Positive electrode material, preparation method thereof and application of positive electrode material in hydrogen negative ion battery

Abstract

The invention relates to a positive electrode material. The positive electrode material contains a coordination aluminum hydride and an electrocatalyst. The chemical formula of the coordination aluminum hydride is AxMy (AlH4) x + y, A is selected from alkali metal, M is selected from alkaline earth metal, x is more than or equal to 0 and less than 5, and y is more than or equal to 0 and less than 5; the electrocatalyst is selected from at least one of simple substances, oxides or halides of transition metal elements. And the reaction kinetics of the coordination aluminum hydride of the electrode active material is improved, and the contact among the components is improved, so that the specific capacity of the electrode and the cycle performance are improved. The method is suitable for primary and secondary hydrogen anion batteries, the reaction degree of hydrogen anion electrode active substances is greatly improved, the energy density of hydrogen anions is improved, and the method has considerable application value.

Description

Technical Field

[0001] This application relates to a positive electrode material, its preparation method, and its application in hydrogen negative ion batteries, belonging to the field of electrode materials. Background Technology

[0002] Currently available lithium-ion batteries boast high energy density and ease of use, but their high cost and flammability have spurred the development of entirely new ion batteries for energy storage. While Na, K, and Mg ion batteries have made promising progress, issues such as dendrite formation and flammable electrolytes remain unresolved, hindering their widespread practical application. Therefore, developing a new generation of ion batteries remains essential. Recently, hydrogen negative ion batteries have garnered significant attention as a new generation of ion batteries based on hydrogen. Hydrogen is a low-cost raw material, and its low cost inherently avoids the flammability and explosion risks associated with dendrite formation.

[0003] Hydrogen energy possesses the dual attributes of both energy and matter, serving as a bridge between fossil fuels and renewable energy sources. Hydrogen-ion batteries, constructed based on hydrogen anion conductors, use hydrogen anion ions as charge carriers, storing and releasing charge while simultaneously completing the mass transfer step of hydrogen, thus showing broad application prospects in the field of energy storage and conversion. - Containing a single valence charge, it has a very low charge density and is easily polarized. Its standard redox potential is -2.3V, close to that of magnesium ions (-2.4V), while its atomic mass is only 1 / 24 that of magnesium. This makes it a promising candidate for a new generation of high-energy-density, high-potential batteries. However, due to the low proportion of electrode active materials participating in the reaction, the specific capacity and energy density of existing hydrogen ion battery electrodes are insufficient to meet application requirements. Summary of the Invention

[0004] This application provides a cathode material that incorporates transition metals, transition metal oxides, or halides as electrode catalysts to improve the reaction kinetics of coordinated aluminum hydrides in the electrode active material. It is suitable for gas-solid, all-solid, and liquid primary or secondary hydrogen anion batteries. It significantly enhances the reactivity of the hydrogen anion cathode and the battery capacity density, possessing strong practicality and application value.

[0005] According to one aspect of this application, a positive electrode material is provided, the positive electrode material comprising a coordinated aluminum hydride, an electrocatalyst, an electronic conductor, and an electrolyte;

[0006] The chemical formula of the coordinated aluminum hydride is A. x M y (AlH4) x+y , where A is selected from alkali metals, M is selected from alkaline earth metals, 0≤x<5, 0≤y<5;

[0007] Optionally, x is selected from any value of 0, 1, 2, 3, 4, 5 or any range of values ​​between two (excluding 5);

[0008] Optionally, y is selected from any value of 0, 1, 2, 3, 4, 5 or any range of values ​​between two (excluding 5);

[0009] The electrocatalyst is selected from at least one of the elemental, oxide, or halide forms of transition metals.

[0010] The alkali metal is selected from at least one of Li, Na, K, Rb, and Cs;

[0011] The alkaline earth metal is selected from at least one of Be, Mg, Ca, Sr, and Ba.

[0012] Optionally, the coordinated aluminum hydride is selected from at least one of LiAlH4, NaAlH4, KAlH4, Mg(AlH4)2, Ca(AlH4)2, and Ba(AlH4)2.

[0013] The transition metal element is selected from at least one element in groups IIIB to VIIB and VIII of the periodic table;

[0014] Optionally, the transition metal element is selected from at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, and Pd;

[0015] Optionally, the oxide of the transition metal is selected from at least one of TiO, V2O5, NiO, MnO, TiO2, MnO2, ZrO2, CrO4, and Ti2O3;

[0016] Optionally, the transition metal halide is selected from at least one of TiF3, TiCl3, CrCl5, ZrCl4, NiCl2, VF5, CoCl4, and MnCl2.

