Parallel energy storage device and preparation method thereof

Abstract

The present application belongs to the technical field of solid hydrogen storage device manufacturing, and particularly relates to a parallel energy storage device and a preparation method thereof. After a hydrogen storage alloy is wrapped with a metal mesh, the hydrogen storage alloy is rolled into an electrode plate, the electrode plate is stacked into an electrode plate group or wound into a winding core, and then the electrode plate group or winding core is loaded into a metal shell to form an energy storage unit, a top cover is welded and sealed, and an air inlet and an air outlet are respectively reserved in front and back of the energy storage unit; the energy storage units are connected in parallel to form an energy storage module, the air inlet and the air outlet of the energy storage module are connected with electromagnetic valves and flow meters, hydrogen inlets and outlets, cold water inlets and outlets, and hot water inlets and outlets are arranged on a tank body, the energy storage module and the tank body are filled with water, and a parallel energy storage device is obtained, and the energy storage module is stored through water cooling and released through water heating. The present application can obtain an energy storage device with a long cycle life, a high hydrogen storage speed, a controllable hydrogen release speed, and high stability, and can solve the problems of high use cost and easy hydrogen storage thermal runaway caused by hole blockage and short cycle life of hydrogen storage alloy powder in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of solid-state hydrogen storage device manufacturing technology, specifically relating to a parallel energy storage device and its preparation method. Background Technology

[0002] Hydrogen is a clean energy source with high energy density, enabling large-scale storage and easy electrothermal conversion, thus attracting widespread attention as a highly efficient and clean secondary renewable energy source. While hydrogen production and application technologies are mature enough, its storage is inconvenient, necessitating consideration of safe, efficient, and low-loss storage methods.

[0003] Solid-state hydrogen storage is gaining increasing attention as a low-pressure and safe hydrogen storage technology. Its hydrogen storage alloy materials have characteristics such as high bulk density, low operating pressure, and heat release during hydrogen filling. The temperature rise during the hydrogen filling process of the hydrogen storage alloy materials will hinder the further hydrogen absorption of the hydrogen storage alloy materials. Therefore, the physical morphology of the hydrogen storage alloy, the control of hydrogen filling and releasing, and efficient thermal management schemes are the engineering foundation for promoting the application of solid-state hydrogen storage technology.

[0004] Currently, most existing solid-state hydrogen storage devices use hydrogen storage alloy powder to fill pipes, with multiple pipes connected in parallel. Heating methods include liquid and electric heating, and cooling methods include liquid cooling and air cooling. Among these, water-cooled and water-heated devices are the simplest and cheapest, and are the most widely used. However, they have always suffered from problems such as the hydrogen storage alloy powder pulverizing faster than expected, increasing gas flow resistance, and the thick pipe walls resulting in low heat conduction efficiency, leading to low efficiency of liquid cooling or liquid heating. For example, Chinese patent application publication number CN117628399A discloses a rapid hydrogen addition / release device based on solid-state hydrogen storage. Although it uses liquid cooling and heating to control hydrogen storage and release, the alloy powder pulverization blocks gas flow, and the thick pipe walls can easily lead to thermal runaway at the end of hydrogen filling, causing difficulties in hydrogen addition or even stopping the process. Chinese patent number CN 215259209 U discloses a solid-state hydrogen storage device with inlet and outlet ports at both ends, guiding gas in and out through the inlet / outlet. Due to the thermal effect of hydrogen storage, although forced air cooling is used, the heat carried away by the gas is low on one side, which cannot meet the requirements for rapid hydrogen storage.

[0005] Furthermore, existing solid-state hydrogen storage methods suffer from problems such as rapid pulverization of the hydrogen storage alloy, leading to a low number of uses and frequent alloy replacements. Therefore, developing energy storage devices and energy storage preparation methods with superior hydrogen storage characteristics is both necessary and urgent. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to provide a method for preparing a parallel energy storage device that can obtain a hydrogen storage device with high safety, low pressure, and long cycle life, fast hydrogen storage speed, and strong stability of the hydrogen storage alloy. This solves the problem in the prior art where the hydrogen storage alloy pulverizes too quickly, resulting in low usage cycles and frequent replacement of the hydrogen storage alloy. This invention also provides an energy storage device prepared by this method.

[0007] A method for preparing a parallel energy storage device includes the following steps: wrapping a hydrogen storage alloy with a metal mesh, rolling it to a certain thickness using a roller press, stacking the electrode plates into an electrode plate group or winding them into a core and then installing them into a metal shell, welding and sealing the top cover, leaving an inlet and an outlet respectively, to obtain an energy storage unit; activating the energy storage unit; connecting multiple activated energy storage units in parallel through the inlet and outlet to form an energy storage module; installing the energy storage module into a tank and mechanically fixing it; connecting the inlet and outlet of the energy storage module to a solenoid valve and a flow meter; providing a hydrogen inlet, a hydrogen outlet, a cold water inlet / outlet, and a hot water inlet / outlet on the tank; filling the space between the energy storage module and the tank with water, to obtain the parallel energy storage device.

[0008] in:

[0009] Preferably, the mesh size of the metal mesh is 100 to 200 mesh, or it can be made of foamed nickel or foamed copper pre-pressed to a certain thickness. The inventors have found that if the mesh size of the metal mesh is too small and the pore size is large, the fine powder will be squeezed out during the pulverization process of the hydrogen storage alloy, resulting in high gas flow resistance. However, the mesh size cannot be too large either, as an excessively high mesh size will result in fine pore size and excessive gas flow resistance.

[0010] Preferably, the thickness of the electrode plate is 0.3~0.8 mm. The inventors have found that the electrode plate thickness cannot be too thin, as this would result in insufficient hydrogen storage alloy material per unit area; nor can it be too thick, as this would make it difficult for the hydrogen storage alloy material at the center of the electrode plate to absorb and release hydrogen. The compaction specific gravity of the electrode plate is preferably 3.8~4.5 g / m³. 3 The inventors discovered that the compaction density cannot be too low, otherwise the hydrogen storage alloy will not be compacted and will not fully bond with the binder; nor can it be too high, otherwise the hydrogen storage alloy will be crushed.

[0011] Preferably, the thickness of the electrode assembly is 28–60 mm.

[0012] The hydrogen storage alloy is preferably composed of one or more of AB5, AB2, and A2B7. It also contains cobalt tetroxide as an additive, polyurethane as a binder, and PTFE powder as a catalyst. The binder is commercially available high-temperature resistant polyurethane, which is soluble in adhesives. Cobalt tetroxide is added as a catalyst to accelerate hydrogen storage. The high-temperature resistant polyurethane buffers the expansion between the hydrogen storage alloy particles. The PTFE powder binder fixes the hydrogen storage alloy powder particles. The addition amount is between 1% and 3%; too little will not achieve the desired effect, while too much will increase costs and reduce the hydrogen absorption per unit area.

[0013] Preferably, the metal shell is made of high-strength alloy or stainless steel, and comes in two shapes: square and cylindrical, with a wall thickness of 0.5~2.0 mm. The metal shell wall thickness cannot be too thin, as this would make it difficult to weld and seal the top cover, and would also result in low mechanical strength. It also cannot be too thick, as this would slow down the heat conduction speed and affect the heat dissipation effect. Welding is performed by argon arc welding or laser welding.

