Advances in MoS₂based Hollow Structural Materials for High‐Performance Metal‐Ion Batteries

Abstract

The construction of a hollow structure could promote the diffusion of electrons and ions to improve the electrochemical performance of MoS2 based materials for metal‐ion batteries. Herein, we summarize the preparation technique of MoS2 hollow structural materials with different dimensions. The approaches to construct 0D hollow MoS2 materials for electrodes of metal‐ion batteries can be divided into the hard template approach, soft template approach, self‐template approach, and template‐free approach. Among them, the hard template approach and self‐sacrifice template approach are controllable but complicated, the soft template approach and template‐free approach are simple and scalable but not controllable. Furthermore, as the electrode material of metal‐ion batteries including lithium‐ion battery, sodium‐ion battery, potassium‐ion battery or magnesium‐ion battery, the 0D hollow structural MoS2 based materials could improve the diffusion kinetics of ion and electron and restrict the stack of MoS2. Furthermore, the 1D hollow MoS2 can provide oriented electron diffusion along with the axial direction, and the 3D hollow MoS2 can offer perforative pores for permeation of electrolytes and more active sites, which results in excellent rate capability and cycling stability. This paper could give inspiration for constructing MoS2 hollow structural materials with different dimensions and provide a constructive suggestion for synthesizing hollow materials with excellent electrochemical performance.

Fe3O4/Fe/FeS Tri‐Heterojunction Node Spawning N‐Carbon Nanotube Scaffold Structure for High‐Performance Sodium‐Ion Battery

“…Meanwhile, according to Fe2p, S2p, and O1s high-resolution of XPS analysis as shown in Figure 6b-d, during the discharging process, the Na x FeS 2 was generated, and the peak intensity attributed to Na 2 S 2 O 3 resulted from reactions between Fe 3 O 4 , FeS, and Na was increased along with the decrease of peak intensity corresponding to Fe-O bond. [53,54] Thus, the formation of Fe 3 O 4 /Fe heterojunction can increase the adsorption of Fe 3 O 4 with Na n S 2 intermedium generated from the reaction between FeS and Na to restrain the shuttle effect, which improved cycling stability. Fourthly, the unique scaffold structure possessed excellent mechanical stability, which prevented aggregation of Fe 3 O 4 /Fe/FeS particles and relieved the volume expansion during the discharging process.…”

“…As shown in Figure 5g, compared to pure Fe 3 O 4 , the d band energy center of Fe 3 O 4 /Fe heterojunction shifted to high energy, which was beneficial to bonding between Fe in Fe 3 O 4 and S in Na n S 2 . [ 53,54 ] Thus, the formation of Fe 3 O 4 /Fe heterojunction can increase the adsorption of Fe 3 O 4 with Na n S 2 intermedium generated from the reaction between FeS and Na to restrain the shuttle effect, which improved cycling stability. Fourthly, the unique scaffold structure possessed excellent mechanical stability, which prevented aggregation of Fe 3 O 4 /Fe/FeS particles and relieved the volume expansion during the discharging process.…”