A High-Power Aqueous Zinc-Organic Radical Battery with Tunable Operating Voltage Triggered by Selected Anions

In contrast to traditional rechargeable rock-chair metal-ion batteries, dual-ion batteries (DIBs) involve redox reactions with anions rather than cations in p-type cathodes. In principle, regulating the electrochemical performance of the DIB by different anion species is highly feasible. Herein, the anion effect on the electrochemical performance of a DIB, the aqueous Zn- organic radical battery (Zn-ORB), consisting of a poly(2,2,6,6tetramethylpiperidinyloxy-4-yl vinyl ether) cathode and a Zn anode, was investigated by DFT calculations. SO₄ ^2- , CF₃ SO₃ ^- , and ClO₄ ^- with different molecular electrostatic potential values were selected as anion models. DFT calculations revealed that a stronger electrostatic interaction of the anion with the organic radical resulted in a higher operating voltage of the Zn-ORB, which was consistent with experimental results. These results bring new insight into the redox chemistry of p-type organic radicals with anions and will promote the development of high-power aqueous Zn-ORBs as well as inspire more investigations into the anion effect towards novel battery designs.