[0014] The energy storage unit needs to undergo activation treatment first. The activation treatment involves: securing the energy storage unit, closing the inlet, connecting the outlet to the main valve of the vacuum pump, placing the energy storage unit in the heating chamber, and heating it at 120-180 °C for 60-120 minutes to degas it. Simultaneously, the vacuum pump continuously evacuates the outlet of the energy storage unit (the energy storage unit has an inlet and an outlet, and the vacuum pump is connected to the outlet; the vacuum pump evacuates the outlet gas from the energy storage unit. When the energy storage unit is heated in the heating chamber, the energy storage material inside will release gas. Under negative pressure, the gas inside the energy storage material can be released more quickly. Many of these gases are impurities; evacuation not only purifies the energy storage material but also activates it for better hydrogen storage later). After this process, close the outlet and turn off the vacuum pump. Then, turn off the heating switch and wait for the energy storage unit to cool to room temperature. Next, open the inlet of the energy storage unit and fill it with hydrogen at a pressure of 0.5-2 MPa for 1-2 minutes. After h, let it stand for another 10~30 min and then let the hydrogen be released naturally until the pressure of the energy storage unit is consistent with the external atmospheric pressure. Then, heat the energy storage unit in a heating chamber at 120~180℃ for another 60~120 min to further remove internal gaseous impurities and complete the activation.

[0015] Hydrogen storage alloys, when processed into electrodes, contain impurities such as air. Furthermore, these alloys require activation to properly absorb hydrogen. Therefore, a certain temperature is needed to expel impurity gases, and hydrogen purging is necessary to activate the alloy. Research in this invention has shown that heating at 120-180°C yields the best degassing effect. The temperature cannot be too low, as this will prevent the adsorbed gases from being removed; nor can it be too high, leading to low production efficiency and difficulty in controlling the heating chamber. Excessive heating time affects production efficiency, while insufficient time is insufficient to expel gas impurities. Too low a hydrogen purging pressure results in inadequate purging, while too high a pressure increases purging costs and can easily cause the hydrogen storage alloy to pulverize. Activating the hydrogen storage alloy simultaneously allows for the attainment of the maximum actual hydrogen storage capacity of the energy storage unit.

[0016] Preferably, the energy storage unit is equipped with an air inlet and an air outlet, with a filter element inside the air inlet to prevent powder from entering or exiting; the air inlets / outlets of all energy storage modules are respectively connected to the main air inlet / outlet valve, which is connected to a solenoid valve. In other words, the main solenoid valve controls the main air inlet and the main air outlet. The main air inlet and the main air outlet can be manually switched periodically, which can activate the hydrogen storage alloy and clean the internal channels, solving the problem that the gas flow is always in the same direction, which can easily cause unidirectional channel blockage, and the filter element at the outlet is covered with dust, affecting the gas flow rate.

[0017] Preferably, the square energy storage module has a built-in set screw device to tighten the wide surface of the energy storage unit. If it is cylindrical, it can be fixed with a clamp. The energy storage module can be one or more to form an energy storage device.

[0018] Multiple activated energy storage units are arranged sequentially, with their inlets and outlets connected in parallel (each energy storage unit has an inlet and an outlet; multiple units are connected in parallel to form an energy storage module: specifically, the inlets are connected in series to form a single main inlet, and the outlets are connected in series to form a single main outlet). One or more sets of energy storage units are installed into a square tank and secured with set screws to form a square energy storage module. Alternatively, one or more sets of energy storage units are installed into a round tank and fixed with clamps to form a cylindrical energy storage module. The entire module is mechanically fixed within the tank, with the energy storage module and tank filled with... The tank is filled with either cooling water or hot water, with the cold water temperature ranging from 5 to 15°C and the hot water temperature from 50 to 80°C. All energy storage modules' inlets / outlets are connected to a main inlet / outlet valve, and the tank door is then closed to achieve a seal. The tank is equipped with a temperature probe, a hot water inlet, a cold water inlet, a main outlet valve, a main inlet valve, a hot water outlet, and a cold water outlet. The main inlet / outlet valve is connected to a hydrogen flow meter. Liquid flow meters are installed on the hot water outlet pipe and the cold water outlet pipe, all controlled by a PLC control cabinet. The PLC automatically controls the opening and closing of the corresponding solenoid valves based on the pre-entered operating program, thus obtaining the energy storage device.

[0019] This invention first connects energy storage units in parallel to form energy storage modules, and then further connects multiple energy storage modules in parallel. The inlet / outlet ports of all energy storage modules are connected to the main inlet / outlet valve located on the tank, resulting in a larger energy storage device. Existing methods of directly connecting energy storage units in parallel to form a large energy storage unit present difficulties in subsequent maintenance.

[0020] The electrode plate contains a hydrogen storage alloy. During hydrogen absorption, the hydrogen storage alloy expands, thus securing the energy storage unit and preventing deformation. During hydrogen storage, the hydrogen storage alloy expands in volume along with the thermal effect; correspondingly, it shrinks in volume when releasing hydrogen. Controlling the amount of stored and released hydrogen controls the expansion volume of the hydrogen storage alloy particles, slowing down the pulverization rate and improving cycle life. During hydrogen storage, a certain amount of heat is generated. If this heat cannot be dissipated in time, further increases in temperature will slow down or even stop hydrogen storage. The generated heat needs to be conducted away through the metal shell, resulting in a temperature difference of 10-15℃. Considering that the hydrogen storage alloy should ideally store hydrogen at a temperature below 40℃ (optimal temperature 15-25℃), and taking into account a 5℃ deviation in practical applications, a cold water temperature of 5-15℃ is preferable (if the cold water temperature is too low, it is prone to freezing and energy consumption will be too high; the cold water temperature should also not be too high, considering the need for a 10-15℃ temperature difference for heat conduction). The hydrogen storage alloy absorbs heat during the hydrogen release process. If rapid hydrogen release is required, a large amount of heat needs to be absorbed. Therefore, a hot water temperature of 50~80℃ is better. The hot water temperature should not be too low, as this will affect the hydrogen release rate. It should also not be too high, as excessively high water temperature will result in excessive energy consumption and premature wear and tear on equipment parts.

[0021] When the energy storage device is idle, the main inlet / outlet valves are closed. When hydrogen storage is needed, the PLC starts and automatically opens the cold water inlet / outlet to maintain cold water circulation in the tank, keeping the main outlet valve closed. The main inlet valve is then opened, and when the intake volume reaches 80-90% of the hydrogen storage capacity, the main inlet valve is closed. The cold water continues to circulate and cool for 30-60 minutes, then remains in the tank, completing the energy storage process. When hydrogen is needed, the PLC starts, first draining the cold water, then automatically opening the hot water inlet / outlet to maintain hot water circulation in the tank, opening the main outlet valve, and closing the main inlet valve. When the intake volume is only 5-20% of the hydrogen storage capacity, a corresponding response indicates insufficient hydrogen storage. When it reaches 5%, the main outlet valve is automatically and forcibly closed, and the hot water is drained, completing the energy release process.

[0022] The hydrogen charging and discharging capacity of hydrogen storage alloys is based on the same principle as the charging and discharging capacity of batteries. Multiple energy storage units are connected in parallel, similar to multiple battery packs connected in parallel. They cannot be fully charged and a certain amount needs to be reserved. When the hydrogen charging capacity exceeds 80% (compared to the maximum value obtained from activation), the probability of thermal runaway of the hydrogen storage alloy increases, and the volume expansion coefficient also increases exponentially. This not only easily causes thermal runaway, resulting in poor water cooling effect, but also easily accelerates the pulverization process of the hydrogen storage alloy, thereby shortening the service life of the hydrogen storage alloy. Therefore, the maximum is 90%. Hydrogen discharging cannot be completely discharged either, as this can easily cause over-discharge of the hydrogen storage alloy, resulting in a rapid change in volume, which will also accelerate pulverization. Usually, a level 1 alarm is triggered at 20%, a level 2 alarm at 10%, and a level 3 alarm at 5%. When the highest level is reached, the PLC program will automatically issue an instruction to stop heating and close the main gas valve.

[0023] Preferably, the method for preparing a parallel energy storage device according to the present invention includes the following steps:

[0024] (1) Prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is coated on the upper and lower surfaces of the nickel-plated steel strip by dry or wet process and dried in a drying oven to obtain the base strip.

