High-stability modified calcium-based energy storage granular material and preparation method thereof
Highly stable modified calcium-based energy storage particles were prepared by mixing and granulating calcium source and aluminum precursor and then doping them by impregnation. This solved the problems of performance degradation and high cost of calcium-based materials during high-temperature sintering, and enabled low-cost, large-scale preparation and industrial application.
Patent Information
- Application Number
- CN202511068873.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-14
AI Technical Summary
Existing calcium-based energy storage materials suffer severe performance degradation during high-temperature sintering, modified materials are costly and difficult to apply directly to industrial applications, and powdered materials are difficult to form.
A calcium source and an aluminum precursor were mixed and granulated, and after one and two calcinations, aluminum-doped spherical particles were formed. The particles were then doped using an impregnation method to prepare highly stable modified calcium-based energy storage particles.
It reduces the cost of material synthesis, facilitates large-scale preparation through the process, improves the cycle stability of the prepared particulate materials, makes them suitable for industrial applications, and avoids the molding problems of powdered materials.
Smart Images
Figure CN120944533A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of materials engineering and high-efficiency thermochemical energy storage, specifically relating to a highly stable modified calcium-based energy storage particle material and its preparation method. Background Technology
[0002] The development and utilization of new energy sources such as solar and wind power can effectively alleviate the energy crisis and reduce carbon dioxide emissions. However, new energy sources are generally unstable, and their power generation characteristics often do not match electricity demand, limiting their further development. New energy power generation systems coupled with energy storage technology integrate energy storage and power generation, offering flexible and controllable power generation and the ability to quickly and deeply participate in power system peak shaving, representing the future direction of new energy development. Among various types of thermal storage systems, calcium-based systems (calcium oxide / calcium carbonate, calcium oxide / calcium hydroxide) have attracted widespread attention due to their advantages such as low raw material cost, wide reaction temperature range, high energy storage density, and environmental friendliness. However, currently, there are two major problems with these materials for industrial applications: firstly, performance degradation caused by high-temperature sintering; and secondly, although modified materials improve stability, they are often in powder form and have high synthesis costs. To meet industrial needs, there is an urgent need to develop a low-cost, easily scalable, and highly stable modified calcium-based particulate material preparation method. Summary of the Invention
[0003] To address the shortcomings of existing technologies in suppressing performance degradation caused by sintering of calcium-based materials, as well as the high cost of modification and the difficulty in directly industrializing powdered materials, the present invention aims to provide a highly stable modified calcium-based energy storage particle material and its preparation method. This method is low-cost and conducive to large-scale production.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] In a first aspect, the present invention provides a method for preparing a highly stable modified calcium-based energy storage particle material, comprising the following steps:
[0006] The calcium source and aluminum precursor aqueous solution were mixed evenly to form a slurry, and the slurry was dried to obtain a solid.
[0007] The solid and binder are mixed and then water is added to granulate the mixture to obtain granules.
[0008] After drying, the particles were calcined once in an oxidizing atmosphere to obtain aluminum-doped calcium-based pre-formed spherical particles.
[0009] Aluminum-doped calcium-based pre-formed spherical particles were impregnated in a precursor solution of the doped element, dried, and then calcined a second time in an oxidizing atmosphere to obtain a highly stable modified calcium-based energy storage particle material.
[0010] Furthermore, the calcium source is calcium carbonate, calcium hydroxide, or calcium oxide.
[0011] Furthermore, the aluminum precursor is aluminum nitrate.
[0012] Furthermore, the molar ratio of calcium source to aluminum precursor is 100:(5-20);
[0013] The calcium source and aluminum precursor aqueous solution were mixed evenly and then ball-milled.
[0014] Furthermore, the binder is microcrystalline cellulose, and the amount of binder is 5-20% of the solid mass; the oxidizing atmosphere during the first calcination is air or an oxygen-containing gas.
[0015] Furthermore, the calcination temperature is 300–500℃ and the time is 30–120 min; the impregnation time is less than 10 min.
[0016] Furthermore, the precursor solution of the dopant element is an alcoholic or aqueous solution of a soluble salt.
