阅读说明：本技术 一种金属硒硫化物纳米晶@多孔碳球材料及其制备和在锂金属电池中的应用 (Metal selenide sulfide nanocrystalline @ porous carbon sphere material, preparation thereof and application thereof in lithium metal battery ) 是由 洪波 赖延清 高春晖 姜怀 张治安 张凯 于 2019-09-03 设计创作，主要内容包括：本发明属于锂金属电池材料技术领域,具体一种金属硒硫化物纳米晶@多孔碳球材料,包括带有装填腔室的多孔碳球,以及负载在多孔碳球碳壁以及装填腔室内的金属硒硫化物纳米晶,所述的金属硒硫化物纳米晶的化学式为M’(Se_xS_(1-x))、M”_2(Se_yS_(1-y))_3中的至少一种；所述的M’为锌和/或镁；M”为铝和/或铟；0<x<1；0<y<1本发明还包含所述材料的制备,以及由所述的材料制得的复合集流体、负极以及锂金属电池。本发明创新地利用所述的金属硒硫化物纳米晶诱导锂金属选择性沉积,可以改善锂金属电池的首圈效率以及循环稳定性。(The invention belongs to the technical field of lithium metal battery materials, and particularly relates to a metal selenide sulfide nanocrystalline @ porous carbon sphere material which comprises a porous carbon sphere with a filling cavity and metal selenide sulfide nanocrystalline loaded on the carbon wall of the porous carbon sphere and in the filling cavity, wherein the chemical formula of the metal selenide sulfide nanocrystalline is M'(Se x S 1‑x )、M” 2 (Se y S 1‑y ) 3 At least one of; m' is zinc and/or magnesium; m' is aluminum and/or indium; 0<x<1；0<y<The invention also comprises the preparation of the material, and a composite current collector, a negative electrode and a lithium metal battery which are prepared from the material. The invention innovatively utilizes the metal selenium sulfide nanocrystalline to induce the selective deposition of lithium metal, and can improve the first-turn efficiency and the cycling stability of the lithium metal battery.)

1. The metal selenide sulfide nanocrystalline @ porous carbon sphere material is characterized by comprising a porous carbon sphere with a filling cavity and metal selenide sulfide nanocrystalline loaded on the carbon wall of the porous carbon sphere and in the filling cavity, wherein the metal selenide sulfide nanocrystalline is a metal selenide sulfide nanocrystallineThe chemical formula of the selenium sulfide nanocrystal is M' (Se)_xS_1-x)、M”₂(Se_yS_1-y)₃At least one of;

m' is zinc and/or magnesium; m' is aluminum and/or indium;

0<x<1；0<y<1。

2. the metal selenide sulfide nanocrystal @ porous carbon sphere material of claim 1, wherein the porous carbon sphere has a sphere wall thickness of 1-500 nm; the specific surface area is 50-1000m²/g。

3. The metal selenide sulfide nanocrystal @ porous carbon sphere material of claim 1, wherein the volume fraction of the internal cavity of the porous carbon sphere is 40-99%.

4. The metal selenide sulfide nanocrystal @ porous carbon sphere material of claim 1, wherein x is from 0.1 to 0.9; and y is 0.1-0.9.

5. The preparation method of the metal selenide sulfide nanocrystal @ porous carbon sphere material as claimed in any one of claims 1 to 4, characterized in that a selenide source of M 'and/or M' metal is subjected to nanocrystallization to prepare the nano metal selenide @ porous carbon sphere, and then the nano metal selenide @ porous carbon sphere is subjected to a sulfurization reaction with a sulfur source at a temperature of 200-500 ℃, so as to dope sulfur element into the selenide, thereby obtaining the metal selenide sulfide nanocrystal @ porous carbon sphere material.

6. The method for preparing the metal selenide sulfide nanocrystal @ porous carbon sphere material as claimed in claim 5, wherein the selenide source is one or more of zinc selenide, magnesium selenide, aluminum selenide and indium selenide;

preferably, the hydrothermal temperature is 120-240 ℃, preferably 140-220 ℃, and more preferably 160-210 ℃; the hydrothermal time is 1-120 h; preferably 5 to 100 hours, more preferably 10 to 96 hours.

