3D Printed Low-Tortuosity and Ultra-Thick Hierarchical Porous Electrodes for High-Performance Wearable Quasi-Solid-State Zn-VOH Batteries.

Rechargeable aqueous Zn-ion batteries have received considerable attention in energy storage systems owing to their merits of high safety, low cost, and excellent rate performance. However, the unsatisfactory areal energy density and poor cycling performance hinder their practical applications. Herein, the VO·6HO (VOH) nanosheet arrays and Zn nanoflake arrays growing on the 3D-printed reduced graphene oxide/carbon nanotubes (3DP-rGO/CNTs) microlattices employing the electrodeposition technique, and further serve as the cathode and anode for 3D-printed aqueous Zn-VOH battery, respectively. Benefiting from 3D-printed low-tortuosity and ultra-thick hierarchical porous electrodes, the battery-type VOH-based cathode enables fast Zn reaction kinetics and electrodeposited Zn-based anode delivers highly reversible Zn stripping/plating. The button-type 3D-printed aqueous Zn-VOH battery exhibits excellent energy/power densities (364.5 Wh kg at 700 W kg) and remarkable cycling performance over 6500 cycles. Impressively, a customizable 3D-printed quasi-solid-state Zn-VOH battery device is fabricated, which presents ultrahigh areal capacity (≈17.06 mAh cm at 0.2 mA cm), long-term durability (≈85.6% capacity retention after 10 000 cycles), and excellent wearable characters. This work provides a novel strategy to gain high-performance Zn-ion batteries based on 3D-printed electrodes, which may pave a new way for the applications of various high-performance, low-cost, and portable integrated energy storage systems.