[0017] Furthermore, the precursor solution for the dopant element is an aqueous solution or an ethanolic solution of one or more of manganese nitrate, ferric nitrate, magnesium nitrate, and manganese acetate.
[0018] Furthermore, the secondary calcination temperature is 800–900℃, the calcination time is 30–120 min, and the oxidizing atmosphere is air.
[0019] Secondly, the present invention provides a highly stable modified calcium-based energy storage particle material prepared according to the above method.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] (1) Low material synthesis cost. This invention uses an inexpensive calcium source to significantly reduce synthesis costs.
[0022] (2) The material processing flow is conducive to large-scale preparation. The mixing, granulation, impregnation, drying and calcination processes involved in this invention are all simple, easy to operate and easy to scale up. Except for the drying and calcination steps, all are carried out at room temperature. Moreover, no flammable or explosive substances are generated during the drying and calcination process, no large amount of toxic and harmful gases are generated, and there is no violent explosion reaction, which is conducive to large-scale preparation.
[0023] (3) Direct preparation of doped calcium-based particles that are easy to use in industrial applications. This invention improves the poor plasticity of calcium-based materials during granulation by using an aluminum precursor, directly producing calcium-based energy storage particles. Furthermore, the material is doped and modified by impregnation without damaging the shape and structure of the particles, effectively overcoming the problems of existing modified calcium-based material powders being difficult to form and the damage to the powder during forming.
[0024] (4) The cycling stability of calcium-based particulate materials is greatly improved. The particulate materials prepared by this invention have aluminum precursor added during granulation, which can generate calcium-aluminum composites to separate the grains and form a porous framework that is easy to transfer mass. Furthermore, manganese, iron and other dopants are attached to the surface of the exposed pores of the particles by impregnation method to inhibit pore fusion and blockage, thereby greatly improving the cycling stability of the particles and overcoming the problem that particulate materials are more prone to sintering and deactivation.
[0025] Furthermore, the main calcium precursors such as calcium carbonate, calcium oxide, and calcium hydroxide are all priced below 1,000 yuan per ton, thereby reducing the preparation cost. Attached Figure Description
[0026] Figure 1 SEM images of Mn and Al doped particles prepared in Example 1;
[0027] Figure 2 SEM images of the interior of fresh Mn and Al doped particles prepared for Example 1;
[0028] Figure 3 SEM images of the interior of Mn and Al doped particles after 160 cycles, as shown in Example 1.
[0029] Figure 4 The cycling performance curves of Mn and Al doped particles prepared in Examples 1, 3 and Comparative Example 1 at 800℃ are compared. Detailed Implementation
[0030] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0031] The present invention discloses a method for preparing a highly stable modified calcium-based energy storage particulate material, the preparation method mainly comprising the following steps:
[0032] S1. After mixing the calcium source and aluminum precursor aqueous solution, grind them to form a slurry, so that the calcium source and aluminum source are fully dispersed and mixed;
[0033] In step S1 above, the grinding of the calcium source and aluminum nitrate aqueous solution is generally carried out using a high-energy ball mill (including but not limited to a planetary ball mill). The molar ratio of calcium source to aluminum precursor is 100:(5-20). The calcium source includes but is not limited to calcium carbonate, calcium hydroxide and calcium oxide.
[0034] If calcium carbonate is used as the calcium source and aluminum nitrate nonahydrate (Al(NO3)3·H2O) is used as the aluminum precursor, 1g of calcium carbonate is ground with 2mL of aluminum nitrate aqueous solution to ensure wet grinding effect and prevent system stratification during standing. The specific process is as follows: first, aluminum nitrate nonahydrate is dissolved in deionized water to form a solution, and then added to the calcium precursor. The aluminum nitrate aqueous solution serves as both a doping precursor and a granulation adhesive solvent to ensure plasticity during extrusion and spheronization.
[0035] Furthermore, when calcium carbonate is chosen as the calcium source, the molar ratio of calcium carbonate to aluminum source is Ca:Al = 100:10;
[0036] S2. Dry the slurry from step S1 in an oven to obtain a solid. Mix the solid with an appropriate amount of binder, add a small amount of water, and then granulate to obtain granules.
