Protonenbatterien: eine innovative Option für die Zukunft der Energiespeicherung

Paper: https://onlinelibrary.wiley.com/doi/10.1002/anie.202412455

Paywalled unfortunately, but there is some data accessible in supporting materials.

There was some discussion of this in https://www.reddit.com/r/science/comments/1htvksi/scientists_built_a_proton_battery_that_could/ but it was moderated for being a summary of a summary (and it had a click-baity headline, unfortunately), this is the link directly to the summary (university press release) with a less editorialized headline.