Designing Quinone-Based Anodes with Rapid Kinetics for Rechargeable Proton Batteries

Quinone compounds, which are capable of accommodating proton (H+), are emerging electrodes in aqueous batteries. However, the storage mechanism of proton in quinone compounds is less known and the energy/power density of quinone-based proton battery is still limited. Here we design a series of quinone anodes and study their electrochemical properties in acidic electrolyte, in which tetramethylquinone (TMBQ) delivers a high capacity of 300 mAh g(-1) with an extremely low polarization of 20 mV at 1 C, and maintains over 50 % theoretical capacity in less than 16 seconds. The fast kinetics of TMBQ is attributed to the continuous H+ migration channel, high H+ diffusion coefficient (10(-6) cm(2) s(-1)), and low H+ migration energy barrier (0.26 eV). When coupling with MnO2 cathode, the battery shows a long lifespan of 4000 cycles with a capacity retention of 77 % at 5 C. This study reveals the proton transport in quinone-electrodes and offers new insights to design advanced aqueous batteries.

Automated summary

In this study, a series of quinone anodes were designed and studied, and it was discovered that tetramethylquinone exhibited high capacity, low polarization, and good capacity retention in acidic electrolyte. The study also revealed the mechanism of proton transport, providing important insights for the design of advanced aqueous batteries.