3D Porous Copper Skeleton Supported Zinc Anode toward High Capacity and Long Cycle Life Zinc Ion Batteries

Zinc ion batteries (ZIBs) have attracted extensive attention in recent years, benefiting from their high safety, eco-friendliness, low cost, and high energy density. Although many cathode materials for ZIBs have been developed, the poor stability of zinc anodes caused by uneven deposition/stripping of zinc has inevitably limited the practical application of ZIBs. Herein, we report a highly stable 3D Zn anode prepared by electrodepositing Zn on a chemically etched porous copper skeleton. The inherent excellent electrical conductivity and open structure of the 3D porous copper skeleton ensure the uniform deposition/stripping of Zn. The 3D Zn anode exhibits reduced polarization, stable cycling performance, and almost 100% Coulombic efficiency as well as fast electrochemical kinetics during repeated Zn deposition/stripping processes for 350 h. Furthermore, full cells with a 3D Zn anode, ultrathin MnO<sub>2</sub> nanosheet cathode, and Zn<sup>2+</sup>-containing aqueous electrolyte delivered a record-high capacity of 364 mAh g<sup>–1</sup> at a current density of 0.1 A g<sup>–1</sup> and good cycling stability with a retained capacity of 173 mAh g<sup>–1</sup> after 300 charge/discharge cycles at 0.4 A g<sup>–1</sup>. This work provides a pathway for developing high-performance ZIBs.