Fast interfacial kinetics on zinc anodes via electron delocalized maleimide additives for high-performance zinc-ion batteries

The sluggish interfacial kinetics at the Zn electrode-electrolyte interface is one of the reasons for the limited cycle stability of aqueous zinc ion batteries (AZIBs). Here, an electrolyte additive with an electron delocalization effect is proposed to improve interfacial kinetics on the anode, achieving a stable and long lifespan of AZIBs. The conjugated maleimide (MI) anion presents an electron delocalization effect and adsorbs on the Zn, which improves the charge transfer process and the interfacial kinetics. Also, a double protective layer of H2O-poor electrical double layer and solid electrolyte interphase with organic substance is formed by the absorption of MI anions. Benefit from the MI additive, a no-dendrite anode is obtained by suppressing the side reactions and guiding the homogeneous deposition of Zn2+. Finally, a stable Zn||Zn symmetric cell performance up to 5600 h is achieved, and an impressive average coulombic efficiency (~99.91%) is obtained in Zn||Cu cell after 2500 cycles. The Zn||MnO2 full cell also exhibits a lifespan of 2000 cycles at 2 A g−1. The method using the electron delocalization effect of MI provides a new idea for additive selection to stabilize the electrode-electrolyte interface and to facilitate interfacial kinetics.