Bio-degradable zinc-ion battery based on a prussian blue analogue cathode and a bio-ionic liquid-based electrolyte

Rechargeable zinc-ion batteries are of high interest for electrical energy storage due to their low cost, high safety, and good energy density. The development of stable and high-performance cathode materials and environmentally friendly electrolytes is of interest for practical applications. Despite many efforts in pursuing batteries with high energy density and long cycle life, relatively little attention has been paid on the environmental aspects. Thus, bio-batteries that contain nontoxic materials and which are bio-degradable are an interesting alternative to conventional batteries. In the present paper, we present our first results on a highly reversible zinc/prussian blue analogue (PBA) bio-battery, where nanostructured PBA is used as a cathode material, a bio-degradable ionic liquid-water mixture as electrolyte, and zinc as anode. Both the PBA cathode and the zinc anode exhibit good compatibility with the bio-degradable electrolyte. The Zn/PBA battery shows good electrochemical performance including an open circuit voltage of 1.6 V, a specific capacity of similar to 54 mAh g(-1) (PBA), and a low self-discharge rate. The zinc anode also shows a good stability since no dendritic growth and shape change are observed after 50 charge-discharge cycles.