Cathode Materials Challenge Varied with Different Electrolytes in Zinc Batteries

The superiority in addressing cost and safety concerns of zinc (Zn) metal has stimulated enthusiasm for the research attention on zinc batteries (ZBs). Because of the slow diffusion of divalent Zn 2+ in the solid state, the kinetics of ZBs in different electrolytes are very different, which can strongly affect the electrochemical performance. This Review focuses on the Zn 2+ storage mechanisms of cathode materials and the various challenges that they face in different electrolytes. In particular, the compatibility of organic electrodes with different electrolytes and corresponding design strategies are introduced, which is the least understood part at present and has made good progress in the past few years. We propose research guidelines for the future development of ZBs materials: (1) develop mixed solvent electrolytes compatible with cathode and anode materials; (2) develop layered inorganic materials with large interlayer spacing; (3) adjust material surface properties to reduce the charge transfer barriers on the electrode interface; and (4) design and develop open frame organic materials with a stable structure.