[0037] In step S2 above, the binder includes, but is not limited to, microcrystalline cellulose. The amount of binder used is about 5-20% of the solid mass. If calcium carbonate is used as the calcium source, the system is conducive to extrusion spheronization granulation.
[0038] In step S2, the drying conditions are 60-80℃ for 12-24 hours.
[0039] S3. After drying the particles obtained in step S2 in an oven, calcinate them at a certain temperature and under an oxidizing atmosphere. By controlling the calcination temperature, the nitrates are decomposed to generate oxides, while avoiding the decomposition of the calcium source, thus obtaining aluminum-doped calcium-based pre-formed spherical particles.
[0040] In step S3 above, the calcination temperature is 300-500℃ and the calcination time is 30-120 min to ensure that the nitrate is completely decomposed, but the calcium carbonate is not decomposed.
[0041] If calcium carbonate is used as the calcium source, the calcination temperature should be around 400℃, not exceeding 500℃, and the calcination should be maintained for 60 minutes to ensure complete decomposition of nitrates, but without decomposition of calcium carbonate.
[0042] The oxidizing atmosphere is air or a mixture of gases containing a certain volume fraction of oxygen.
[0043] S4. The aluminum-doped calcium-based pre-formed spherical particles are immersed in a precursor solution of a certain concentration of dopant element for 10 minutes, filtered out from the immersion solution, dried, and then calcined at high temperature in an oxidizing atmosphere to obtain modified calcium-based thermal storage material particles.
[0044] In step S4 above, the precursor solution of the doped element includes alcoholic or aqueous solutions of soluble salts of various elements, including but not limited to aqueous or ethanolic solutions of one or more of manganese nitrate, ferric nitrate, magnesium nitrate and manganese acetate, with concentrations below the saturated solution concentration.
[0045] For example, using a manganese nitrate aqueous solution with a mass fraction of 60-75% as a precursor solution for manganese doping, manganese-aluminum modified calcium-based particles can be prepared.
[0046] In step S4 above, the aluminum-doped calcium-based pre-made spherical particles are immersed in a precursor solution of a certain concentration of doping element for thorough impregnation. This impregnation can be performed once or multiple times. When impregnating multiple times, the particles can be immersed in the same precursor solution of doping element or in different precursor solutions of doping element.
[0047] In step S4 above, the method of thorough impregnation includes, but is not limited to, ultrasonic impregnation;
[0048] If ultrasonic impregnation is used, the time is generally within 2 minutes to prevent the particles from being destroyed in the liquid.
[0049] In step S4 above, the high-temperature calcination temperature is 800-900℃, the calcination time is 30-120 min, and the oxidizing atmosphere includes, but is not limited to, air atmosphere.
[0050] Furthermore, the calcination temperature is 900℃ and the calcination time is 90min to ensure that the material is calcined completely and that the solid-phase reaction in the doped material is completed.
[0051] In steps S3 and S4, the drying conditions are 60–80°C for 1–2 hours.
[0052] The present invention will be described in detail below with reference to specific examples. These specific examples are preferred solutions. Those skilled in the art can extend the invention in similar and identical ways without departing from its spirit. Therefore, the disclosed examples should not be regarded as limitations on the present invention.
[0053] Example 1
[0054] First, 13.4953g of calcium carbonate was placed in a ball mill jar. Then, 5.0625g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:10) was dissolved in 28mL of deionized water to form a transparent solution. The solution was added to the ball mill jar and mixed with the calcium carbonate. Then, about 50g of zirconia balls with a diameter of 6mm were added. The mixture was then ball-milled in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0055] The ball-milled slurry was dried in an oven at 80°C for 12 hours. About 6 mL of deionized water and 1.5 g of microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly moist dough. The material was then extruded into long strips (1 mm extrusion plate) in an extruder and rolled into spherical granules in a rounding machine.
