A sodium-sulfur battery system with a temperature-controlled energy storage device

Abstract

The present invention provides a sodium-sulfur battery system with a temperature control energy storage device, which consists of a sodium-sulfur battery pack, a photovoltaic power generation device, a rectifier voltage regulator, a thermoelectric conversion device, and a temperature control energy storage device; the rectifier voltage regulator supplies the electrical energy generated by the photovoltaic power generation device and / or the thermoelectric conversion device to the sodium-sulfur battery pack; the temperature control energy storage device is arranged at the sodium-sulfur battery pack and controls its temperature to always remain within the normal working temperature range. Different from the conventional design of heating with heating plates at various parts of the battery, the present invention first heats the heater in the temperature control energy storage tube through an electric pile to make the battery reach the working temperature, and then uses the phase change characteristics of the phase change material with a relatively high enthalpy value for energy storage. This part of the energy will be released when the temperature drops to the phase change temperature of the material, so as to maintain the temperature required for the battery to work, thereby enabling the entire system to operate continuously for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium-sulfur batteries for new energy, and specifically, to a sodium-sulfur battery system with a temperature control energy storage device. Background Art

[0002] Since the new century, China's automobile industry has developed rapidly, and the role of the automobile market as a pillar in the national economy has been continuously strengthened. However, traditional fuel vehicles have brought a series of problems. On the one hand, fuel vehicles are highly dependent on fossil energy. On the other hand, the exhaust emissions of fuel vehicles also cause environmental pollution. In response to the above problems, the global automobile industry is accelerating its transformation towards intelligence and electrification.

[0003] Currently, especially in the field of new energy vehicles, many countries have adjusted their development strategies to seize the new high ground. Some countries, including the Netherlands, Germany, France, and the UK, have formulated timetables for stopping the production and sales of traditional energy vehicles. To seek future survival and development, the automotive giants have also taken action at the news. Almost all mainstream automakers have taken actions globally. At present, we focus on the innovation development strategy of intelligent vehicles to make it the guiding program for leading the development of China's intelligent vehicle industry. Relevant departments have also launched relevant research and will formulate China's timetable in conjunction with relevant departments. These measures will surely drive profound changes in the environment and driving force for the development of China's automobile industry.

[0004] As an important part of new energy vehicles, power batteries are the core components of new energy vehicles, with a cost accounting for more than 30%. Due to the imperfect factors such as the current battery safety, energy and power density, and price, various technical routes such as lithium batteries and fuel cells have emerged. Sodium-sulfur batteries are more favored by R & D personnel and manufacturers due to their advantages such as high specific energy, large current, high-power discharge, fast charging time, good durability, pollution-free, safe and reliable, etc.

[0005] Sodium-sulfur batteries were first invented in the mid-1960s of the last century. The early research mainly targeted the application goal of electric vehicles. The advanced structural design of high-power sodium-sulfur batteries enables their theoretical specific energy to reach up to 760 Wh / kg, and in practice, it can also reach 160 Wh / kg, which is four times that of lithium batteries, five times that of nickel batteries, and ten times that of aluminum acid batteries. High-power sodium-sulfur batteries have a fast charging time. The one-time charging time is about 20 to 30 minutes, and their discharge current density can generally reach 200 - 300 mA / cm 2 2, and can instantaneously release three times its inherent energy, with an operating life of up to 15 years.

[0006] Although sodium-sulfur batteries were initially mainly used as power batteries for electric vehicles, their operating conditions are relatively harsh in mobile applications. They have stagnated due to limitations in space and safety, especially since sodium-sulfur batteries use solid electrolytes and must operate in an ambient temperature of 300 - 350°C. Therefore, a heating and insulation device is required during battery operation. If the vacuum insulation method is used, it is difficult to ensure a vacuum state during manufacturing and use, making it difficult to achieve the purpose of heat preservation and insulation. Summary of the Invention

[0007] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a sodium-sulfur battery system with a temperature control energy storage device.

[0008] According to one aspect of the present invention, there is provided a sodium-sulfur battery system with a temperature control energy storage device, comprising a sodium-sulfur battery pack, a photovoltaic power generation device, a rectifier voltage regulator, a thermoelectric conversion device, and a temperature control energy storage device.

[0009] The photovoltaic power generation device utilizes the photovoltaic effect and uses amorphous silicon photovoltaic materials to convert solar energy into electrical energy.

