Qingtang Zhang

Incorporation of MnO nanoparticles inside porous carbon nanotubes originated from conjugated microporous polymers for lithium storage

Porous carbon nanotubes (PCNTs) were synthesized and incorporation of MnO nanoparticles inside PCNTs (MnO–PCNTs) was successfully achieved by simple pyrolysis of conjugated microporous polymer (CMP) nanotubes and manganese acetate adsorbed CMP nanotubes, respectively. PCNTs exhibit good performance as anode materials for lithium ion batteries. The performance of PCNTs can be further enhanced by incorporation of MnO nanoparticles. MnO–PCNTs show excellent cycling stability (572.6 mA h g−1 after 300 cycles at 1C) and large rate performance (160.8 mA h g−1 at 30C), which are much higher than carbon nanotubes (CNTs) supported MnO composites (MnO–CNTs). This may be due to the unique structure of MnO–PCNTs, where MnO nanoparticles are located inside the tubes, preferably resolving the pulverization issue of MnO during repeated charge–discharge cycles.

Fabrication of a fayalite@C nanocomposite with superior lithium storage for lithium ion battery anodes

A fayalite (α-Fe2SiO4)@C nanocomposite is successfully fabricated by a solid state reaction under the flow of nitrogen gas. The fayalite@C nanocomposite delivers a high specific capacity, excellent rate capability and good cycling performance as an anode material for lithium ion batteries (LIB). The initial discharge capacity and reversible charge capacity of the fayalite@C nanocomposite at 0.1 C reach up to 849.0 mA h g−1 and 514.5 mA h g−1, respectively. The capacity ratio of 2 C/0.5 C is 90% indicating the excellent rate performance of the fayalite@C anode. In addition, the fayalite@C anode retains 84.3% of its original capacity after 100 cycles at 1 C. Taking into account the low cost and simple fabrication process, this kind of abundant mineral silicate has great potential for next generation LIB.

Novel MnO/conjugated microporous polymer derived-porous hard carbon nanocomposite for superior lithium storage

A MnO/porous hard carbon (PHC) nanocomposite was prepared by thermolysis of the conjugated microporous polymer incorporated with Mn(CH3COO)2. The results obtained from scanning electron microscopy, transmission electron microscope and Brunauer–Emmett–Teller analysis show that MnO nanocrystals are uniformly dispersed in the PHC matrix. The rate performance of MnO/PHC electrode at current rates over 5 C is remarkably higher than that of MnO electrode. After 200 charge/discharge cycles, the capacity retention ratio of the MnO/PHC electrode still reaches up to 91.1%. Such a unique performance of the MnO/PHC nanocomposite makes it a promising candidate as an anode material for high performance lithium ion batteries.

Synthesis of novel porous graphene nanocomposite and its use as electrode and absorbent

A novel three-dimensional nanostructured porous graphene nanocomposite was synthesized by sol–gel polymerization of hydroquinol (H) and formaldehyde (F) with sodium carbonate as a catalyst in graphene oxide (GO) suspension, followed by carbonization of HF and thermal reduction of GO to graphene at high temperature. The resulting material shows a BET surface area of 427 m2 g−1 and a total volume of 1.2764 cm3 g−1 with abundant mesopores. The porous graphene nanocomposite (HFG) can be used as anode for lithium ion batteries due to the porosity and thermal stability. Also, with the strong surface hydrophobicity, high mesopore ratio and pore volume, the HFG shows good absorption capacity for various organics, which makes the HFG a candidate for removal of organic contaminants from water.