the first cycle charge capacity measured after being assembled into a lithium-selenium battery is 300mA h g ^-1 , the second cycle starts, and the capacity gradually stabilizes at around 100mA h g ^-1 .

Example 2

Other conditions are the same as in Example 1, except that the binder used in step (2) is not sodium alginate (with water as solvent), but polyvinylidene fluoride (PVDF) (with N-methyl pyrrolidone (NMP) as solvent). The assembled lithium-selenium battery uses a charge-discharge instrument to perform a constant-current charge-discharge test on the above-mentioned lithium-selenium battery. The test voltage range is 1.0-3.0V, and the test temperature is 25°C. The battery capacity and charge and discharge current are calculated based on the mass of elemental selenium. Fig. 5 is the charge-discharge curve of the lithium-selenium battery described in this example at a rate of 0.1C (equivalent to 68mA g ^-1 ) in carbonate electrolyte. The first cycle discharge capacity of the lithium-selenium battery in the above voltage range is 932mA h g ^-1 , the first cycle charge capacity is 578mA h g ^-1 , and after 50 cycles from the second cycle, the discharge capacity remains at 550mA h g ^-1 The above has better capacity retention rate and good Coulombic efficiency, and its discharge voltage is also close to 2V, but compared with the embodiment, the capacity and efficiency are slightly worse.

Example 3

(1) Preparation of mesoporous carbon supports

The mesoporous carrier used in the experiment is mesoporous carbon with a specific surface area of 1789m ² g ^-1 , a pore volume of 2.37cm ³ g ^-1 and an average pore diameter of 3.8nm.

The preparation method of mesoporous carbon is as follows:

Dissolve 1.25g of sucrose in 5mL of aqueous solution containing 0.14g of concentrated sulfuric acid, then add 1.0g of nanoporous silica-based molecular sieve (purchased from Shanghai Carbon Union Environmental Protection Technology Co., Ltd.), ultrasonically disperse for 1h, then heat to 100°C and maintain Heating for 12h, then heating to 160°C and maintaining heating for 12h. Then add 0.8g sucrose, 0.09g concentrated sulfuric acid and 5mL water, repeat heating to 100°C and maintain heating for 12h, then heat to 160°C and maintain heating for 12h. The product was heated to 900°C at a heating rate of 10°C min ^-1 under an argon atmosphere and maintained for 5 hours to completely carbonize the organic matter, and finally the product was stirred in dilute hydrofluoric acid for 4 hours to remove silicon and obtain a mesoporous carbon support .

(2) Preparation of Se-Mesoporous Carrier Complex

The mass fraction of selenium in the selenium-mesoporous carbon composite prepared in the experiment was 70%.

The preparation method of selenium-mesoporous carbon composite is as follows:

(1) Weigh selenium and mesoporous carbon according to the mass ratio of 7:3 and mix them evenly;

(2) Heat the mixture of selenium and mesoporous carbon in a constant-capacity reactor filled with argon to 260°C at a heating rate of 5°C min ^-1 and keep heating for 20h to fully disperse selenium into the mesoporous carbon ;

(3) Stop heating and return to room temperature to obtain a selenium-mesoporous carbon composite.

(3) Preparation of selenium-mesoporous carrier composite positive electrode

The selenium-mesoporous carbon composite prepared above is mixed with Super-P, the binder sodium alginate (SA) and water in a certain proportion, and the selenium-mesoporous carbon is obtained through pulping, smearing, drying and other processes. Composite positive electrode.

(4) Assemble lithium-selenium battery

The above-prepared selenium-mesoporous carbon composite positive electrode and lithium negative electrode were assembled into a lithium-selenium battery, and the electrolyte was selected from carbonate electrolyte (1M LiTFSI EC/DMC (1:1 volume ratio) solution).

(5) Lithium-Selenium Battery Test

A charge-discharge instrument is used to perform a constant-current charge-discharge test on the lithium-selenium battery, and the test voltage range is 1.0-3.0V. The test temperature is 25°C, and the battery capacity and charge and discharge current are calculated based on the mass of elemental selenium. Fig. 6 is the charge-discharge curve of the lithium-selenium battery in the carbonate electrolyte solution at a rate of 0.1C (equivalent to 68mA g ^-1 ). The first cycle discharge capacity of the lithium-selenium battery in the above voltage range is 862mA h g ^-1 , the first cycle charge capacity is 602mA h g ^-1 , the second cycle discharge capacity is 621mA h g ^-1 , and the capacity gradually increases from the third cycle It is stable at 550mA h g ^-1 , the cycle curve is stable, the coulombic efficiency is about 100%, and the discharge platform is a single platform, which is about 2V. Fig. 7 is the cycle performance of the lithium-selenium battery in the carbonate electrolyte solution at a rate of 0.1C. The capacity of the lithium-selenium battery gradually stabilized at 550mA h g ^-1 from the third cycle at the 0.1C rate in the above voltage range, and the coulombic efficiency was close to 100%. The lithium-selenium battery was cycled for 20 cycles at the 0.1C rate , the capacity remains at 525mA h g ^-1 .

