MoS2 nanosheets fixed on network carbon derived from apple pomace for fast Na storage kinetics

Abstract

Molybdenum disulfide (MoS 2 ), as a typical two-dimensional material with high theorical capacity (670 mAh g −1 ), is widely used for electrode material in energy storage systems. However, the inferior electronic conductivity, low stability, and sluggish kinetics make it prone to stack during cycling, resulting in a poor lifespan and rate performance. In this work, a 3D network porous structure MoS 2 /OAPC composite was fabricated by carbonizing biowaste apple pomace (AP) collected from concentrated juice factory, then oxidizing apple pomace carbon (APC), and finally sulfurizing (NH 4 ) 6 Mo 7 O 24 ∙4H 2 O/OAPC preform. The oxidization process ensures rich surface oxygen-containing functional groups on OAPC, which will provide necessary nucleation sites for the growth of MoS 2 , enhance the interfacial bonding strength and effectively avoid the agglomeration of MoS 2 sheets resulting in a stable structure and high conductivity. In addition, the 3D porous connectivity structure provides necessary guarantee for the fast kinetics of sodium transport. Therefore, the MoS 2 /OAPC anode exhibits a high capacity of 601.8 mAh g −1 after 50 cycles at a current density of 0.2 A g −1 . When the current density is as high as 2 A g −1 , a promising rate capacity of 297.2 mAh g −1 can still be maintained. • Porous network MoS 2 /OAPC was synthesized by oxidation and sulfurization of method. • Unique C-O-Mo provides stable bonding between MoS 2 and OAPC during cycling. • The OAPC network skeleton ensures a stable structure and accelerates charge transfer. • The MoS 2 /OAPC electrode exhibited fast sodium storage kinetics.