Non-polymerised organic materials, insoluble in salt water (Zn2+) in all their redox states (neutral and salt).

Zn-ion batteries comprise a Zn metal anode, coupled with a cathode material which usually contains inorganic compounds such as Mn and V metal oxides. Despite their ability to deliver high electrical capacity, they exhibit relatively low cycle-life and Zn2+ insertion kinetics, along with toxicity issues. Search has thus been made to substitute these inorganic cathode materials by organic ones.
Quinone derivatives are considered promising candidates to obtain performant batteries. They show good environmental friendliness and provide the advantage of simple synthesis, corresponding to reduced costs. However, many quinone molecules are prone to dissolution in aqueous electrolytes, which induces a loss of capacity of the battery, along with possible corrosion or dendrite problems on the zinc anode.

To render the use of quinone type molecules more suitable in aqueous zinc-ion battery, the inventors have functionalized the hydroquinones with hydrophobic groups that strongly mitigate their solubility in zinc aqueous electrolytes. Consequently, the capacity of the battery upon cycling is maintained. They also improved the battery operating potential (+300 mV gain vs Li+) by associating these hydrophobized hydroquinones with an appropriate aqueous zinc electrolyte.