New breakthrough in all-solid-state batteries! USTC develops new sulfide solid electrolyte

July 23 news: The industry's exploration of all-solid-state batteries has never stopped, and today, good news came.

The Voice of the Chinese Academy of Sciences officially announced that the University of Science and Technology of China has developed a new sulfide solid electrolyte for all-solid-state batteries. While this material has the inherent advantages of sulfide solid electrolytes, it is cheaper and more suitable for commercialization than other sulfide solid electrolytes.

It is reported that Professor Ma Cheng of the University of Science and Technology of China has developed a new sulfide solid electrolyte Li7P3S7.5O3.5 (LPSO) for all-solid-state batteries. The relevant research results have been published in "Angewandte Chemie" (DOI: 10.1002/anie.202407892).

"Well-known companies such as Toyota of Japan and Samsung of South Korea have invested heavily in research and development of such materials over the past decade or so," said Professor Ma Cheng, but the cost of sulfide solid electrolytes generally exceeds $195 per kilogram, far higher than the $50 per kilogram required for commercialization.

The synthesis of this new material does not require expensive Li2S (no less than $650 per kilogram), and the cost of raw materials per kilogram is only $14.42 (currently about RMB 105), which is far lower than the commercialization threshold of $50/kilogram for most solid electrolytes.

此外，LPSO的密度为1.70g/cm3，显著低于氧化物（通常在5g/cm3以上）和氯化物（约2.5g/cm3）固体电解质的密度，并且还展现出了优异的阳极相容性。

This material retains the unique advantages of sulfide solid electrolytes. The symmetrical battery composed of it and lithium metal can achieve stable cycling at room temperature for more than 4,200 hours. The all-solid-state soft-pack battery composed of it, silicon negative electrode and high-nickel ternary positive electrode still has a capacity retention rate of 89.29% after cycling 200 times at 60°C.

Ma Cheng explained: "Our work shows that the cost problem of sulfide solid electrolytes is not unsolvable. As a new material, lithium phosphorus oxysulfide is still expected to achieve further improvement in performance, and we are continuing to work hard on this."