Rational Design of Hierarchical Nanotubes through Encapsulating CoSe₂ Nanoparticles into MoSe₂/C Composite Shells with Enhanced Lithium and Sodium Storage Performance

Abstract

Transition-metal diselenides have been extensively studied as desirable anode candidates for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) because of their high theoretical capacities. However, it is of great challenge to achieve satisfactory cycling performance, especially for larger sodium ion storage, originated from electrode deterioration upon large volume change. Herein, we reported the construction of hierarchical tubular hybrid nanostructures through encapsulating CoSe nanoparticles into MoSe/C composite shells via a simple two-step strategy including a hydrothermal method followed by vapor-phase selenization process. The unique tubular structure enables the highly reversible Li/Na storage with high specific capacity, enhanced cycling stability, and superior rate performance. It is indicated that the contribution of partial pseudocapacitive behavior greatly improves the rate capability for SIBs, where a high capacity retention of 81.5% can be obtained when the current densities range from 0.1 to 3 A g (460 mA h g at 0.1 A g vs 379 mA h g at 3 A g). This work provides an effective design rationale on transition-metal diselenide-based tubular nanostructures as superior hosts for both Li and Na ions, which could push forward the development of practical applications of transition-metal diselenide-based anodes in LIBs and SIBs.

Facile Synthesis of Ultra‐Small Few‐Layer Nanostructured MoSe2 Embedded on N, P Co‐Doped Bio‐Carbon for High‐Performance Half/Full Sodium‐Ion and Potassium‐Ion Batteries

“…As shown in Figure 5c,t he prolongedc ycling performance and coulombic efficiency of the MoSe 2 /NP-C-2 electrode were investigated at 1a nd 5Ag À1 .I mpressively, the MoSe 2 /NP-C-2 electrode deliversasuperior stable capacity of 276 mAh g À1 at 1.0 Ag À1 after 500 cycles and 192 mAh g À1 at 5.0 Ag À1 even after 1000 cycles, whichi so ne of the bestp erformances for MoSe 2 -based anode materials forS IBs reported so far ( Table S1 in the Supporting Information). [23,25,41,47,52,64,68,76,[79][80][81] The CEs of the MoSe 2 /NP-C-2a node approach9 6% in the second cycle and increased to about1 00 %i nt he subsequentc ycles.T he superior electrochemical performance of the MoSe 2 /NP-C-2 composite could be attributed to the appropriate addition of PMA, so that the few-layered MoSe 2 nanosheets are uniformly dispersed in the N, Pc o-dopedb io-carbon materials.…”

Electrochemical Performance Optimization of Layered P2‐Type Na0.67MnO2 through Simultaneous Mn‐Site Doping and Nanostructure Engineering

“…Benefitting from the dual manipulation of optimized Ni doping level and faceted hollow polyhedron, the NNMO‐FHP cathode exhibits outstanding cycling stability with 96.8 % capacity retention after 120 cycles at the rate of 100 mA g −1 , which is much higher than bulk Na 0.67 Ni 0.15 Mn 0.85 O 2 (48.8 % capacity retention). More importantly, the full cell was further assembled based on NNMO‐FHP cathode and our previously reported CoSe 2 ⊂MoSe 2 /C HNT anode without pre‐sodiation treatment for both electrodes, where promising performance can be achieved with a high energy density of 133.1 Wh kg −1 (at a power density of 20 W kg −1 ), demonstrating its great potential for practical applications.…”

In‐Situ Fabrication of Bone‐Like CoSe2 Nano‐Thorn Loaded on Porous Carbon Cloth as a Flexible Electrode for Na‐Ion Storage

“…As displayed in Figure 5a, an evident cathodic peak at 0.79 and 0.51 V is due to the decomposition of electrolyte and the formation of solid electrolyte interphase (SEI) layer at the first cycle. [16] During the subsequently cathodic sweeps, the three peaks appear at 1.41, 1.19, and 0.59 V correspond to the intercalation of Na + into CoSe 2 crystals (CoSe 2 !Na x CoSe 2 ) and the two conversion steps (Na x CoSe 2 !CoSe + Na 2 Se!Co + Na 2 Se), respectively. [14,27] The distinct anodic peaks appearing on desodiation process at 1.90 V are pertaining to the recombination of Co nanoparticles and Na 2 Se into CoSe 2 .…”

“…[12,13] Furthermore, CoSe 2 is particularly appropriate for Na-ion storage owing to its stable physical and chemical properties as well as earth abundant nature, and has been extensively investigated for SIBs in recent years. [14][15][16] However, low conductivity and large volume expansion of CoSe 2 are ongoing challenges leading to poor cycle stability, which cause the hindrance of potentially commercial applications. [17] Substantial studies have been driven to address the aforementioned issues of similar electrode material.…”