Ionic accelerator based on metal-semiconductor contact for fast electrode kinetics and durable Zn-metal anode

Abstract

The development of Zn metal anodes with high reversibility and fast kinetics is critical for achieving high-performance aqueous Zn-metal batteries. Herein, we report a Zn@SiC electrode with an Ohmic contact that exhibits excellent durability and enhanced electrode process kinetics. The Ohmic contact barrier (Phi(b)) inhibited electron transfer from the metal to the SiC passivation layer and effectively regulated Zn deposition under the passivation layer, thus suppressing dendrite growth. The built-in potential (V-bi) accelerated the Zn transfer and reaction kinetics and decreased the nucleation energy, thereby enhancing the charge-discharge platform po-tential (similar to 40 mV) in full cells. Coupled with the good anti-side reaction ability of the SiC layer, the Zn@SiC electrode successfully delivered a highly reversible stripping/plating process after 3770 h under a 1.0 mA cm(-2) current density with a low overpotential of 33.7 mV. Furthermore, by analyzing the energy band structure of the Ohmic contacts, the critical current density was quantitatively determined. This clarified the relationship be-tween the deposition position and the current density, thus providing a standard for practical semiconductor design.