ALEXANDRIA, Va., Aug. 12 -- United States Patent no. 12,384,689, issued on Aug. 12, was assigned to Natron Energy Inc. (Santa Clara, Calif.).

"Low vacancy Fe-substituted Mn-based prussian blue analogue" was invented by Ashenafi Damtew Mamuye (Milpitas, Calif.), Daniel Friebel (San Carlos, Calif.) and Aniruddh Shrivastava (San Jose, Calif.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A system and method implementing and manufacturing transition metal cyanide coordination compounds (TMCCC) comprising Na, Fe, Mn, C, H, N, S, and O, wherein the TMCCC have 0-14% hexacyanometallate vacancies such as for application in electrochemical cells, including sodium ion secondary batteries."

The patent was filed on Dec....