Polyoxometalate@MOF derived porous carbon-supported MoO2/MoS2 octahedra boosting high-rate lithium storage

Dalton Trans. 2021 Oct 26;50(41):14595-14601. doi: 10.1039/d1dt02475b.

Abstract

Structural stability and rapid charge-discharge capability of electrode materials are required for high performance lithium-ion batteries (LIBs). The materials derived from polyoxometalates (POMs) show special advantages in inhibiting capacity attenuation, and good dispersion or combination of POMs with metal-organic frameworks (MOFs) is an important method to obtain high activity anode composites for LIBs. In this study, a uniform MoO2/MoS2 heterostructure with surface supported carbon (C-MoO2/MoS2) was successfully fabricated from a [Cu2(BTC)4/3(H2O)2]6[H3PMo12O40] precursor, which showed not only the designed octahedral morphology but also fast charge transfer, long working life, and high rate performance. Superior reversible lithium storage capacity of 1047 mA h g-1 after 300 cycles was obtained at 1 A g-1. Even after 700 cycles at 5 A g-1, the discharge specific capacity of 646 mA h g-1 was maintained, and rate capability of 610 mA h g-1 could be achieved at 10 A g-1. The high capacitive contribution could be explained by the relatively large specific surface area of porous C-MoO2/MoS2, which was mainly caused by the supported carbon network and MoS2 nanosheets, resulting in fast lithiation/delithiation processes.