Binding MoSe2 with carbon constrained in carbonous nanosphere towards high-capacity and ultrafast Li/Na-ion storage

Abstract

Mostly reported MoSe2 suffered from easily stacking problem, volume expansion and relative low capacity. From the experience of Li/Na-Se batteries, the exfoliated and encapsulated MoSe2 inside carbon nanospheres with C-O-Mo bonds and large layer distance (0.89 nm) are successfully constructed. This unique effective structure has C-O-Mo bonding allowing high conductivity across the Se-O insulation layer and promoting its reversible conversion. The first-principles calculations demonstrated that the frontier molecular orbitals of C-O-Mo interface structure are mainly localized on the MoSe2 sheet fragment with an appropriate HOMO-LUMO gap (< 4eV),suggesting its good stability and conductivity. Utilized as anodes for LIBs allows a Li-storage capacity to be realized of 1208 mAh g -1 after 150 cycles at 1.0 A g -1 and 519 mAh g -1 after 200 cycles at 4.0 A g -1 . The Na-storage capacity is found to be 543, 491 mAh g -1 after 120 cycles at 0.1, 1.0 A g -1 . Focusing on the analysis of CV, the reducing particle may improve the capacitive behaviors, further resulting the high-rate performance. Ex-situ techniques demonstrated that the emerging Se was constrained uniformly. The controlling of by-product Se plays a key role in achieving a high rate 2 capacity and cycling stability, and opens up a potential avenue for these metal-selenide anodes designs for battery storage systems.

Self‐Assembling of Conductive Interlayer‐Expanded WS2 Nanosheets into 3D Hollow Hierarchical Microflower Bud Hybrids for Fast and Stable Sodium Storage

“…According to the EIS equivalent circuit (the inset of Figure g), the R ct value of H‐WS 2 @NC (49 Ω) is much lower than that of S‐WS 2 @NC (113 Ω) and bare WS 2 (374 Ω), confirming the remarkably enhanced kinetics of electronic transportation provided by the architecture of H‐WS 2 @NC electrode. Furthermore, the diffusion kinetics of Na + ion in the electrode material can be determined by the Z′–ω −1/2 (ω = 2πf) curves in the low‐frequency region and diffusion coefficient ( D Na , cm 2 s −1 ) can be estimated according to the following formulae …”

A 3D Trilayered CNT/MoSe2/C Heterostructure with an Expanded MoSe2 Interlayer Spacing for an Efficient Sodium Storage

“…The full survey spectrum ( Figure S3, Supporting Information) clearly showed that the Mo, Se, C signals and some traces of O 2 delineated the high purity of the product. [38] Besides, a weak peak at 230.4 eV is also observed in the high-resolution spectrum of Mo, which is attributed to Se 3s. [38] Besides, a weak peak at 230.4 eV is also observed in the high-resolution spectrum of Mo, which is attributed to Se 3s.…”

Hierarchical Tubular‐Structured MoSe2 Nanosheets/N‐Doped Carbon Nanocomposite with Enhanced Sodium Storage Properties

“…[34][35][36][37][38] Recently,s everal research groups have attempted to maximize the sodium-ion storage properties of anodesb yi ntegrating the two strategiesm entioned above. [18][19][20][21][22][23][24][25][26][27][28][39][40][41][42][43] This could significantly improve the structural and physicalp ropertieso f electrode materials to achieve high electrochemical performance. For example, Tu and co-workersp repared 3D carbon-MoSe 2 -reducedg raphene oxide composites through a facile hydrothermalm ethod.…”