The sulfur source is a sulfur simple substance;

the vulcanization reaction is carried out in a double-temperature-zone tubular furnace; wherein the heating temperature of the sulfur source is 150-400 ℃; the temperature of the region where the nano metal selenide @ porous carbon spheres is located is 200-500 ℃; the heating rate is 0.1-15 ℃/min, the heat preservation time is 10-600min, and the cooling rate is 0.1-15 ℃/min.

7. The lithium metal negative electrode active material is characterized in that the metal selenide sulfide nanocrystalline @ porous carbon sphere material in any one of claims 1-4 or the metal selenide sulfide nanocrystalline @ porous carbon sphere material prepared by the preparation method in any one of claims 5-6 is filled with lithium metal to obtain the lithium metal negative electrode active material.

8. The lithium metal negative electrode composite current collector is characterized by comprising a current collector and an active layer compounded on the surface of the current collector; the active layer comprises the metal selenide sulfide nanocrystalline @ porous carbon sphere material as defined in any one of claims 1 to 4, or the metal selenide sulfide nanocrystalline @ porous carbon sphere material prepared by the preparation method as defined in any one of claims 5 to 6 and a binder;

preferably, the thickness of the active layer is 1 to 1000 μm, preferably 20 to 500 μm, and more preferably 50 to 300 μm; wherein the binder accounts for 1-50%, preferably 2-20%;

preferably, the material of the planar metal current collector is at least one of copper, titanium, nickel, iron and cobalt; the thickness thereof is preferably 2 to 200 μm;

preferably, the binder is at least one of polyvinyl alcohol, polytetrafluoroethylene, sodium carboxymethylcellulose, polyethylene, polypropylene, polyvinylidene chloride, SBR rubber, fluorinated rubber and polyurethane.

9. A lithium metal negative electrode, which is characterized by comprising the lithium metal negative electrode composite current collector of claim 8, and a lithium metal simple substance filled in the metal selenide sulfide nanocrystalline @ porous carbon sphere material of the active layer of the composite current collector;

filled metalThe amount of lithium is 0.4-200 mAh/cm²(ii) a Further preferably 5 to 160mAh/cm²(ii) a Further preferably 30 to 100mAh/cm²。

10. A lithium metal battery equipped with the lithium metal negative electrode of claim 9; preferably, the metal lithium battery is a lithium sulfur battery, a lithium oxygen battery, a lithium iodine battery, a lithium selenium battery, a lithium tellurium battery or a lithium carbon dioxide battery.

Technical Field

The invention relates to the field of electrode materials of lithium metal batteries, in particular to a negative electrode material of a lithium metal battery.

Background

The negative electrode of the metal lithium battery is usually a simple substance of metal lithium, the action mechanism in the battery is the deposition and dissolution of the metal lithium, and the charge and discharge mechanism is as follows: charging of Li⁺+ e ═ Li; discharge Li-e ═ Li⁺(ii) a What occurs with the negative electrode unlike conventional lithium ion batteries is the intercalation and deintercalation of lithium ions in the graphite negative electrode. Lithium metal batteries and lithium ion batteries are brand-new battery systems with different mechanisms.

The lithium metal negative electrode is called "holy-cup grade" negative electrode material in secondary batteries due to its extremely high capacity and relatively negative electrochemical potential, and batteries using lithium metal as the negative electrode are promising next-generation high specific energy batteries. However, the lithium metal negative electrode is easy to grow dendrite and generate pulverization in the reaction deposition/dissolution process, thereby greatly reducing the coulombic efficiency of the battery and seriously causing safety problems such as explosion and the like.

