The Preparation And Properties Of Carbon-based Composite Materials With High Photovoltaic Conversion And Energy Storage

Traditional solar cells only have the function of energy conversion and lack electron storage directly, making the application’s of solar cells limited in a large extent. In our paper, we use the in-situ method to obtain uniformly dispersed TiO2/carbon aerogel composite as the anode material and achieve the integration by a single component containing both solar energy conversion and electron storage, which will greatly promote the development of photovoltaic cells to a wide range of applications. We also use SBA-15 as a template to prepare cathode materials of lithium-sulfur batteries and obtain regular structure S/carbon aerogel composite samples. Then, we use the X-ray diffraction,UV-visible absorption test, field emission scanning electron microscopy and field emission transmission electron microscopy and other analytical methods to characterize the morphology and structure of the samples. Cyclic voltammetry, AC impedance, charge and discharge cycles et al are tested to characterize the battery performances.The results show that the TiO2/carbon aerogel composite prepared in situ under the sintering temperature of 550℃, shows uniform spherical porous structure. Wherein, TiO2 and carbon aerogel distribute uniformly with the TiO2 average crystals diameter of ～7nm and the lattice spacing of 0.35 nm, and has a high specific surface area of 556.1 m2g-1. Electrochemical tests show that an efficient photovoltaic cell with energy conversion and electron storage has been successfully prepared, and exhibits excellent electrochemical properties with the highest open-circuit photo voltage of 750 mV, the maximum short-circuit current density of 15.3 mA cm-2 and the capacity retention rate of 88% after 50 cycles. SBA-15 plays a key regulatory role in the preparation of the S/carbon aerogel composite. The prepared S/carbon aerogel composite has the morphology like lotus root in the best ratio of sulfur and carbon aerogel, with the average length of ～650nm and the diameter of ～300 nm. Electrochemical tests show that the discharge capacity can reach to 1572 mAh g-1 at 0.5 C, and still remain 1140.7 mAh g-1 after 50 cycles, keeping the capacity retention rate of 72.5%.