[0056] The rolled-out particles were placed in an oven and dried at 80°C for 1 hour. Then, in an air atmosphere, the temperature was increased from room temperature to 400°C in a muffle furnace and held for 1 hour. After cooling to room temperature, aluminum-doped calcium-based pre-formed spherical particles were obtained.
[0057] A certain mass of manganese nitrate tetrahydrate was weighed and dissolved in deionized water to prepare a 65% manganese nitrate aqueous solution. Aluminum-doped calcium-based pre-formed spherical particles were added to the manganese nitrate aqueous solution. The mixture was ultrasonicated for 2 minutes in an ultrasonic cleaner, then allowed to stand for 10 minutes. After filtering out the particles, excess solution was absorbed on dry filter paper. The particles were then dried in an oven at 80°C for 1 hour. The temperature was then increased from room temperature to 900°C in a muffle furnace at a rate of 10°C / min and maintained for 1.5 hours. The temperature was then reduced to room temperature to obtain Mn and Al modified calcium-based particle material, i.e., high-stability modified calcium-based energy storage particle material.
[0058] Example 2
[0059] First, 13.4953g of calcium carbonate was placed in a ball mill jar. Then, 5.0625g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:10) was dissolved in 28mL of deionized water to form a transparent solution. The solution was added to the ball mill jar and mixed with the calcium carbonate. Then, about 50g of zirconia balls with a diameter of 6mm were added. The mixture was then ball-milled in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0060] The ball-milled slurry was dried in an oven at 80°C for 12 hours. About 6 mL of deionized water and 1.5 g of microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly moist dough. The material was then extruded into long strips (1 mm extrusion plate) in an extruder and rolled into spherical granules in a rounding machine.
[0061] The rolled-out particles were placed in an oven and dried at 80°C for 1 hour. Then, in an air atmosphere, the temperature was increased from room temperature to 400°C in a muffle furnace and held for 1 hour. After cooling to room temperature, aluminum-doped calcium-based pre-formed spherical particles were obtained.
[0062] A certain mass of manganese nitrate tetrahydrate and magnesium nitrate hexahydrate were weighed and dissolved together in deionized water to prepare an aqueous solution of 65% manganese nitrate and 20% magnesium nitrate. Aluminum-doped calcium-based pre-formed spherical particles were added to the aqueous solution and ultrasonicated for 2 minutes. After standing for 10 minutes, the particles were filtered out and placed on dry filter paper to absorb excess solution. Then, they were dried in an oven at 80°C for 1 hour. The temperature was increased from room temperature to 900°C in a muffle furnace at a rate of 10°C / min and maintained for 1.5 hours. After cooling to room temperature, Mn, Al, and Mg modified calcium-based particle material was obtained, namely, a highly stable modified calcium-based energy storage particle material.
[0063] Example 3
[0064] First, 13.4953g of calcium carbonate was placed in a ball mill jar. Then, 5.0625g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:10) was dissolved in 28mL of deionized water to form a transparent solution. The solution was added to the ball mill jar and mixed with the calcium carbonate. Then, about 50g of zirconia balls with a diameter of 6mm were added. The mixture was then ball-milled in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0065] The ball-milled slurry was dried in an oven at 80°C for 12 hours. About 6 mL of deionized water and 1.5 g of microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly moist dough. The material was then extruded into long strips (1 mm extrusion plate) in an extruder and rolled into spherical granules in a rounding machine.
[0066] The rolled-out particles were placed in an oven and dried at 80°C for 1 hour. Then, in an air atmosphere, the temperature was increased from room temperature to 400°C in a muffle furnace and held for 1 hour. After cooling to room temperature, aluminum-doped calcium-based pre-formed spherical particles were obtained.
[0067] A certain mass of manganese nitrate tetrahydrate was weighed and dissolved in deionized water to prepare a 50% manganese nitrate aqueous solution. Aluminum-doped calcium-based pre-formed spherical particles were added to the manganese nitrate aqueous solution. The mixture was ultrasonicated for 2 minutes in an ultrasonic cleaner, then allowed to stand for 10 minutes. After filtering out the particles, excess solution was absorbed on dry filter paper. The particles were then dried in an oven at 80°C for 1 hour. The temperature was increased from room temperature to 400°C in a muffle furnace at a rate of 10°C / min and maintained for 1 hour. The temperature was then reduced to room temperature to ensure the decomposition of manganese nitrate, resulting in manganese-impregnated spherical particles.
