Facile CVD Fabrication of Vertically Aligned MoS₂ Nanosheets with Embedded MoO₂ on Molybdenum for High-Performance Binder-Free Lithium-Ion Battery Anodes

Abstract

The demand for compact energy storage devices necessitates the development of high-performance anode materials directly integrated with current collectors, minimizing or eliminating the need for binders or additives. With its layered structure and high theoretical capacity, molybdenum disulfide (MoS 2 ) is regarded as a promising anode material for lithium-ion batteries (LIBs). Here, we report chemical vapor deposition (CVD) growth of self-integrated, vertically aligned MoS 2 nanosheets with embedded molybdenum dioxide (MoO 2 ) directly on a molybdenum foil and explore its potential as an anode material for LIBs. The results show that the formation of the MoO 2 /MoS 2 hybrid structure occurs through partial conversion of the initially grown MoO 2 crystals to MoS 2 layers under controlled sulfurization reactions. The self-integrated hybrid material, devoid of additional conductive or binder agents, exhibits remarkably efficient transfer of ions and electrons, facilitated by the high electrical conductivity of MoO 2 and exposed active sites of MoS 2 . Electrochemical studies reveal an impressive areal capacity of 253 μA h cm −2 for the MoO 2 /MoS 2 hybrid material on a molybdenum foil. In addition, the Li-ion diffusion coefficient value is estimated to be 0.798 × 10 −10 and 1.14 × 10 −10 cm 2 /s for the delithiation and lithiation processes, respectively. The capacity of LIBs can be significantly enhanced by engineering the MoO 2 /MoS 2 anode material, making it a promising candidate for overcoming the limitations of singleanode materials. Our findings show that CVD can be a potential approach toward the fabrication of binder and conducting agentfree anodes directly on current collectors for advanced LIBs.