CN113013402A

CN113013402A - Glass positive electrode material, preparation method and application thereof

Info

Publication number: CN113013402A
Application number: CN202110175030.6A
Authority: CN
Inventors: 李长久; 孔凡厚; 梁雪; 易兰林; 张瑞翔; 饶寅朝
Original assignee: Hainan University
Current assignee: Hainan University
Priority date: 2021-02-07
Filing date: 2021-02-07
Publication date: 2021-06-22

Abstract

The invention provides a glass anode material, which comprises active substance glass powder; the active material glass powder comprises a network-forming adult halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_n(ii) a The network forms the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (10-50): (30-80): (10-40); a. the values of y and n balance the valency. Compared with the prior art, the glass cathode material provided by the invention takes the specific glass powder as the active substance, so that the glass cathode material takes the specific glass powder as the active substanceThe lithium ion battery assembled by the glass anode material has large specific capacity, high voltage and small loss rate of the first circle; and the preparation method of the glass anode material is simple, easy to implement and beneficial to popularization and application.

Description

Glass positive electrode material, preparation method and application thereof

Technical Field

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a glass cathode material, and a preparation method and application thereof.

Background

The lithium ion battery is a new generation of green high-energy battery with excellent performance, and has become one of the key points of high and new technology development. The lithium ion battery has the following characteristics: high voltage, high capacity, low consumption, no memory effect, no public hazard, small volume, small internal resistance, less self-discharge and more cycle times. Because of the above characteristics, lithium ion batteries have been applied to various civil and military fields such as mobile phones, notebook computers, video cameras, digital cameras, and the like.

The main constituent materials of the lithium ion battery include electrolyte, isolating material, anode and cathode materials and the like. The anode material of the lithium ion battery is mainly cobalt, manganese, nickel and the like and composite oxides thereof. Commercial applications have demonstrated high potential and stability of these materials, but with low specific capacity (205 mAh/g). For example, lithium cobaltate (LiCoO) is the earliest commercially available positive electrode material₂) The theoretical specific capacity of the catalyst is 273mAh/g, but the actual specific capacity is only about 140mAh/g, and the catalyst also has the defects of high price and high toxicity; albeit lithium nickelate (LiNiO)₂) The specific capacity can reach 150mAh/g, which is slightly higher than LiCoO₂However, in LiNiO₂In the synthesis process, lithium is easy to be lost, and LiNiO meeting the standard chemical composition is synthesized₂Is difficult; with LiCoO₂In contrast, lithium manganate (LiMnO)₄) The price is low, but the theoretical specific capacity is lower (148mAh/g), and the cycle performance is poor; lithium iron phosphate (LiFeO)₄) The theoretical specific capacity of the material can reach 170mAh/g, but the conductivity is poor, and the energy density is low. The theoretical specific capacity of the graphite of the negative electrode is 372mAh/g, and the actual specific capacity reaches 360 mAh/g. Therefore, the specific capacity of the lithium ion battery is limited by the positive electrode material. These factors restrict the improvement of the performance of the lithium ion battery, and research and development of a novel high-performance anode material are urgently needed to meet the application of energy storage equipment. The search space for high energy density cathode materials is expanded to cation disordered lithium transition metal oxides.

Publication No. isCN105742616A China patent general Li_1+aNi_bTi_cNb_dO₂Adding into NaOH solution, adding Bi (NO)₃)₃And Ca (NO)₃)₂Continuously stirring at the temperature of 50-80 ℃, finally filtering, and heating the solid-phase substance at the temperature of 400-700 ℃ for 5-15 h to obtain CaO/Bi₂O₃/Li_1+aNi_bTi_cNb_dO₂. XRD tests show that the prepared anode material has a disordered rock salt structure; electrochemical performance tests show that the material is charged and discharged between 1.5 and 4.5V, and the first discharge capacity is up to 262mAhg^-1And has good rate performance and cycle performance, and 1C discharge capacity reaches 205mAhg^-1And the capacity retention rate after 50 cycles of 1C is 94.5%.

Chinese patent publication No. CN107925080A discloses embodiments relating to cation-disordered lithium metal oxide compounds, methods of making and uses thereof. In one embodiment, the cation-disordered lithium metal oxide comprises Li with a greater than 1_aM_bM′_cO₂. M comprises at least one redox-active substance having a first oxidation state n and an oxidation state n' greater than n, and M is chosen so as to have the formula LiMO₂The lithium-M oxide of (a) forms a cation-disordered rock salt structure. M' comprises at least one charge compensating species having an oxidation state y greater than n.