[0025] (2) Prepare a metal mesh with metal mesh on the top and bottom and a base strip in the middle. Roll it continuously with a roller press in a three-layer sandwich manner, and then cut it according to certain size requirements to obtain an electrode plate of a certain thickness.

[0026] (3) After the plates are stacked into a plate group of a certain thickness or wound into a core, they are pre-pressed, installed into a metal shell, and the top cover is sealed by laser or argon arc welding. An air inlet and an air outlet are left respectively to obtain an energy storage unit, which is then activated.

[0027] (4) Arrange multiple activated energy storage units in sequence, with the air inlet and outlet connected in parallel, and load one or more sets of energy storage units into a square tank and tighten them with set screws to form a square energy storage module, or load one or more sets of energy storage units into a round tank and fix them with clamps to form a cylindrical energy storage module.

[0028] (5) The square or cylindrical energy storage module obtained in step (4) is installed into the tank and mechanically fixed inside the tank. The space between the energy storage module and the tank is filled with cooling water or hot water. The inlet / outlet of all energy storage modules is connected to the main inlet / outlet valve. Then the tank door is closed to achieve a seal. The tank is equipped with a temperature probe, a hot water inlet, a cold water inlet, a main outlet valve, a main inlet valve, a hot water outlet, and a cold water outlet. The main inlet / outlet valve is connected to a hydrogen flow meter. Liquid flow meters are installed on the hot water outlet pipe and the cold water outlet pipe. All are controlled by a PLC control cabinet to obtain the energy storage device.

[0029] (6) When the energy storage device is in a standby state, the main inlet / outlet valve is closed. When hydrogen storage is required, the PLC starts and automatically opens the cold water inlet / outlet to maintain cold water circulation in the tank, keeps the main outlet valve closed, opens the main inlet valve, and when the gas intake reaches 80-90% of the hydrogen storage capacity, closes the main inlet valve. The cold water continues to circulate and cool for 30-60 minutes and then keeps the cold water in place to complete the energy storage process. When hydrogen is needed, the PLC starts, first discharges the cold water, then automatically opens the hot water inlet / outlet to maintain hot water circulation in the tank, opens the main outlet valve, and closes the main inlet valve. When the gas intake is only 5-20% of the hydrogen storage capacity, it prompts that the hydrogen storage is insufficient. When it reaches 5%, it will automatically force the main outlet valve to close and drain the hot water to complete the energy release process.

[0030] (7) Use the hydrogen storage device according to step (6). After a certain number of cycles, replace the hydrogen inlet and outlet so that the hydrogen storage alloy in the energy storage unit can be regenerated and the filter pores can be cleared.

[0031] in:

[0032] When step (1) adopts a dry process, step (1) is as follows: prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is preferably composed of one or more of AB5, AB2, and A2B7. The nickel-plated steel strip needs to be passed through an adhesive tank beforehand. The adhesive tank contains 3-6% PTFE powder by mass. The PTFE powder is dissolved in NMP (N-methylpyrrolidone) to form adhesive so that the hydrogen storage alloy powder can adhere to the surface of the steel strip. The hydrogen storage alloy is coated on the upper and lower surfaces of the nickel-plated steel strip by a dry process and dried in a drying oven to obtain the base strip.

[0033] When step (1) adopts a wet process, step (1) is as follows: prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is preferably composed of one or more of AB5, AB2, and A2B7. Mix the hydrogen storage alloy and glue (the glue is specifically: dissolve 3-6% PTFE powder in NMP (N-methylpyrrolidone) to form glue. Add 0.5-1.5% cobalt tetroxide as an additive and 1-3% high-temperature resistant polyurethane as a binder to the glue) to form a slurry. Pass the nickel-plated steel strip through a slurry tank containing the slurry and then enter a drying oven to dry to obtain the base strip. The nickel-plated steel strip is inexpensive, has high mechanical strength, and the slurry drawing speed can reach 12m / min. Other materials such as carbon cloth and foam metal such as foam nickel and foam copper can also be used, but they are either expensive or have low mechanical strength, resulting in high production costs or low production efficiency.

[0034] The hydrogen storage alloy is preferably composed of one or more of AB5, AB2, and A2B7. It also contains cobalt tetroxide as an additive, polyurethane as a binder, and PTFE powder as a catalyst. The binder is commercially available high-temperature resistant polyurethane, which is soluble in adhesives. Cobalt tetroxide is added as a catalyst to accelerate hydrogen storage. The high-temperature resistant polyurethane buffers the expansion between the hydrogen storage alloy particles. The PTFE powder binder fixes the hydrogen storage alloy powder particles. The addition amount is between 1% and 3%; too little will not achieve the desired effect, while too much will increase costs and reduce the hydrogen absorption per unit area. PTFE powder has properties such as high temperature resistance (-200℃ to 260℃), chemical corrosion resistance, and electrical insulation. It also possesses unique properties such as low friction, anti-aging, and no static electricity, making it very suitable as a binder.

[0035] The electrode plates are stacked to a certain thickness and then inserted into the metal shell. However, this is not done by directly inserting the stacked plates into the metal shell after reaching a certain thickness. The stacked plate assembly needs to be pre-compressed using a clamp for 30-60 minutes, then clamped by an external plastic plate. Within 10 minutes, the plate is inserted into the metal shell, and the plastic plate is then removed. This effectively controls the tightness of the electrode plate assembly within the metal shell to between 90-95%. It cannot be too loose, as the hydrogen storage alloy particles will easily pulverize due to the lack of reverse pressure during hydrogen expansion. It also cannot be too tight, as this makes insertion into the shell difficult. The smooth surface of the plastic plate guides the electrode plate assembly into the shell. If it is a cylindrical metal shell, there is also a hollow metal rod in the middle of the core. This prevents over-winding of the electrode plates and also serves as a channel for guiding gas flow.

[0036] The present invention also provides a parallel energy storage device prepared by the above preparation method.

[0037] The parallel energy storage device obtained by this invention includes a tank, a PLC control cabinet, and an energy storage module. The energy storage module is installed inside the tank. The tank is equipped with a temperature probe, a hot water inlet, a cold water inlet, a main exhaust valve, a main intake valve, a hot water outlet, and a cold water outlet. The hot water inlet, cold water inlet, main exhaust valve, main intake valve, hot water outlet, and cold water outlet are respectively connected to the hot water inlet pipe, cold water inlet pipe, exhaust pipe, intake pipe, hot water outlet pipe, and cold water outlet pipe. The exhaust pipe and intake pipe are respectively equipped with a hydrogen flow meter and a dryer / dust collector. The hot water outlet pipe and cold water outlet pipe are respectively equipped with a liquid flow meter. The valves, temperature probe, hydrogen flow meter, and liquid flow meter on the hot water inlet pipe, cold water inlet pipe, exhaust pipe, intake pipe, hot water outlet pipe, and cold water outlet pipe are all connected to the PLC control cabinet. If the energy storage unit is square, the energy storage module it forms will also be square. The tank should preferably be square, as the energy storage module can be placed inside the tank to the maximum extent. If the energy storage unit is cylindrical, the tank should preferably be elliptical, as the utilization rate inside the tank can be maximized.

[0038] The control cabinet PLC contains a control program that automatically controls the opening and closing of the corresponding solenoid valves based on the collected signals, and can also trigger alarms accordingly. Multiple energy storage modules can be connected in parallel as needed to increase the hydrogen storage capacity of a single tank. Explosion-proof valves are also installed on the tanks.

[0039] In summary, the present invention has the following advantages:

[0040] (1) The preparation method of the parallel energy storage device provided by the present invention involves wrapping the hydrogen storage alloy with a metal mesh, rolling it to a certain thickness using a roller press, stacking the electrode plates into an electrode plate group of a certain thickness or winding it into a core and then installing it into a metal shell to form an energy storage unit. The top cover is welded and sealed, with an air inlet and an air outlet respectively. Multiple energy storage units are connected in parallel through the air inlet and the air outlet to form an energy storage module, which together with the tank and PLC control cabinet constitutes a high-safety, low-pressure, long-cycle-life hydrogen storage device. The hydrogen storage speed is fast, the hydrogen release speed is controllable, and the hydrogen storage alloy has strong stability. It can solve the problems of low usage times, pore blockage, frequent replacement of hydrogen storage alloy, and short cycle life caused by the excessively fast pulverization speed of the hydrogen storage alloy in the prior art, as well as the high cost of use and the easy thermal runaway of stored hydrogen.

