Ultrathin Metallic-Phase Molybdenum Disulfide Nanosheets Stabilized on Functionalized Carbon Nanotubes Via Covalent Interface Interaction for Sodium- and Lithium-Ion Storage

Abstract

Two-dimensional (2D) ultrathin MoS2 nanosheets, owing to their abundant active sites, tunable interlayer space, and favored ion and mass diffusion, show promise as anode materials for energy storage. However, the low electronic conductivity due to the intrinsic semiconductor structure (2H-MoS2), the spontaneous aggregation caused by the large van der Waals force between layers, and the huge volume alteration during the entire reaction hinder the practical applications of MoS2-based anodes. Here, by employing a facial solvothermal approach, we uniformly disperse metallic-phase MoS2 (1T-MoS2) nanosheets on the functionalized carbon nanotube (CNT) surface to form a 1D@2D hierarchical architecture. The obtained CNT@1T-MoS2 composites show strong covalent interface interaction and improved electronic conductivity. The distinct phase layout, morphology, and component impart the CNT@1T-MoS2 electrode with outstanding sodium-storage performance. The CNT@1T-MoS2 electrode retains a capacity of 542.3 mA h g–1 at 0.1 A g–1 after 50 cycles. Even at a large current density of 20 A g–1, the electrode still gives a high capacity of 153.4 mA h g–1. Moreover, when it is applied in lithium storage, the CNT@1T-MoS2 electrode also possesses good stability with a capacity up to 913.5 mA h g–1 experiencing 50 cycles at 0.1 A g–1 as well as satisfactory fast-charging capability (613.6 mA h g–1 at 5A g–1). This work shows that controlling the phase structure and interface interaction is effective to boost the application of transition-metal dichalcogenide-based composite electrodes in energy storage and conversion.

Conductive Co-based metal organic framework nanostructures for excellent potassium- and lithium-ion storage: kinetics and mechanism studies

“…where a and b are constants, and the b value can be used to judge the ion storage mechanism, either controlled by diffusion (b ¼ 0.5) or by pseudocapacitance (b ¼ 1.0). 64,65 From Fig. 5B, the tted b value using the oxidation peak is 0.89, indicating that the potassiation/depotassiation process is mainly controlled by the pseudocapacitance process.…”

Cotton textile inspires MoS2@reduced graphene oxide anodes towards high-rate capability or long-cycle stability sodium/lithium-ion batteries

“…Nevertheless, for CC/MoS 2 @RGO-700, the distinct peak at 13.5°is replaced by the (002) and (004) planes at 9°and 18°, respectively, suggesting the formation of 1T-MoS 2 with expanded interlayer spacing, in agreement with TEM observation. 19,20 In the subsequent parts, the optimum compositions with the addition of 150 mg Na 2 MoO 4 •2H 2 O are selected for further investigation, and they are designated as PCC/MoS 2 , CC/MoS 2 , and CC/MoS 2 @RGO-X (X represents the combustion temperature) for short.…”

Covalent Pinning of Highly Dispersed Ultrathin Metallic-Phase Molybdenum Disulfide Nanosheets on the Inner Surface of Mesoporous Carbon Spheres for Durable and Rapid Sodium Storage

“…Similar results can be obtained from the high-resolution spectrum of S 2p (Figure d). The peaks at 226.5 and 235.9 eV correspond to S 2s and the Mo–O–C covalent bond, , respectively. The covalent bond formation indicates the interface interaction between M-MoS 2 and HCS, which may arise from the surface structure of HCS.…”