Sandwich-like Co3O4/MXene composites as high capacity electrodes for lithium-ion batteries†
MXenes have been considered as promising anode materials for lithium-ion batteries (LIBs), owing to their specific surface chemistry, high electron conductivity and large specific surface. However, the low theoretical capacity and restack tendency of layers during the lithiation/delithiation process hinder their further development. In this work, sandwich-like Co3O4/Ti3C2Tx composites were prepared by a simple ultrasound treatment. In the composites, Co3O4 nanoparticles distributed in the interlayers of Ti3C2Tx prevent layers from restacking, enhancing the structural stability of the Ti3C2Tx matrix in the longitudinal direction. Acting as the substrate, Ti3C2Tx not only improves electronic conductivity of the composites but also provides a high specific surface area to load Co3O4 nanoparticles. Besides, the lithiation-induced refining architecture enhances reaction kinetics and provides more active sites. In short, the synergistic effect of Co3O4 and Ti3C2Tx and the effective architecture make the Co3O4/Ti3C2Tx composite with a Co3O4 content of 50% (Co3O4/Ti3C2Tx-3) exhibit remarkable performance. The capacity of Co3O4/Ti3C2Tx-3 remains at 999.3 mA h g−1 after 900 cycles at a current density of 500 mA g−1.