Dendrite-Free Zn/rGO@CC Composite Anodes Constructed by One-Step Co-Electrodeposition for Flexible and High-Performance Zn-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) with good flexibility have attracted great demands for portable and wearable electronics. However, the low Coulombic efficiency and poor cycling performance caused by uncontrolled Zn dendrite growth limit their practical applications. Herein, a novel strategy is proposed to construct a flexible and dendrite-free composite anode by one-step co-electrodeposition. Interestingly, the reduction of Zn2+ ions to Zn nanoflakes is synchronously accompanied by graphene oxide reduction, leading to a composite anode comprised of Zn with an interpenetrated conductive network of reduced graphene oxide (rGO) on a carbon cloth (CC) substrate, namely Zn/rGO@CC. The 3D rGO network not only improves the electrical conductivity and wettability of the composite anode to lower the interfacial resistance but also homogenizes the electric field distribution and Zn2+ ion flux, thus effectively inhibiting the growth of Zn dendrites. As expected, the Zn/rGO@CC anode exhibits long cycle stability for nearly 1000 h at 1 mA cm(-2) with low voltage hysteresis. Furthermore, the Zn/rGO@CC composite anode provides the corresponding aqueous Zn||MnO2 full cells with remarkable rate capability and stunning long-term durability. The as-fabricated quasi-solid-state ZIBs also demonstrate coveted flexibility, showing high potential in future wearable and portable electronic devices.

Automated summary

A flexible and dendrite-free composite anode, Zn/rGO@CC, is successfully fabricated through a one-step co-electrodeposition, which consists of Zn nanoflakes and a 3D conductive network of reduced graphene oxide (rGO) on a carbon cloth (CC) substrate. This composite anode not only improves the conductivity and wettability, but also inhibits the growth of Zn dendrites by homogenizing the electric field distribution and Zn2+ ion flux. The Zn/rGO@CC anode exhibits long cycle stability and remarkable rate capability, showing potential for future wearable and portable electronic devices.