The lithium metal negative electrode has infinite volume expansion theoretically due to no host deposition, so in the long run, the lithium metal negative electrode must have a deposition framework for realizing industrialization. The existing three-dimensional framework is mainly divided into a metal-based current collector and a carbon-based current collector, but the density of the metal-based current collector is higher, so that the mass ratio energy is lower, the energy density of a large battery is seriously influenced, and the cost of the metal current collector is higher and the price is high; the carbon-based current collector is low in price and mature in manufacturing process, but the problem of low space utilization rate in the carbon-based three-dimensional current collector still exists.

Disclosure of Invention

The invention provides a metal selenide sulfide nanocrystalline @ porous carbon sphere material, which aims to selectively induce uniform deposition of lithium, improve the uniformity of lithium deposition under high current, reduce the volume effect and interface side reaction and improve the cycle performance of a lithium metal cathode.

The second purpose of the invention is to provide a preparation method of the metal selenide sulfide nanocrystalline @ porous carbon sphere material.

The third purpose of the invention is to provide a composite current collector containing the metal selenide sulfide nanocrystalline @ porous carbon sphere material.

The fourth purpose of the invention is to provide a preparation method of the composite current collector.

The fifth purpose of the invention is to provide a lithium metal negative electrode active material (also called lithium active material) containing the metal selenide sulfide nanocrystalline @ porous carbon sphere material.

The sixth purpose of the invention is to provide a preparation method of the lithium metal negative electrode active material.

A seventh object of the present invention is to provide a lithium metal negative electrode comprising the lithium metal negative electrode active material.

An eighth object of the present invention is to provide a method for producing a lithium metal negative electrode (also referred to as a lithium negative electrode in the present invention).

A ninth object of the present invention is to provide a lithium metal battery comprising the lithium metal negative electrode.

The metal selenide sulfide nanocrystalline @ porous carbon sphere material comprises a porous carbon sphere (also called a carbon hollow sphere) with a filling cavity, and metal selenide sulfide nanocrystalline loaded on the carbon wall of the porous carbon sphere and in the filling cavity, wherein the chemical formula of the metal selenide sulfide nanocrystalline is M' (Se)_xS_1-x)、M”₂(Se_yS_1-y)₃At least one of;

m' is zinc and/or magnesium; m' is aluminum and/or indium;

0<x<1；0<y<1。

due to the intrinsic characteristics of the metallic lithium cathode, dendritic growth is easily generated in the electrodeposition process, and the coulombic efficiency of the battery is reduced due to the dendritic crystal problem of lithium deposition in the charging and discharging processes. To overcome this technical problem, the present invention innovatively utilizes the metal selenide sulfide nanocrystals, which are sulfur-doped selenides of the metal; the method can induce the selective deposition of lithium metal, not only greatly improve the deposition position of the lithium metal, but also change the deposition morphology of the lithium metal, in addition, the nano-scale metal selenide sulfide nanocrystalline can be used as a nucleation site for lithium deposition, the nucleation barrier for lithium deposition is reduced, the deposition morphology of the lithium metal is more smooth due to the multiple and uniformly dispersed nucleation sites, the loss of active lithium is reduced due to the smooth lithium deposition morphology, and the volume expansion of the lithium deposition is also reduced. The material of the invention can improve the cycle performance and the safety performance of the metal lithium cathode.

In the invention, the nanometer particle shape of the metal selenium sulfide nanometer crystal and the crystal lattice mutual doping cooperativity of Se and S are the key points for inducing the selective deposition of lithium metal and improving the cycle performance.

Preferably, x is 0.1 to 0.9; more preferably 0.1 to 0.5.

Preferably, y is 0.1 to 0.9; more preferably 0.1 to 0.3.

The loading amount of the metal selenide sulfide nanocrystal provided by the invention can be adjusted according to needs, and can be 0.01-10 wt.%, preferably 1-9 wt.%, and more preferably 1-7 wt.%.

The porous carbon sphere is a carbon hollow sphere, the sphere wall of the carbon hollow sphere is porous carbon, and the aperture of the porous carbon is 0.2-50nm, for example.

Research also finds that controlling the structural characteristics of the porous carbon spheres, such as the thickness of the sphere wall, the specific surface area, the volume of the internal cavity and the like, is helpful for further improving the electrical properties of the material in cooperation with the metal selenide sulfide nanocrystal.

