1T-MoS2 nanosheets with enlarged interlayer spacing vertically bonded on rGO for high-performance lithium-ion capacitors

Abstract

1T-MoS 2 nanosheets, with metallic conductivity and high capacity, hold great potential for lithium-ion capacitors (LICs), but suffer from sluggish reaction kinetics due to dense stacking. Herein, 1T-MoS 2 nanosheets with enlarged interlayer spacing, vertically bonded to reduced graphene oxide (rGO) (1T-MoS 2 /rGO), were designed using a hydrothermal-assisted dispersion and intercalation strategy. The active nitrogen species derived from N, N-dimethylformamide (DMF) not only bridge the rGO and MoS 2 through strong Mo-N-C bonds to promote the formation of dispersed MoS 2 nanosheets, but also intercalate into the MoS 2 structure, further enlarging the interlayer spacing. This unique structure synergistically enhances meso- and microscale mass transfer outside and inside of the few-layered nanosheets, significantly improving electrochemical reaction kinetics and reducing the kinetic mismatch between the anode and cathode. Consequently, the resulting 1T-MoS 2 /rGO achieves a capacity of 500 mAh g -1 after 500 cycles at 5 A g -1 and a high rate performance of 587 mAh g -1 at a high rate of 10 A g -1 . Moreover, the assembled 3D vertical 1T-MoS 2 /rGO//AC LIC delivers a high energy density of 100.3 Wh kg -1 at a power density of 1.0 kW kg -1 , and long cycle stability with capacity retention as high as 91.02% after 5000 cycles at 2 A g -1 . This work provides a generalizable strategy for engineering two-dimensional material-based electrodes, offering new insights into high-performance energy storage systems. Vertically aligned evenly distributed 1T-MoS 2 nanosheets with expanded interlayer spacing are bonded to rGO via robust Mo-N-C bonds, synergistically enhancing Li ion/electron transfer for high-performance LICs. • Vertically aligned 1T-MoS 2 nanosheets are uniformly grown on rGO through Mo-N-C bonds • The formation mechanism of 3D vertical 1T-MoS 2 /rGO composites is proposed • The enhanced reaction kinetic is obtained for 3D vertical 1T-MoS 2 /rGO composite • The 3D vertical 1T-MoS 2 /rGO composites deliver excellent electrochemical performance

Topics & Concepts