[0017] The electronic conductor has an electronic conductivity >10 under operating conditions. -4 Materials;

[0018] The electronic conductor is selected from one or more of carbon nanotubes, graphene, acetylene black, layered graphite, carbon fiber, and carbon black.

[0019] The electrolyte is selected from at least one rare earth metal hydride;

[0020] Optionally, the electrolyte is selected from YH x 、ScH x 、LaH x CeH x 、PrH x 、NdHx 、PmH x One or more of rare earth metal hydrides such as SmHx and EuHx.

[0021] The particle size of the electrode catalyst is 1 nm to 1 mm;

[0022] Optionally, the particle size of the electrode catalyst is 10 nm to 100 μm;

[0023] The particle size of the positive electrode active material is 10 nm to 1 mm.

[0024] Reducing particle size can significantly increase the specific surface area of ​​materials. Using active materials with smaller particle sizes and electrode catalysts can significantly increase the contact area between them, thereby optimizing the electrode reaction rate and extent.

[0025] In the cathode material, the content of the electrocatalyst is 0.1–50 wt%.

[0026] Optionally, the content of the electrocatalyst in the cathode material is 1 to 20 wt%.

[0027] Optionally, the content of the electrocatalyst in the cathode material is any value or a range between 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, and 20wt%.

[0028] In the cathode material, the content of the coordinated aluminum hydride is 20-90 wt%.

[0029] Optionally, the content of the coordinated aluminum hydride is 20-80 wt%.

[0030] Optionally, the content of the coordinated aluminum hydride is 40-80 wt%.

[0031] Optionally, the content of the coordinated aluminum hydride is 50-80 wt%.

[0032] Optionally, in the positive electrode material, the content of the coordinated aluminum hydride is any value or a range between 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, and 90wt%.

[0033] According to another aspect of this application, a method for preparing the above-mentioned positive electrode material is provided, comprising the following steps:

[0034] The cathode material is obtained by mixing raw materials containing coordinated aluminum hydride, electrocatalyst, electronic conductor and electrolyte.

[0035] The mixed atmosphere contains hydrogen and inactive gases;

[0036] The inactive gas is selected from at least one of nitrogen, argon, and helium;

[0037] The mixing process includes manual grinding, mechanical ball milling, and stirring.

[0038] For manual grinding; grinding time 5min≤x≤1h; choose agate, ceramic or stainless steel mortars; grind in the opposite direction at least 3 times during the grinding process.

[0039] For the aforementioned mechanical ball mill; the mechanical ball mill is a planetary ball mill; the ball milling speed is 100rpm≤x≤500rpm; the ball-to-material ratio is 50≤x≤100; and the ball milling time is 10min≤x≤20h.

[0040] For the stirring described above, the stirring can be done with a magnetic stirrer; the stirring speed is 100 rpm ≤ x ≤ 1000 rpm; the amount of material stirred in a single batch is 50 mg ≤ x ≤ 1 kg; and the stirring time is not less than 30 min.

[0041] According to another aspect of this application, an application of the above-mentioned positive electrode material in a hydrogen negative ion battery is provided, wherein the hydrogen negative ion battery is a primary or secondary battery.

[0042] The hydrogen negative ion battery is a liquid battery, a semi-solid battery, or an all-solid battery.

[0043] The hydrogen negative ion battery has hydrogen negative ions as part or all of its charge carriers.

[0044] The hydrogen negative ion battery is an energy storage battery that uses hydrogen negative ions as the sole or partial charge carriers and can provide charge once or multiple times.

[0045] The beneficial effects that this application can produce include:

[0046] (1) This invention provides a simple method for optimizing the positive electrode material of hydrogen negative ion batteries. Referring to the design concept of traditional pyrolysis hydrogen storage catalysts, it innovatively introduces hydrogen dissociation catalysts through mechanical mixing and improves the contact between components to enhance electrode reaction kinetics, thereby improving the utilization rate of coordinated aluminum hydride of electrode active material and achieving the goal of higher discharge specific capacity.

