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.