According to the Daily Science Daily report on November 30, researchers at Stanford University have recently developed a new battery cathode using nanocomposites made of copper compounds that can be recharged 40,000 times. Professor Cui Yi, associate professor of materials science and engineering at Stanford University, said: "Because the technology is inexpensive and durable, it can meet the large-scale energy storage needs of the power grid." Cui Yi said: "This research provides solutions for wind power and solar energy that cause sudden drop in power generation due to the weather. Because there is no guarantee that every day is a sunny day, and there is no guarantee that it will wind every day, so if you want a large-scale development Optoelectronics, intermittent is its main obstacle.If we can have an efficient, durable and reusable battery, then we can store excess power generated by wind energy and solar energy. At the same time, the cost of the battery can not be too expensive. Otherwise, no commercial expansion can be achieved." 40,000 charge and discharge At present, researchers at Stanford University have partially realized this idea. That is to say, new electrodes made of copper compound nanomaterials can retain 83% of their battery capacity after being recharged 40,000 times. However, the number of charge and discharge times of conventional lithium-ion batteries is 400, and then the capacity drops rapidly. Stanford University's Graduate School of Materials Science and Engineering Colin Wells said: "Through several charge-discharge experiments per day, we expect the electrode life to reach 30 years." The current research has been published in Nature News. In the magazine, Kline Wales is the main author. The co-author of the study, Cui Wei's tutor, Cui Yi, said: "Battery can be recharged so many times, performance did not diminish, this is a breakthrough." Researchers first used Prussian blue (ie, ferrocyanide). They then replaced one half of the iron with copper, used the resulting compound to make crystalline nanoparticles, and applied the particles to a cloth-like carbon matrix. Then, they immersed this electrode in a potassium nitrate electrolyte solution. Colin Wells said: "Because potassium ions can move freely, the charge and discharge cycles of the electrodes are very fast, which is very important." According to reports, the new battery uses cheap materials for chemical reactions. The principle is the same as that of lithium ion. Sodium or potassium ions move between the electrodes for charge and discharge. Cui Yi said: "To be connected to storage, the battery will be very large, and sodium and potassium are attractive, because they produce more and cheap." Stronger performance than lithium-ion batteries Many research groups led by Cui Yi are based on lithium ion. Lithium-ion batteries have a high energy density, which means that they are relatively small and are more suitable for portable electronic products such as notebook computers. However, when it comes to energy storage in the grid, energy density is not as important. You can have a battery that is as big as a house. It doesn't need to be portable. In addition, the cost is also a big consideration. Some components of lithium-ion batteries are expensive, and the construction of a large-scale lithium-ion battery for energy storage in the grid is still not clear. Welsh said: "At that time we thought that if we want to develop batteries for grid energy storage, we should consider raw materials other than lithium ions. The materials we choose, such as iron, copper and nitrogen, are very cheap. we use water-based electrolyte, instead of organic electrolyte, which in turn reduces the cost of some. " Robert Huggins, emeritus professor of the School of Materials Science and Engineering at Stanford University, said that although no complete battery has been formed at present, the performance of the new electrode has exceeded that of any existing battery. This discovery provides a good solution for energy storage in wind power systems. Cui Yi said: “The electrode materials that have been developed have great prospects in the laboratory stage, but there are difficulties in commercialization. There is no such problem for this new electrode. Commercialization of new electrodes is not difficult. We will chemical substances. Put in the flask to get the electrode material, you can get more raw materials. We don't have great technical challenges to produce this kind of battery." New electrode charging capacity is lower In addition, there are also industry insiders who have made deficiencies in this technology. Jay Whitaker, professor of materials science and engineering at Carnegie Mellon University, said: "This electrode has a good cycle time compared to other electrodes, but it also has its own shortcomings. Its charge capacity is lower, per gram. When the material has a capacity of only 60 mAh, compared to the manganese oxide cathode of 100 mAh, although the cost is low, the cost of using copper instead of iron has increased. Donald Shadevi, professor of materials science and engineering at the Massachusetts Institute of Technology, said: “The most important indicator for large-scale grid-connected storage is the price of energy generated per charge cycle. This new material has a clear advantage because it can be realized. With tens of thousands of cycles of charge and discharge, the cost will also be reduced. The overall performance will be better than sodium-sulfur batteries." According to Battery Researcher Christophe Johnson of Argonne National Laboratories, “In addition to cost and cycle time, the round-trip energy efficiency is also very important for grid energy storage so that no energy is wasted during the charging process. The cost of the electrode, however, is excellent for its efficiency and cycle life.†Researchers also need to develop an anode to form a complete battery cell. †Metallographic Microscope ,Optical Microscope For Metallographic Observation,Inverted Metallographic Microscope,Portable Metallographic Microscope Ningbo Beilun Kalinu Optoelectronic Technology Co.,Ltd , https://www.yxmicroscope.com
The main limitation of the new electrode is its chemical properties that make it suitable only as a high voltage electrode. However, each battery requires two electrodes - a high-voltage cathode and a low-voltage anode, to generate power by a voltage difference. Researchers need to find another kind of material to make an anode before they can make a battery. Cui Yi said: "At present, they are testing various substances to make anodes, and there are already some potential suitable materials."