I have no documentation, but when I was collecting 7.9 x 57, I had a case exactly as pictured, as well as a loaded round with CNCS FMJ Type S bullet and a black primer seal. Typical WWI Type S Ball except for the unheadstamped aluminum case.
Based on those items, I would say they did. I also had a M88 round with CNCS FMJ RN bullet, with aluminum case body and steel case head, with “Polte Magdeburg” headstamp. A small quantity of these rounds came in the U.S. in the possession of a US military officer c.1907, contain in an envelope basically just saying they were German. I forget the envelope’s exact markings, but I believe it is in the Woodin collection. They were likely made some years before 1907 from the style of the headstamp. They are the earliest example of a military rifle cartridge that I know of which had an aluminum case. It would seem that the Germans were pioneers in trying to develop a useful aluminum case for full-caliber rifle ammunition.