[0068] A certain mass of aluminum nitrate nonahydrate was dissolved in deionized water to prepare a 10% aluminum nitrate aqueous solution. Spherical particles of aluminum-impregnated manganese were added to the aluminum nitrate aqueous solution without ultrasonic impregnation to prevent the separation of manganese substances formed on the surface of the particle pores during the previous calcination step. After standing for only 10 seconds, the particles were filtered out and placed on dry filter paper to absorb excess solution. Then, they were placed in an oven and dried at 80°C for 1 hour. The temperature was increased from room temperature to 900°C in a muffle furnace at a rate of 10°C / min and maintained for 1.5 hours. After cooling to room temperature, Mn and Al modified calcium-based particle materials were obtained, namely, highly stable modified calcium-based energy storage particle materials.
[0069] Example 4
[0070] First, place 10g of calcium hydroxide into a ball mill jar. Then, dissolve 2.5313g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:5) in 28mL of deionized water to form a transparent solution. Add the solution to the ball mill jar and mix with the calcium hydroxide. Then, add about 50g of zirconia balls with a diameter of 6mm. Ball mill in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0071] The ball-milled slurry was dried in an oven at 80°C for 12 hours to obtain the dried material. About 6 mL of deionized water and microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly wet dough. The mass of microcrystalline cellulose was 5% of the mass of the dried material. The material was extruded into long strips (1 mm extrusion plate) in an extruder and rolled into spherical granules in a rounding machine.
[0072] The rolled-out particles were placed in an oven and dried at 80°C for 1 hour. Then, under air atmosphere, the temperature was increased from room temperature to 300°C in a muffle furnace and held for 120 minutes. After cooling to room temperature, aluminum-doped calcium-based pre-formed spherical particles were obtained.
[0073] A certain mass of manganese nitrate tetrahydrate was dissolved in deionized water to prepare a 75% manganese nitrate aqueous solution. Aluminum-doped calcium-based pre-formed spherical particles were added to the manganese nitrate aqueous solution. The mixture was ultrasonicated for 1 minute in an ultrasonic cleaner, then allowed to stand for 10 minutes. After filtering out the particles, excess solution was absorbed on dry filter paper. The particles were then dried in an oven at 80°C for 1 hour. The temperature was then increased from room temperature (10°C / min) to 800°C in a muffle furnace and maintained for 120 minutes. The temperature was then reduced to room temperature to obtain a highly stable modified calcium-based energy storage particle material.
[0074] Example 5
[0075] First, 7.5676g of calcium oxide was placed in a ball mill jar. Then, 10.125g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:20) was dissolved in 28mL of deionized water to form a transparent solution. The solution was added to the ball mill jar and mixed with the calcium oxide. Then, about 50g of zirconia balls with a diameter of 6mm were added. The mixture was then ball milled in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0076] The ball-milled slurry was dried in an oven at 80°C for 12 hours to obtain the dried material. About 6 mL of deionized water and microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly wet dough. The mass of the microcrystalline cellulose was 20% of the mass of the dried material. The material was extruded into long strips (1 mm extrusion plate) in an extruder and rolled into spherical granules in a rounding machine.
[0077] The rolled-out particles were placed in an oven and dried at 70°C for 18 hours. Then, under air atmosphere, the temperature was increased from room temperature to 500°C in a muffle furnace at a rate of 10°C / min and held for 30 minutes. The temperature was then reduced to room temperature to obtain aluminum-doped calcium-based pre-formed spherical particles.
[0078] A certain mass of manganese acetate was weighed and dissolved in deionized water to prepare a 30% manganese acetate aqueous solution. Aluminum-doped calcium-based pre-formed spherical particles were added to the manganese acetate aqueous solution. The mixture was ultrasonically cleaned for 2 minutes, then allowed to stand for 10 minutes. After filtering out the particles, excess solution was absorbed on dry filter paper. The mixture was then dried in an oven at 80°C for 12 hours. The temperature was then increased from room temperature to 900°C in a muffle furnace at a rate of 10°C / min and held for 30 minutes. The temperature was then reduced to room temperature to obtain a highly stable modified calcium-based energy storage particle material.
