Preparation Of New Active Component / Graphitized Mesoporous Carbon Composites And Its Application In Energy Environment

Lithium ion battery is widely used in portable electron apparatus and cars due to its highlights, such as high voltage, low discharge rate by itself little volume, light weight and nonmemeory effect. The anode material is one of the most important factors in determining the performance of lithium-ion battery. However, the traditional carbon cathode materials with low energy density and poor rate performance are difficult to meet the demand of industry, so the development of new low-cost and high-performance lithium-ion battery cathode materials has important significance to promote the development of new energy industry. Sn/Ti/Si/Fe and other elements and their oxides are new active anode material of high specific capacity, but due to expansion effect during the process of charge and discharge, the cycle performances of these materials are poor. Porous material can lead the formation of "reinforced concrete" structure with active components and effectively alleviate of the volume expansion. Graphitized mesoporous carbon (GMC) is a new type of promising carbon frame material with regular pore structure, excellent stability and electronic conductivity. This paper use Sn/Ti as active components, choose simple methods to load active components nanoparticles onto GMC frame material to develop a new type of practical active GMC based anode materials for lithium-ion batteries.New Sn-GMC nanocomposite with metallic tin nanocrystals embedded into graphitic mesoporous carbon walls has been synthesized via a simple one-step solid-liquid grinding/templating route. X-ray diffraction, nitrogen adsorption-desorption, transmission electron microscopy and thermogravimetric analysis techniques are used to characterize the samples. It is observed that high content of metallic tin nanocrystals with the sizes of3-5nm are well dispersed into the highly conductive graphitic carbon walls, and synthesized tin graphitic mesoporous carbon (Sn-GMC) nanocomposite possesses ordered2D hexagonal mesostructures with moderate surface area (223.9m2/g), large pore volume (0.611cm3/g) and hierarchical porosity. Due to its novel structures, the Sn-GMC nanocomposite exhibits high initial coulombic efficiency, excellent cyclability and rate performance when employed as an anode material in lithium ion batteries.Mesostructured TiO2/graphitic carbon (TiO2-GC) composites were synthesized by a simple one-step nanocasting method. The as-prepared materials were characterized by XRD, TEM and BET. The results show that the mesostructured TiO2-GC composites have a moderate specific surface area (110.28-528.95m2/g) and large pore volume (0.063～0.351cm3/g), which are beneficial for Li+ion diffusion during charge-discharge processes. The electrochemical tests exhibit that the20TiO2-GC composite show more excellent reversibility and cyclability than other proportion of composite materials, it possesses a high initial discharge capacity of1076mAh/g, and the discharge capacity still remains326mAh/g at50th cycle.Lithium ion batteries contain heavy metals such as cobalt, copper, manganese and cadmium, which have great harm to the environment and human health. Thereby, it is very significant to remove the heavy metal ions in the waste water. Mesostructured magnetic Fe@-γFe2O3/graphitic carbon composites were synthesized through a simple one-step nanocasting route using iron nitrate and soybean oil as iron source and carbon precursor, respectively, for the gelation reaction of tetraethyl orthosilicate and citric acid. The ultimately formed magnetic Fe@γ-Fe2O3nanoparticles were homogeneous dispersed into the matrix of mesostructured carbon with graphitic frameworks. Such mesostructured magnetic Fe@γ-Fe2O3/graphitic carbon composites have a high specific surface area (249.44-701.72m2/g), large pore volume (3.56～3.85nm), and high saturation magnetization (1.29～6.92emu/g), giving the materials wide potential applications as catalyst supports or absorbents. Compared with activated carbon, Fe@γ-Fe2O3/GC composites show better adsorption performance of Cu2+and Co2+and good magnetic recoverable capacity.