According to foreign media reports, although lithium-ion batteries still have room for improvement, most people in the industry believe that solid-state batteries will become the first choice for the next generation. Now, Tesla's battery research partners have announced a method for lithium-ion batteries to achieve higher energy density, which can make everyone no longer focus on solid-state batteries. A team led by Professor Jeff Dahn at Dalhousie University, Canada, collaborated with colleagues at Tesla ’s Canada R & D Center, and the University of Waterloo, Canada, demonstrated the use of double salt electrolyte Ester (FEC): Ethylene carbonate (DEC) solution contains 1M lithium difluorooxalate borate LiDFOB and 0.2M lithium tetrafluoroborate LiBF4) non-anode lithium metal battery. The researchers said that their results may shift people's research focus from solid state batteries (SSB) to rechargeable, high energy density batteries. Replacing traditional graphite anodes with lithium metal is one of the most popular methods to increase the energy density of lithium ion batteries, which can increase the energy density of batteries by 40% to 50%. However, only when the lithium metal anode is very thick can the energy density be significantly increased, but in practice it is impossible to use a very thick anode, so the researchers said that the thickness of the lithium metal anode needs to be limited to 50 microns. Limiting excessive lithium is a huge challenge, because the metal lithium surface is very easy to form dendrites, which will increase the reactivity of the anode and the electrolyte, isolate the metal lithium, resulting in low battery cycle efficiency. In the case of batteries without anodes, the performance of such cycle inefficiencies is particularly obvious, because these batteries are directly constructed with bare copper anodes, and lithium is deposited directly on the cathode during the first charge cycle. Since there is not too much lithium in the battery, the battery volume is minimized and the energy density is maximized, but the performance may be very poor because there is no stored lithium in the cycle to continuously recharge the battery. In order to improve the cyclic stability of liquid electrolytes, many different methods have been adopted, such as high salt concentration electrolytes, ether solvents, fluorinated compounds, electrolyte additives, anode surface coatings, and external pressure. In addition, there is a method that uses a solid electrolyte, but the solid electrolyte has not successfully eliminated the lithium dendrite problem, and it is not clear whether the technology is compatible with existing lithium-ion battery production equipment, and currently in lithium-ion batteries The investment in production equipment has reached billions of dollars. However, if a liquid electrolyte can be used to produce a safe, long-life lithium metal battery, then the existing production equipment can quickly realize the commercialization of high energy density batteries. In this study, the researchers used electrolytes made of LiDFOB and LiBF4 to maximize the cycle life of existing non-anode batteries. After 90 cycles, they can still maintain 80% of their capacity. Since the lithium metal anode is composed of lithium with a packed diameter of 50 microns, dendrites will not grow even after 50 cycles. In addition, compared with single-salt electrolyte composites, double-salt electrolyte composites perform better at different voltages and do not rely on external pressure to achieve good cycle performance. In new batteries, lithium ions are extracted from the cathode of the battery. During the initial charge, lithium ions are deposited on the current collector (Cu) in the form of metallic lithium. During discharge, lithium ions are stripped from the current collector and directly enter the cathode. (Author: Yuqiu Yun) Face Mask,Earloop Surgical Mask,Earloop Face Mask,Disposable Earloop Face Mask QD Cloudy Inernational Pre Ltd , https://www.qdcloudy.com