A mild route to mesoporous Mo2C–C hybrid nanospheres for high performance lithium-ion batteries

Abstract

In this work, we have developed a mild route to fabricate typically mesoporous Mo2C-C hybrid nanospheres based on a solvothermal synthesis and reduction-carbonization process. This work opens a low-temperature route to synthesize valuable carbides. The resultant Mo2C-C hybrid, for the first time, is used as an anode material in lithium ion batteries (LIBs). Compared with bulk Mo2C, the Mo2C-C hybrid exhibits much better electrochemical performance. Remarkably, the hybrid electrode can deliver a specific capacity of over 670 mA h g(-1) after 50 cycles at 100 mA g(-1), which is much higher than that of the bulk material (113 mA h g(-1)). Even cycled at a high current density of 1000 mA g(-1), high capacities of around 400-470 mA h g(-1) can still be retained for the Mo2C-C hybrid. It might benefit from the synergistic effect of the nanohybridization, effectively relieving the volume change during the repeated lithium insertion-extraction reactions and maintaining the integrity of the electrical connections. It is expected that the present synthesis strategy for the Mo2C-C hybrid can be extended to other nanostructured carbides with good energy storage performance.

Hybridization and pore engineering for achieving high-performance lithium storage of carbide as anode material

“…Figure 2c shows the high resolution Mo 3d XPS spectrum of HP-Mo 2 C-C, which can be deconvoluted into five peaks. The peaks at 229.0 and 232.9 cm -1 can be ascribed to Mo 3d of Mo 2 C, while those at 235.9, 231.9 and 230.2 cm -1 are related to MoO x mainly derived from the surface oxidation of Mo 2 C during the test process [26][27][28][29][30]. The deconvoluted C 1s spectrum was utilized to investigate the surface carbon ( Figure 2d).…”

“…Furthermore, compositing nanoscale carbides with carbon is also an efficient approach to alleviate the agglomeration or oxidation of carbides [26,27]. Recently, the core-shell bimetallic carbide/N-doping carbon three-dimensional (3D) hybrid used as an anode material for lithium storage was reported by our group [23].…”

Effective and Highly Selective CO Generation from CO2 Using a Polycrystalline α-Mo2C Catalyst

“…Only in some cases, very low intensity bands at ~1350 cm -1 and ~1580 cm -1 (D and G bands), were detected, indicating that negligible contents of carbonaceous residues would be present in the synthesized α-Mo 2 C. Although the Raman spectrum in the zone 100-1000 cm -1 is complex, it points to the presence of different surface molybdenum oxide species, such as MoO 3 and other intermediate oxides The C 1s peak can be deconvoluted into four components at 283.8 eV, 284.8 eV, 286.0 eV, and 288.7 eV, ( Figure S7a), which can be assigned to C-Mo, C-C, C-O and O=C-O species, respectively. 33,[35][36][37][38] Finally, Figure 3 shows the H 2 -TPR profile of the sample; the main peak at 554 K can be assigned to the reduction of molybdenum oxycarbide. 39 The reduction of surface molybdenum oxides could account for the H 2 consumption at temperatures higher than 590 28 As far as the (001)-C termination is concerned, Han et al 41,42 described CO adsorption on its reconstructed surface.…”

MoO2/Mo2C/C spheres as anode materials for lithium ion batteries

“…The high specific conductance of Mo 2 C minimizes the charge transport resistance, leading to better electronic conductivity, and the electrochemical inactivity improves structural stability [24,25]. Moreover, Gao et al synthesized Mo 2 C-C hybrid nanospheres through solvothermal synthesis and a reduction-carbonization method, and they demonstrated capacity of 672.7 mAh g -1 after 50 cycles at a current density of 100 mA g -1 [26].…”