Pengxiang Wang

Kinetics enhancement of lithium–sulfur batteries by interlinked hollow MoO2 sphere/nitrogen-doped graphene composite

The shuttle effect and poor redox kinetics are vital issues restricting the evolution of lithium sulfur batteries; it is therefore exigent to rationally design an effective sulfur host. Hence, this paper reports a hollow MoO2 sphere anchored on nitrogen-doped graphene. The hollow MoO2 sphere controls the polysulfide dissolution, and the nitrogen-doped graphene provides a conductive network and high sulfur loading. Meanwhile, the C–O–Mo bond interlinking MoO2 and N-doped graphene provides a pathway for electron transfer, and the synergistic effect enhances the kinetics of lithium sulfur batteries profitably. Ascribed to the unique structure of MoO2/nitrogen-doped graphene, the obtained electrode exhibits a substantially enhanced electrochemical performance.

In-situ synthesis of CuCo2S4@N/S doped graphene composites with pseudocapacitive properties for high performance lithium ion batteries

To satisfy the demand of high power application, lithium-ion batteries (LIBs) with high power density have gained extensive research effort. The pseudocapacitive storage of LIBs is considered to offer high power density through fast faradic surface redox reactions rather than the slow diffusion-controlled intercalation process. In this work, CuCo2S4 anchored on N/S-doped graphene is in situ synthesized and a typical pseudocapacitive storage behavior is demonstrated when applied in the LIB anode. The pseudocapacitive storage and N/S-doped graphene enable the composite to display a capacity of 453 mA h g-1 after 500 cycles at 2 A g-1 and a ultrahigh rate capability of 328 mA h g-1 at 20 A g-1. We believe that this work could further promote the research on pseudocapacitive storage in transition-metal sulfides for LIBs.

N doped carbon coated V2O5 nanobelt arrays growing on carbon cloth toward enhanced performance cathodes for lithium ion batteries

Highly flexible, binder-free cathodes for lithium ion batteries were fabricated by utilizing N doped carbon to coat V2O5 (V2O5@N-C) nanobelt arrays growing on carbon cloth. Such a robust architecture endows the electrode with effective ion diffusion and charge transport, resulting in high rate capability (135 mA h g−1 at 10C) and excellent cycling performance (215 mA h g−1 after 50 cycles at 0.5C).