[0079] Example 6
[0080] First, 13.4953g of calcium carbonate was placed in a ball mill jar. Then, 7.5937g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:15) was dissolved in 28mL of deionized water to form a transparent solution. The solution was added to the ball mill jar and mixed with the calcium carbonate. Then, about 50g of zirconia balls with a diameter of 6mm were added. The mixture was then ball-milled in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0081] The ball-milled slurry was dried in an oven at 60°C for 24 hours to obtain the dried material. About 6 mL of deionized water and microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly wet dough. The mass of the microcrystalline cellulose was 15% of the mass of the dried material. The material was extruded into long strips (1 mm extrusion plate) in an extruder, and the long strips were rolled into spherical granules in a rounding machine.
[0082] The rolled-out particles were placed in an oven and dried at 80°C for 1 hour. Then, under an air atmosphere, the temperature was increased from room temperature to 350°C in a muffle furnace at a rate of 10°C / min and held for 100 min. The temperature was then reduced to room temperature to obtain aluminum-doped calcium-based pre-formed spherical particles.
[0083] A certain mass of ferric nitrate was dissolved in deionized water to prepare a 30% ferric nitrate aqueous solution. Aluminum-doped calcium-based pre-formed spherical particles were added to the ferric nitrate aqueous solution. The mixture was ultrasonically cleaned for 2 minutes, then allowed to stand for 10 minutes. After filtering out the particles, excess solution was absorbed on dry filter paper. The mixture was then dried in an oven at 60°C for 24 hours. The temperature was then increased from room temperature to 850°C in a muffle furnace at a rate of 10°C / min and held for 60 minutes. The temperature was then reduced to room temperature to obtain a highly stable modified calcium-based energy storage particle material.
[0084] Comparative Example 1
[0085] In this comparative example, the Mn precursor was added directly during ball milling without a pre-calcination impregnation process. MnO was selected as the Mn precursor because the material has poor formability when using soluble manganese salts.
[0086] First, 13.4953g of calcium carbonate and 1.3995g of manganese monoxide powder were placed in a ball mill jar. Then, 5.0625g of aluminum nitrate nonahydrate (molar ratio Ca:Al = 100:10) was dissolved in 28mL of deionized water to form a transparent solution. The solution was added to the ball mill jar and mixed with the calcium carbonate. Then, about 50g of zirconia balls with a diameter of 6mm were added, and the mixture was ball milled in a planetary ball mill (400rpm, 30min forward + 30min reverse + 30min forward + 30min reverse) to obtain a slurry.
[0087] The ball-milled slurry was dried in an oven at 80°C for 12 hours. About 6 mL of deionized water and 1.5 g of microcrystalline cellulose were added to the dried material and kneaded thoroughly to form a slightly moist dough. The material was then extruded into long strips (1 mm extrusion plate) in an extruder and rolled into spherical granules in a rounding machine.
[0088] The particles were placed in an oven and dried at 80°C for 1 hour. Then, the temperature was increased from room temperature to 900°C in a muffle furnace at a rate of 10°C / min and held for 1.5 hours. The temperature was then reduced to room temperature to obtain the modified calcium-based particle material.
[0089] Cyclic performance test:
[0090] The cycling performance of the modified calcium-based energy storage particles in Examples 1, 3, and Comparative Example 1 was tested using a quartz tube fixed-bed reactor. Approximately 60 mg of sample was packed into the quartz tube of the reactor, and the sample section was placed in an electric furnace and heated to 800 °C at a rate of 10 °C / min for reaction. One cycle included a carbonation stage and a calcination decomposition stage. During carbonation, 50 sccm of argon and 50 sccm of carbon dioxide were introduced for a total of 10 min. Then, the carbon dioxide was turned off, and only 50 sccm of argon was introduced for 9 min for calcination, completing one cycle. Then, carbon dioxide was introduced again for the next cycle. During the cycle, the composition information of the outlet gas was detected and collected using an online mass spectrometer.