[0041] (2) The energy storage device provided by the present invention allows the gas to pass through the energy storage unit evenly through the gas inlet pipe when the gas is introduced, thereby making the gas evenly distributed in the electrode plate and also allowing the gas to be further regulated, reducing the heat generated during hydrogen storage, preventing thermal runaway effect, and thus reducing damage to the hydrogen storage alloy.

[0042] (3) This invention is easy to operate. By controlling each component through the control cabinet, heating, cooling and flow can be integrated. The entire process is automatically controlled by the control cabinet, which not only improves production efficiency but also saves manpower. The electrode plates and baseband required by this invention can utilize the vacuum mixer and slurry machine of current water-based secondary battery equipment, which facilitates continuous production and is conducive to large-scale supply.

[0043] (4) The energy storage device provided by the present invention can reduce the hydrogen release by less than 3-5% after 1000 cycles, and the hydrogen storage capacity can reach 75-90% within 15 minutes and the hydrogen release capacity can be greater than 70-85% within 30 minutes. When storing hydrogen, the temperature is stable within 30°C, and there is a large safe zone away from the temperature warning value of thermal runaway. The device and its method can meet the requirements of commercialization. Attached Figure Description

[0044] Figure 1 : A schematic diagram of the square energy storage device in an embodiment of the present invention;

[0045] Figure 2 : A cross-sectional view of the energy storage unit in an embodiment of the present invention;

[0046] Figure 3: A schematic diagram of the square energy storage unit in an embodiment of the present invention;

[0047] Figure 4 : A schematic diagram of the cylindrical energy storage unit in an embodiment of the present invention;

[0048] Figure 5 : A schematic diagram of the square energy storage module in an embodiment of the present invention;

[0049] In the diagram: 1-PLC control cabinet, 2-tank body, 3-temperature probe, 4-hot water inlet pipe, 5-cold water inlet pipe, 6-outlet pipe, 7-hydrogen flow meter, 8-inlet pipe, 9-hot water outlet pipe, 10-cold water outlet pipe, 11-dryer dust collector, 12-liquid flow meter, 13-electrode plate, 14-square metal shell, 15-inlet, 16-outlet, 17-filter element, 18-inlet of square energy storage unit, 19-outlet of square energy storage unit, 20-inlet of cylindrical energy storage unit, 21-outlet of cylindrical energy storage unit, 22-fastening strip, 23-partition plate, 24-energy storage unit, 25-set screw, 26-fixing channel steel. Detailed Implementation

[0050] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0051] Example 1

[0052] A parallel energy storage device, the preparation method of which includes the following steps:

[0053] (1) Wet process: Prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is composed of AB5, AB2, A2B7 in equal molar ratio. Mix the hydrogen storage alloy and glue (the glue is made by dissolving 4% PTFE powder in NMP (N-methylpyrrolidone) to form glue, adding 1.0% cobalt tetroxide as an additive and 2.0% high-temperature resistant polyurethane as a binder) to form a slurry. The nickel-plated steel strip is passed through a slurry tank containing the slurry and then enters a drying oven for drying. The slurry drawing speed reaches 12m / min to obtain the base strip.

[0054] (2) Prepare a metal mesh with a mesh count of 150. The top and bottom surfaces are metal mesh, and the middle is a base strip. The mesh is continuously rolled in a three-layer sandwich manner using a roller press. Then, it is cut to a certain size to obtain an electrode plate with a thickness of 0.3 mm. The compacted specific gravity of the electrode plate is 4.5 g / m³. 3 ;

[0055] (3) After the electrode plates are stacked into a 30 mm thick electrode plate assembly, they need to be pre-pressed with a clamp for 45 min, then clamped with an external plastic plate, and the metal shell is inserted within 10 min. The plastic plate is then removed. This effectively controls the tightness of the electrode plate assembly in the metal shell to be between 90 and 95%. The wall thickness of the metal shell is 1.0 mm. The top cover is sealed by laser or argon arc welding, with an air inlet and an air outlet respectively, to obtain the energy storage unit. The cross-sectional view of the prepared energy storage unit is shown below. Figure 2 As shown, the square metal shell 14 is provided with an electrode plate 13, and the square metal shell 14 is provided with an air inlet 15 and an air outlet 16. The air inlet 15 is provided with a filter element 17, which can prevent powder from entering or leaving.

[0056] The energy storage unit is then activated as follows: The energy storage unit is secured, the inlet is closed, and the outlet is connected to the main valve of the vacuum pump. The energy storage unit is placed in the heating chamber and heated at 150 °C for 100 min to degas it. Simultaneously, the vacuum pump continuously evacuates gas from the outlet of the energy storage unit. After this process, the outlet and vacuum pump are closed. The heating switch is then turned off, and the energy storage unit is allowed to cool to room temperature. The inlet of the energy storage unit is then opened, and hydrogen is introduced at a pressure of 1.0 MPa for 1.5 h. After resting for 20 min, hydrogen is naturally released until the pressure of the energy storage unit matches the external atmospheric pressure. The energy storage unit is then further heated and degassed in the 150 °C heating chamber for 100 min to further remove internal gaseous impurities, thus completing the activation process.

[0057] (4) Arrange multiple activated energy storage units in sequence, with the air inlet and outlet connected in parallel (e.g., Figure 2 , Figure 3 As shown, each energy storage unit has an air inlet and an air outlet. Multiple energy storage units are connected in parallel to form an energy storage module: specifically, the air inlets are connected in series to form a single main air inlet, and the air outlets are connected in series to form a single main air outlet. Multiple sets of energy storage units are installed into a square tank and tightened with set screws to form a square energy storage module, which is mechanically fixed inside the tank. A structural diagram of the square energy storage module is shown below. Figure 5 Multiple energy storage units 24 are arranged sequentially, with partitions 23 between adjacent energy storage units 24. Air inlets and outlets are connected in parallel. The outer sides of the multiple energy storage units 24 are fastened by fastening strips 22, with both ends of the fastening strips 22 secured by set screws. The multiple energy storage units 24 are fixed to the square tank body by fixing channel steel 26. A structural schematic diagram of the square energy storage unit is shown below. Figure 3 The square energy storage unit tank is equipped with a square energy storage unit inlet 18 and a square energy storage unit outlet 19; multiple energy storage modules can be connected in parallel as needed to increase the hydrogen storage capacity of a single tank; the tank is also equipped with an explosion-proof valve.

