3D Interconnected and Multiwalled Carbon@MoS₂@Carbon Hollow Nanocables as Outstanding Anodes for Na-Ion Batteries

Abstract

Currently, the specific capacity and cycling performance of various MoS /carbon-based anode materials for Na-ion storage are far from satisfactory due to the insufficient structural stability of the electrode, incomplete protection of MoS by carbon, difficult access of electrolyte to the electrode interior, as well as inactivity of the adopted carbon matrix. To address these issues, this work presents the rational design and synthesis of 3D interconnected and hollow nanocables composed of multiwalled carbon@MoS @carbon. In this architecture, (i) the 3D nanoweb-like structure brings about excellent mechanical property of the electrode, (ii) the ultrathin MoS nanosheets are sandwiched between and doubly protected by two layers of porous carbon, (iii) the hollow structure of the primary nanofibers facilitates the access of electrolyte to the electrode interior, (iv) the porous and nitrogen-doping properties of the two carbon materials lead to synergistic Na-storage of carbon and MoS . As a result, this hybrid material as the anode material of Na-ion battery exhibits fast charge-transfer reaction, high utilization efficiency, and ultrastability. Outstanding reversible capacity (1045 mAh g ), excellent rate behavior (817 mAh g at 7000 mA g ), and good cycling performance (747 mAh g after 200 cycles at 700 mA g ) are obtained.

Interlayer Nanoarchitectonics of Two‐Dimensional Transition‐Metal Dichalcogenides Nanosheets for Energy Storage and Conversion Applications

“…Such 3D-HCNFs@MoS 2 @carbon electrode exhibits outstanding reversible capacity (1045 mA h g −1 at current of 35 mA g −1 ), excellent rate behavior (817 mA h g −1 at 7 A g −1 ), and good cycling performance (747 mA h g −1 after 200 cycles at 700 mA g −1 ), which are significantly higher than those of the bulk MoS 2 anode. [113] The above mentioned MX 2 /C composite nanostructures usually have limited MX 2 /C heterointerfaces and interlayer expansion of MX 2 nansheets requires certain additional conditions. Atomic interface engineering of layered MX 2 nanosheets and carbon materials should be further considered to improve intrinsic conductivity and achieve interlayer expansion of MX 2 simultaneously.…”

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

“…Most of the reported MoS 2 electrode materials are in the powder form and thus require current collector, binder, and conductive agent for their fabrication. [62] Table S5 in the Supporting Information provides a comparison of our trilayered CNT/MoSe 2 /C hybrid with common MoS 2 -based composites. [62][63][64][65][66][67][68] In contrast, our 3D trilayered CNT/MoSe 2 /C framework is freestanding as it used the bulk CNT framework as a template to grow MoSe 2 layers.…”

Hollow Structured Carbon@FeSe Nanocomposite as a Promising Anode Material for Li‐Ion Batteries

“…During the following positive-going scan, the significant oxidation peak at 1.9 V results from the extraction of Li-ions accompanied by the formation of Li x FeSe; the other small peak at 2.25 V indicates the further deintercalation of Li-ion from Li x FeSe to form FeSe. [35][36][37] For practical application in portable electronic devices and electric vehicles, a stable working voltage of LIBs, depending on the working potential of both the cathode and anode, is always required. [30] The initial three galvanostatic discharge/charge profiles of SÀ C@FeSe and TÀ C@FeSe in the potential region of 0.01-3 V at the current rate of 0.1 C (1 C = 800 mA g À 1 ) are shown in Figure 5b.…”

“…Some conversion-type anode materials such as metal oxides and sulfides exhibit poorly defined potential plateau. [35][36][37] For practical application in portable electronic devices and electric vehicles, a stable working voltage of LIBs, depending on the working potential of both the cathode and anode, is always required. It can be seen that the carbon@FeSe electrodes possess high capacity and meanwhile exhibit obvious discharge/charge plateaus.…”