Stable bismuth-antimony alloy cathode with a conversion-dissolution/deposition mechanism for high-performance zinc batteries

Although a large number of intercalation cathode materials for aqueous Zn batteries have been reported, limited capacity precludes achieving higher energy density. Here we develop high-performance battery based on BiSb alloy (Bi0.5Sb0.5) using high-concentrated strong-basic polyelectrolyte. We demonstrate that conversion-dissolution/deposition electrochemical mechanism (BiSb ? Bi + SbO2? SbO3? Bi2O3) through in situ X-ray diffraction (XRD), Raman, and ex-situ photoelectron spectrometry (XPS) characterizations with the help density functional theory calculations. The delivers 512 mAh g?1 at 0.3 Ag?1 superior rate capability 90 even 20 Ag?1, long-term cyclability retentions 184 after 600 cycles 0.5 130 1300 1 Ag?1. Remarkably, temperatures as low ?10 ?20 °C, capacities 210 197 are reserved respectively. Moreover, prepared pouch Zn//BiSb high 303 Wh kg?1BiSb When coupled concentration polyelectrolyte, Zn/BiSb exhibits an excellent performance over wide temperature range (?40 to 40 °C). Our research reveals metal is promising achieve unique alloys can be effective approach stabilize electrodes cycling.