Chinese patent publication No. CN111225877A discloses a disordered halite lithium metal oxide and oxyfluoride, such as manganese-vanadium oxide and oxyfluoride, that is well suited for use in high capacity lithium ion battery electrodes, such as electrodes in lithium ion rechargeable batteries. Examples of lithium metal oxides or oxyfluorides are those having the general formula: one of LixM' aM "bO 2-yFy, wherein the lithium metal oxide or oxyfluoride has a cation disordered rock salt structure of one of (a) or (b), wherein (a) 1.09. ltoreq. x.ltoreq.1.35, 0.1. ltoreq. a.ltoreq.0.7, 0.1. ltoreq. b.ltoreq.0.7, and 0. ltoreq. y.ltoreq.0.7; m' is a lower-valent transition metal, and M "is a higher-valent transition metal; and (b) 1.1. ltoreq. x.ltoreq.1.33, 0.1. ltoreq. a.ltoreq.0.41, 0.39. ltoreq. b.ltoreq.0.67 and 0. ltoreq. y.ltoreq.0.3; m' is Mn; m "is V or Mo. The oxide or oxyfluoride balances the available lithium capacity and the transition metal capacity. One straightforward example of an application is high density energy storage lithium cathode battery materials where cathode energy is a critical factor in overall performance. The second structure (b) is optimized for the maximum available Li capacity.

Chinese patent publication No. CN109417169A discloses a disordered rock salt composition used as a positive electrode active material. The stoichiometry of the lithium, niobium, oxygen, and transition metal components of the disordered halite is varied to improve performance in an electrochemical cell while substantially maintaining the disordered halite crystal structure.

Chinese patent with publication number CN109305700A discloses a preparation method of a niobium/tantalum cation-containing disordered rock salt structure cathode material, belonging to the field of new energy materials. The method adopts a stable water-soluble citric acid Nb/Ta precursor, synthesizes the oxide anode material containing the Nb/Ta cation disordered rock salt structure by a wet chemical method, and has the advantages of simple synthesis process, easy reaction control, high production efficiency and no need of special equipment/protection. The invention can improve the phase purity of the oxide, optimize the grain size and the like, and simultaneously improve the electrochemical performance of the oxide anode material.

Chinese patent publication No. CN107546384A discloses a lithium ion battery positive electrode material with a disordered rock salt structure and a preparation method thereof, wherein lithium salt, nickel salt and chromium salt are weighed according to stoichiometric ratio, and are dissolved in absolute ethyl alcohol to prepare a metal salt solution; and then, adding the metal salt solution while stirring the complexing agent solution under the action of an ultrasonic external field for reaction, controlling the temperature to be 40-60 ℃, and controlling the adding speed of the complexing agent solution to uniformly disperse ions in the reaction system. Putting the reacted solution in an ultrasonic external field, stirring uniformly, adding an acetic acid solution, adding a titanium salt solution, and finally adding ZrO (C)₃H₇)₄And MgF₂Continuously stirring until jelly is formed, drying and cooling to obtain dry gel; then, the dry gel is placed in a ball milling tank for ball milling treatment; and finally, placing the dried gel subjected to ball milling treatment in a muffle furnace for calcining to obtain a sample.

Chinese patent publication No. CN110372039A discloses a method for preparing a positive electrode material with a cation disordered rock salt structure by a high valence transition metal ion displacement combination strategy, which comprises mixing a lithium salt with an oxide of a high valence transition metal element M (at least one of Ti, V2, Nb, Mo, and Zr), an oxide of M' (at least one of Fe, Ni, and Mn), and a fluorine salt by a solid phase ball milling method, and then performing high temperature treatment, thereby obtaining the positive electrode material with high charge-discharge specific capacity and cycle stability.