[0058] (5) The energy storage module obtained in step (4) is installed into the tank and mechanically fixed. The space between the energy storage module and the tank is filled with cooling water or hot water. The internal air inlet / outlet is connected to the main air inlet / outlet valve. Then, the tank door is closed to achieve a seal. The structural schematic diagram of the prepared parallel energy storage device is shown below. Figure 1 As shown, the system includes a tank 2, a PLC control cabinet 1, and an energy storage module. The energy storage module is located inside the tank 2. The tank is equipped with a temperature probe 3, a hot water inlet, a cold water inlet, a main exhaust valve, a main intake valve, a hot water outlet, and a cold water outlet. The hot water inlet, cold water inlet, main exhaust valve, main intake valve, hot water outlet, and cold water outlet are respectively connected to a hot water inlet pipe 4, a cold water inlet pipe 5, an exhaust pipe 6, an intake pipe 8, a hot water outlet pipe 9, and a cold water outlet pipe 10. Hydrogen flow meter 7 and dryer / dust collector 11 are respectively installed on the exhaust pipe 6 and exhaust pipe 8. Liquid flow meter 12 is installed on the hot water exhaust pipe 9 and cold water exhaust pipe 10. Valves, temperature probe 3, hydrogen flow meter 7, and liquid flow meter 12 on the hot water exhaust pipe 4, cold water exhaust pipe 5, exhaust pipe 6, exhaust pipe 8, hot water exhaust pipe 9, and cold water exhaust pipe 10 are all connected to the PLC control cabinet. The PLC control cabinet is equipped with alarm devices, emergency stop buttons, and start buttons. Temperature, flow, and other signal lines are collected by the PLC device for no-load operation testing to verify that all connections are ready and all actions are in place. After passing the test, the energy storage device can be put into use at any time. The PLC control cabinet is equipped with alarm devices, emergency stop buttons, and start buttons. The PLC control cabinet contains control operation programs that automatically control the opening and closing of corresponding solenoid valves based on the collected signals and can trigger corresponding alarms.

[0059] (6) When the energy storage device is idle, the main inlet / outlet valve is closed. When hydrogen storage is needed, the PLC starts and automatically confirms that the hydrogen supply interface is connected in place. The program runs as follows: the cold water inlet / outlet is automatically opened, the main outlet valve is kept closed, the main inlet valve is opened, and when the gas intake reaches 85% of the hydrogen storage capacity, the main inlet valve is closed. The cold water continues to circulate and cool for 45 minutes and then the cold water is kept at 10°C to complete the energy storage process. If hydrogen is needed, the PLC starts and automatically confirms that the hydrogen outlet interface is connected in place. The program runs as follows: the cold water is discharged first, and then the hot water inlet / outlet is automatically opened. The hot water temperature is 65°C. The main outlet valve is opened and the main inlet valve is kept closed. When the gas intake is only 5-20% of the hydrogen storage capacity, the corresponding hydrogen storage is insufficient. When it reaches 5%, the main outlet valve is automatically closed and the hot water is drained to complete the energy release process.

[0060] (7) After using the hydrogen storage device in step 6 and cycling a certain number of times, the hydrogen inlet and outlet need to be replaced so that the hydrogen storage alloy in the energy storage unit can be regenerated and the filter pores can be cleared.

[0061] With the above operating parameters, a small energy storage device with a hydrogen storage capacity of 0-20 kg can be cycled 1000 times with a hydrogen release rate of less than 3%. The hydrogen storage capacity can reach 80% within 15 minutes and the hydrogen release rate can be greater than 70% within 30 minutes. The temperature is stable below 30°C when storing hydrogen, and there is a large safe zone away from the temperature warning value for thermal runaway. It meets the requirements for commercialization.

[0062] Example 2

[0063] A parallel energy storage device, the preparation method of which includes the following steps:

[0064] (1) Dry process: Prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is composed of AB5, AB2, A2B7 in equal molar ratio. The nickel-plated steel strip needs to be pre-passed through an adhesive tank containing 4% PTFE powder by mass. The PTFE powder is dissolved in NMP (N-methylpyrrolidone) to form adhesive so that the hydrogen storage alloy powder can adhere to the surface of the steel strip. The hydrogen storage alloy is coated on the upper and lower sides of the nickel-plated steel strip by a dry process and dried in a drying oven to obtain the base strip.

[0065] (2) Prepare a metal mesh with a mesh count of 200. The top and bottom surfaces are metal mesh, and the middle is a base strip. The mesh is continuously rolled in a three-layer sandwich manner using a roller press. Then, it is cut according to certain size requirements to obtain an electrode plate with a thickness of 0.8 mm. The compaction density of the electrode plate is 3.8 g / m³. 3 ;

[0066] (3) After the electrode plates are stacked into a 60 mm thick electrode plate assembly, they need to be pre-pressed with a clamp for 30-60 min. Then, the outer plastic plate is clamped in, and the metal shell is installed within 10 min. The plastic plate is then removed. This can effectively control the tightness of the electrode plate assembly in the metal shell to be between 90-95%. The wall thickness of the metal shell is 0.5-2.0 mm. The top cover is sealed by laser or argon arc welding, with an air inlet and an air outlet respectively, to obtain the energy storage unit. The cross-sectional view of the prepared energy storage unit is shown in the figure. Figure 2 As shown, the square metal shell 14 is provided with an electrode plate 13, and the square metal shell 14 is provided with an air inlet 15 and an air outlet 16. The air inlet 15 is provided with a filter element 17, which can prevent powder from entering or leaving.

[0067] The energy storage unit is then activated as follows: The energy storage unit is secured, the inlet is closed, and the outlet is connected to the main valve of the vacuum pump. The energy storage unit is placed in the heating chamber and heated at 120 °C for 120 min to degas it. Simultaneously, the vacuum pump continuously evacuates gas from the outlet of the energy storage unit. After this is complete, the outlet and the vacuum pump are closed. The heating switch is then turned off, and the energy storage unit is allowed to cool to room temperature. The inlet of the energy storage unit is then opened, and hydrogen is introduced at a pressure of 2 MPa for 1 h. After resting for 10 min, hydrogen is naturally released until the pressure of the energy storage unit matches the external atmospheric pressure. The energy storage unit is then heated in the 120 °C heating chamber for another 120 min to further remove internal gaseous impurities, thus completing the activation process.

[0068] (4) Arrange multiple activated energy storage units in sequence, with the air inlet and outlet connected in parallel (e.g., Figure 4 As shown, each energy storage unit has an air inlet and an air outlet. Multiple energy storage units are connected in parallel to form an energy storage module: specifically, the air inlets are connected in series to form a common air inlet, and the air outlets are connected in series to form a common air outlet. Multiple sets of energy storage units are installed into a cylindrical tank and fixed with clamps to form a cylindrical energy storage module. The entire module is mechanically fixed inside the tank. A schematic diagram of the cylindrical energy storage unit can be seen in [the diagram]. Figure 4 The cylindrical energy storage unit tank is equipped with a cylindrical energy storage unit inlet 20 and a cylindrical energy storage unit outlet 21; multiple energy storage modules can be connected in parallel as needed to increase the hydrogen storage capacity of a single tank; the tank is also equipped with an explosion-proof valve.

[0069] (5) The energy storage module obtained in step (4) is installed into the tank and mechanically fixed. The space between the energy storage module and the tank is filled with cooling water or hot water. The internal air inlet / outlet is connected to the main air inlet / outlet valve. Then, the tank door is closed to achieve a seal. The structural schematic diagram of the prepared parallel energy storage device is shown below. Figure 1As shown, the system includes a tank 2, a PLC control cabinet 1, and an energy storage module. The energy storage module is located inside the tank 2. The tank is equipped with a temperature probe 3, a hot water inlet, a cold water inlet, a main exhaust valve, a main intake valve, a hot water outlet, and a cold water outlet. The hot water inlet, cold water inlet, main exhaust valve, main intake valve, hot water outlet, and cold water outlet are respectively connected to a hot water inlet pipe 4, a cold water inlet pipe 5, an exhaust pipe 6, an intake pipe 8, a hot water outlet pipe 9, and a cold water outlet pipe 10. Hydrogen flow meter 7 and dryer / dust collector 11 are respectively installed on the exhaust pipe 6 and exhaust pipe 8. Liquid flow meter 12 is installed on the hot water exhaust pipe 9 and cold water exhaust pipe 10. Valves, temperature probe 3, hydrogen flow meter 7, and liquid flow meter 12 on the hot water exhaust pipe 4, cold water exhaust pipe 5, exhaust pipe 6, exhaust pipe 8, hot water exhaust pipe 9, and cold water exhaust pipe 10 are all connected to the PLC control cabinet. The PLC control cabinet is equipped with alarm devices, emergency stop buttons, and start buttons. Temperature, flow, and other signal lines are collected by the PLC device for no-load operation testing to verify that all connections are ready and all actions are in place. After passing the test, the energy storage device can be put into use at any time. The PLC control cabinet is equipped with alarm devices, emergency stop buttons, and start buttons. The PLC control cabinet contains control operation programs that automatically control the opening and closing of corresponding solenoid valves based on the collected signals and can trigger corresponding alarms.

