Dimensional Effects of MoS2 Nanoplates Embedded in Carbon Nanofibers for Bifunctional Li and Na Insertion and Conversion Reactions.

ABSTRACT

Controlling structural and morphological features of molybdenum disulfide (MoS2) nanoplates determines anode reaction performance for Li-ion and Na-ion batteries. In this work, we investigate dimensional effects of MoS2 nanoplates randomly embedded in twisted mesoporous carbon nanofibers (MoS2@MCNFs) on Li and Na storage properties. Considering dimensions of the MoS2 nanoplates (e.g., interlayer, lateral distance, and slabs of stacking in number), we controlled thermolysis temperature to synthesize the MoS2 nanoplates with different geometry and optimize them in the hybrid anode for delivering high performance. The MoS2@MCNFs electrode exhibits reversible Li and Na capacities greater than 1000 cycles even at high current density of 1.0 A g-1 (1221.94 mAh g-1 with capacity retention of 95.6% for Li-ion batteries and 447.29 mAh g-1 with capacity retention of 87.11% for Na-ion batteries). We elucidated the insertion, conversion, and interfacial reaction characteristics of the thermosensitive MoS2 nanoplates in the MCNFs, especially associated with a reversible capacity. Our study will hint at rational design of the nanostructured MoS2 electrodes and focus on significance of their dimensional effects on anode performance.