Chinese patent with publication number CN111211319A discloses a group IV-VI-VIII lithium-rich disordered rock salt structure cathode material and a preparation method thereof, belonging to the technical field of energy storage materials and electrochemistry. The IV-VI-VIII family lithium-rich disordered rock salt structure cathode material provided by the patent has a three-dimensional disordered cation framework structure, can stabilize oxygen crystal lattices in a lithium-rich oxide cathode material and oxygen valence-change reaction, improves the lithium ion migration capacity and improves the material cycle performance; in addition, fluorine doping is beneficial to improving the capacity retention rate of the material and inhibiting the irreversible oxygen loss of the material, so that the electrochemical performance of the material is further improved.

In lithium ion batteries, the phenomenon of anomalous excess capacity beyond the theoretical limit of transition metal compound materials has attracted considerable attention. The amorphous material has no fixed structure at grain boundaries, and lithium ions can be stored at various positions, such as vacancies, voids, clusters, or interstitial positions of cations and anions. Due to the lack of irreversible transformation and trapping of lithium, and the large number of vacancies that lithium ions can readily enter. The solid solution can effectively solve the problem of high solubility; the components of the solid solution can be flexibly adjusted according to the microstructure and the performance of the solid solution; the glass may partially crystallize during heat treatment.

Semiconductor oxide glass is considered to be an electrode material of a lithium ion battery with great potential application prospect. Prior patents have disclosed the use of composite vanadium phosphorus glasses for lithium ion battery positive electrode materials, such as V₂O₅-Li₃PO₄-CaC₂(CN111484247A)、V₂O₅-LiBO₂Graphene (CN111668468A), the lithium ion battery assembled by the anode material has high specific capacity and strong battery cycling stability, and can improve electricityThe transport rate of ions and the suppression of volume expansion during charge and discharge. But the problems of small specific capacity, large internal resistance, low voltage, large loss rate of the first ring and the like.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a glass positive electrode material, a preparation method and an application thereof, and a lithium ion battery assembled by the glass positive electrode material has the advantages of large specific capacity, high voltage and small first-turn loss rate.

The invention provides a glass anode material, which comprises active substance glass powder; the active material glass powder comprises a network-forming adult halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_n；

The network forms the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (10-50): (30-80): (10-40);

a. the values of y and n balance the valency.

Preferably, the network-forming adult MX halide_aM in (A) is selected from one or more of Be, Al, Zn, Ag and Pb;

the network forms the halide MX_aX in the formula (I) is selected from one or more of F, Cl, Br and I;

said transition metal oxide DO_yD in (A) is selected from one or more of Fe, V, Zr, Sb, Mo, Cr, Nb, Ta, Ni, Co, Cu and Mn;

said network exo-oxide AO_nA In (A) is selected from one or more of Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, In, La, Zr, Th, Be, Mg, Zn, Al and Ga.

Preferably, the network-forming adult MX halide_aSelected from BeF₂、AlF₃、ZnCl₂、AgCl、AgBr、AgI、PbCl₂、PbBr₂And PbI₂One or more of;

said transition metal oxide DO_ySelected from Fe₂O₃、V₂O₅、Nb₂O₅、Ta₂O₅、NiO、Co₂O₃With Mn₂O₇One or more of;

said network exo-oxide AO_nSelected from Li₂O、Na₂O、K₂O、Rb₂O、Cs₂O、CaO、SrO、BaO、Y₂O₃、In₂O₃、La₂O、ZrO₂、ThO₂、BeO、MgO、ZnO、Al₂O₃、Ga₂O₃、SnO、PbO、SnO₂、Te₂O₅、Te₂O₃And Sb₂O₃One or more of (a).

Preferably, the network-forming adult MX halide_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (15-40): (40-70): (10-20).

Preferably, the glass cathode material further comprises a binder and a conductive filler; the mass ratio of the active substance glass powder to the binder to the conductive filler is (6-10): (2-3): (1-2).

The invention also provides a preparation method of the glass cathode material, which comprises the following steps:

formation of the network into the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nMixing, heating to 500-800 ℃ in a protective atmosphere, preserving heat for 100-300 min, continuing heating to 1000-2000 ℃, preserving heat for 10-30 min, cooling and forming, and annealing to obtain glass;

grinding the glass to obtain active substance glass powder;

and mixing the active material glass powder, the binder, the conductive filler and the solvent, ball-milling, and coating on a current collector to obtain the glass anode material.

Preferably, the temperature of the annealing treatment is 200-300 ℃; the time of the annealing treatment is 200-2000 min.

Preferably, the particle size of the active material glass powder is not more than 400 mesh.