Preferably, the specific surface area of the porous carbon spheres is 50-1000m²A/g, preferably from 70 to 700m²(ii)/g, more preferably 100-300m²/g。

Preferably, the thickness of the spherical wall of the porous carbon sphere is 1 to 500nm, preferably 3 to 250nm, and more preferably 10 to 100 nm.

Preferably, the volume of the inner cavity of the porous carbon ball accounts for 40-99%; preferably 60 to 97%; further preferably 80 to 95%.

The invention provides a preparation method of a metal selenide sulfide nanocrystalline @ porous carbon sphere material, which comprises the steps of carrying out nanocrystallization treatment on an M 'and/or M' metal selenide source to prepare a nano metal selenide @ porous carbon sphere, then carrying out a vulcanization reaction on the nano metal selenide @ porous carbon sphere and a sulfur source at the temperature of 200-500 ℃, and doping sulfur elements into the selenide to obtain the metal selenide sulfide nanocrystalline @ porous carbon sphere material.

The preparation method of the invention innovatively utilizes hydrothermal reaction to carry out nanocrystallization on the selenide, loads the selenide in the filling cavity of the carbon ball, and further cooperates with subsequent low-temperature vulcanization operation to carry out lattice mutual doping on the selenide by sulfur, thereby synergistically inducing the deposition of lithium metal and improving the electrical property of the material.

The key point of the preparation method is that the special treatment mode of doping selenide by sulfur and the temperature control of the vulcanization process are required, so that the material with excellent electrical properties in the lithium metal battery can be prepared.

Preferably, the selenide source is one or more of zinc selenide, magnesium selenide, aluminum selenide and indium selenide.

Preferably, the hydrothermal temperature is 120-240 ℃, preferably 140-220 ℃, and more preferably 160-210 ℃; the hydrothermal time is 1-120 h; preferably 5 to 100 hours, more preferably 10 to 96 hours.

The sulfur source is sulfur simple substance.

The vulcanization reaction is carried out in a double-temperature-zone tubular furnace; wherein the heating temperature of the sulfur source is 150-400 ℃; the temperature of the region where the nano metal selenide @ porous carbon spheres is located is 200-; the heating rate is 0.1-15 ℃/min, the heat preservation time is 10-600min, and the cooling rate is 0.1-15 ℃/min.

Preferably, the temperature of vulcanization is 200-350 ℃.

The invention also provides an application of the metal selenide sulfide nanocrystalline @ carbon hollow sphere material, and the metal selenide sulfide nanocrystalline @ carbon hollow sphere material is used for preparing a lithium negative electrode active material or a composite current collector.

The invention also provides a lithium metal negative electrode composite current collector, which comprises a current collector and an active layer compounded on the surface of the current collector; the active layer comprises the metal selenide sulfide nanocrystalline @ carbon hollow sphere material and a binder.

Preferably, in the composite current collector, the thickness of the active layer is 1 to 1000 μm, preferably 20 to 500 μm, and more preferably 50 to 300 μm; wherein the binder accounts for 1-50%, preferably 2-20%;

preferably, the material of the planar metal current collector is at least one of copper, titanium, nickel, iron and cobalt; the thickness thereof is preferably 2 to 200 μm;

preferably, the binder is at least one of polyvinyl alcohol, polytetrafluoroethylene, sodium carboxymethylcellulose, polyethylene, polypropylene, polyvinylidene chloride, SBR rubber, fluorinated rubber and polyurethane.

The amount of the binder can be adjusted according to the use habit well known in the industry, for example, the content of the binder in the active layer is 1-10 wt.%.

The invention also provides a lithium metal negative electrode active material, and lithium metal is filled in the metal selenide sulfide nanocrystalline @ porous carbon sphere material, so that the lithium metal negative electrode active material is obtained.

