TU-TESL

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(source: spectrum) solid inorganic electrolyte itself is not flammable compared with flammable organic electrolyte; moreover, using lithium metal instead of graphite as negative electrode can greatly increase energy density (up to 10 times). Therefore, solid-state battery is expected to become a breakthrough technology of electric vehicles. However, to bring solid-state batteries to the market, there is still a big problem, that is, how to make a solid and thin electrolyte as a good ionic conductor. Ideally, these electrolytes should be only tens of microns thick, similar to today's lithium-ion battery partitions, but most solid electrolytes are made of ceramic materials, which are easily broken if they are too thin. According to foreign media reports, Ping Liu, a materials scientist at the University of California, San Diego, and researchers from the University of Maryland and the California start-up company liox power have developed a new technology for the manufacture of solid-state battery electrolytes. In the manufacturing process, the solution is dried to form an ionic conductive composite, which can be used as both an electrolyte and a positive coating. The electrolyte solution is a sulfide based material containing β - li3ps4. The team synthesized the material in a variety of ways, including the use of different nucleophiles, solvents and mechanical supports, but the most critical starting ingredients are lithium sulfide (Li2S) and phosphorus sulfide (P2S5). The resulting β - li3ps4 solution is very clear and forms a very uniform electrolyte layer when dried, which can be directly deposited on the lithium sulfide anode. "We make batteries in a continuous process without having to make separate layers, so we don't have to deal with very thin materials," Liu said Traditional lithium-ion battery and solid-state battery manufacturing technology, usually stack single-layer electrolyte together. This kind of energy intensive technology needs to use ball mill to mix powder and adhesive, then cast it into plate, and then sinter or press it through high temperature and high pressure platform. Liu's method solves these problems. In addition, the researchers adjusted the β - li3ps4 solution to prevent dendrite growth, so as to create a safer battery. The formation of lithium dendrites is due to the uneven electric field, surface chemistry or other reasons, resulting in the uneven deposition of lithium ions on the negative electrode surface, thus forming needle like protrusions. If dendrites are allowed to form, a fire will occur. CSIRO's best said: "the dendrites growing on the negative electrode, contacting the positive electrode, will cause local overheating, and the temperature may be as high as 1500-2000 ℃ The electrolyte developed by the research team can react spontaneously with dendrites to form inert products, which can help prevent battery short circuit. "It's very similar to the process of scarring the wound," Liu said. Therefore, we call it a mechanism of self-healing and self-formation. " So far, researchers have applied for five patents for this unique electrolyte manufacturing technology. In the next two to three years, the research team hopes to produce a solid-state battery prototype with a capacity of 2ah at a cost of less than $100 per kilowatt hour, which is close to the capacity of most smart phone batteries today, and further promote the commercialization process of solid-state batteries.