Battery cell maker SVOLT, spun off from Chinese automaker Great Wall, reports progress in developing solid-state cells. The company claims to have successfully developed and tested 20Ah cells with a solid sulfide-based electrolyte.
These cells offer an energy density of 350 to 400 Wh/kg. According to projections, this should allow a range of more than 1,000 kilometers with the latest production cells of an electric car.
The tests the prototype 20Ah cell has already undergone would include the nail penetration test common in China and heating the battery cell to 200 degrees Celsius. The results are not directly mentioned in either case – it only says that these tests were passed.
The 20 Ah battery is the fifth generation. From the mAh range, the capacity has gone from one and five Ah to the first ten and now to 20 Ah. The cell is under development in SVOLT’s solid-state battery lab. It is a laboratory resulting from the merger of SVOLT’s Wuxi Lithium Battery Innovation Center with the Ningbo Institute of Materials Technology and Engineering.
But there also appears to be progress in increasing production. According to the report, the synthesis of the sulfide-based electrolyte material is already taking place in the kilogram range, but this is still far from the scale needed for mass production. In addition, the continuous production of the electrolyte film is a challenge.
To date, SVOLT claims to have filed 109 patents in the area of solid state sulfide batteries.