The invention also provides a lithium metal negative electrode, which comprises the lithium metal negative electrode composite current collector and a lithium metal simple substance filled in the metal selenide sulfide nanocrystalline @ porous carbon sphere material of the active layer of the composite current collector.

The lithium metal negative electrode is obtained by filling lithium into the composite current collector.

Preferably, the lithium metal negative electrode is filled with metal lithium in an amount of 0.4 to 200mAh/cm²(ii) a Further preferably 5 to 160mAh/cm²(ii) a Further preferably 30 to 100mAh/cm²。

The invention also provides a metal lithium battery, which is provided with the metal lithium battery anode; preferably, the metal lithium battery is a lithium sulfur battery, a lithium oxygen battery, a lithium iodine battery, a lithium selenium battery, a lithium tellurium battery or a lithium carbon dioxide battery.

Has the advantages that:

1. the invention provides a novel metal selenide sulfide nanocrystalline @ porous carbon sphere material, wherein the morphology and the contained metal selenide sulfide nanocrystalline can induce the nucleation of a lithium metal simple substance, the problems of uneven lithium deposition and easy generation of dendrite can be effectively solved, and the capacity and the cycle performance can be effectively improved.

2. The invention provides a metal selenium sulfide nanocrystalline @ porous carbon sphere material prepared by hydrothermal nanocrystallization and low-temperature in-situ vulcanization, and researches show that the material with excellent performance can be prepared by controlling a special mutual doping mode and vulcanization conditions.

Drawings

FIG. 1 is a schematic diagram of a nanoparticle-loaded porous carbon sphere

FIG. 2 is an SEM photograph of carbon spheres before being undoped in example 1

Detailed Description

The following examples are intended to illustrate the invention in further detail; and the scope of the claims of the present invention is not limited by the examples.

Example 1

0.12g of porous carbon spheres (specific surface area 100 m)²The thickness of the carbon wall is 5nm, the volume of the internal cavity accounts for 90 percent of the total volume), 2.38g of magnesium selenide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, the temperature is kept at 180 ℃ for 80 hours, and the material is cleaned, filtered and dried to obtain magnesium selenide @ porous carbonAnd then, taking elemental sulfur as a sulfur source (the using amount is 3.2g), carrying out vulcanization doping in a double-temperature-zone tube furnace, wherein the temperature of the sulfur source is 200 ℃, the temperature of a sample zone (the temperature of a magnesium selenide @ porous carbon sphere zone, namely the vulcanization temperature) is 250 ℃, the heating rate is 3 ℃/min, the heat preservation time is 30min, and the cooling rate is 5 ℃/min, so that the selenium-loaded magnesium sulfide nano particles (MgS) are obtained_0.16Se_0.84) Porous carbon sphere material (MgS)_0.16Se_0.84@ porous carbon spheres). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. The electrode (composite copper foil current collector) is used as a working electrode, a metal lithium sheet is used as a counter electrode, and 1M LiTFSI/DOL/DME (volume ratio of 1: 1) contains 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 3mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Comparative example 1

Pure copper foil is used as a working electrode, a metal lithium sheet is used as a counter electrode, and 1M LiTFSI/DOL DME (volume ratio of 1: 1) contains 2 wt.% LiNO₃Assembling the button cell for the electrolyte at 2mA/cm²The charge-discharge cycle test was carried out at the current density of (1). The relevant results of the tests are shown in table 1.

Comparative example 2

Pure copper foil is used as a working electrode, a metal lithium sheet is used as a counter electrode, and 1M LiTFSI/DOL DME (volume ratio of 1: 1) contains 2 wt.% LiNO₃Assembling the soft package battery for the electrolyte at 2mA/cm²The charge-discharge cycle test was carried out at the current density of (1). The relevant results of the tests are shown in table 1.

