Cu nanoparticles derived from CuO electrodes in lithium cells.

Nanosheet cupric oxide (CuO) was synthesized by a hydrothermal synthesis method and its electrochemical performance was tested with Li metal as the reference anode. This CuO electrode showed a good capacity retention with a reversible capacity of 400 mA h g(-1) during up to 100 cycles. Copper (Cu) nanoparticles were produced and separated from the lithiated CuO electrode. Structural analyses by means of electron microscopy (field emission scanning electron microscopy and transmission electron microscopy) indicated that rather uniform spherical copper particles of 30-40 nm were obtained. These copper nanoparticles were collected as the lithiation product and this electrochemical reduction method was put forward as a new approach for synthesizing metal nanoparticles.