Preparation And Electrochemical Energy Storage Performances Of Transition Metal Oxide Electrode Materials

Under the circumstance of energy and resources crisis, one of the most serious problems need to be solved is to search for high-power, low-cost and environmentally friendly energy storage devices. Among various energy storage devices, electrochemical capacitors, also called supercapacitors, have been extensively studies, which is a new kind of energy storage device combining the features of conventional capacitors (high power density, long cycling life) and rechargeable batteries (high energy density). Various applications in electric equipment and hybrid electric vehicles make electrochemical capacitors highly desirable. In the present work, we investigate the synthesis and the electrochemical performances of base metal oxides for pseudo capacitors. We fabricated the composite transition metal oxides with nanostructure, which can improve the organizational structure and the electrochemical properties of supercapacitor electrode, as well as reduce the cost.We have illustrated a fast and facial hydrothermal method for the growth of MnCo2O4 nanowire array. The MnCo2O4 nanowire array exhibits noticeable pseudocapacitive performance with a high capacitance of 349.8 F g-1 at 1 A g-1 and 328.9 F g-1 at 20 A g-1 as well as excellent cycling stability. As an anode material for LIBs, the MnCo2O4 nanowire array delivers an initial specific discharge capacity of 1288.6 mAh g-1 at 100 mA g-1, with capacity retention of 92.7% after 50 cycles. The excellent electrochemical performances are due to the nanowire architecture. The MnCo2O4 nanowire array is a promising electrochemical energy storage material for supercapacitor and LIBs applications.Highly crystalline Mn-Ni-Co ternary oxide nanowire array was synthesized by a facile hydrothermal method. The MNCO nanowire array electrode delivers noticeable pseudo-capacitive performance with a high capacitance of 638 F g-1 at 1 A g-1 and a capacitance retention of 95.9% after 4000 cycles. To be more practical application, a novel and durable ASC on MNCO//C is fabricated, the device shows electrochemical capacitance performance within voltage range of 0-1.5 V and exhibits high specific capacitance from 109.9 F g-1 to 60.7 F g-1 as the current density increasing from 0.1 F g-1 to 5 A g-1, as well as high energy density and good electrochemical stability. The MNCO nanowire array is expected to be promising candidate for application in high-performance electrochemical capacitors and the as-fabricated ASC also shows great potential in developing energy storage devices with high energy and power densities.