Comparative example 3

Mixing acetylene black and polyvinylidene fluoride according to a mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 2 wt.% LiNO₃Assembling the button cell for the electrolyte at 2mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Comparative example 4

Porous carbon spheres (specific surface area 100 m)²The carbon wall has the thickness of 5nm, the volume of the internal cavity accounts for 90 percent of the total volume), and the polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 2 wt.% LiNO₃Assembling the button cell for the electrolyte at 2mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Comparative example 5

Preparation of magnesium sulfide @ porous carbon spheres:

0.12g of porous carbon spheres (specific surface area 100 m)²The thickness of the carbon wall is 5nm, the volume of the internal cavity accounts for 90 percent of the total volume), 0.16g of magnesium sulfide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, and the mixture is subjected to heat preservation at 180 ℃ for 80 hours to obtain the porous carbon sphere material loaded with the magnesium sulfide nano particles. Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 3mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Comparative example 6

Preparation of magnesium selenide @ porous carbon spheres:

0.12g of porous carbon spheres (specific surface area 100 m)²The thickness of the carbon wall is 5nm, the volume of the internal cavity accounts for 90 percent of the total volume), 2.38g of magnesium selenide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, and the mixture is subjected to heat preservation at 180 ℃ for 80 hours to obtain the porous carbon sphere material loaded with the magnesium selenide nano particles. Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. The electrode is used as a working electrode, and a metal lithium sheet is used as a counter electrode1 wt.% LiNO in 1M LiTFSI/DOL DME (1: 1 by volume)₃Assembling the button cell for the electrolyte at 3mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Comparative example 7

The doping of sulfide by selenide is specifically as follows:

0.12g of porous carbon spheres (specific surface area 100 m)²The preparation method comprises the following steps of mixing 0.16g of magnesium sulfide powder and 50mL of particle-removed water, adding the mixture into a hydrothermal reaction kettle after mixing, keeping the temperature at 180 ℃ for 80 hours, cleaning, filtering and drying the material, taking elemental selenium as a selenium source, carrying out selenium doping in a double-temperature-zone tubular furnace, wherein the temperature of the selenium source is 400 ℃, the temperature of a sample zone is 350 ℃, the heating rate is 3 ℃/min, the heat preservation time is 30min, and the cooling rate is 5 ℃/min, so as to obtain the porous carbon sphere material loaded with selenium magnesium sulfide nanoparticles. Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 3mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Example 2

Full cell case:

0.3 porous carbon spheres (specific surface area 150 m)²0.81g of zinc selenide powder and 60mL of deionized water are mixed and then added into a hydrothermal reaction kettle, the temperature is kept at 160 ℃ for 75 hours, the material is cleaned, filtered and dried to obtain zinc selenide @ porous carbon spheres, elemental sulfur is used as a sulfur source, sulfur doping is carried out in a double-temperature-zone tube furnace, the temperature of the sulfur source is 180 ℃, the temperature of a sample zone (vulcanization temperature) is 200 ℃, the heating rate is 1 ℃/min, the heat preservation time is 550min, and the cooling rate is 3 ℃/min, so that the selenium-loaded zinc sulfide nanoparticles (ZnS) are obtained_0.81Se_0.19) Porous carbon sphere material (ZnS)_0.81Se_0.19@ duoPorous carbon spheres). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 20 μm. Then depositing 50mAh/cm into the hollow carbon sphere cavity through electrochemical deposition²The lithium metal (2) was used as a negative electrode, a sulfur positive electrode (sulfur loading 52%) was used as a positive electrode, and 1M LiTFSI/DOL DME (volume ratio 1: 1) contained 1 wt.% LiNO₃The whole cell was assembled for the electrolyte (E/S20) at 3mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 1.

Example 3

0.3g of porous carbon spheres (specific surface area 146 m)²Mixing 2.77g of indium selenide powder and 55mL of deionized water, adding the mixture into a hydrothermal reaction kettle, keeping the temperature at 170 ℃ for 72 hours, cleaning, filtering and drying the material, carrying out sulfur doping In a double-temperature-zone tube furnace, wherein the temperature of a sulfur source is 250 ℃, the temperature of a sample zone is 200 ℃, the heating rate is 3 ℃/min, the heat preservation time is 450min, and the cooling rate is 6 ℃/min to obtain the selenium-loaded indium sulfide nano particles (In)₂(S_0.74Se_0.26)₃) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (thickness 10 μm) to a coating thickness of 50 μm. Then depositing 50mAh/cm into the cavity of the porous carbon sphere through electrochemical deposition²The metal lithium of (2) was used as a negative electrode, the ternary material (811) was used as a positive electrode, and 1.0M LiPF was used₆in EC: DMC: DEC: 1:1:1 Vol% with 1.0% VC as electrolyte (E/S: 5) to carry out the whole cell assembly, and the charge-discharge cycle test is carried out under the current of 1C. The results of the tests are shown in table 1.

