Si/TiO₂ carbon fiber core encapsulated in hierarchical multiple MXene@Co-MoS₂ shells for constructing a free-standing anode of lithium storage

Silicon-based (Si-based) materials offer more possibilities for generating new portable electronic devices due to their high specific capacities. However, their inferior electrical conductivity and volume expansion during cycling seriously limit their development. The optimum solution is to select specific materials to establish an exceptionally conductive and volume buffer structure, which can assist Si materials in developing their excellent lithium storage properties. In this study, Si particles were confined in TiO₂ carbon fibers (TiO₂ CFs) via electrospinning, after which they were encapsulated with MXene and Co-MoS₂ (CMS) nanosheets to fabricate hierarchical ST-2@MXene@CMS films. TiO₂ CF, MXene and CMS were employed to establish a coherent conductive network with one-, two- and three-dimensional electronic pathways to permit the unimpeded flow of electrons inside the electrode material. TiO₂ CF, MXene and CMS acted precisely as multilayered buffers to ameliorate the volume change of Si particles during cycling. In addition, the CMS nanosheets were involved in lithium storage, contributing to the final electrochemical performance. Ultimately, the ST-2@MXene@CMS films served as free-standing electrodes, avoiding the impact of inactive interfaces on the electrochemical performance and fulfilling the lightweight requirement for new energy storage devices. Graphical abstract: (Figure presented.)