Performance evaluation of a de-embedded de-alloyed Cu2+1O/cu/Si@C anode material used in lithium-ion batteries

Lithium-ion batteries (LIBs) are widely used in new energy vehicles, portable electronic products and power batteries owing to their high open-circuit voltage, high specific energy and low self-discharge rate. The embedded graphite anodes of LIBs have a low theoretical specific capacity and cannot meet the requirements of high-energy-density electronic devices. Herein, an Al–Mg–Cu–Si–Sn alloy was first prepared via melting, and a Cu 2+1 O/Cu/Si composite was subsequently synthesized via de-alloying. Furthermore, the composite was coated with carbon to obtain Cu 2+1 O/Cu/Si@C—an LIB anode material exhibiting a high energy density. The physical phase, microstructure and lithium-storage performance of the de-embedded Cu 2+1 O/Cu/Si@C anode material were analyzed via characterization methods such as X-ray diffraction, scanning electron microscopy–energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy–EDS and electrochemical analysis. The anode material exhibited a specific capacity of 995.6 mAh/g, a first-time Coulombic efficiency of 75.5%, a specific capacity of 604.4 mAh/g after 500 charge/discharge cycles and good multiplicative rate performance at current densities of <1C. • A microporous–nanoporous Cu 2+1 O/Cu/Si composite was prepared via de-alloying using Al–Mg–Cu–Si–Sn alloy precursors, which contained Cu 2+1 O featuring a haematite structure and Cu 6 Sn 5 phases with a microspherical–nanospherical structure. • The Cu 2+1 O/Cu/Si composite and graphite were subjected to high-energy spheroidal inking and high-temperature activation to obtain a Cu 2+1 O/Cu/Si@C anode material. • The Cu 2+1 O/Cu/Si@C anode material exhibited a high first-time Coulombic efficiency as well as cycling and multiplicative performances in a lithium-ion battery.