Structural regulation of 1T-MoS2/Graphene composite materials for high-performance lithium-ion capacitors

Heterogeneous composite structures are considered an effective strategy by utilizing the advantages of heterogeneous components. However, the relationship between structural modifications and electrochemical performance remains inadequately understood. In this study, we leveraged DFT calculations to elucidate the key advantages of the 1T-MoS2/Gr heterostructure, including its exceptional electrical conductivity, enhanced Li+ adsorption capabilities, and improved Li+ diffusion kinetics. To synthesize the 1T-MoS2/Gr composite, we developed a facile, one-step hydrothermal method using glucose as a reducing agent, achieving an optimal heterostructure that maximized the synergistic properties of the components. By comparing different levels of graphene content, the relationship between structural regulation and electrochemical performance has been studied, and a remarkably significant heterostructure composite material (1T-MoS2/Gr-0.8) was identified. As the anode material for lithium-ion batteries (LIBs), 1T-MoS2/Gr-0.8 presents excellent cycle performance with 467 mAh g- 1 under the condition (0.5 A g- 1, 600 cycles). Simultaneously, when assembling the lithium-ion capacitor (LIC) device with an activated carbon (AC) cathode, even at a high power density of 11.7 kW kg- 1, the energy density of the 1T-MoS2/Gr-0.8//AC LIC is as high as 137.0 Wh kg- 1. Moreover, the capacity retention rate remains at 89.9 % even after 2000 cycles at 2 A g- 1, demonstrating its candidacy as a high-performance anode material for LICs.