Example 4

Porous carbon spheres (specific surface area 205 m)²(g), the carbon wall thickness is 20nm, the volume of an internal cavity accounts for 83 percent of the total volume), 0.15g of aluminum selenide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, the temperature is kept at 140 ℃ for 84 hours, the material is cleaned, filtered and dried, sulfur doping is carried out in a double-temperature-zone tubular furnace, the temperature of a sulfur source is 270 ℃, and the temperature of a sample zone is 280 DEG CHeating rate of 4 ℃/min, heat preservation time of 420min and cooling rate of 10 ℃/min to obtain the selenium-loaded aluminum sulfide nano particles (Al)₂(S_0.71Se_0.29)₃) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 40 μm. Then depositing 50mAh/cm into the hollow carbon sphere cavity through electrochemical deposition²The lithium metal of (2) was used as a negative electrode, air was used as a positive electrode, and 1.0M LiClO was used as a negative electrode₄in DMSO was used as an electrolyte (E/S ═ 10) to perform all-cell assembly, and a charge-discharge cycle test was performed at a current of 1C. The results of the tests are shown in table 1.

TABLE 1

Compared with the comparative examples 1 to 4 and 1 to 7, the composite planar metallic lithium anode loaded with the metal selenide sulfide nano particles has the best cycle performance.

Example 5

0.3g of porous carbon spheres (the specific surface area is 224m2/g, the carbon wall thickness is 32nm, and the volume of an internal cavity accounts for 78% of the total volume), 1.64g of zinc selenide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, the mixture is subjected to heat preservation at 150 ℃ for 24 hours, the material is cleaned, filtered and dried, sulfur doping is carried out in a dual-temperature-zone tube furnace, the temperature of a sulfur source is 300 ℃, the temperature of a sample zone is 320 ℃, the temperature rise rate is 5 ℃/min, the heat preservation time is 300min, and the temperature drop rate is 8 ℃/min, so that the selenium-loaded zinc sulfide nanoparticles (ZnS)_0.69Se_0.31) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 40 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 2 wt.% LiNO₃Assembling the button cell for the electrolyte at 4mA/cm²At the current density of (3), a charge-discharge cycle test was performed. Results of the testAs shown in table 2.

Example 6

0.3g of hollow carbon spheres (specific surface area 150 m)²The carbon wall thickness is 30nm respectively, the internal cavity volume accounts for 90 percent of the total volume), 1.03g of magnesium selenide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, the temperature is kept at 120 ℃ for 96 hours, the material is cleaned, filtered and dried, sulfur doping is carried out in a double-temperature-zone tube furnace, the temperature of a sulfur source is 200 ℃, the temperature of a sample zone is 250 ℃, the temperature rising rate is 2 ℃/min, the temperature keeping time is 200min, and the temperature reducing rate is 12 ℃/min, thus obtaining the selenium-loaded magnesium sulfide nano particles (ZnS) (ZnS with the temperature of a sample zone being 2 ℃/_0.81Se_0.19) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (thickness 10 μm) to a coating thickness of 30 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 5mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 2.