[0047] (2) The electrode optimization method provided by the present invention has a wide range of applications, is simple to operate, does not involve precise control of material preparation conditions or adjustment of material structure, has obvious cost advantages, and is applicable to all-solid-state and liquid primary or secondary hydrogen negative ion batteries, and greatly improves the applicability of coordination hydrogen storage materials as electrode materials for hydrogen negative ion batteries.

[0048] (3) The optimized hydrogen negative ion battery cathode material has a high theoretical specific capacity (>1000mAh / g), which is significantly better than the known rare earth metal hydride electrode materials (<100mAh / g), greatly improving the application potential and value of hydrogen negative ion batteries in the field of energy storage. Attached Figure Description

[0049] Figure 1 The charge-discharge curves of the hydrogen negative ion battery constructed using the optimized cathode material in Example 1 are shown.

[0050] Figure 2 The results are high-resolution XRD patterns of the cathode material after discharge in Example 1.

[0051] Figure 3 The charge-discharge curves are for the hydrogen negative ion battery constructed using the positive electrode material in Example 2.

[0052] Figure 4 The charge-discharge curves of the battery constructed for the unoptimized cathode material in Comparative Example 1. Detailed Implementation

[0053] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0054] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0055] The analysis method in the embodiments of this application is as follows:

[0056] High-resolution XRD analysis was performed using the Shanghai Synchrotron Radiation Facility.

[0057] The performance of the positive electrode was evaluated using a battery cycle tester from Shenzhen Xinwei Company.

[0058] Example 1

[0059] In an inert gas protective glove box, NaAlH4 active material and La were weighed out in a mass ratio of 1:0.5:0.1:0.1. 0.8 Sr 0.2 H 2.3 O 0.15 1g of electrolyte, graphene conductive agent, and TiO2 electrode catalyst were loaded into an agate mortar and simply ground and mixed for 20 minutes to obtain the optimized cathode material.

[0060] (1) Weigh out 50mg of positive electrode material and 90mg of La in the glove box. 0.8 Sr 0.2 H 2.3 O 0.15 The electrolyte and 50mg of La anode material were placed into the solid-state battery test mold in sequence and pressed into shape.

[0061] (2) The battery performance was evaluated using a Newway battery cycle tester. Electrode performance was evaluated using a current density of 0.1 mA / g. The battery charge-discharge curves calculated based on the mass of the positive electrode active material are shown below. Figure 1 As shown;

[0062] (3) The state of the positive electrode active material after discharge was characterized by high-resolution XRD, and the results are as follows: Figure 2 .

[0063] The charge-discharge curves of the battery show that the optimized cathode material has a discharge capacity of close to 300 mAh / g, which is of practical value. It also has good cycle performance and high charge-discharge coulombic efficiency. High-resolution XRD characterization shows that the cathode active material changes from NaAlH4 to Na3AlH6 after discharge, which confirms that most of the active material participated in the reaction.

[0064] Example 2

[0065] In an inert gas protective glove box, Ca(AlH4)2 active material and LaH2O were weighed out in a mass ratio of 1:0.2:0.1:0.1. 3-2x O x The electrolyte, carbon nanotube conductive agent, and electrode catalyst TiCl3 were loaded into a ball mill jar and ball-milled at 200 rpm and a ball-to-material ratio of 90:1 for 5 hours to obtain the optimized cathode material.

[0066] (1) Weigh out 50mg of negative electrode material and 90mg of LaH in the glove box. 3-2x O x Electrolyte and 50mg of Y anode material were placed into a solid-state battery test mold in sequence and pressed into shape.

[0067] (2) The battery performance was evaluated using a Newway battery cycle tester. Electrode performance was evaluated using a current density of 0.1 mA / g. The battery charge-discharge curves calculated based on the mass of the negative electrode active material are shown below. Figure 3 As shown.

[0068] As can be seen from the charge-discharge curves of the battery, the optimized cathode material has a discharge capacity of close to 200 mAh / g, which is of practical value. It also has good cycle performance and high charge-discharge coulombic efficiency.

[0069] Example 3

[0070] In an inert gas protective glove box, 1g of Mg(AlH4)2 positive electrode active material, LaH3 electrolyte, carbon nanotube conductive agent, and FeCl3 electrode catalyst were weighed in a mass ratio of 1:0.2:0.2:0.2 and loaded into a ball mill jar. The mixture was ball milled at 500rpm and a ball-to-material ratio of 90:1 for 1h to obtain the optimized positive electrode material.

