  MXene and its derivatives have attracted considerable attention for potential
application in energy storage like batteries and supercapacitors owing to its
ultrathin metallic structures. However, the complexity of the ionic and
electronic dynamics in MXene based hybrids, which are normally needed for
device integration, triggers both challenges and opportunities for its
application. In this paper, as a prototype of metallic hybrids of MXene,
heterostructures consisting of Ti3C2T2 (T= None, O and F atoms) and metallic
MoS2 (1T phase) are investigated. Through density functional theory, we
investigate the interfacial electronic variation, thermal activation, and anode
performance in the lithium-ion battery (LIB) of Ti3C2T2/1T-MoS2. We found that
different surface atomic groups in MXene can significantly alter the affinity,
redox reaction and kinetics of Li atoms in the interface of the Ti3C2T2 and
1T-MoS2. Through examining the three possible pathways of Li by climbing
image-nudged elastic band (CI-NEB) and ab-initio molecular dynamics (AIMD)
simulation, the diffusion curve becomes significantly flattened from the naked
to O- and F-terminated Ti3C2 MXene with activation barriers reducing from 0.80
to 0.22 and 0.29 eV, respectively, and room-temperature diffusion coefficients
increasing from 1.20x10-6 to 2.75x10-6, 1.70x10-4 cm2 s-1, respectively. The
functionalization with O or F eliminates the steric hindrance of Li
intercalation by breaking the strong interaction between two layers and
provides additional adsorption sites for Li diffusion in the meantime. Our work
suggests that surface functional groups play a significant role in
Ti3C2T2/1T-MoS2 modification and Ti3C2F2/1T-MoS2 with the high diffusion
coefficient and theoretical capacity could be a promising anode material for
LIBs.
