  Current advancements in battery technologies require electrodes to combine
high-performance active material such as Silicon (Si) with two-dimensional
materials such as transition metal carbides (MXenes) for prolonged cycle
stability and enhanced electrochemical performance. More so, it is the
interface between these materials, which is the nexus for their applicatory
success. Herein, the interface strength variations between amorphous Si and
Ti3C2Tx MXene are determined as the MXene surface functional groups (Tx) are
changed using first principle calculations. Si is interfaced with three Ti3C2
MXene substrates having surface -OH, -OH and -O mixed, and -F functional
groups. Density functional theory (DFT) results reveal that completely
hydroxylated Ti3C2 has the highest interface strength of 0.6 J/m2 with
amorphous Si. This interface strength value drops as the proportion of surface
-O and -F groups increases. Additional analysis of electron redistribution and
charge separation across the interface is provided for a complete understanding
of underlying physico-chemical factors affecting the surface chemistry and
resultant interface strength values. The presented comprehensive analysis of
the interface aims to develop sophisticated MXene based electrodes by their
targeted surface engineering.