[0091] Energy storage density calculation formula:
[0092]
[0093] Among them, D i —Energy storage density / kJ·kg -1 V i,cal —Volume of carbon dioxide released during the calcination stage (L); V m —Standard molar volume of gas, 22.4 L·mol -1 ;ΔH r 0 —Standard molar enthalpy of reaction, 178 kJ·kg -1 m sample —Sample mass (sample after calcination) / kg.
[0094] Figure 1 The SEM image of the Mn and Al doped particles prepared in Example 1 shows that the particles maintain good sphericity.
[0095] Figure 2 The SEM image of the interior of fresh Mn and Al doped particles prepared in Example 1 shows that the interior of the particles is a loose porous structure composed of small particles.
[0096] Figure 3 The SEM image of the interior of the Mn and Al doped particles prepared in Example 1 after 160 cycles shows that there is no severe pore closure phenomenon inside the particles, and they still exhibit a porous framework structure, which effectively avoids performance degradation.
[0097] Figure 4Cyclic performance curves of Mn and Al doped particles prepared in Examples 1, 3 and Comparative Example 1 at 800℃ were obtained. It can be seen that after the initial performance evolution, the performance of Example 1 is basically stable at 1140 kJ / kg and the performance of Example 3 is basically stable at 1220 kJ / kg after 160 cycles. However, the performance of Comparative Example 1 showed a sharp performance decay after 90 cycles, indicating that the pre-calcination and impregnation process after particle preparation has a good promoting effect on long-term cycling stability.
[0098] This invention directly produces doped calcium-based spherical particles using low-cost raw materials and a simple, easily scalable, optimized process, facilitating industrial applications. Simultaneously, the pre-doped aluminum precursor and impregnated dopant precursors create a stable porous framework structure within the particles, preventing pore blockage, accelerating carbon dioxide mass transfer, and significantly improving the cycling stability of the calcium-based particles. These low-cost, easily scalable, high-performance calcium-based energy storage particles possess enormous potential for industrial applications.
[0099] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.
[0100] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
Claims
1. A method for preparing a highly stable modified calcium-based energy storage particulate material, characterized in that, Includes the following steps: The calcium source and aluminum precursor aqueous solution were mixed evenly to form a slurry, and the slurry was dried to obtain a solid. The solid and binder are mixed and then water is added to granulate the mixture to obtain granules. After drying, the particles were calcined once in an oxidizing atmosphere to obtain aluminum-doped calcium-based pre-formed spherical particles. Aluminum-doped calcium-based pre-formed spherical particles were impregnated in a precursor solution of the doped element, dried, and then calcined a second time in an oxidizing atmosphere to obtain a highly stable modified calcium-based energy storage particle material.
2. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The calcium source is calcium carbonate, calcium hydroxide, or calcium oxide.
3. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The aluminum precursor is aluminum nitrate.
4. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The molar ratio of calcium source to aluminum precursor is 100:(5-20); The calcium source and aluminum precursor aqueous solution were mixed evenly and then ball-milled.
5. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The binder is microcrystalline cellulose, and the amount of binder is 5-20% of the solid mass; the oxidizing atmosphere for the first calcination is air or an oxygen-containing gas.
6. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The calcination temperature is 300-500℃ and the time is 30-120 minutes; the impregnation time is less than 10 minutes.
7. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The precursor solution of the dopant element is an alcoholic or aqueous solution of a soluble salt.
8. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The precursor solution for the dopant element is an aqueous solution or an ethanol solution of one or more of manganese nitrate, ferric nitrate, magnesium nitrate and manganese acetate.
9. The method for preparing the highly stable modified calcium-based energy storage particulate material according to claim 1, characterized in that, The secondary calcination temperature is 800-900℃, the calcination time is 30-120 min, and the oxidizing atmosphere is air.
10. A highly stable modified calcium-based energy storage particle material prepared by the method according to any one of claims 1-9.