Sn and 3D reticular TiO2 composite flexible electrodes synergistically electrochemical lithium storage

People have an urgent need for high energy density and high current charging of lithium-ion batteries (LIBs). Although TiO2 exhibits attractive high-current charging characteristics as an anode material for lithium-ion batteries, its application is limited by its poor conductivity and low capacity. In this paper, 3D nanometer reticular TiO2 (r-TiO2) will be grown on a Ti substrate by hydrothermal method, and then high-conductivity and high-capacity Sn metal will be deposited on the r-TiO2 structure by electroless plating modification technology. And finally, the sn-loaded 3D nanometer reticular TiO2 composite (r-Sn/TiO2) will be prepared. TiO2 is grown on a Ti substrate, avoiding complex mixing of binders and conductive additives, which can enhance charge transfer. Using a simple electroless plating modification technique, the combination of r-TiO2 and Sn can effectively increase the capacity of the composite electrode while also improve poor conductivity of r-TiO2. The electrochemical performance results, the formation of r-Sn/TiO2 enlarged the specific surface area of the whole electrode, and the specific capacity increased by 140 mAh/g, especially the r-Sn/TiO2 electrode can show an excellent rate capability of 92 mAh/g at a high current density of 6400 mA g−1. The calculation results, proved that the coefficient of diffusion of r-Sn/TiO2 lithium-ions (DLi = 4.63 × 10-13 cm2 s−1) is twice that of TiO2 (DLi = 2.5 × 10-13 cm2 s−1). The Sn metal of r-TiO2 is alloyed with lithium, thereby improving the conductivity of TiO2 while achieving higher discharge capacity and rate capability. And the network structure of r-Sn/TiO2 buffers the volume expansion of Sn, accelerates lithium ions diffusion and the synergistic effect of pseudocapacitive properties brought by high specific surface area.