Example 7

0.3g of porous carbon spheres (specific surface area 250 m)²The method comprises the steps of mixing 1.42g of aluminum selenide powder and 50mL of deionized water, adding the mixture into a hydrothermal reaction kettle after mixing the aluminum selenide powder and 50mL of deionized water, preserving heat for 48 hours at 160 ℃, cleaning, filtering and drying the material, carrying out sulfur doping in a double-temperature-zone tube furnace, wherein the temperature of a sulfur source is 280 ℃, the temperature of a sample zone is 360 ℃, the heating rate is 4 ℃/min, the heat preservation time is 180min, and the cooling rate is 8 ℃/min, thus obtaining the selenium-loaded aluminum sulfide nano particles (Al-loaded aluminum sulfide nano particles)₂(S_0.86Se_0.14)₃) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (thickness 10 μm) to a coating thickness of 30 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 2mA/cm²At the current density of (3), a charge-discharge cycle test was performed. Test knotAs shown in table 2.

TABLE 2

Example 8

0.3g of porous carbon spheres (specific surface area 210 m)²Mixing the powder of indium selenide 1.2g and 50mL of deionized water, adding the mixture into a hydrothermal reaction kettle, preserving the temperature at 120 ℃ for 84 hours, cleaning, filtering and drying the material, carrying out sulfur doping in a tubular furnace with double temperature regions, wherein the temperature of a sulfur source is 260 ℃, the temperature of a sample region is 250 ℃, the heating rate is 2 ℃/min, the heat preservation time is 30min, and the cooling rate is 2 ℃/min to obtain the selenium-loaded indium sulfide nanoparticles (Al)₂(S_0.86Se_0.14)₃) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 40 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 8mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 3.

Example 9

0.3g of porous carbon spheres (specific surface area 250 m)²The preparation method comprises the following steps of (1)/g, the carbon wall thickness is 25nm, the internal cavity volume accounts for 92%), mixing 0.91g of zinc selenide powder and 50mL of deionized water, adding the mixture into a hydrothermal reaction kettle, preserving heat at 150 ℃ for 72 hours, cleaning, filtering and drying the material, carrying out sulfur doping in a dual-temperature-zone tube furnace, wherein the sulfur source temperature is 300 ℃, the sample zone temperature is 200 ℃, the heating rate is 8 ℃/min, the heat preservation time is 100min, and the cooling rate is 8 ℃/min, so that the selenium-loaded zinc sulfide nanoparticles (ZnS) are obtained_0.47Se_0.53) The porous carbon sphere material of (1). . Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (10 μm thick) to a coating thickness of 40 μm. The electrode is used as a working electrode and is made of goldThe lithium sheet is used as a counter electrode, 1M LiTFSI/DOL: DME (volume ratio of 1: 1) contains 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 5mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 3.

Example 10

0.3g of porous carbon spheres (specific surface area 240 m)²The carbon wall thickness is 24nm, the internal cavity volume accounts for 86 percent), 3g of aluminum selenide powder and 50mL of deionized water are mixed and then added into a hydrothermal reaction kettle, the temperature is kept at 140 ℃ for 60 hours, the material is cleaned, filtered and dried, sulfur doping is carried out in a dual-temperature-zone tubular furnace, the sulfur source temperature is 320 ℃, the sample zone temperature is 480 ℃, the temperature rise rate is 10 ℃/min, the heat preservation time is 30min, and the temperature drop rate is 12 ℃/min, thus obtaining the selenium-loaded aluminum sulfide nano particles (Al)₂(S_0.24Se_0.76)₃) The porous carbon sphere material of (1). Then mixing the mixture with polyvinylidene fluoride according to the mass ratio of 9: 1, slurried with NMP, and coated on a copper foil (thickness 10 μm) to a coating thickness of 200 μm. The electrode was used as a working electrode, a lithium metal sheet was used as a counter electrode, and 1M LiTFSI/DOL: DME (volume ratio 1: 1) contained 1 wt.% LiNO₃Assembling the button cell for the electrolyte at 4mA/cm²At the current density of (3), a charge-discharge cycle test was performed. The results of the tests are shown in table 3.

TABLE 3

By adopting the material provided by the invention, the sulfur is doped into the selenide, so that the obtained co-doped compound has a good effect of inducing lithium deposition, and the coulomb efficiency and the cycle capacity of the first circle of the Li-jin book battery can be improved.