Template-free fabrication of 1D core-shell MoO2@MoS2/nitrogen-doped carbon nanorods for enhanced lithium/sodium-ion storage

A universal anode material of 1D core-shell MoO2@MoS2/nitrogen-doped carbon (MoO2@MoS2/NC) nanorods has been elaborately synthesized via a facile fabrication route for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBS), in which MoO2 core not only acts as a conductive backbone for efficient electron transport, but creates structural disorders in MoS2 nanosheets to prevent aggregation and expose more active sites for alkali-ions. Meanwhile, the MoO2 core is tightly encapsulated by the parallelly aligned MoS2 nanosheets to constrain the size of crystals, which greatly shortens the ionic diffusion path and accelerates diffusion rate, thus ensuring fast reaction kinetics. Additionally, the resilient and conductive N-doped carbon matrix in the hybrid could maintain the structural integrity and enhance the electrical conductivity of the electrodes, improving the rate capability and life span. The flexible 1D nanorods could contract freely during the charge/discharge process, further assuring the structural stability of the electrodes. Benefiting from the above-mentioned advantages, the MoO2@MoS2/NC electrodes still remains a specific capacity of 583.5 mA h g(-1) after 1500 cycles at a high current density up to 10 A g(-1) in LIBs, and a capacity of 419.8 mA h g(-1) is steadily kept over 800 cycles at 2 A g(-1) in SIBS. (C) 2020 Elsevier Inc. All rights reserved.