Researchers at the Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene in China have synthesized onion-like nanospheres of carbon encapsulated few-layer MoS2 nanosheets for use as an anode material in Li-ion batteries.

The nanocomposite delivers a specific capacity of 1119 mAh g⁻¹ and shows excellent rate and cycling performance. A paper on their work is published in the Journal of Power Sources.

The synthesis of the material is based on a simple polymerization and sulfidation/carbonation process. Mo-containing polyoxometalate enables polymerization of polypyrrole accompanying with uniform encapsulation of Mo-nanoclusters.

The hybrid precursor confines the growth of few-layer MoS₂ nanosheets (≤5 layers) into a N-doped carbon framework, which is of great benefit in enhancing the electrical conductivity and structural integrity.

As a result, the nanospherical MoS₂@C hybrid electrode manifests high Li-ion storage capacity (1119 mAh g⁻¹ at 0.1 A g−1), excellent rate capability (616 mAh g⁻¹ at 2 A g−1), and long cycling stability.

The substantial improvement is rationalized by fast electrode kinetics and great pseudocapacitive contribution.

The researchers suggest that their work may offer a powerful engineering strategy of MoS₂@C nanomaterials for Li/Na-ion batteries and electrocatalysts.

Resources

• Jian-Gan Wang, Huanyan Liu, Rui Zhou, Xingrui Liu, Bingqing Wei (2018) “Onion-like nanospheres organized by carbon encapsulated few-layer MoS₂ nanosheets with enhanced lithium storage performance,” Journal of Power Sources, Volume 413, Pages 327-333 doi: 10.1016/j.jpowsour.2018.12.055