The battery cell manufacturer SVOLT, which emerged from the Chinese carmaker Great Wall, reports progress in the development of solid cells. The company says it has developed and successfully tested 20 Ah cells with solid sulphide-based electrolyte.
These cells offer an energy density of 350 to 400 Wh/kg. According to projections, this should make a range of over 1,000 kilometres possible with the later series cells in an electric car.
The tests that the 20 Ah prototype cell has already undergone reportedly include the nail penetration test common in China and heating the battery cell to 200 degrees Celsius. Results are not directly mentioned in either case – it is only said that these tests have been passed successfully.
The 20 Ah cell is the fifth generation. Starting with the mAh range, the capacity has been increased from one and five Ah to first ten and now 20 Ah. The cell is being developed in SVOLT’s solid-state battery laboratory. This is a laboratory that resulted from the merger of SVOLT’s Wuxi Lithium Battery Innovation Center with the Ningbo Institute of Materials Technology & Engineering.
But there also seems to be progress in scaling up production. According to the report, the synthesis of the sulphide-based electrolyte material is already taking place in the kilogram range, but this is still a long way from the scale needed for mass production. Moreover, the continuous production of the electrolyte film is a challenge.
So far, SVOLT says it has filed 109 patents in the field of solid-state sulphide batteries.