[0070] (6) When the energy storage device is idle, the main inlet / outlet valve is closed. When hydrogen storage is needed, the PLC starts and automatically confirms that the hydrogen supply interface is connected in place. The program runs as follows: the cold water inlet / outlet is automatically opened, the main outlet valve is kept closed, the main inlet valve is opened, and when the gas intake reaches 90% of the hydrogen storage capacity, the main inlet valve is closed. The cold water continues to circulate and cool for 30 minutes and then the cold water is kept at 5°C to complete the energy storage process. If hydrogen is needed, the PLC starts, the cold water is discharged first, and then the hydrogen outlet interface is automatically confirmed to be connected in place. The program runs as follows: the hot water inlet / outlet is automatically opened, the hot water temperature is 80°C, the main outlet valve is opened, and the main inlet valve is kept closed. When the gas intake is only 5~20% of the hydrogen storage capacity, the corresponding hydrogen storage is insufficient. When it reaches 5%, the main outlet valve is automatically closed and the hot water is drained to complete the energy release process.

[0071] (7) After using the hydrogen storage device in step 6 and cycling a certain number of times, the hydrogen inlet and outlet need to be replaced so that the hydrogen storage alloy in the energy storage unit can be regenerated and the filter pores can be cleared.

[0072] The cylindrical metal shell contains a hollow metal rod in the center of the core. This rod is used to prevent over-winding inside the electrode plates and also serves as a channel to guide gas flow.

[0073] With the above operating parameters, a small energy storage device with a hydrogen storage capacity of 10 kg to 2000 kg can achieve a hydrogen release rate of less than 5% after 1000 cycles, with a hydrogen storage capacity of 75% within 15 minutes and a hydrogen release rate of more than 85% within 30 minutes; the temperature is stable below 30℃ when storing hydrogen, and there is a large safe zone away from the thermal runaway temperature warning value of 75℃; thus meeting the requirements for commercialization.

[0074] Example 3

[0075] A parallel energy storage device, the preparation method of which includes the following steps:

[0076] (1) Wet process: Prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is composed of AB5, AB2, A2B7 in equal molar ratio. Mix the hydrogen storage alloy and glue (the glue is made by dissolving 6% PTFE powder in NMP (N-methylpyrrolidone) to form glue, adding 1.0% cobalt tetroxide as an additive and 3.0% high-temperature resistant polyurethane as a binder) to form a slurry. The nickel-plated steel strip is passed through a slurry tank containing the slurry and then enters a drying oven for drying. The slurry drawing speed reaches 12m / min to obtain the base strip.

[0077] Prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is coated on both sides of the nickel-plated steel strip using a dry process and then dried in a drying oven to obtain the base strip.

[0078] (2) Prepare a 100-mesh metal mesh. The top and bottom surfaces are metal mesh, and the middle is a base strip. The mesh is continuously rolled in a three-layer sandwich manner using a roller press. Then, it is cut to a certain size to obtain an electrode plate with a thickness of 0.6 mm. The compacted specific gravity of the electrode plate is 4.0 g / m³. 3 ;

[0079] (3) After the electrode plates are stacked into a 40 mm thick electrode plate assembly, they need to be pre-pressed with a clamp for 30-60 min. Then, the outer plastic plate is clamped in, and the metal shell is inserted within 10 min. The plastic plate is then removed. This can effectively control the tightness of the electrode plate assembly in the metal shell to be between 90-95%. The wall thickness of the metal shell is 0.5-2.0 mm. The top cover is sealed by laser or argon arc welding, with an air inlet and an air outlet respectively, to obtain the energy storage unit. The cross-sectional view of the prepared energy storage unit is shown in the figure. Figure 2 As shown, the square metal shell 14 is provided with an electrode plate 13, and the square metal shell 14 is provided with an air inlet 15 and an air outlet 16. The air inlet 15 is provided with a filter element 17, which can prevent powder from entering or leaving.

[0080] The energy storage unit is then activated as follows: The energy storage unit is secured, the inlet is closed, and the outlet is connected to the main valve of the vacuum pump. The energy storage unit is placed in the heating chamber and heated at 180°C for 60 minutes to degas it. Simultaneously, the vacuum pump continuously evacuates the outlet of the energy storage unit. After this process, the outlet and vacuum pump are closed. The heating switch is then turned off, and the energy storage unit is allowed to cool to room temperature. The inlet of the energy storage unit is then opened, and hydrogen is introduced at a pressure of 0.5 MPa for 2 hours. After resting for 30 minutes, hydrogen is naturally released until the pressure of the energy storage unit matches the external atmospheric pressure. The energy storage unit is then further heated in the 180°C heating chamber for 60 minutes to degas it, further removing internal gaseous impurities and completing the activation process.

[0081] (4) Arrange multiple activated energy storage units in sequence, with the air inlet and outlet connected in parallel (e.g., Figure 2 , Figure 3 As shown, each energy storage unit has an air inlet and an air outlet. Multiple energy storage units are connected in parallel to form an energy storage module: specifically, the air inlets are connected in series to form a single main air inlet, and the air outlets are connected in series to form a single main air outlet. Multiple sets of energy storage units are installed into a square tank and tightened with set screws to form a square energy storage module, which is mechanically fixed inside the tank. A structural diagram of the square energy storage module is shown below. Figure 5 Multiple energy storage units 24 are arranged sequentially, with partitions 23 between adjacent energy storage units 24. Air inlets and outlets are connected in parallel. The outer sides of the multiple energy storage units 24 are fastened by fastening strips 22, with both ends of the fastening strips 22 secured by set screws. The multiple energy storage units 24 are fixed to the square tank body by fixing channel steel 26. A structural schematic diagram of the square energy storage unit is shown below. Figure 3 The square energy storage unit tank is equipped with a square energy storage unit inlet 18 and a square energy storage unit outlet 19; multiple energy storage modules can be connected in parallel as needed to increase the hydrogen storage capacity of a single tank; the tank is also equipped with an explosion-proof valve.

[0082] (5) The energy storage module obtained in step (4) is installed into the tank and mechanically fixed. The space between the energy storage module and the tank is filled with cooling water or hot water. The internal air inlet / outlet is connected to the main air inlet / outlet valve. Then, the tank door is closed to achieve a seal. The structural schematic diagram of the prepared parallel energy storage device is shown below. Figure 1As shown, the system includes a tank 2, a PLC control cabinet 1, and an energy storage module. The energy storage module is located inside the tank 2. The tank is equipped with a temperature probe 3, a hot water inlet, a cold water inlet, a main exhaust valve, a main intake valve, a hot water outlet, and a cold water outlet. The hot water inlet, cold water inlet, main exhaust valve, main intake valve, hot water outlet, and cold water outlet are respectively connected to a hot water inlet pipe 4, a cold water inlet pipe 5, an exhaust pipe 6, an intake pipe 8, a hot water outlet pipe 9, and a cold water outlet pipe 10. Hydrogen flow meter 7 and dryer / dust collector 11 are respectively installed on the exhaust pipe 6 and exhaust pipe 8. Liquid flow meter 12 is installed on the hot water exhaust pipe 9 and cold water exhaust pipe 10. Valves, temperature probe 3, hydrogen flow meter 7, and liquid flow meter 12 on the hot water exhaust pipe 4, cold water exhaust pipe 5, exhaust pipe 6, exhaust pipe 8, hot water exhaust pipe 9, and cold water exhaust pipe 10 are all connected to the PLC control cabinet. The PLC control cabinet is equipped with alarm devices, emergency stop buttons, and start buttons. Temperature, flow, and other signal lines are collected by the PLC device for no-load operation testing to verify that all connections are ready and all actions are in place. After passing the test, the energy storage device can be put into use at any time. The PLC control cabinet is equipped with alarm devices, emergency stop buttons, and start buttons. The PLC control cabinet contains control operation programs that automatically control the opening and closing of corresponding solenoid valves based on the collected signals and can trigger corresponding alarms.

