Solid-state batteries have the potential to make EVs much more affordable and practical, but their commercial development has been riddled with false promises, even surpassing Tesla’s self-driving cars. This means that reporting on solid-state batteries is difficult, but there is some promising news coming from Imec, a well-established Belgium-based R&D giant.
As part of the SOLiDIFY project, the EU-backed company and 13 partners have produced a solid-state battery prototype with an energy density of 1070 Wh/L, nearly 25 percent higher than the best lithium-ion batteries (800 Wh/L). Even better, the battery uses a manufacturing process that works at room temperature, is adaptable to current lithium-ion battery product lines, and is predicted to cost less than 150 euros (about $167) per kWh, compared to about $140 per kWh for current batteries. “The process enables affordable transfer to industry,” Imec said in a press release.
The breakthrough was called “liquid-to-solid” solidification: the prototype solid-state electrolyte uses a “doped polymerized ionic liquid” in a 50-micrometer-thin layer. A high-capacity composite cathode is placed on one side of the electrolyte, and a thin lithium metal anode on the other, enabling a compact battery cell stack.
The consortium overcame challenges in mechanical strength and cathode impregnation, enabling it to increase the cell’s charging speed to three hours and its lifespan to 100 cycles, while also reducing the use of cobalt thanks to a nanometer-thin protective coating.
Clearly, charging times and cycle counts need to be improved (modern lithium-ion car batteries can be charged 2,000 times, with some able to be charged in under an hour), and the technology needs further scale-up before it can be used at an industrial level, but the end result of solid-state batteries offering higher energy density, faster charging times, and improved safety, all at a lower cost, makes it worth the effort.
