Printable Two-Dimensional Nanomaterials: Approaching Low-Cost Electrodes for High-Efficiency Li/Na-Ion Batteries and Photodetectors

Molybdenum disulfide (MoS2)/graphene composites have garnered significant attention as promising materials for high-performance electrodes and optoelectronic devices owing to their exceptional electrochemical and photodetection properties. However, the fabrication of these composite electrodes remains challenging, primarily due to the low yield, suboptimal quality, and structural stability of MoS2 and graphene, which pose significant barriers to their practical applications. Here, a high-performance inkjet-printed flexible electrode based on a MoS2-graphene heterostructure is demonstrated. The process parameters during ejection and the adhesion force between inkjet-printed film and the substrate have been systematically studied. As a result, it allows the rapid and cost-effective production of robust anodes for lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), and high-performance photodetectors. The graphene-MoS2 NF anodes demonstrate remarkable specific capacities of 856 mAh g(-1) after 450 cycles for LIBs and 505 mAh g(-1) after 650 cycles for SIBs at 0.6 A g(-1), exhibiting superior cycling stability and rate capability compared to doctor-blade-coated anodes. The enhanced stability is attributed to the inkjet printing's precise layer-by-layer deposition, leading to better interfacial adhesion and reduced structural degradation during cycling. Moreover, the photodetectors, featuring MoS2 nanosheets (NSs) as the channel and graphene as the electrode, achieve enhanced photocurrents and high on/off ratios with the flexible devices maintaining excellent performance after over 500 bending cycles. These findings underscore the potential of inkjet-printed graphene-MoS2 heterostructures for scalable, durable, and multifunctional applications in energy storage and optoelectronics, showcasing the advantages of high uniformity and rapid low-cost fabrication.