Cathode Material Composed of Manganese Cobalt Hexacyanoferrate Nanoparticles for Aqueous Zinc Ion Intercalation Batteries

To accommodate the global shift towards increased energy production from renewable sources, further advancements in storage technology are needed to mitigate the intermittent nature of wind and solar. Aqueous zinc ion intercalation batteries (ZIBs) offer an inexpensive and safe alternative to the traditional lithium ion battery (LIB), making them a prime candidate for large scale storage. Metal hexacyanoferrates have been shown to be suitable cathode materials for ZIBs, allowing for the reversible insertion/extraction of the doubly charged zinc ion. In this work, we report on the performance of a cathode material composed of mixed manganese-cobalt hexacyanoferrate nanoparticles for a rechargeable ZIB. The cathode exhibits a reversibly capacity of 111 mAh/g at 25 mA/g and good capacity retention after extended cycling at 100 mA/g. X-ray diffraction and SEM imaging reveal nanoparticles with a rhombohedral structure and sizes on the order of 20 - 60 nm. The combination of the nontoxic hexacyanoferrate cathode, with the aqueous zinc ion electrolyte offers a promising system for large scale energy storage.