Zinc/selenium conversion battery: a system highly compatible with both organic and aqueous electrolytes†

Zinc ion batteries (ZIBs) typically work well in aqueous electrolytes. Most high-performance cathode materials of aqueous ZIBs exhibit much-deteriorated capacity, voltage plateau and rate capability in organic electrolytes. It remains a challenge to have a Zn battery that is highly compatible with both aqueous and organic electrolytes. Herein, a conversion-type Zn-Se battery is constructed, which delivers a superior performance in both organic and aqueous electrolytes benefiting from a highly reversible conversion reaction between Se and ZnSe. Extraordinary capacities in organic systems (551 mA h g(Se)(-1)) and aqueous systems (611 mA h g(Se)(-1)) were successfully achieved, accompanied by a remarkable rate performance and cycling performance in each of the two systems. In addition, very low voltage plateau slopes, 0.94 V/(A h g(-1)) and 0.61 V/(A h g(-1)), are obtained for organic and aqueous systems, respectively, due to the advanced conversion mechanism. These unique features equip these Zn-Se batteries with unprecedented energy densities of up to 581 W h kg(Se)(-1) (290 W h kg(Se/CMK-3)(-1)) for the organic system and 751 W h kg(Se)(-1) (375 W h kg(Se/CMK-3)(-1)) for the aqueous system. Our research has developed a new Zn battery chemistry that benefits from a conversion mechanism and is highly compatible with both organic and aqueous electrolytes, opening a door for zinc batteries to achieve a higher energy density and better compatibility with various electrolytes.

Automated summary

A new conversion-type Zn-Se battery has been developed, showing superior performance in both organic and aqueous electrolytes with extraordinary capacities, rate capability, and cycling performance. The battery also exhibits very low voltage plateau slopes, allowing for high energy densities and compatibility with various electrolytes, opening new possibilities for zinc batteries.