Single-crystal Cr2O3nanoplates with differing crystalinities, derived from trinuclear complexes and embedded in a carbon matrix, as an electrode material for supercapacitors.
As one kind of important p-type semiconductors, Cr2O3has been widely used for optical and electronic devices due to its high electrical conductivity and special optoelectronic characteristics, as well as high chemical and thermal stability. In this paper, single-crystalline Cr2O3nanoplates embedded in carbon matrix were successfully synthesized through direct thermal decomposition of a trinuclear cluster complex of [Cr3O(CH3CO2)6(H2O)3]NO3·CH3COOH ([Cr3O]) in Ar atmosphere. The synergetic effect of the plate-like structure and embedding in carbon matrix contributes to the enhanced electrochemical performance of the Cr2O3-C nanoplates. Owing to different crystallinity and composition, the obtained products at 400, 500, 600, and 700°C with different carbon content of 12.52, 8.26, 5.35 and 3.27% exhibited enhanced battery-type electrode materials in three-electrode system with high specific capacitance (823.11, 781.65, 720.72, and 696.73Fg-1at 1Ag-1) and remarkable cycling stability (about 0.3, 2.7, 4.5 and 5.6% loss of its initial capacitance after 5000 charge-discharge cycles at a current density of 5Ag-1). Furthermore, an assembled asymmetric device (Cr2O3-C nanoplates (positive electrode)//activated carbon (AC, negative one)) with an extended operating voltage window of 1.8V achieves a specific capacitance of 58.06Fg-1at the current density of 1Ag-1and an energy density of 26.125Whkg-1at power density of 0.9kWkg-1, as well as superior cycling stability with 91.4% capacitance retention after 10,000 cycles. The results indicate that the Cr2O3nanoplates embedded in carbon matrix show promising potential to construct high-performance energy storage devices.
National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
Jikui
J
Zhu
National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
Yuqian
Y
Jiang
College of Mechanics and Materials, Hohai University, Nanjing 210098, China.
Zhiyong
Z
Lu
National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
Chenglan
C
Zhao
National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
Li
L
Xie
National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China. Electronic address: lychen@cqu.edu.cn.
Lingyun
L
Chen
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing 210009, China. Electronic address: duanjingui@njtech.edu.cn.
Jingui
J
Duan
Asymmetric supercapacitors; Carbon composite; Chromium oxide nanoplate; Electrochemical energy storage; Trinuclear complex