Example 4

(1) Preparation of mesoporous iron oxide support

The mesoporous carrier used in the experiment is mesoporous iron oxide with a specific surface area of 205m ² g ^-1 , a pore volume of 0.262cm ³ g ^-1 and an average pore diameter of 7.1nm.

The preparation method of mesoporous iron oxide is as follows:

Add NaOH (0.1M) dropwise to FeCl ₃ solution (0.1M) according to the ratio of OH ^- :Fe ³⁺ =2:1, and after stirring for 12 hours, put the mixed liquid droplet in an oil bath at 80°C while stirring Add it to the aqueous solution of sodium lauryl sulfate (purchased from Sinopharm Chemical Reagent Co., Ltd.) and keep it for 8h. After centrifugal washing, drying at 120°C for 5 hours, pre-calcining at 250°C for 2 hours in the air, and then roasting at 450°C for 5 hours, the mesoporous iron oxide was obtained.

(2) Preparation of Se-Mesoporous Carrier Complex

The mass fraction of selenium in the selenium-mesoporous iron oxide composite prepared in the experiment was 33.3%.

The preparation method of selenium-mesoporous iron oxide composite is as follows:

(1) Weigh selenium and mesoporous iron oxide at a mass ratio of 0.5:1 and mix them uniformly;

(2) Heat the mixture of selenium and mesoporous iron oxide in a constant-capacity reactor filled with argon to 240°C at a heating rate of 3°C min ^-1 and keep heating for 24h to fully disperse selenium into mesoporous iron oxide middle;

(3) Stop heating and return to room temperature to obtain the selenium-mesoporous iron oxide composite.

(3) Preparation of selenium-mesoporous carrier composite positive electrode

The selenium-mesoporous iron oxide composite prepared above was mixed with Ketjen black, binder gelatin (purchased from Sinopharm Chemical Reagent Co., Ltd.) and water in a certain proportion, and then prepared by pulping, smearing, drying and other technological processes. A selenium-mesoporous iron oxide composite positive electrode is obtained.

(4) Assemble lithium-selenium battery

Assemble the lithium-selenium battery with the positive electrode of the selenium-mesoporous iron oxide composite prepared above and the negative electrode of lithium. The electrolyte is an ester electrolyte (1M LiClO ₄ EC/PC/EMC (volume ratio: 1:1:1) solution) ).

(5) Lithium-Selenium Battery Test

A charge-discharge instrument is used to perform a constant-current charge-discharge test on the lithium-selenium battery, and the test voltage range is 1.0-3.0V. The test temperature is 25°C, and the battery capacity and charge and discharge current are calculated by the mass of selenium. The lithium-selenium battery has a discharge capacity of 1170mA hg ^-1 in the first cycle at a rate of 0.1C in the above voltage range, and the capacity gradually stabilizes at about 650mA h g ^-1 from the second cycle. The lithium-selenium battery has a capacity of more than 520mA h g ^-1 after 30 cycles at a rate of 0.1C. Has a good capacity retention rate.

In summary, the lithium-selenium battery of the present invention maintains high cycle capacity, excellent room temperature cycle stability and a single discharge platform, and its main component, the selenium-mesoporous carrier composite positive electrode, has a simple preparation method and easy-to-obtain raw materials , suitable for large-scale production, so the lithium-selenium battery of the present invention is expected to replace the widely used lithium ion battery as a new type of high volume energy density energy storage device, and has a good application prospect.

The above content is only a preferred embodiment of the present invention. It should be recognized that this description is not intended to limit the implementation of the present invention. Those skilled in the art can easily make corresponding modifications or changes according to the main idea and spirit of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection required by the claims.