[0010] The thermoelectric conversion device is based on the Seebeck effect. By establishing a temperature gradient field between the hot end and the cold end of the thermoelectric unit, electron flow is caused to form an electric potential difference and generate current, which converts the surplus heat energy during the operation of the device to which the battery system is applied into electrical energy.

[0011] The rectifier voltage regulator supplies the electrical energy generated by the photovoltaic power generation device and / or the thermoelectric conversion device to the sodium-sulfur battery pack.

[0012] The temperature control energy storage device is arranged at the sodium-sulfur battery pack and controls its temperature to always remain within the normal operating temperature range.

[0013] Preferably, the temperature control energy storage device includes:

[0014] A temperature control energy storage tube, which is arranged at the solid electrolyte of the sodium-sulfur battery pack.

[0015] A capsule, which fills the temperature control energy storage tube, and a phase change material is arranged inside the capsule.

[0016] A heater, which is arranged at the temperature control energy storage tube to provide heat to the capsule.

[0017] A temperature detector, which detects the real-time temperature of the temperature control energy storage tube.

[0018] A controller, which is connected to the heater and the temperature detector, and controls the heater according to the real-time temperature detected by the temperature detector.

[0019] Preferably, the temperature control energy storage device further comprises:

[0020] A temperature control battery located outside the temperature control energy storage tube, which forms a closed loop in series with the heater and the temperature detector;

[0021] A switch located on the closed loop, which is connected to the controller and is turned on or off according to its control instruction.

[0022] Preferably, the temperature control energy storage tube is made of a non-metallic material and is spirally wound around the outer surface of the solid electrolyte in an S shape.

[0023] Preferably, the body of the capsule is made of an inert material; the inside of the capsule contains particles made of a phase change material, and the particles account for 80%-90% of the volume of the capsule, and the particle size of the phase change particles is 0.1-1000 μm.

[0024] Preferably, the phase change material is a material capable of storing / releasing latent heat and part of sensible heat, and the phase change temperature is between 310 and 320 °C; the phase change material includes one or more of crystalline hydrates, metals and alloys, paraffins, non-paraffin organics, and ceramic-based composite phase change materials.

[0025] Preferably, the heater is a silica gel heating wire, a Teflon heating wire or a heating wire made of a composite material of the two, which is uniformly distributed in the temperature control energy storage tube.

[0026] Preferably, it further includes a heat insulation material located between the sodium-sulfur battery pack and its outer shell.

[0027] Preferably, during operation, when the temperature of the sodium-sulfur battery pack drops to 310 °C, the controller receives the feedback information of the lowest temperature from the temperature detector, closes the switch, and the sodium-sulfur battery pack starts to continuously heat the heater, so that the temperature of the phase change material gradually increases;

[0028] When the temperature rises to the phase change temperature of the phase change material, the phase change material in the capsule undergoes a phase change and starts to store energy;

[0029] When the temperature reaches 350 °C, the control system receives the feedback information of the highest temperature from the temperature detector, disconnects the switch, and stops heating;

[0030] The temperature of the entire sodium-sulfur battery pack will gradually decrease over time until it drops to the phase change temperature of the phase change material, and the phase change material undergoes a phase change again to release heat to maintain the sodium-sulfur battery pack within the normal operating range.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The operating conditions of the sodium-sulfur battery are relatively harsh, and the operating temperature must be within 300 - 350 °C. Different from the conventional design of heating the battery with heating plates at various parts, in this invention, the heater in the temperature control energy storage tube is first heated through an electric pile to make the battery reach the operating temperature, and then the phase change characteristics of the phase change material with a relatively high enthalpy value are used for energy storage. This part of the energy will be released when the temperature drops to the phase change temperature of the material, so as to maintain the temperature required for the battery to operate, enabling the entire system to operate continuously for a long time;

[0033] This invention utilizes the photovoltaic power generation system to utilize primary energy such as light energy and heat energy. At the same time, the thermoelectric conversion system can convert the waste heat in the automobile exhaust gas and the waste heat of the engine into electrical energy, achieving the purpose of being clean, efficient, energy-saving and environmental-friendly;

[0034] After the vehicle of this invention is charged through an electric pile, the electric quantity will be continuously consumed during the subsequent driving process. This part of the electric quantity can be supplemented by the photovoltaic power generation system and the thermoelectric conversion system, thereby improving the endurance of the sodium-sulfur battery, reducing the number of charging times and the inconvenience caused by being far away from the charging pile. Description of the Drawings

[0035] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, objectives and advantages of the present invention will become more obvious:

