Research Projects

Yunjian Chen PHD Student

Yunjian Chen

Current PhD Student

Electrochemical Devices for Energy Conversion and Storage

Research Project Summary:

The rapid increase in fossil fuel consumption, energy crisis and environmental pollution has stimulated the development of energy storage devices. Compared with other energy storage devices, supercapacitors stand out due to their rapid charge-discharge capability, excellent cycling stability and ultrahigh power density. Supercapacitors could be divided into electric double layer capacitors (EDLCs) and pseudocapacitors. The pseudocapacitors could achieve higher specific capacity and energy density compared with EDLCs.

Among the pseudocapacitors, Co3O4 as an ideal electroactive material for supercapacitors due to its superior theoretical specific capacitancem, splendid redox activity, excellent stability, low cost and environmentally friendly. However, the low electrical conductivity and low power density of Co3O4 as an electrode limits the specific capacitance and rate performance of supercapacitors. most Co3O4 based electrode materials are still far from the theoretical capacitance. Hence, overcoming the drawbacks of Co3O4 based electrodes materials is urgent.

Bio:

Yunjian obtained a bachelor in Chemistry from University of Electronic and Science of China, which focused on energy conversion and storage. Yunjian started his PhD of materials science and engineering in 2019 in University of Electronic and Science of China and joined in Nano-Bio Group in 2021. Yunjian possess many materials synthesize methods, which include hydrothermal method, electrodeposition and sol-gel methods. Besides, Yunjian also possess a wide range of analytical skills, which include scanning electronic microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), N2 adsorption and desorption isotherms (BET), Raman spectrometer, UV-visible spectrometer and electrochemical workstation.

Papers

Yunjian Chen, Haohui Hu,Ni Wang*, Baolong Sun, Mengqi Yao and Wencheng Hu*, Cu(I)/Cu(II) partially substituting the Co(II) of spinel Co3O4 nanowires with 3D interconnected architecture on carbon cloth for high-performance solid-state supercapacitors, Chem. Eng. J., 2020, 391, 123536.

Yunjian Chen, Jia Zhu*, Ni Wang, Huanyu Cheng, Xianzhong Tang, Sridhar Komarneni* and Wencheng Hu*, Significantly improved conductivity of spinel Co3O4 porous nanowires partially substituted by Sn in tetrahedral sites for high-performance quasi-solid-state supercapacitors, J. Mater. Chem. A, 2021, 9, 7005-7017.

Yunjian Chen, Ni Wang*, Wencheng Hu and Sridhar Komarneni*, In situ construction of Ni/Co-MOF@Carbon cloth electrode with honeycomb-like structure for high-performance energy storage, J. Porous Mat., 2019, 26, 921-929.

Yunjian Chen, Bo Wu, Baolong Sun, Ni Wang*, Wencheng Hu, and Sridhar Komarneni*, N-doped porous carbon self-generated on nickel oxide nanosheets for electrocatalytic N2 fixation with a Faradaic efficiency beyond 30%, ACS Sustain. Chem. Eng., 2019, 7, 18874-18883.

Presentations

In situ fabrication of mesoporous NiO@ Graphite paper electrode with multilayered nanosheet wall structures for high-performance supercapacitors