Superconducting energy storage
Superconducting energy storage is a device that uses the characteristic of zero resistance of superconductors to store electrical energy. It can not only store electrical energy losslessly in the superconductor inductance coil, but also can quickly exchange active and reactive power with external systems through the power electronic converter, which is used to improve the stability of the power system and improve the quality of power supply. Superconducting energy storage can be divided into low temperature superconducting energy storage and high temperature superconducting energy storage according to the classification of coil materials.
A superconductor ring is placed in a magnetic field, the temperature is reduced to below the critical temperature of the ring material, and the magnetic field is removed. Due to electromagnetic induction, an induced current is generated in the ring. As long as the temperature is kept below the critical temperature, the current will continue. Tests have shown that the decay time of this current is not less than 100,000 years. Obviously this is an ideal energy storage device, called superconducting energy storage. Superconducting energy storage has many advantages, mainly high power, light weight, small size, low loss, fast response, etc. Therefore, it has high expectations in the fields of renewable energy power generation and grid connection, power system load regulation, and military. In recent years, as the research on practical superconducting materials has made significant progress, countries around the world have successively carried out research and development and application demonstrations of superconducting energy storage. However, because the superconducting coil requires liquid ammonia to maintain the superconductor below the critical temperature, high investment is required. Therefore, to realize the large-scale application of superconducting energy storage, it is also necessary to increase the critical temperature of superconductors, develop superconducting wires with good mechanical and electromagnetic properties, and improve system stability and service life.
At present, research projects on superconducting energy storage are mainly concentrated in the United States, Japan, Europe and other developed countries and regions, but the only manufacturer that can provide superconducting energy storage products in the world is the American Superconducting Company. Its products mainly include uninterruptible power supplies for low-temperature superconducting energy storage and distributed power supplies for power distribution.
Lead storage battery
Lead storage battery refers to a storage battery whose electrodes are made of lead and its oxides, and the electrolyte is sulfuric acid solution. In the charged state, the main component of the positive electrode of the lead storage battery is lead dioxide, and the main component of the negative electrode is lead; in the discharged state, the main component of the positive and negative electrodes are lead sulfate.
Lead storage battery is the earliest secondary battery used on a large scale. It has a history of more than 150 years since it was invented by French scientist Gaston Plante in 1859. Lead-acid batteries have become indispensable and mature products in various fields such as transportation, communications, electric power, national defense, navigation, and aviation. However, problems such as slow charging speed, low energy density, short cycle life, easy gas evolution during overcharging, and environmental pollution due to sulfuric acid overflow make it unsuitable for applications in electric vehicles, new energy power generation and other fields.
In recent years, many companies around the world have devoted themselves to developing modified lead storage batteries with better performance and meeting various requirements, mainly include super battery, bipolar battery, lead cloth horizontal battery, wound battery, flat tube battery, foil roll battery, etc. This article focuses on super batteries and bipolar batteries for further discussion.
Super battery is a combination of lead storage battery and super capacitor. It has the advantages of fast charging and discharging, high power density, and long battery life. It is mainly used in hybrid vehicles, grid-connected new energy power generation and smart grids. This technology was jointly invented by Australia’s CSIRO National Laboratory and Japan’s Furukawa Battery Company. In addition, the US Axion company is also developing similar products. China’s Zhejiang Tianneng, Zhejiang Chaowei, Zhejiang Nandu, Wuhan Yintai, Zhejiang Huitong, Jilin Huineng and other companies have also begun to invest in research and development.
Bipolar battery is a lead storage battery made of bipolar plates. Compared with ordinary lead storage battery, it has the advantages of higher specific energy, high power performance, long life and suitable for high voltage design. This field is still in its infancy. Currently, only a few manufacturers can produce samples, but none of them can be mass-produced. American Arias and BPC companies, Swiss OERLIKON company (OERLIKON) leading technology, China’s several traditional lead battery companies such as Nandu, Fengfan, Shuangdeng, etc. are also conducting bipolar battery research and development.