Preferably, the temperature is increased to 500-800 ℃ at the speed of 5-15 ℃/min;

heating to 1000-2000 ℃ at the speed of 5-15 ℃/min.

The invention also provides a lithium ion battery which comprises the glass anode material.

The invention provides a glass anode material, which comprises active substance glass powder; the active material glass powder comprises a network-forming adult halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_n(ii) a The network forms the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (10-50): (30-80): (10-40); a. the values of y and n balance the valency. Compared with the prior art, the glass anode material provided by the invention takes the specific glass powder as the active substance, so that the lithium ion battery assembled by the glass anode material has large specific capacity, high voltage and small first-turn loss rate; and the preparation method of the glass anode material is simple, easy to implement and beneficial to popularization and application.

Drawings

FIG. 1 is an XRD spectrum of a glass powder obtained in example 3 of the present invention;

FIG. 2 is a SEM scanning electron microscope photograph of the glass powder obtained in example 5 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a glass anode material, which comprises active substance glass powder; the active material glass powder comprises a network-forming adult halide MX_aTransition metal oxide DO_yWith exo-network oxide AO_n(ii) a The network forms the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (10-50): (30-80): (10-40); a. the values of y and n balance the valency.

In the present invention, the sources of all raw materials are not particularly limited, and they may be commercially available.

The glass cathode material provided by the invention takes glass powder as an active substance. The molecular arrangement of the glass is random, with the molecules having statistical uniformity in space. Ideally, the physical and chemical properties (e.g., refractive index, hardness, elastic modulus, coefficient of thermal expansion, thermal conductivity, electrical conductivity, etc.) of homogeneous glasses are the same in all directions. The glassy substance is generally obtained by rapidly cooling a molten body, when the glassy substance is converted from a molten state to a glassy state, the viscosity is rapidly increased in the cooling process, particles are not in time to be regularly arranged to form crystals, and latent heat of crystallization is not released, so that the glassy substance contains higher internal energy than the crystalline substance, and the energy of the glassy substance is between the molten state and the crystalline state and belongs to a metastable state. From a mechanical point of view, glass is an unstable high-energy state, and has a tendency to transform into a low-energy state, i.e., to devitrify, and therefore, is a metastable solid material. Moreover, the process of the glassy substance from a molten state to a solid state is gradual, and the change of the physical and chemical properties of the glassy substance is continuous and gradual. This is in marked contrast to the crystallization of melts, which necessarily involves the appearance of new phases, and near the crystallization temperature point, many properties are subject to abrupt changes. The glassy substance is finished in a wider temperature range from a molten state to a solid state, the viscosity of the glass melt is gradually increased along with the gradual reduction of the temperature, and finally solid glass is formed, but no new phase is formed in the process. Conversely, the process of heating the glass to become molten is also gradual.

The main raw materials for glass production comprise a glass forming body, a glass modifier and a glass intermediate, and the balance is auxiliary raw materials. Wherein, the main raw materials refer to an oxide, an intermediate oxide and an extranet oxide which are introduced into the glass to form a network; the auxiliary raw materials comprise a clarifying agent, a fluxing agent, an opacifier, a coloring agent, a decoloring agent, an oxidant, a reducing agent and the like.

In the present invention, the active material powder comprises a network-forming adult halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_n(ii) a The network forms the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (10-50): (30-80): (10-40), preferably (15-40): (40-70): (10-20); in some embodiments provided herein, the network-forming agent is MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (A) to (B) is specifically 20: 60: 20; in some embodiments provided herein, the network-forming agent is MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (A) to (B) is specifically 15: 65: 20; in some embodiments provided herein, the network-forming agent is MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (A) to (B) is specifically 20: 65: 15; in some embodiments provided herein, the network-forming agent is MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (A) to (B) is specifically 25: 60: 15; in other embodiments provided herein, the network-forming agent is MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (A) to (B) is specifically 40: 50: 10.

the network forms the halide MX_aM in (3) is preferably one or more of Be, Al, Zn, Ag and Pb; the network forms the halide MX_aX in (3) is preferably one or more of F, Cl, Br and I; in the present invention, the network-forming adult MX halide_aPreferably BeF₂、AlF₃、ZnCl₂、AgCl、AgBr、AgI、PbCl₂、PbBr₂And PbI₂One or more of (a).

