The Chinese research team from the Tsinghua University has created a sulfide-based solid electrolyte low cost, high electrical conductivity, good chemical stability and withstanding a wide range of voltages. This material, developed as a thin and flexible membrane, has made it possible for a solid-state lithium battery to maintain its energy capacity at a 92% after 1,000 charge and discharge cycles and 71% after 21,000 cyclesyes
Solid electrolyte lithium batteries continue to attract research and studies around the world. For many, this technology will be the protagonist of the next generation batteries. This solution mainly addresses the safety issue of batteries with organic liquid electrolyte, which have a more likely to ignite causing serious accidents.
At the same time, this type of battery can raise energy density and life cycles of lithium batteries, also reducing production costs by not requiring such a complex thermal management system or so many security systems to prevent overheating.
The key to being able to commercialize solid-state lithium-ion batteries is to find an electrolyte material that brings together all the advantages. Technically, it must provide high electrical conductivity, good chemical stability and be able to work in a wide voltage window. In addition, it must also be economically viable, that is, it must be a material with a low production cost.
Among the wide variety of electrolyte materials that have been tested for these batteries, solid-state sulfur electrolytes are one of the candidates that have received the most interest. Although great progress has been made in the ionic conductivity of sulfide electrolytes, their application in solid-state lithium batteries still faces many challenges, according to the team.
The preparation of thin-walled solid electrolytes with high ionic conductivity is crucial for excellent performance in the development of solid-state lithium batteries. In this context, a research team from Chinese Tsinghua University promises a very important advance in the performance of this type of battery after making his research public in an article through the journal Advanced Energy Materials.
Nan Cewen and Shen Yang of the University’s School of Materials Science and Engineering and director of the research, claim to have created a highly conductive, flexible, composite solid electrolyte ultra-thin film that enables solid-state lithium-ion batteries. have the longest life cycle to date. The team developed a thin, flexible solid electrolyte membrane composed of argyrodite sulfide Li6PS5Cl and a polyvinylidene fluoride-co-trifluoroethylene (P(VDF-TrFE)) polar backbone.
The thus assembled battery showed excellent cycling performance with an energy retention capacity of 92% after 1,000 cycles at a current density at room temperature of 1.0 mA/cmtwo. Even after 20,000 cyclesthe cells were able to still retain a 71% of its energy capacitywhich is the longest life cycle to date achieved by a solid-state lithium battery at room temperature, according to the team.