Remodeling Zinc Deposition via Multisite Zincophilic Chlorophyll for Powerful Aprotic Zinc Batteries.

ABSTRACT

The organic electrolyte can resolve the hurdle of hydrogen evolution in aqueous electrolytes but suffers from sluggish electrochemical reaction kinetics due to a compromised mass transfer process. Herein, we introduce a chlorophyll, zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (Chl), as a multifunctional electrolyte additive for aprotic zinc batteries to address the related dynamic problems in organic electrolyte systems. The Chl exhibits multisite zincophilicity, which significantly reduces the nucleation potential, increases the nucleation sites, and induces uniform nucleation of Zn metal with a nucleation overpotential close to zero. Furthermore, the lower LUMO of Chl contributes to a Zn-N-bond-containing SEI layer and inhibits the decomposition of the electrolyte. Therefore, the electrolyte enables repeated zinc stripping/plating up to 2000 h (2 Ah cm-2 cumulative capacity) with an overpotential of only 32 mV and a high Coulomb efficiency of 99.4%. This work is expected to enlighten the practical application of organic electrolyte systems.