Said transition metal oxide DO_yD in (1) is preferably Fe, V, Zr,One or more of Sb, Mo, Cr, Nb, Ta, Ni, Co, Cu and Mn; in the present invention, the transition metal oxide DO_yPreferably Fe₂O₃、V₂O₅、Nb₂O₅、Ta₂O₅、NiO、Co₂O₃With Mn₂O₇One or more of (a).

Said network exo-oxide AO_nA In (A) is preferably one or more of Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, In, La, Zr, Th, Be, Mg, Zn, Al and Ga; said network exo-oxide AO_nPreferably Li₂O、Na₂O、K₂O、Rb₂O、Cs₂O、CaO、SrO、BaO、Y₂O₃、In₂O₃、La₂O、ZrO₂、ThO₂、BeO、MgO、ZnO、Al₂O₃、Ga₂O₃、SnO、PbO、SnO₂、Te₂O₅、Te₂O₃And Sb₂O₃One or more of (a).

According to the present invention, the glass positive electrode material preferably further comprises a binder and a conductive filler; the mass ratio of the active substance glass powder to the binder to the conductive filler is preferably (6-10): (2-3): (1-2), more preferably (6-8): (2-3): (1-2); in the embodiment provided by the invention, the mass ratio of the active material glass powder to the binder to the conductive filler is specifically 7: 2: 1; the binder is preferably polyvinylidene fluoride; the conductive filler is preferably conductive carbon black.

The glass anode material provided by the invention takes the specific glass powder as an active substance, so that the lithium ion battery assembled by the glass anode material has large specific capacity, high voltage and small first-turn loss rate; and the preparation method of the glass anode material is simple, easy to implement and beneficial to popularization and application.

The invention also provides a preparation method of the glass cathode material, which comprises the following steps: formation of the network into the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nMixing, heating to 500-800 ℃ in a protective atmosphere, preserving heat for 100-300 min, continuing heating to 1000-2000 ℃, preserving heat for 10-30 min, cooling and forming, and annealing to obtain glass; grinding the glass to obtain active substance glass powder; and mixing the active material glass powder, the binder, the conductive filler and the solvent, ball-milling, and coating on a current collector to obtain the glass anode material.

Wherein the network forms a somatic halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nThe types and the proportions of the components are the same as those described above, and are not described herein again.

Formation of the network into the halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_nMixing, heating to 500-800 ℃ in a protective atmosphere, and keeping the temperature for 100-300 min; the protective atmosphere is not particularly limited as long as it is known to those skilled in the art, and argon is preferred in the present invention; in the invention, the temperature is preferably raised to 500-800 ℃ at the speed of 5-15 ℃/min, and more preferably raised to 500-800 ℃ at the speed of 5-10 ℃/min; in the present invention, the temperature is preferably raised to 600 to 800 ℃, more preferably raised to 650 to 750 ℃ for heat preservation; in the embodiment provided by the invention, the temperature is specifically raised to 700 ℃ for heat preservation; the heat preservation time is preferably 100-200 min.

Then continuously heating to 1000-2000 deg.C, preferably continuously heating to 1000-1500 deg.C, and making heat preservation; the heat preservation time is 10-30 min, preferably 10-20 min; in the invention, the temperature is preferably raised to 1000-2000 ℃ at a rate of 5-15 ℃/min, and more preferably raised to 1000-2000 ℃ at a rate of 10-15 ℃/min.

After the heat preservation is finished, cooling and forming; in the invention, the liquid tin surface is preferably cooled and formed; spreading and flattening the molten glass on the molten tin surface to form flat upper and lower surfaces, hardening, cooling and introducing into a transition roller table.

Finally, annealing treatment is carried out to obtain glass; the temperature of the annealing treatment is preferably 200-300 ℃; the time of the annealing treatment is preferably 200-2000 min, more preferably 200-1000 min, and further preferably 200-500 min; in the embodiment provided by the invention, the time of the annealing treatment is specifically 300 min.

Grinding the glass to obtain active substance glass powder; the grinding is preferably carried out by means of a ball mill; the particle size of the active material glass powder is preferably 400 mesh or less.

