1 research outputs found
3D Foam-Like Composites of Mo<sub>2</sub>C Nanorods Coated by N‑Doped Carbon: A Novel Self-Standing and Binder-Free O<sub>2</sub> Electrode for Li–O<sub>2</sub> Batteries
The
development of self-standing and binder-free O<sub>2</sub> electrodes
is significant for enhancing the total specific energy density and
suppressing parasitic reactions for Li–O<sub>2</sub> batteries,
which is still a formidable challenge thus far. Here, a three-dimensional
foam-like composite composed of Mo<sub>2</sub>C nanorods decorated
by different amounts of N-doped carbon (Mo<sub>2</sub>C-NR@<i>x</i>NC (<i>x</i> = 5, 11, and 16 wt %)) was directly
employed as the O<sub>2</sub> electrode without applications of any
binders and current collectors. Mo<sub>2</sub>C-NR@<i>x</i>NC presents a network microstructure with interconnected macropore
and mesoporous channels, which is beneficial to achieving fast Li<sup>+</sup> migration and O<sub>2</sub> diffusion, facilitating the electrolyte
impregnation, and providing enough space for Li<sub>2</sub>O<sub>2</sub> storage. Additionally, the coated N-doped carbon layer can largely
improve the electrochemical stability and conductivity of Mo<sub>2</sub>C. The cell with Mo<sub>2</sub>C-NR@11NC shows a considerable cyclability
of 200 cycles with an overpotential of 0.28 V in the first cycle at
a constant current density of 100 mA g<sup>–1</sup>, a superior
reversibility associated with the formation and decomposition of Li<sub>2</sub>O<sub>2</sub> as desired, and a high electrochemical stability.
On the basis of the experimental results, the electrochemical mechanism
for the cell using Mo<sub>2</sub>C-NR@11NC is proposed. These results
represent a promising process in the development of a self-standing
and binder-free foam-based electrode for Li–O<sub>2</sub> batteries