Coupling ultrafine SiO2 nanoparticles with three-dimensional porous Ti3C2Tx MXene as anode materials for high-performance lithium-ion batteries

Silicon dioxide with high-capacity and abundant resource is regarded as a promising anode material for lithium-ion batteries, but the poor intrinsic electrical conductivity and large volume change during the discharge/charge cycles impede its practical application. Herein, a three-dimensional porous composite of Ti3C2Tx@SiO2 was fabricated with a low-temperature liquid phase method, and the ratio of SiO2 and Ti3C2Tx was regulated. The as-prepared A-MX@SiO2-2 with the optimal composition exhibits the best cycle performance (437.9 mAh g−1 after 1000 cycles at 0.1 A g−1) and rate performance (130.0 mA h g−1 at 2 A g−1), which are much higher than pure SiO2 and MXene. The excellent electrochemical performance can be ascribed to the synergistic effect of ultrafine SiO2 nanoparticles and three-dimensional porous Ti3C2Tx, which can shorten the Li+ transport pathway, accelerate electron transfer, and relieve the stress caused by the volume expansion of SiO2. The composite structure effectively inhibits both the aggregation of SiO2 and restacking of Ti3C2Tx. Furthermore, the in-situ formed SiO2 can firmly anchored on the surface of Ti3C2Tx nanosheet by robust interfacial bonding, which enhances the structural stability and conductivity. This research provides a feasible design strategy for synthesis of Ti3C2Tx@SiO2 composite to be employed as advanced energy storage materials.