Environmentally friendly additives for crystal surface modulation and suppression of dendrites for aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) as promising energy storage devices provide synergistic advantages of high safety, low cost and high energy density. However, it has been observed that underestimated but not negligible dendrites of Zn and H2 production affect battery performance and limit applications of AZIBs. In this work, a functional electrolyte strategy is reported by adding polyhydroxy chlorinated organic compound-sucralose (SCL), which can improve the lifetime of battery. A combination of experimental and theoretical research reveals that SCL could induce the deposition behavior of Zn2+, i.e. the preferential deposition of Zn2+ on the (002) crystal plane, which is conducive to suppress dendrite formation. In the presence of 0.5 mA cm−2 and 1.0 mAh cm−2, compared with pure ZnSO4 electrolyte, the electrolyte with SCL significantly improves the cycle lifespan of Zn||Zn symmetrical cells (3200 h compared to 125 h). To validate the feasibility of SCL, we assemble Zn||MnO2 full cells, which exhibit excellent specific capacity (149 mAh g−1) and capacity retention (89 %) over 2000 cycles at 1.0 A g−1.