Jicui Dai

Nafion-sulfonated organosilica composite membrane for all vanadium redox flow battery

A novel Nafion-sulfonated diphenyldimethoxysilane (N-sDDS) composite membrane is prepared and employed in vanadium redox flow battery (VRB). Ion exchange capacity, proton conductivity, water transport behavior, and the cell performances are characterized. Fourier transform-infrared and X-ray diffraction analysis indicate that the sulfonated diphenyldimethoxysilane (sDDS) particles are successfully introduced into the Nafion matrix. In VRB single cell test, the VRB with N-sDDS membrane exhibits nearly the same coulombic efficiency as the unmodified Nafion membrane, but higher voltage efficiency than that of the VRB with unmodified Nafion membrane. The VRB with N-sDDS composite membrane keeps a stable performance after 60 times charge–discharge test. In the self-discharge test, the VRB with the N-sDDS membrane presented a lower self-discharge rate than that of the VRB with Nafion membrane. All results show that the addition of s-DDS is a simple and efficient way to improve the conductivity of Nafion, and the composite membrane shows good potential use for VRB.

Preparation of a novel carbon nanofiber as a high capacity air electrode for nonaqueous Li-O2 batteries

A new carbon nanofiber codoped with nitrogen and phosphorus (NPCNF) that has a high specific surface area and good electrocatalytic properties for the oxygen reduction reaction (ORR) was synthesized using a template‐free method. The fabrication process involves the pyrolysis of phytic acid doped polyaniline aerogel. A nonaqueous Li‐O2 battery with a specific capacity as high as 12 607 mA h g−1 was constructed by using an oxygen electrode based on NPCNFs supported by Ni foam. The NPCNF electrode showed a lower overpotential than pure carbon. The observed excellent electrochemical performance could be because of the unique foamlike N‐ and P‐codoped carbon microstructure, which had a high ORR catalytic activity. These results indicate that the use of NPCNF as a cathode material could be a feasible approach to obtain a high‐capacity Li–O2 battery.