Cobalt and oxygen double doping induced C@MoS-CoS-O@C nanocomposites with an improved electronic structure and increased active sites as a high-performance anode for sodium-based dual-ion batteries

A cobalt-doping induced heterogeneous structure of MoS 2 -CoS 2 grown on one-dimensional tubular carbon (ODTC) has been synthesized. The CoS 2 nanoparticles can inhibit the free growth of MoS 2 nanosheets and obtain a MoS 2 -CoS 2 heterostructure with an ultra-small size, which improves the electronic conductivity of the electrode material affected by the internal electric field. Furthermore, oxygen-incorporated C@MoS 2 -CoS 2 accompanied by a double carbon coating process can add active sites, provide a buffer layer and further improve the electronic conductivity of the electrode material, which overcomes the shortcomings of intrinsic low electronic conductivity and structural instability of MoS 2 . Serving as an anode material for sodium ion batteries, the C@MoS 2 -CoS 2 -O@C nanocomposites show superior sodium storage performance with high capacity (466.1 mA h g −1 at 1 A g −1 after 200 cycles) and excellent rate capability. And the sodium dual-ion full batteries deliver a reversible discharge capacity of 182.2 mA h g −1 at 1 A g −1 over the voltage range of 1.0-4.4 V after 1000 cycles. Cobalt and oxygen double doping induced C@MoS 2 -CoS 2 -O@C nanocomposites has been synthesized. The special structure improves electronic structure, increases active sites and possesses superior electrochemical performance.