The good reactivity of lithium with nanostructured copper phosphide

Abstract

In Li-ion battery technology, Li diffusion in the electrode is mainly limited by the quality of the interfaces. To take advantage of the large capacity gain offered by the transition metal phosphides (TMP) as negative electrode, a new self-supported TMP/Cu nanoarchitectured electrode concept is proposed. This specific design allows one to fine-tune control of both (TMP)/current collector and (TMP)/electrolyte interfaces of the electrode. This new electrode preparation process is based on an electrochemical templated synthesis of copper nanorods followed by a phosphorus vaporization. The P vapour reacts with the Cu nanorods leading to Cu₃P nanorods. Preliminary electrochemical tests of the as-obtained Cu₃P nanorods/Li half cell show the great interest of using such a nanostructured TMP electrode in a Li battery. These nanoarchitectured phosphide electrodes can sustain a C-rate (a full discharge in 1h) cycling without exhibiting any important reversible capacity loss for 20 cycles.