Metal

Kirkendall effect

Composite number

Engineering

Nanoparticle

Electrochemistry

Metallurgy

Materials science

Cellulose

Carbon fibers

Chemical engineering

Physical chemistry

Nanotechnology

Organic chemistry

Microsphere

Carbonization

Thermal treatment

Composite material

Chemistry

Scanning electron microscope

Electrode

Anode

Chemical Engineering Journal

Biomass derived carbon with hollow metallic structures is considered as eco-friendly and sustainable materials, especially as electrode materials, absorbents and catalysts. Herein, hollow CuO nanoparticles (NPs)@carbon (C) microspheres were fabricated by directly using a cellulose-cuprammonium solution as the starting metallic precursor along with the carbonization and oxidation processes. The hollow CuO NPs were formed spontaneously during the oxidation process following a modified Kirkendall effect. The cellulose derived carbon assisted the formation of the hollow structure and prevented the aggregation of CuO NPs during the thermal treatment. As an integrated material, [email protected] microspheres were used as anodes for lithium-ion batteries. The anodes of [email protected] microspheres exhibited a good cycling stability with a discharge capacity of 630 mA h/g at a rate of 0.1 C (1 C = 1 A/g), which is close to the theoretical specific capacity of the anodes of the pure CuO (670 mA h/g), and a good rate performance with high discharge capacities of 361 mA h/g at a rate of 5 C, which is much higher than that of the bare CuO microspheres (57 mA h/g at 5C). The excellent electrochemical performance could be attributed to the unique carbon combined hollow CuO NPs. This work provided a new pathway for preparing biochar based metallic materials with the inexpensive precursor and high applicable performance.

Hollow CuO nanoparticles in carbon microspheres prepared from cellulose-cuprammonium solution as anode materials for Li-ion batteries