Redistributing zinc-ion flux by constructing a hybrid conductor interface for dendrite-free zinc anode

Abstract

Rechargeable aqueous zinc-metal batteries have attracted soaring attention as alternative to conventional lithium-ion batteries for energy storage systems due to the high safety, low cost, and environmental benignancy. However, the spontaneous side reaction and dendrite growth lead to the poor electrochemical performance as well as serious safety issues. Herein, a multifunctional layer composed of zinc alginate (ZA) and vermiculite sheets (VS) is coating on zinc foil surface to simultaneously suppress the side reaction and dendrite growth. Unique Zn2+ channels built by ZA polymer and VS endow the ZAVS film with high zinc-ion transference number (tZn2+ = 0.81), which can both improve the migration of Zn2+ and redistribute the Zn2+ flux on the electrode surface. Consequently, dendrite growth is obviously inhibited. In addition, ZAVS film can serves as a buffer layer to isolate zinc anode from aqueous electrolyte, alleviating the zinc corrosion and hydrogen generation. Benefiting from the inhibition of dendrite growth and side reaction, superior electrochemical performance can be achieved as evidenced by the high Coulombic efficiency of 99.18% for 520 cycles, and ultra-long cycling stability over 1000 h with small voltage hysteresis. The construction of ZAVS artificial layer could be a promising strategy for advanced RAZMBs.