Therefore, we synthesized phase pure nano-crystalline Na 3 Fe 2 Li 3 F 12 (NFLF) powder at room temperature by precipitation from an aqueous solution and thoroughly characterized it by using a wide spectrum of characterization techniques. Indeed, we found that NFLF displays pseudocapacitive properties after first lithium insertion, which fits well to the fast EDL charging of high surface area nanoporous carbon electrodes. Thus, the designed LIC displays high cycle life and rate performance that makes it adaptable for a range of applications to quickly harvest and deliver energy.