Herein, we report a charge-transfer complex electrolyte
additive,
7,7,8,8-tetracyanoquinodimethane (TCNQ), with high Zn affinity, which
was tightly adsorbed on the surface of a Zn anode to form a dense
and robust interfacial complex layer and suppress the activity of
H2O. As verified by comprehensive experimental and computational
analyses, this complex layer could construct a Zn–Zn(TCNQ)2 Ohmic contact interface, guide rapid ion/electron transport,
ameliorate electric field distribution, and inhibit the direct contact
between the active H2O and Zn anode, demonstrating a dendrite-free
Zn anode and facile Zn plating/stripping kinetics. Consequently, the
Zn||Zn symmetrical cell exhibits a high Zn plating/stripping reversibility
of over 1000 h at 20 mA cm–2 and 5 mA h cm–2 and a high depth of discharge (43%). Moreover, the Zn||MnO2 full cell delivers a high capacity of 143.3 mA h g–1 at 2000 mA g–1 even after 4000 cycles and a capacity
retention of 94.7% after returning to 100 mA g–1.