Research Interests: 1. CVD synthesis of 2D materials including graphene, MoS2 and other TMDC.
2. 3D carbon based material in electrochemcial applciation including supercapacitor and hydrogen evolution reaction.
3. multiscale simulation (FEA, DFT, MD)of mechanical, electrical, and optical properties of graphene.Job Interests: Academic
Xining Zang received her B.E. degree in Materials Science and Engineering from Shanghai Jiao Tong University in 2012. She has been pursuing her PhD degree in Mechanical Engineering from UC Berkeley since 2012.
3D Carbon-Based Materials for Electrochemical Applications [BPN742]
We design and develop both the electrode and electrolyte to address a new energy storage system with high energy and high power density. TiS¬2 is the cheapest and lightest sulfate in the transition metal di- chalcogenide (TMDC) family, with the highest energy storage potential as lithium-ion battery anode material. In this paper, TiN coated onto carbon nanotube (CNT) by atomic layer deposition is converted to TiS2 annealing in sulfur vapor flow. Combining the high surface area and high conductivity induced by CNT and the interlayer ion storage of TiS2, the hybrid material results in a specific capacitance of ~170F/cm3 (roughly 170F/g). We introduce the salt lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) which has only been applied in Li+ battery before in aqueous supercapacitors, and prove a working voltage of 3 V which not only breaks the water splitting limit of 1.23 V but also power the energy density up to 212 Wh/kg. Cyclic voltammetry test of TiS2/CNT LiTFSI cell shows the character of supercapacitors, while TiS2 intercalation with Li+ introduce battery character instead of redox reaction in pseduocapacitors. Addressing this hybrid supercapacitor-battery, highest power density and energy density based on aqueous electrolyte. LiTFSI, the water in salt electrolyte is also dissolve in PVA/H2O gel to make semi solid state electrolyte for device assembly. Flexible supercapacitors-battery based on the LiTFSI with symmetric double electrode performs at 2.5 V with a high device projection capacitance of ~ 60mF/cm2.