QINGDAO, July 5 (Xinhua) -- The Advanced Energy Storage Materials and Technologies Research Group led by researcher Wu Jianfei of the Qingdao Institute of Bioenergy and Processes of the Chinese Academy of Sciences has made a series of breakthroughs in the basic science of sulfide all-solid-state lithium-ion batteries and in the large-scale preparation technology of batteries, the reporter learned from Qingdao Institute of Bioenergy and Processes of the Chinese Academy of Sciences on July 5. The related results were published in the international journal Chemical Electrochemistry.

With the advantages of high energy, fast charging and discharging, good low temperature performance, high safety and long life, the sulfide all-solid-state lithium-ion battery is a pioneering solution to a series of problems such as low energy density, flammability and explosion of liquid lithium batteries, and has become a disruptive frontier technology. The sulfide solid electrolyte has many advantages, making the sulfide all-solid lithium battery high energy density and high multiplier performance at the same time. Many car companies around the world have invested in the research and development of sulfide all-solid-state lithium batteries and released mass production plans.

The key core material of sulfide all-solid-state lithium-ion battery is sulfide electrolyte, and the reported room temperature ionic conductivity of sulfide electrolyte is getting higher and higher, comparable to the ionic conductivity of organic electrolyte used in commercial lithium-ion batteries.

Over the years, the research team has been dedicated to developing high performance sulfide solid electrolytes. Using high throughput calculation methods, the high conductivity sulfide solid electrolytes have been developed, and their room temperature ionic conductivity have reached the international level, and a pilot production line of sulfide solid electrolytes has been established with kilogram-level batch preparation capability.

On the basis of this, the research team has recently made key progress in the research of air stability of sulfide electrolytes, and obtained sulfide electrolyte materials with high ionic conductivity, excellent electrochemical stability and air stability by double doping of soft acid and hard base substances into the electrolyte.

According to the introduction, in order to break through the technical bottleneck of industrial preparation of sulfide all-solid soft pack lithium battery, the research team has independently innovated a number of key technologies, such as the preparation of ultra-thin electrolyte film technology with thickness less than 20 microns, the development of high stability electrode coating technology, the construction of a stable electrode/electrolyte interface technology, as well as homogenization, coating, electrode molding and other technologies, and also successfully developed a soft pack battery with excellent multiplier and low temperature The team has also successfully developed soft pack batteries with excellent multiplier and low temperature performance, and has taken the lead in breaking through the technical difficulty of poor cycle life of all-solid-state soft pack lithium batteries and successfully developed long cycle life all-solid-state soft pack lithium batteries with 850 cycles and 94% capacity retention.

At present, the research team has completed the laboratory technology manufacturing, has established a laboratory production line for all-solid-state soft pack batteries, explored the production mode of sulfide all-solid-state lithium-ion batteries, and laid the foundation for promoting the industrial production of high-performance, low-cost, high-capacity and high-safety sulfide all-solid-state soft pack batteries.

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