All solid state batteries, a major breakthrough!

All solid state batteries, a major breakthrough!

On July 23rd, it was reported that the industry's exploration of all solid state batteries has never stopped. Today, good news came.

According to the official announcement on the Weibo account of the Voice of the Chinese Academy of Sciences, the University of Science and Technology of China has developed a new type of sulfide solid electrolyte for all solid state batteries. This material not only has the inherent advantages of sulfide solid electrolytes, but also has a lower cost and is more suitable for commercialization compared to other sulfide solid electrolytes.

It is reported that Professor Ma Cheng from 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 related research results have been published in the German Journal of Applied Chemistry (DOI: 10.1002/anie. 202407892).

Famous companies such as Toyota in Japan and Samsung in South Korea have invested heavily in the research and development of such materials over the past decade, "said Professor Ma Cheng. However, 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 (not less than $650 per kilogram), and the cost of raw materials per kilogram is only $14.42 (currently about RMB 105), far below the commercial threshold of $50 per kilogram for most solid electrolytes.

In addition, the density of LPSO is 1.70g/cm3, significantly lower than that of solid electrolytes such as oxides (usually above 5g/cm3) and chlorides (about 2.5g/cm3), and it also exhibits excellent anode compatibility.

This material retains the unique advantages of sulfide solid electrolytes. Its symmetrical battery composed of lithium metal can achieve stable cycling at room temperature for more than 4200 hours, while its all solid state soft pack battery composed of silicon negative electrode and high nickel ternary positive electrode still has a capacity retention rate of 89.29% after 200 cycles at 60 ℃.

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

The reviewer of this paper believes that lithium oxysulfide solid electrolyte "has low density, good negative electrode compatibility, and strong cost competitiveness", and the all solid state battery composed of lithium oxysulfide has "excellent cycling performance". Its discovery has an important role in promoting the practical application of all solid state batteries.