Claims (10)

1. A selenium-mesoporous carrier complex, said compound is prepared by selenium and mesoporous carrier, and said selenium is uniformly dispersed in said selenium in the form of single ring selenium molecule and/or amorphous chain selenium molecule In the mesoporous channels of the mesoporous carrier; the mass percentage of the selenium in the mesoporous carrier is 10-90%. 2. The compound according to claim 1, characterized in that: said mesoporous carrier is selected from one or more of carbon mesoporous carrier and non-carbon mesoporous carrier; The specific surface of the mesoporous carrier is 200-3000m ² g ^-1 , the pore volume is 0.2-10cm ³ g ^-1 , the average pore diameter is 2-50nm, preferably, the pore volume is 0.5-5.0cm ³ g ^{- 1.} More preferably, the pore volume is 0.8-3.0 cm ³ g ^-1 ; also preferably, the average pore diameter is 2-10 nm, more preferably 2-5 nm. Preferably, the non-carbon mesoporous carrier is specifically selected from one or more of mesoporous metals, mesoporous metal oxides, mesoporous semiconductor ceramics, mesoporous molecular sieves and mesoporous phosphate materials; Wherein, the mesoporous metal is selected from one or more of mesoporous gold, mesoporous platinum, mesoporous aluminum, mesoporous nickel and mesoporous titanium; The mesoporous metal oxide is selected from one or more of mesoporous ferric oxide, mesoporous ferric oxide, mesoporous titanium dioxide and mesoporous ruthenium oxide; The mesoporous semiconductor ceramic is selected from one or more of mesoporous silicon carbide and mesoporous zinc oxide; The mesoporous molecular sieve is one or more of the MCM series and SBA series mesoporous molecular sieves. The mesoporous phosphate material is selected from one or more of mesoporous aluminum phosphate, mesoporous titanium phosphate, mesoporous vanadium phosphate, mesoporous iron phosphate, and mesoporous zinc phosphate. 3. a method for preparing the arbitrary described selenium-mesoporous carrier composite of claim 1-2, comprises the steps: after selenium is mixed with the described mesoporous carrier, be full of one or more of nitrogen, argon etc. A constant-capacity reactor in an inert gas atmosphere is heated to 220-300°C to keep the temperature, and then the heating is stopped and cooled to room temperature to obtain the selenium-mesoporous carrier composite. Preferably, the mass ratio of the selenium to the mesoporous support is 0.1:1-9:1, more preferably 0.25:1-4:1. 4. A selenium-mesoporous carrier composite cathode material, which comprises the composite according to any one of claims 1-2. 5. A preparation method for preparing the selenium-mesoporous carrier composite positive electrode material described in claim 4, comprising the steps of: mixing selenium with the mesoporous carrier and filling it with one or more inert materials such as nitrogen, argon, etc. The temperature of the constant-capacity reaction kettle in the gas atmosphere is raised to 220-300°C to keep the temperature, and then the heating is stopped and cooled to room temperature to obtain the selenium-mesoporous carrier composite. 6. The method according to claim 5, characterized in that: the mass ratio of the selenium to the mesoporous carrier is 0.1:1 to 9:1, preferably 0.25:1 to 4:1, and is also preferably 1:1. 1～3:1. 7. A selenium-mesoporous carrier composite electrode and preparation method thereof, characterized in that said material contains the selenium-mesoporous carrier composite described in claim 1-2 or the selenium-mesoporous carrier composite described in claim 4. The mesoporous carrier composite positive electrode material contains conductive additives, binders and corresponding solvents. If the preparation method is protected, the method includes preparing the positive electrode material of the selenium-mesoporous carrier composite through the technological process of pulping, smearing and drying. 8. Selenium-mesoporous carrier composite electrode according to claim 7, is characterized in that: preferably, described conductive additive is one or more in carbon black, Super-P, Ketjen black; Preferably, the binder and the corresponding solvent are polyvinylidene fluoride (PVDF) (with N-methylpyrrolidone (NMP) as solvent) or polyacrylic acid (PAA), sodium carboxymethyl cellulose (CMC), butyl One or more of styrene rubber/sodium carboxymethyl cellulose, sodium alginate (SA), gelatin (all using water as solvent); preferably, the binder is sodium alginate, preferably the Sodium alginate is used in the form of an aqueous solution. 9. A lithium-selenium battery comprising lithium metal as a negative electrode, the selenium-mesoporous carrier composite electrode and an organic electrolyte as a positive electrode according to any one of claim 7 or 8. Preferably, the organic electrolyte is carbonate electrolyte or ether electrolyte, the concentration is 0.1-2M, preferably 0.5-1.5M; In the carbonate electrolyte, the solvent is selected from dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC) and propylene carbonate (PC). One or more, the solute is selected from one or more of lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI); In the ether electrolyte, the solvent is selected from one or more of 1,3-dioxolane (DOL), ethylene glycol dimethyl ether (DME) and triethylene glycol dimethyl ether (TEGDME), The solute is selected from one or more of lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI). 10. The application of the lithium-selenium battery according to claim 9 in the preparation of high volume energy density type energy storage devices.

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