Mixing the active material glass powder, the binder, the conductive filler and the solvent, ball-milling, and coating on a current collector; the mass ratio of the active substance glass powder to the binder to the conductive filler is preferably (6-10): (2-3): (1-2), more preferably (6-8): (2-3): (1-2); in the embodiment provided by the invention, the mass ratio of the active material glass powder to the binder to the conductive filler is specifically 7: 2: 1; the binder is preferably polyvinylidene fluoride; the particle size of the conductive filler is preferably 1-10 mu m; the conductive filler is preferably conductive carbon black. The solvent is preferably N-methylpyrrolidone; the current collector is preferably an aluminum foil; the coating thickness is 60-120 μm.

After coating, the resultant was dried to obtain a glass positive electrode material.

The preparation method provided by the invention is simple, easy to implement and beneficial to popularization and application.

In order to further illustrate the present invention, the following describes a glass cathode material, a preparation method and applications thereof in detail with reference to examples.

The reagents used in the following examples are all commercially available.

Example 1

20 parts of BeF by weight ₂60 parts of Fe₂O₃20 parts of Li₂And O, mixing, stirring and grinding uniformly, and transferring the obtained mixed raw material into an alumina crucible. Melting in a tubular heating furnace under the protection of argon, heating to 700 ℃ at the heating rate of 5 ℃/min, and keeping the temperature for 100 min; raising the temperature to 1000 ℃ at the heating rate of 15 ℃/min, and keeping the temperature for 30 min; quickly mix the mixed solutionPouring liquid tin on the surface to form the glass. Spreading and flattening the molten glass on the molten tin surface to form flat upper and lower surfaces, hardening, cooling and leading the glass to a transition roller table. The rollers of the roller table rotate to pull the glass ribbon out of the tin bath and enter an annealing furnace, the furnace body temperature is 200 ℃, and the glass is obtained after annealing for 300 min.

The glass was crushed, sufficiently ground using a ball mill, and sieved (400 mesh) to obtain a glass powder.

And (3) mixing the following components in a mass ratio of 7: 2: 1, mixing glass powder, a binder (polyvinylidene fluoride) and conductive carbon black (the particle size distribution is 1-10 mu m) powder, then dripping a proper amount of solvent N-methyl pyrrolidone (accounting for 20 percent of the powder) for ball milling, coating the obtained slurry on an aluminum foil, drying, coating the aluminum foil with the thickness of 120 mu m, then taking the aluminum foil as a positive electrode, and adding 1mol/L LiPF₆Is ethylene carbonate/dimethyl carbonate (volume ratio 1:1) electrolyte, Celgard 2025 is a diaphragm, a lithium sheet is a counter electrode, and the CR2025 type coin cell is assembled in a glove box. And testing the charge and discharge performance of the comparative sample lithium ion battery under different current densities within the voltage range of 2.0-4.2V on an electrochemical workstation.

Examples 2 to 5

Following the procedure of example 1, the different networks formed the body halide MX_a，VO_yTransition metal oxide, AO_nThe type and amount of exo-network oxide added are shown in Table 1.

TABLE 1 kinds and amounts of raw materials used for preparing glass cathode materials in examples 1 to 5

Examples	MSx	Number of parts	VO_y	Number of parts	AO_n	Number of parts
							1	BeF₂	20	Fe₂O₃	60	Li₂O	20
2	AlF₃	15	V₂O₅	65	K₂O	20
							3	PbCl ₂	20	Nb₂O₅	65	Te₂O₅	15
4	PbBr₂	25	Co₂O₃	60	Al₂O₃	15
							5	AgBr	40	Mn₂O₇	50	Te₂O₅	10

FIG. 1 is an XRD spectrum of a glass powder prepared in example 3 of the present invention;

FIG. 2 is a SEM scanning electron microscope photograph of glass powder prepared in example 5 of the present invention.

Comparative example 1

Drying the V₂O₅Powder with P₂O₅Mixing the powders at stoichiometric ratio, melting in hydrogen atmosphere to obtain 80V powder₂O₅·20P₂O₅Glass samples. The mixture was stirred and mixed uniformly and then put into a quartz crucible. And melting the glass by adopting a tube furnace. Heating at 800 ℃ for 5min to obtain a vanadium phosphorus glass sample melt. The molten glass was poured onto an iron plate, followed by annealing in a muffle furnace at 250 ℃ for 2 hours, and then furnace-cooled. Grinding the prepared glass into powder with agate mortar and the particle size<20μm。