[0083] (6) When the energy storage device is idle, the main inlet / outlet valve is closed. When hydrogen storage is needed, the PLC starts and automatically confirms that the hydrogen supply interface is connected in place. The program runs as follows: the cold water inlet / outlet is automatically opened, the main outlet valve is kept closed, the main inlet valve is opened, and when the gas intake reaches 80% of the hydrogen storage capacity, the main inlet valve is closed. The cold water continues to circulate and cool for 60 minutes and then the cold water is kept at 15°C to complete the energy storage process. If hydrogen is needed, the PLC starts, the cold water is discharged first, and then the hydrogen outlet interface is automatically confirmed to be connected in place. The program runs as follows: the hot water inlet / outlet is automatically opened, the hot water temperature is 50°C, the main outlet valve is opened, and the main inlet valve is kept closed. When the gas intake is only 5-20% of the hydrogen storage capacity, the corresponding hydrogen storage is insufficient. When it reaches 5%, the main outlet valve is automatically closed and the hot water is drained to complete the energy release process.

[0084] (7) After using the hydrogen storage device in step 6 and cycling a certain number of times, the hydrogen inlet and outlet need to be replaced so that the hydrogen storage alloy in the energy storage unit can be regenerated and the filter pores can be cleared.

[0085] The cylindrical metal shell contains a hollow metal rod in the center of the core. This rod is used to prevent over-winding inside the electrode plates and also serves as a channel to guide gas flow.

[0086] With the above operating parameters, a small energy storage device with a hydrogen storage capacity of 0-10 kg can be cycled 1000 times with a hydrogen release rate of less than 4%. The hydrogen storage capacity can reach 90% within 15 minutes and the hydrogen release rate can be greater than 85% within 30 minutes. The temperature is stable below 30℃ when storing hydrogen, and there is a large safe zone away from the thermal runaway temperature warning value of 80℃, which meets the requirements for commercialization.

[0087] Comparative Example 1

[0088] The parallel energy storage device and its preparation method are the same as in Example 1. The only difference is that in step (6), when the hydrogen charge reaches 100% each time, that is, when the gas intake reaches 100% of the hydrogen storage capacity, the main gas intake valve is closed.

[0089] After using the method described in Comparative Example 1, for small energy storage devices with a hydrogen storage capacity of 0-20 kg, after 50 cycles, the hydrogen release decreased by 40%, and the water temperature rose abnormally during the hydrogen storage process, reaching a maximum of 65℃, indicating thermal runaway.

[0090] Comparative Example 2

[0091] The parallel energy storage device and its preparation method are the same as in Example 2, except that the amount of hydrogen released in step (6) is 0% each time.

[0092] After using the method described in Comparative Example 2, for small energy storage devices with a hydrogen storage capacity of 10 kg to 2000 kg, after 50 cycles, the hydrogen release decreased by 60%, and the hydrogen storage capacity of the hydrogen storage material decreased significantly, which was insufficient to support commercial operation.

[0093] Comparative Example 3

[0094] The parallel energy storage device and its preparation method are the same as in Example 3, except that the hydrogen storage process in step (5) is not water-cooled.

[0095] During the hydrogen storage process in Comparative Example 3, the temperature rose sharply. When the hydrogen storage volume exceeded 65%, the temperature was already above 85°C, and hydrogen storage almost stopped, making it impossible to continue storing hydrogen.

[0096] Comparative Example 4

[0097] The parallel energy storage device and its preparation method are the same as in Example 1, except that the hot water heating is not turned on during the hydrogen release process in step (5).

[0098] In Comparative Example 4, the hydrogen release was less than 30%, and the flow rate was slow, so more hydrogen was not released.

[0099] Comparative Example 5

[0100] The parallel energy storage device and its preparation method are the same as in Example 1, except that the mesh size of the metal mesh is 30 mesh.

[0101] Comparative Example 5 showed slow hydrogen storage speed and less than 30% of the theoretical value. The hydrogen storage alloy particles were large, making it difficult for hydrogen to diffuse from the surface into the interior of the alloy material for storage.

[0102] Comparative Example 6

[0103] The parallel energy storage device and its preparation method are the same as in Example 1, except that the mesh size of the metal mesh is 500 mesh.

[0104] Comparative Example 6 shows a fast hydrogen storage speed but a slow hydrogen release speed. With the support of external hot water, the hydrogen release speed drives the flow of very fine hydrogen storage alloy particles, which gradually squeeze together at the outlet, increasing the resistance to hydrogen flow and further resulting in low hydrogen output pressure, making it difficult to meet the pressure requirements for hydrogen use.

[0105] Comparative Example 7

[0106] The parallel energy storage device and its preparation method are the same as in Example 1, except that the thickness of the electrode plate is 0.1 mm and the compaction density of the electrode plate is 6.5 g / m³. 3 .

[0107] Comparative Example 7 had an extremely slow hydrogen storage speed, but also a small amount of hydrogen release. After more than ten uses, the gas flow rate was very slow, and disassembly revealed that the hydrogen storage alloy powder on the electrode plate had almost all been pulverized.

[0108] Comparative Example 8

[0109] The parallel energy storage device and its preparation method are the same as in Example 1, except that the thickness of the electrode plate is 2.0 mm and the compaction density of the electrode plate is 1.9 g / m³. 3 .

[0110] Comparative Example 8 showed extremely fast hydrogen storage speed, but also rapid hydrogen release. After more than 100 uses, the gas flow rate became very slow, and disassembly revealed that the hydrogen storage alloy powder on the electrode plate had almost completely pulverized.

[0111] Comparative Example 9

[0112] The parallel energy storage device and its preparation method are the same as in Example 1, except that the activation process is as follows: the energy storage unit is secured, the inlet is closed, the outlet is connected to the main valve, the energy storage unit is placed in the heating chamber, and heated at 90 °C for 150 min to degas it. At the same time, the pump continuously pumps gas from the outlet of the energy storage unit. After completion, the outlet and the pump are closed. Then, the heating switch is turned off, and the energy storage unit is allowed to cool to room temperature. The inlet of the energy storage unit is then opened, and hydrogen is charged at a hydrogen pressure of 0.1 MPa for 1.5 h. After resting for 20 min, hydrogen is naturally released until the pressure of the energy storage unit is consistent with the external atmospheric pressure. The energy storage unit is then heated in a heating chamber at 100 °C for another 150 min to further remove internal gaseous impurities, thus completing the activation.

[0113] With the above operating parameters, the hydrogen released from a small energy storage device weighing 0-20 kg after storage has never met the purity requirements of a fuel cell.

[0114] Comparative Example 10

[0115] The parallel energy storage device and its preparation method are the same as in Example 1, except that the activation process is as follows: the energy storage unit is secured, the inlet is closed, the outlet is connected to the main valve, the energy storage unit is placed in the heating chamber, and heated at 220 °C for 120 min to degas it. At the same time, the pump continuously pumps gas from the outlet of the energy storage unit. After completion, the outlet and the pump are closed. Then, the heating switch is turned off, and the energy storage unit is allowed to cool to room temperature. The inlet of the energy storage unit is opened, and hydrogen is charged at a hydrogen pressure of 5 MPa for 1.5 h. After resting for 20 min, hydrogen is naturally released until the pressure of the energy storage unit is consistent with the external atmospheric pressure. The energy storage unit is then heated in the heating chamber at 220 °C for another 120 min to degas it, further removing internal gaseous impurities and completing the activation.