[0071] (1) Weigh 50mg of negative electrode material, 90mg of LaH3 electrolyte and 50mg of Nd negative electrode material in the glove box, and put them into the solid battery test mold in order and press them into shape.

[0072] (2) Use the Xinwei Battery Cycling Tester to evaluate the battery performance.

[0073] The test results were similar to those of Examples 1 and 2.

[0074] Example 4

[0075] In an inert gas protective glove box, Li₂Mg(AlH₄)₄ positive electrode active material and La ... were weighed in a mass ratio of 1:0.2:0.2:0.2. 0.8 Sr 0.2 H 2.3 O 0.15 The electrolyte, carbon nanotube conductive agent, and electrode catalyst ZrCl3 were all packaged into a small bottle and stirred at 500 rpm for 3 hours on a magnetic stirrer to obtain the optimized cathode material.

[0076] (1) Weigh out 50mg of negative electrode material and 90mg of La in the glove box. 0.8 Sr 0.2 H 2.3 O 0.15 Electrolyte and 50mg Ce negative electrode material were placed into a solid-state battery test mold in sequence and pressed into shape.

[0077] (2) Use the Xinwei Battery Cycling Tester to evaluate the battery performance.

[0078] The test results were similar to those of Examples 1 and 2.

[0079] Example 5

[0080] In an inert gas protective glove box, LiAlH4 positive electrode active material and La were weighed out in a mass ratio of 1:0.5:0.1:0.1. 0.8 Sr 0.2 H 2.3 O 0.15 1g of electrolyte, graphene conductive agent, and NiO electrode catalyst were loaded into an agate mortar and simply ground for 10 minutes to obtain the optimized cathode material.

[0081] (1) Weigh out 50mg of positive electrode material and 90mg of La in the glove box. 0.8 Sr 0.2 H 2.3 O 0.15 Electrolyte and 50mg of Y anode material were placed into a solid-state battery test mold in sequence and pressed into shape.

[0082] (2) The battery performance was evaluated using the Xinwei Battery Cycling Tester. Electrode performance was evaluated at a current density of 0.1 mA / g.

[0083] The test results were similar to those of Examples 1 and 2.

[0084] Example 6

[0085] In an inert gas protective glove box, Ba(AlH4)2 positive electrode active material and LaH2O were weighed in a mass ratio of 1:0.5:0.1:0.1. 2.8 O 0.1 1g of electrolyte, graphene conductive agent, and TiO electrode catalyst were loaded into an agate mortar and simply ground for 10 minutes to obtain the optimized cathode material.

[0086] (1) Weigh out 50mg of positive electrode material and 90mg of LaH in the glove box. 2.8 O 0.1 Electrolyte and 50 mg Nd anode material were placed into a solid-state battery test mold in sequence and pressed into shape; (2) The battery performance was evaluated using a Newway battery cycle tester. Electrode performance was evaluated at a current density of 0.1 mA / g.

[0087] The test results were similar to those of Examples 1 and 2.

[0088] Example 7

[0089] In an inert gas protective glove box, 1g of KAlH4 positive electrode active material, LaH3 electrolyte, graphene conductive agent, and CrCl3 electrode catalyst were weighed in a mass ratio of 1:0.2:0.2:0.2 and loaded into a ball mill jar. The mixture was ball milled at 200 rpm and a ball-to-material ratio of 90:1 for 1 hour to obtain the optimized positive electrode material.

[0090] (1) Weigh 50mg of positive electrode material, 90mg of LaH3 electrolyte and 20mg of Pr negative electrode material in the glove box, and put them into the solid battery test mold in order and press them into shape.

[0091] (2) Use the Xinwei Battery Cycling Tester to evaluate the battery performance.

[0092] The test results were similar to those of Examples 1 and 2.

[0093] Example 8

[0094] In an inert gas protective glove box, LiBa(AlH4)3 positive electrode active material and LaH2O were weighed out in a mass ratio of 1:0.2:0.2:0.2. 2.8 O 0.1 The electrolyte, graphene conductive agent, and electrode catalyst TOCl3, totaling 1g, were loaded into a ball mill jar and ball-milled at 100rpm and a ball-to-material ratio of 100:1 for 5h to obtain the optimized cathode material.