[0036] Figure 1 It is the structure block diagram of the sodium-sulfur battery system with a temperature control energy storage device in the embodiment of the present invention;

[0037] Figure 2 It is the structure schematic diagram of the temperature control energy storage mechanism of the sodium-sulfur battery system with a temperature control energy storage device in the embodiment of the present invention;

[0038] In the figure: 1 - temperature control energy storage tube; 2 - capsule; 3 - heater; 4 - temperature detector; 5 - heat insulation material; 6 - current collector; 7 - electromagnetic negative electrode; 8 - solid electrolyte; 9 - battery positive electrode; 10 - sodium-sulfur battery pack. Detailed Embodiments

[0039] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention. For example Figure 1As shown in the figure, the present invention provides an embodiment, a sodium-sulfur battery system with a temperature-controlled energy storage device, including a sodium-sulfur battery pack 10 composed of at least one sodium-sulfur battery; wherein, the sodium-sulfur battery includes a battery positive electrode 9, a battery negative electrode 7, a solid electrolyte 8 and a temperature-controlled energy storage device; wherein, the battery positive electrode 9 is made of a sulfur-based material; the battery negative electrode 7 is made of a sodium-based material; the solid electrolyte 8 is located between the battery positive electrode 9 and the battery negative electrode 7; the temperature-controlled energy storage device is arranged at the solid electrolyte 8 to control the temperature of the solid electrolyte 8 to always be between its corresponding ambient temperatures for normal operation. The number of sodium-sulfur batteries can be determined according to actual needs.

[0040] In a preferred embodiment of the present invention, a photovoltaic power generation device, a thermoelectric conversion device and a rectifier voltage regulator are used to improve the endurance of the battery system. Among them, the photovoltaic power generation system is a power generation system that uses the photovoltaic effect and adopts amorphous silicon photovoltaic materials to convert solar energy into electrical energy. It has high reliability, a long service life, and does not pollute the environment, and has broad development prospects.

[0041] Among them, the thermoelectric conversion system is based on the Seebeck effect. By establishing a temperature gradient field between the hot end and the cold end of the thermoelectric unit, the flow of electrons is caused to form a potential difference and generate current. It can convert the surplus heat energy, including the waste heat of automobile exhaust and the waste heat of the engine, running in the equipment into electrical energy.

[0042] The rectifier voltage regulator supplies the electrical energy generated by the photovoltaic power generation device and / or the thermoelectric conversion device to the sodium-sulfur battery pack. The rectifier voltage regulator regulates the voltage to make the voltage stable, so as not to damage the battery pack due to too high voltage. After the vehicle is charged through the charging pile, the battery power will be continuously consumed during the subsequent driving process. This part of the electrical energy can be supplemented by the photovoltaic power generation system and the thermoelectric conversion system, thereby improving the endurance of the sodium-sulfur battery, reducing the number of charging times and the inconvenience caused by being far away from the charging pile, and reducing the mileage anxiety of users. In a preferred embodiment of the present invention, the solid electrolyte is selected as an aluminum oxide ceramic tube.

[0043] In a preferred embodiment of the present invention, the temperature-controlled energy storage device includes a temperature-controlled energy storage tube 1, a capsule, a heater 3, a temperature detector 4 and a controller. Among them, the temperature-controlled energy storage tube 1 is arranged at the solid electrolyte 8, and the capsule 8 fills the temperature-controlled energy storage tube 1; the heater 3 is arranged at the temperature-controlled energy storage tube 1 to provide heat for the capsule 2; the temperature detector 4 detects the real-time temperature of the temperature-controlled energy storage tube 1; the controller is connected to the heater 3 and the temperature detector 4, and controls the heater 3 according to the real-time temperature detected by the temperature detector 4.

[0044] There are various forms of heating, so there are no restrictions on the heater, and any device that can achieve the heating function can be used. In a preferred embodiment, the heater uses electric heating, and a temperature control battery is connected in series with the heater 3 and the temperature detector 4; a switch K1 is connected to the controller and is turned on or off according to its control instructions, so that the temperature of the sodium-sulfur battery can always be maintained within the normal operating temperature range.

[0045] In a preferred embodiment of the present invention, the temperature control energy storage tube 1 is spirally wound in an S shape on the outer surface of the solid electrolyte 8. The temperature control energy storage tube is preferably made of ceramic, and metal materials are avoided to prevent the sulfur in the battery from reacting with the metal.

