MoSe2 nanoflakes-decorated vertically aligned carbon nanotube film on nickel foam as a binder-free supercapacitor electrode with high rate capability.

A new type of composite electrode material, MoSe2 nanoflakes grown on the vertically aligned carbon nanotube array film (VACNTF) with binder-free nickel foam as current collector (VACNTF@MoSe2/NF), was fabricated by a simple spraying chemical vapor deposition method combined with the solvothermal technique. Owing to the introduction of the VACNTF with ordered channels and appropriate intertube spacing, which facilitate electrolyte ions quickly transferring and alleviate the volume changes in the electrochemical measurements, the VACNTF@MoSe2/NF sample presents superior electrochemical performance compared to pure MoSe2/NF sample. The VACNTF@MoSe2/NF sample exhibits high specific capacitance of 435 F·g-1 at 1 A·g-1, remarkable cycling stability (92% of the original capacitance maintaining over 5000 cycles) and especially excellent rate capability (84.1% capacitance retention with the current density changed from 1 to 15 A·g-1). Moreover, the VACNTF@MoSe2/NF based asymmetric supercapacitor exhibits a high energy density with 22 Wh·kg-1 for a power density of 330 W·kg-1. This paper offers a new strategy to prepare transition metal dichalcogenides based electrode materials with high rate performance.

Interfacial engineering of Ag nanodots/MoSe2 nanoflakes/Cu(OH)2 hybrid-electrode for lithium-ion battery.

Although the Lithium ion batteries (LIBs) have attracted remarkable attentions, their practical development is hindered by the low rate performance and poor unit area capacity, which is significantly caused by the low conductivity of the active electrode materials. Herein, a three-dimensional (3D) architecture consisting of Ag nanodots embedded MoSe2 sheets wrapping Cu(OH)2 nanorods (Cu(OH)2/MoSe2/Ag) hybrids were in-situ synthesized on self-standing Cu- foam collector for LIBs application. The 2D MoSe2 nanoflakes supported on 1D highly conductive Cu nanowires provides efficient pathways for both electrons and ions. The embedded Ag nanodots in the MoSe2 as the internal-plane active sites not only improves the intrinsic conductivity but also allows the reversible formation and decompose of Ag-Li alloy, and thus leading to the promotion of Li+ ion storage. As a result, the Cu(OH)2/MoSe2/Ag electrode exhibits a high reversible discharge capacity of 1285.5 mAh g-1 (current density of 0.2 C), good rate performance (discharge-specific capacity remained 544.8 mAh g-1 at 5.0C), and excellent cycling stability (with almost no decay after 500 cycles). Significantly, the 3D Cu(OH)2/MoSe2/Ag electrode exhibits a high areal capacity of 2.50 mAh cm-2 at a high current density of 1.82 mA cm-2. This work provides the new insight into interfaces engineering for 3D architecture toward advanced self-standing LIB electrodes.