Danfeng Qiu

In situ growth of NiO nanoparticles on graphene as a high-performance anode material for lithium-ion battery anodes with enhanced strain accommodation

Nickel oxide (NiO) nanoparticles were directly formed on graphene nanosheets through in situ thermal decomposition of Ni(NO3)2·6H2O and were anchored tightly on the graphene surface. During the charge–discharge process, graphene nanosheets served as a three-dimensional conductive network for the NiO nanoparticles. The lithiation-induced strain was naturally accommodated because of the constraint effect of graphene. Thus, pulverization of NiO nanoparticles was effectively prevented.

In-situ synthesize of graphene-Mn3O4 nanocomposites for high-rate pseduocapacitive electrodes

pseduocapacitive electrodes Danfeng Qiu, Xiao Ma, Jingdong Zhang, Bin Zhao, Zixia Lin 1 Key Laboratory of Radar Imaging and Microwave Photonics (Nanjing Univ. Aeronaut. Astronaut.), Ministry of Education, College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China; dfqiu@nuaa.edu.cn (D.Q.); 2792359285@qq.com (X.M.); zhangjd@nuaa.edu.cn (J.Z.) 2 National Laboratory of Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing, China; binzcaptain@gmail.com (B.Z.); 267319441@qq.com (Z.L.) * Correspondence: dfqiu@nuaa.edu.cn; Abstract: Mn3O4 /graphene nanosheets (GNS) composites serve as very excellent electrode materials for supercapacitors. They can fully combine the advantages of two materials such as graphene and metal oxide. Meanwhile, they can improve not only the specific energy and specific power of the materials, but also the cyclic stability of the materials. The results of the cyclic voltammetry and constant current charge discharge test on the composite electrode material have shown that the Mn3O4 /GNS powder sample has good capacitive performance. When the scanning rate is 5~50mV, the specific capacity retention rate of the composite electrode is 80.3% and 88% respectively. Mn3O4 nanoparticles, with the highest ratio of network coated GNS, exhibit a specific capacitance value of 957.6 F g at a current density of 2 A g in 1 M Na2SO4 solution. Besides, its network structure demonstrates high specific capacity and multiplying performance.