[0046] In a preferred embodiment of the present invention, the body of the capsule 2 is made of an inert material; the inside of the capsule 2 contains particles made of a phase change material, and the particles account for 80%-90% of the volume of the capsule, reserving space for the volume expansion of the phase change material; the particle size of each phase change particle is 0.1-1000 μm.

[0047] In a preferred embodiment of the present invention, the phase change material is a material that can store / release latent heat and part of the sensible heat (for example, the phase change temperature is 320 °C, but the phase change material can be heated to 350 °C, and the heat exceeding the phase change storage is sensible heat, and the relative latent heat accounts for a relatively low proportion), and the phase change temperature is between 310 and 320 °C; the phase change material includes one or more of crystalline hydrated salts, metals and alloys, paraffins, non-paraffin organics, and ceramic-based composite phase change materials, and sodium hydroxide material is preferred. In a preferred embodiment of the present invention, the heater selects a silicone electric heating wire, a Teflon electric heating wire or a composite electric heating wire of the two evenly distributed between the temperature control energy storage tubes 1. The electric heater can directly heat the phase change material for energy storage, improving the utilization rate of electric energy; making the phase change material heated evenly, enabling the particles made of the phase change material to be stably heated above the phase change point without local overheating, thereby extending its service life.

[0048] In a preferred embodiment of the present invention, the space between the sodium-sulfur battery and the outer shell is filled with a heat-insulating material 5. The heat-insulating material can reduce heat loss and extend the working time; the heat-insulating material is preferably a heat-insulating material composed of nano-insulating fibers, special vacuum materials and glass fibers. This structure can insulate from the outside world, thereby reducing heat loss and extending the working time of the battery pack.

[0049] For a clearer and deeper understanding of the present invention, the circuit principle and operation process (including the charging process of the charging pile and the operation process of the sodium-sulfur battery) of a sodium-sulfur battery system with a temperature control energy storage device of the present invention will be introduced below.

[0050] Charging process of the charging pile:

[0051] S101. Connect the sodium-sulfur battery system of the entire temperature-controlled energy storage device to the charging pile. Close switch K1. The charging pile charges and heats the electric heater 3 in the temperature-controlled energy storage tube 1, gradually increasing the temperature of the phase change particles packaged in the capsule 2.

[0052] S102. Initially, since the temperature of the sodium-sulfur battery has not reached the operating temperature range, the sodium-sulfur battery cannot work properly and is regarded as an insulator.

[0053] S103. When the temperature of the sodium-sulfur battery reaches 300 °C, the sodium-sulfur battery starts to charge.

[0054] S104. When the phase change temperature of 320 °C is reached, the phase change particles undergo a phase change and continuously absorb the energy provided by the charging pile.

[0055] S105. When the temperature reaches 350 °C, the temperature detector feeds this temperature information back to the controller.

[0056] S106. The controller disconnects switch K1, stops heating and energy storage until the sodium-sulfur battery finishes charging.

[0057] Operation process of the sodium-sulfur battery:

[0058] S201. During the discharge process of the sodium-sulfur battery in the electric vehicle, the temperature will gradually decrease. When the battery temperature drops to 310 °C, the controller receives the feedback information of the lowest temperature and controls switch K1 to close to maintain the conduction state.

[0059] S202. The battery that continuously provides power to the vehicle as a power source starts to continuously heat the electric heater 3, and the temperature of the phase change particles gradually increases.

[0060] S203. When the temperature rises to the phase change temperature of the phase change material, the phase change particles in the capsule 2 undergo a phase change and start to store energy; as the temperature continues to rise, the energy absorbed by the phase change particles also continuously increases.

[0061] S204. When the temperature reaches 350 °C, the controller receives the feedback information of the highest temperature, controls switch K1 to disconnect, disconnects the connection between the electric heater and the battery, and stops heating, causing the phase change particles to end energy storage. The operating temperature during S202 - S205 is mainly provided by the self-discharge of the sodium-sulfur battery to heat the electric heater.

[0062] S205. After reaching the temperature peak of 350 °C, the temperature of the entire battery pack will gradually decrease over time until it drops to the phase change temperature of the phase change particles. At this time, the temperature required for the sodium-sulfur battery to work is provided by the energy released by the phase change particles.

[0063] During the above two processes, the power supplied by the sodium-sulfur battery to the vehicle and the heater is continuously supplemented by the photovoltaic power generation system and the thermoelectric conversion system, which not only ensures that the temperature remains within the operating temperature range of the battery but also improves the battery's endurance, enabling the entire system to operate continuously, uninterruptedly, and sustainably for a long time.

