Preparation of hierarchical C@MoS2@C sandwiched hollow spheres for Lithium ion batteries

TL;DR

This paper reports a novel hierarchical C@MoS2@C hollow sphere structure synthesized via a modified template method, enhancing lithium-ion battery performance through improved stability and electron/ion transfer pathways.

Contribution

The study introduces a new synthesis approach for hierarchical C@MoS2@C hollow spheres with enhanced electrochemical properties for batteries.

Findings

High specific capacity (~900 mAh/g after 50 cycles)

Excellent cycling stability up to 200 cycles

Superior rate performance

Abstract

Hierarchical C@MoS2@C hollow spheres with the active MoS2 nanosheets being sandwiched by carbon layers have been produced by means of a modified template method. The process applies polydopamine (PDA) layers which inhibit morphology change of the template thereby enforcing the hollow microsphere structure. In addition, PDA forms complexes with the Mo precursor, leading to an in-situ growth of MoS2 on its surface and preventing the nanosheets from agglomeration. It also supplies the carbon that finally sandwiches the 100-150 nm thin MoS2 spheres. The resulting hierarchically structured material provides a stable microstructure where carbon layers strongly linked to MoS2 offer efficient pathways for electron and ion transfer, and concomitantly buffer the volume changes inevitably appearing during the charge-discharge process. Carbon-sandwiched MoS2-based electrodes exhibit high specific capacity of approximately 900 mA h g-1 after 50 cycles at 0.1 C, excellent cycling stability up to 200 cycles, and superior rate performance. The versatile synthesis method reported here offers a general route to design hollow sandwich structures with a variety of different active materials.