Hierarchical 3D Cuprous Sulfide Nanoporous Cluster Arrays Self-Assembled on Copper Foam as a Binder-Free Cathode for Hybrid Magnesium-Based Batteries.

On account of easy accessibility, high theoretical volumetric capacity and dendrite-free magnesium (Mg) anode, Mg battery has a great promise to be next generation rechargeable batteries, yet still remains a challenging task in acquiring fast Mg2+ kinetics and effective cathode materials. Herein, hierarchical 3D cuprous sulfide porous nanosheet decorated nanowire cluster arrays with robust adhesion on copper foam (Cu2 S HP/CF), which is employed as a binder-free conversion cathode material for magnesium/lithium hybrid battery, delivering impressively initial and reversible specific capacity of 383 and 311 mAh g-1 at 100 mA g-1 , respectively, which are obviously outperformed corresponding powder cathode in a traditional method by using polymer binder, is reported. Intriguingly, benefiting from the hierarchical nanoporous array architecture and self-assembly feature, Cu2 S HP/CF cathode shows a remarkable cycling stability with a high capacity of 129 mAh g-1 at 300 mA g-1 over 500 cycles. This work not only highlights a guide for designing hierarchical nanoporous materials derived from metal-organic frameworks, but also provides a novel strategy of in situ formation to fabricate binder-free cathodes.