Facile One-Step Solution-Phase Route to Synthesize Hollow Nanoporous Cu_xO Microcages on 3D Copper Foam for Superior Li Storage

In this report, we develop a simple and effective one-step solution-phase route to in situ synthesize hollow nanoporous CuxO microcages on 3D copper foam. When used as an anode for lithium-ion batteries, the unique 3D electrode exhibits superior Li storage properties with a first reversible capacity of 2.82 mAh cm-2 and 78.4% capacity retention after 400 cycles at 2 mA cm-2. The excellent electrochemical performance can be ascribed to the stable hollow structure and robust nanoporous shells of CuxO microcages, as well as in situ growth of microcages on a copper foam substrate with a 3D porous architecture, which is greatly beneficial to buffer large volume changes, increase the loading mass of active material, and boost the binding force between the active material and substrate, as well as shorten the Li+ and electron migration distance.