researchers at the University of Science and Technology of China developed all-solid-state batteries that match cutting-edge performance at just 4 per cent of the cost.
Performance of all-solid-state device developed by Chinese researchers akin to that of advanced varieties, findings published in Nature Communications say.
I'm from Canada, and I see both usages. As the article says, colloquial usage tends to be one word, but legalese usage will sometimes use two. In this case, I just took it straight from the article though.
Upvoting since I came searching for this after struggling to understand what battery could possibly be made 4 for $0.01 before it finally clicked for me how to properly read the title. Learned something new too, thanks for asking so I didn’t.