[0095] (1) Weigh out 50mg of positive electrode material and 90mg of LaH in the glove box. 2.8 O 0.1 (1) Electrolyte and 20mg Sm negative electrode material were placed into the solid-state battery test mold in sequence and pressed into shape; (2) The performance of the battery was evaluated using the Xinwei Battery Cycling Tester.

[0096] The test results were similar to those of Examples 1 and 2.

[0097] Comparative Example 1

[0098] In an inert gas protective glove box, NaAlH4 active material and La were weighed out in a mass ratio of 1:0.5:0.1. 0.8 Sr 0.2 H 2.3 O 0.15 1g of electrolyte and graphene conductive agent were placed in an agate mortar and simply ground and mixed for 20 minutes to obtain unoptimized cathode material.

[0099] (1) Weigh out 50mg of positive electrode material and 90mg of La in the glove box. 0.8 Sr 0.2 H 2.3 O 0.15 The electrolyte and 50mg of La anode material were placed into the solid-state battery test mold in sequence and pressed into shape.

[0100] (2) The battery performance was evaluated using a Newway battery cycle tester. Electrode performance was evaluated using a current density of 0.1 mA / g. The battery charge-discharge curves calculated based on the mass of the positive electrode active material are shown below. Figure 4 As shown, due to the lack of an electrode catalyst, the reaction degree is very low, and the electrode capacity is very low, only about 60 mAh / g after stabilization.

[0101] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A positive electrode material, characterized in that, The cathode material contains coordinated aluminum hydride, electrocatalyst, electronic conductor, and electrolyte; The chemical formula of the coordinated aluminum hydride is A. x M y (AlH4) x+y , where A is selected from alkali metals, M is selected from alkaline earth metals, 0≤x<5, 0≤y<5; The electrocatalyst is selected from at least one of the elemental, oxide, or halide forms of transition metals.

2. The cathode material according to claim 1, characterized in that, The alkali metal is selected from at least one of Li, Na, K, Rb, and Cs; The alkaline earth metal is selected from at least one of Be, Mg, Ca, Sr, and Ba; Preferably, the coordinated aluminum hydride is selected from at least one of LiAlH4, NaAlH4, Li3AlH6, Na3AlH6, KAlH4, Mg(AlH4)2, Ca(AlH4)2, and Ba(AlH4)2.

3. The cathode material according to claim 1, characterized in that, The transition metal element is selected from at least one element in groups IIIB to VIIB and VIII of the periodic table; Preferably, the transition metal element is selected from at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, and Pd; Preferably, the oxide of the transition metal is selected from at least one of TiO, V2O5, NiO, MnO, TiO2, MnO2, ZrO2, CrO4, and Ti2O3; Preferably, the transition metal halide is selected from at least one of TiF3, TiCl3, CrCl5, ZrCl4, NiCl2, VF5, CoCl4, and MnCl2.

4. The cathode material according to claim 1, characterized in that, The particle size of the electrode catalyst is 1 nm to 1 mm; Preferably, the particle size of the electrode catalyst is 10 nm to 100 μm; The particle size of the positive electrode active material is 10 nm to 1 mm.

5. The cathode material according to claim 1, characterized in that, In the cathode material, the content of the electrocatalyst is 0.1–50 wt%. Preferably, the content of the electrocatalyst in the cathode material is 1-20 wt%.

6. The cathode material according to claim 1, characterized in that, In the positive electrode material, the content of the coordinated aluminum hydride is 20-90 wt%; Preferably, the content of the coordinated aluminum hydride in the positive electrode material is 50-80%.

7. A method for preparing the cathode material according to any one of claims 1 to 6, characterized in that, Includes the following steps: The cathode material is obtained by mixing raw materials containing coordinated aluminum hydride, electrocatalyst, electronic conductor and electrolyte.

8. The preparation method according to claim 7, characterized in that, The mixed atmosphere contains hydrogen and inactive gases; The inactive gas is selected from at least one of nitrogen, argon, and helium; The electronic conductor is selected from at least one of carbon nanotubes, graphene, acetylene black, layered graphite, carbon fiber, and carbon black. The electrolyte is selected from at least one rare earth metal hydride.

9. The application of the positive electrode material according to any one of claims 1 to 6 in a hydrogen anion battery, characterized in that, The hydrogen ion battery is either a primary or secondary battery.

10. The application according to claim 9, characterized in that... The hydrogen negative ion battery is a liquid battery, a semi-solid battery, or an all-solid battery.

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