Titanosilicate Derived SiO2/TiO2@C Nanosheets with Highly Distributed TiO2 Nanoparticles in SiO2 Matrix as Robust Lithium Ion Battery Anode

Carbon-coated SiO₂/TiO₂ (SiO₂/TiO₂@C) nanosheets consisting of TiO₂ nanoparticles uniformly embedded in SiO₂ matrix and a carbon-coating layer are fabricated by using acidified titanosilicate JDF-L1 nanosheets as template and precursor. SiO₂/TiO₂@C has unique structural features of sheetlike nanostructure, ultrafine TiO₂ nanoparticles distributed in SiO₂ matrix, and carbon coating, which can expedite ion diffusion and electron transfer and relieve volume expansion efficiently, and thus, the synergetic combination of these advantages significantly enhances its Li storage capability. As anode of lithium-ion batteries (LIBs), SiO₂/TiO₂@C nanosheets exhibit a high capacity of 998 mAh g^-1 at 100 mA g^-1 after 100 cycles. Moreover, an ultrahigh capacity of 410 mAh g^-1 retains at 2000 mA g^-1 after 400 cycles. A mixed reaction mechanism of capacitance and diffusion-controlled intercalation is revealed by qualitative and quantitative analysis.