[0064] The above description is only a preferred embodiment of the present invention and does not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural variations made to the above embodiments based on the technical essence of the present invention all fall within the protection scope of the technical solution of the present invention.

[0065] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific implementation manners. Those skilled in the art can make various deformations or modifications within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be combined arbitrarily without conflict.

Claims

1. A sodium-sulfur battery system with a temperature-controlled energy storage device, including a sodium-sulfur battery pack, characterized in that, It also includes a photovoltaic power generation device, a rectifier voltage regulator, a thermoelectric conversion device, and a temperature control energy storage device; The photovoltaic power generation device utilizes the photovoltaic effect and adopts amorphous silicon photovoltaic materials to convert solar energy into electrical energy; The thermoelectric conversion device is based on the Seebeck effect. By establishing a temperature gradient field between the hot end and the cold end of the thermoelectric unit, the flow of electrons is caused to form a potential difference and generate current, which converts the surplus heat energy during the operation of the battery system application equipment into electrical energy; The rectifier voltage regulator supplies the electrical energy generated by the photovoltaic power generation device and / or the thermoelectric conversion device to the sodium-sulfur battery pack; The temperature control energy storage device is arranged at the sodium-sulfur battery pack and controls its temperature to always remain within the normal operating temperature range; The thermoelectric conversion device uses the waste heat of automobile exhaust as the heat source for the hot end temperature; The temperature control energy storage device includes: A temperature control energy storage tube, which is arranged at the solid electrolyte of the sodium-sulfur battery pack; A capsule, which fills the temperature control energy storage tube, and a phase change material is provided inside the capsule; A heater, which is arranged at the temperature control energy storage tube to provide heat to the capsule; A temperature detector, which detects the real-time temperature of the temperature control energy storage tube; A controller, which is connected to the heater and the temperature detector, and controls the heater according to the real-time temperature detected by the temperature detector; A temperature control battery, which is located outside the temperature control energy storage tube and forms a closed loop in series with the heater and the temperature detector; A switch, which is located on the closed loop and is connected to the controller and opens or closes according to its control instruction.

2. The sodium-sulfur battery system with a temperature-controlled energy storage device according to claim 1, wherein The temperature control energy storage tube is made of a non-metallic material and is spirally wound in an S shape on the outer surface of the solid electrolyte.

3. The sodium-sulfur battery system with a temperature-controlled energy storage device according to claim 1, characterized in that, characterized in that, The body of the capsule is made of an inert material; the inside of the capsule contains particles made of a phase change material, and the particles account for 80%-90% of the volume of the capsule, and the particle size of the phase change particles is 0.1 to 1000 μm.

4. The sodium-sulfur battery system with a temperature-controlled energy storage device according to claim 3, characterized in that, The phase change material is a material that can store / release latent heat and part of the sensible heat, and the phase change temperature is between 310 and 320 °C; the phase change material includes one or several of crystalline hydrated salts, metals and alloys, paraffins, non-paraffin organics, and ceramic matrix composite phase change materials.

5. The sodium-sulfur battery system with a temperature-controlled energy storage device according to claim 1, characterized in that, The heater is a silica gel heating wire, a Teflon heating wire, or a heating wire made of a composite material of the two, which is uniformly distributed in the temperature control energy storage tube.

6. The sodium-sulfur battery system with a temperature-controlled energy storage device according to claim 1, characterized in that, It also includes a heat insulation material, which is located between the sodium-sulfur battery pack and its outer shell.

7. The sodium-sulfur battery system with a temperature-controlled energy storage device according to claim 1, characterized in that, During operation, when the temperature of the sodium-sulfur battery pack drops to 310 °C, the controller receives the feedback information of the lowest temperature from the temperature detector, closes the switch, and the sodium-sulfur battery pack starts to continuously heat the heater, so that the temperature of the phase change material gradually rises; When the temperature rises to the phase change temperature of the phase change material, the phase change material in the capsule undergoes a phase change and starts to store energy; When the temperature reaches 350 °C, the control system receives the feedback information of the highest temperature from the temperature detector, disconnects the switch, and stops heating; The temperature of the entire sodium-sulfur battery pack will gradually decrease over time. When it drops to the phase change temperature of the phase change material, the phase change material will undergo a phase change again to release heat and maintain the sodium-sulfur battery pack within the normal operating range.

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