The electrode is formed by mixing an active material (vanadium phosphorus glass powder), carbon black and a Polytetrafluoroethylene (PTFE) binder according to a mass ratio of 8:1.5: 0.5. The weighed vanadium phosphorus glass powder and carbon black are put into an agate mortar to be ground for 30 minutes to obtain a uniform mixture. Then, polytetrafluoroethylene was added to the prepared mixture, and vigorous mixing was performed to obtain a uniform film (thickness 80 μm). Punching the prepared cathode film into a wafer by using a circular cutter with the diameter of 8mm, and then uniformly punchingThe ground is stuck on the aluminum net. Then, a CR2032 coin cell (316L stainless steel, polypropylene gasket) was used as a cathode, and 1mol/L LiPF was used₆Is ethylene carbonate/dimethyl carbonate (volume ratio 1:1) electrolyte, Celgard 2025 is a diaphragm, a lithium sheet is a counter electrode, and the CR2032 coin cell is assembled in a glove box. And testing the charge and discharge performance of the comparative sample lithium ion battery under different current densities within the voltage range of 2.0-4.2V on an electrochemical workstation. The test data showed a first time of 270mAh g^-1Has a capacity retention rate of about 90% after 100 cycles. Furthermore, after 300 cycles at 85mA g^-1Can provide 220mAh g under high current density^-1The specific capacity of (A) corresponds to a capacity retention rate of 80%.

The performance test results of the lithium ion batteries assembled by the glass cathode materials prepared in examples 1 to 5 and comparative example 1 are shown in table 2.

TABLE 2 Performance test results for glass cathode assembled batteries prepared in examples 1-5 of the present invention

As can be seen from the above examples, the present invention provides a glass positive electrode material, the active material composition form of the glass positive electrode material is MX_a-DO_y-AO_nThe concrete weight portions are respectively 10-50 portions of MX_a30-80 parts by mass of network product halide_y10-40 parts by mass of transition metal oxide (AO)_nA network exo-oxide. Performance range: the open-circuit voltage is 3.8-4.2V; the first discharge capacity is 263-304 mAh/g; the first circulation coulombic efficiency is 87% -94%; the 100-cycle discharge capacity of the battery is 264-286 mAh/g, and the cycle efficiency is 91.5% -95%. The glass anode material provided by the invention has the problems of large specific capacity, high voltage, small first-turn loss rate and the like, and the preparation method provided by the invention has the advantages of simple process, easiness in implementation and contribution to popularization and application.

Claims

1. A glass anode material, which is characterized in thatCharacterized by comprising active material glass powder; the active material glass powder comprises a network-forming adult halide MX_aTransition metal oxide DO_yWith network exo-oxides AO_n；

a. the values of y and n balance the valency.

2. The glass positive electrode material as defined in claim 1, wherein the network-generating body MX is a halide_aM in (A) is selected from one or more of Be, Al, Zn, Ag and Pb;

3. The glass positive electrode material as defined in claim 1, wherein the network-generating body MX is a halide_aSelected from BeF₂、AlF₃、ZnCl₂、AgCl、AgBr、AgI、PbCl₂、PbBr₂And PbI₂One or more of;

4. The glass positive electrode material as defined in claim 1, wherein the network-generating body MX is a halide_aTransition metal oxide DO_yWith network exo-oxides AO_nThe mass ratio of (15-40): (40-70): (10-20).

5. The glass positive electrode material according to claim 1, further comprising a binder and a conductive filler; the mass ratio of the active substance glass powder to the binder to the conductive filler is (6-10): (2-3): (1-2).

6. A preparation method of a glass cathode material is characterized by comprising the following steps:

grinding the glass to obtain active substance glass powder;

7. The preparation method according to claim 6, wherein the temperature of the annealing treatment is 200 ℃ to 300 ℃; the time of the annealing treatment is 200-2000 min.

8. The production method according to claim 6, wherein the particle size of the active material glass powder is 400 mesh or less.

9. The preparation method according to claim 6, wherein the temperature is raised to 500-800 ℃ at a rate of 5-15 ℃/min;

heating to 1000-2000 ℃ at the speed of 5-15 ℃/min.

10. A lithium ion battery, characterized by comprising the glass cathode material according to any one of claims 1 to 5 or the glass cathode material prepared by the preparation method according to any one of claims 6 to 9.