[0116] With the above operating parameters, small energy storage devices with a hydrogen storage capacity of 0-20 kg experienced a decrease in hydrogen release of more than 30% after 400 cycles, which is difficult to meet the commercial life requirements; disassembly revealed that the hydrogen storage alloy of the electrode plates was severely pulverized and detached.

Claims

1. A method for preparing a parallel energy storage device, comprising the following steps: After wrapping the hydrogen storage alloy with a metal mesh, it is rolled to a certain thickness using a roller press. The plates are stacked into plate groups or wound into cores and then installed into a metal shell. The top cover is welded and sealed, with an air inlet and an air outlet respectively, to obtain an energy storage unit. The energy storage unit is activated, and multiple activated energy storage units are connected in parallel through the air inlet and air outlet to form an energy storage module. The energy storage module is installed in a tank and mechanically fixed. The air inlet and air outlet of the energy storage module are connected to a solenoid valve and a flow meter. The tank is equipped with a hydrogen inlet, a hydrogen outlet, a cold water inlet and outlet, and a hot water inlet and outlet. Water is filled between the energy storage module and the tank to obtain the parallel energy storage device. The specific steps include the following: (1) Prepare nickel-plated steel strip and hydrogen storage alloy. The hydrogen storage alloy is coated on the upper and lower surfaces of the nickel-plated steel strip by dry or wet process and dried in a drying oven to obtain the base strip. (2) Prepare a metal mesh with metal mesh on the top and bottom and a base strip in the middle. Roll it continuously with a roller press in a three-layer sandwich manner, and then cut it according to certain size requirements to obtain an electrode plate of a certain thickness. (3) After the plates are stacked into a plate group of a certain thickness or wound into a core, they are pre-pressed, installed into a metal shell, and the top cover is sealed by laser or argon arc welding. An air inlet and an air outlet are left respectively to obtain an energy storage unit, which is then activated. (4) Arrange multiple activated energy storage units in sequence, with the air inlet and outlet connected in parallel, and load one or more sets of energy storage units into a square tank and tighten them with set screws to form a square energy storage module, or load one or more sets of energy storage units into a round tank and fix them with clamps to form a cylindrical energy storage module. (5) The square or cylindrical energy storage module obtained in step (4) is installed into the tank and mechanically fixed inside the tank. The space between the energy storage module and the tank is filled with cooling water or hot water. The inlet / outlet of all energy storage modules is connected to the main inlet / outlet valve. Then the tank door is closed to achieve a seal. The tank is equipped with a temperature probe, a hot water inlet, a cold water inlet, a main outlet valve, a main inlet valve, a hot water outlet, and a cold water outlet. The main inlet / outlet valve is connected to a hydrogen flow meter. Liquid flow meters are installed on the hot water outlet pipe and the cold water outlet pipe. All are controlled by a PLC control cabinet to obtain the energy storage device. (6) When the energy storage device is in a standby state, the main inlet / outlet valve is closed. When hydrogen storage is required, the PLC starts and automatically opens the cold water inlet / outlet to maintain cold water circulation in the tank, keeps the main outlet valve closed, opens the main inlet valve, and when the gas intake reaches 80-90% of the hydrogen storage capacity, closes the main inlet valve. The cold water continues to circulate and cool for 30-60 minutes and then keeps the cold water in place to complete the energy storage process. When hydrogen is needed, the PLC starts, first drains the cold water, then automatically opens the hot water inlet / outlet to maintain hot water circulation in the tank, opens the main outlet valve, and closes the main inlet valve. When the gas intake is only 5-20% of the hydrogen storage capacity, it prompts that the hydrogen storage is insufficient. When it reaches 5%, it will automatically force the main outlet valve to close and drain the hot water to complete the energy release process. (7) Use the hydrogen storage device according to step (6). After a certain number of cycles, replace the hydrogen inlet and outlet so that the hydrogen storage alloy in the energy storage unit can be regenerated and the filter pores can be cleared.

2. The method for preparing the parallel energy storage device according to claim 1, characterized in that: The metal mesh has a mesh count of 100 to 200; the electrode plate has a thickness of 0.3 to 0.8 mm; and the electrode plate assembly has a thickness of 28 to 60 mm.

3. The method for preparing the parallel energy storage device according to claim 1, characterized in that: The metal shell is made of alloy or stainless steel and has a thickness of 0.5~2.0 mm; the welding is argon arc welding or laser welding.

4. The method for preparing the parallel energy storage device according to claim 1, characterized in that: The activation process is as follows: Secure the energy storage unit, close the inlet, connect the outlet to the main valve of the vacuum pump, place the energy storage unit in the heating chamber, and heat it at 120~180℃ for 60~120 min to degas it. At the same time, the vacuum pump continuously evacuates the outlet of the energy storage unit. After completion, close the outlet and turn off the vacuum pump. Then turn off the heating switch and wait for the energy storage unit to cool to room temperature. Open the inlet of the energy storage unit and charge it with hydrogen at a hydrogen pressure of 0.5~2 MPa for 1~2 h. After resting for 10~30 min, let the hydrogen be released naturally until the pressure of the energy storage unit is consistent with the external atmospheric pressure. Continue to heat the energy storage unit in the heating chamber at 120~180℃ for 60~120 min to degas it, further removing internal gaseous impurities and completing the activation.

5. The method for preparing the parallel energy storage device according to claim 1, characterized in that: When step (1) adopts a dry process, step (1) is as follows: prepare nickel-plated steel strip and hydrogen storage alloy, wherein the hydrogen storage alloy is one or more of AB5, AB2, and A2B7. The nickel-plated steel strip needs to be passed through an adhesive tank beforehand. The adhesive tank contains 3-6% PTFE powder by mass. The PTFE powder is dissolved in NMP to form adhesive. The hydrogen storage alloy is coated on the upper and lower surfaces of the nickel-plated steel strip by a dry process. The strip is then dried in a drying oven to obtain the base strip. When step (1) adopts a wet process, step (1) is as follows: prepare nickel-plated steel strip and hydrogen storage alloy, wherein the hydrogen storage alloy is one or more of AB5, AB2, and A2B7, mix the hydrogen storage alloy and glue into a slurry, wherein the glue is: dissolve PTFE powder with a mass fraction of 3~6% in NMP to form glue, and add cobalt tetroxide with a mass fraction of 0.5~1.5% as an additive and high-temperature resistant polyurethane with a mass fraction of 1~3% as a binder to obtain the glue; The nickel-plated steel strip is passed through a slurry tank containing the slurry and then enters a drying oven for drying. The slurry drawing speed reaches 12m / min to obtain the base strip.

6. A parallel energy storage device, characterized in that: It is prepared according to any one of the preparation methods described in claims 1-5.

7. The parallel energy storage device according to claim 6, characterized in that: The system includes a tank (2), a PLC control cabinet (1), and an energy storage module. The energy storage module is located inside the tank (2). The tank is equipped with a temperature probe (3), a hot water inlet, a cold water inlet, a main exhaust valve, a main intake valve, a hot water outlet, and a cold water outlet. The hot water inlet, cold water inlet, main exhaust valve, main intake valve, hot water outlet, and cold water outlet are respectively connected to the hot water inlet pipe (4), cold water inlet pipe (5), exhaust pipe (6), intake pipe (8), hot water outlet pipe (9), and cold water outlet pipe (1). 10) Connected to each other, the outlet pipe (6) and the inlet pipe (8) are respectively equipped with a hydrogen flow meter (7) and a dryer dust collector (11), and the hot water outlet pipe (9) and the cold water outlet pipe (10) are respectively equipped with a liquid flow meter (12); the valves, temperature probes (3), hydrogen flow meter (7) and liquid flow meter (12) on the hot water inlet pipe (4), cold water inlet pipe (5), outlet pipe (6), inlet pipe (8), hot water outlet pipe (9) and cold water outlet pipe (10) are all connected to the PLC control cabinet.

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