Analysis on the development prospects of lithium-sulfur battery technology in the future
What is a lithium-sulfur battery? In life, you may have been exposed to various electronic products, then you may not understand some of its components, such as the lithium-sulfur battery it may contain, then let the editor lead Let's learn about lithium-sulfur batteries together. As an efficient energy storage system, from a variety of electronic products to electric vehicles to the extended application of large-scale energy storage in the grid, lithium-ion batteries are increasingly participating in the important process of energy ecological evolution. Lithium-ion batteries (LIBs) have been dominant in the past few decades. However, their high cost and the current situation of getting closer to the theoretical limit, and in my country’s 13th Five-Year Plan, it is mentioned that the battery will be used in 2020. The capacity has been increased to 500Wh/kg. These market conditions and policy trends have made academic and industrial circles seek new chemical energy storage batteries beyond lithium ion insertion to meet rising energy demand. According to the current progress, the lithium-sulfur (Li-S) battery based on the new energy conversion mechanism is more likely to win the top spot. Lithium-ion batteries are batteries that use sulfur as the positive electrode material and lithium metal as the negative electrode material. The theoretical capacity density of sulfur as a cathode material is about 1670mAh/g, which is more than 6 times that of ternary materials commonly used in lithium-ion batteries. On the other hand, the theoretical capacity density of metallic lithium as a positive electrode material is 3861 mAh/g, which is about 10 times that of carbon (372 mAh/g), which is a commonly used positive electrode material for lithium-ion batteries. Its energy density is expected to be much higher than current lithium-ion batteries. Lithium-sulfur battery is a kind of lithium ion battery in which sulfur is used as the positive electrode of the battery and metal lithium is used as the negative electrode. Sulfur is used as the cathode material because the theoretical specific capacity of the material and the theoretical specific energy of the battery are as high as 1675mAh/g and 2600Wh/kg, respectively, which are much higher than the commercially widely used lithium cobalt oxide battery (<150mAh/g). More importantly, the closed Li-S system is similar to LIB. In terms of battery manufacturing, the conversion from LIB to Li-S battery is simpler and more effective, making it more commercially viable than an open lithium-air system. The latest developments in lithium-sulfur batteries are beginning to make their commercialization possible. Elemental sulfur is rhombohedral sulfur at room temperature, and it is a yellow solid in the form of S8 cyclic molecules. The high energy density and high specific capacity of lithium-sulfur batteries stem from the breaking and rebonding of S-S bonds in S8 molecules. Most of the cathode materials currently studied for lithium-sulfur batteries are obtained by combining sulfur with porous carbon materials, carbon nanotubes, graphene, metal oxides, conductive polymers, etc., and lithium sheets are used as anode materials. The electrochemical reaction principle of lithium-sulfur battery: S8+16Li2→8Li2S. Prior to this, sulfides and oxides have been extensively studied as solid electrolytes. Although there are many types of ionic conductivity that can be used in batteries, not many types of ionic conductivity have the stability required for battery operation. Complex hydride refers to a substance composed of metal cation M (Li+, Na+, Mg2+, etc.) and complex anion M'hn((BH4)-, (NH2)-, (AlH4)-, (AlH6)3-, etc. 。At 150℃, thermal decomposition is not easy. The components can be composed of light elements, and a good electrolyte can be produced by pressing on a uniaxial shaft at room temperature. However, the ion conductivity is low and the operating temperature is high. Discharge. In the process, the lithium metal anode (negative electrode) is oxidized to form lithium ions and electrons. The lithium ions move to the cathode through the electrolyte, and the electrons reach the cathode (positive electrode) through the external circuit wire. At the positive electrode, sulfur reacts with lithium ions and electrons to form sulfide. Lithium. The charging process is the opposite. I believe that by reading the above content, everyone has a preliminary understanding of lithium-sulfur batteries. At the same time, I hope that everyone will make a summary during the learning process so that they can continuously improve their design level.