摘要:
The present invention provides an asymmetric hybrid capacitor, in which metal oxide containing lithium and capable of producing lithium ions by an electrochemical reaction and supplying the lithium ions in an electrolyte in the capacitor is used as a positive electrode active material, and metal oxide capable of accepting the lithium ions supplied through the electrolyte is used as a negative electrode active material, such that the lithium ions of the same participate in the electrochemical reactions at both electrodes. As a result, it is possible to minimize reduction in ionic conductivity during charge/discharge, compared with conventional asymmetric hybrid capacitors, in which metal oxide and a carbon material are used as electrode materials, respectively. Moreover, since metal oxide having high specific capacitance is used to form both electrodes, it is possible to maximize energy density and power density.
摘要:
A method for the synthesis of nanocomposites is provided. The method comprises the steps of mixing carbon nanotubes with a urea solution to form urea/carbon nanotube composites (first step), mixing the urea/carbon nanotube composites with a solution of a metal oxide or hydroxide precursor to prepare a precursor solution (second step), and hydrolyzing the urea in the precursor solution to form a metal oxide or hydroxide coating on the carbon nanotubes (third step). Further provided are nanocomposites synthesized by the method. In the nanocomposites, a metal oxide or hydroxide is coated to a uniform thickness in the nanometer range on porous carbon nanotubes. Advantageously, the thickness of the coating can be easily regulated by controlling the urea content of urea/carbon nanotube composites as precursors. In addition, the nanocomposites are nanometer-sized powders and have high electrical conductivity and large specific surface area. Therefore, the nanocomposites are useful as electrode active materials for electrochemical capacitors, including pseudo capacitors and electrochemical double layer capacitors, lithium secondary batteries, and polymer batteries. Further provided is a capacitor comprising the nanocomposites.
摘要:
There is provided a method for manufacturing a lithium manganese oxide-carbon nano composite by mixing a lithium ion solution with a manganese ion solution, dispersing a carbon material in the solution in which the lithium ion is mixed with the manganese ion, and forming the lithium manganese oxide on a surface of the carbon material by maintaining the solution in which the carbon material is dispersed at a predetermined temperature. In addition, there is provided the lithium manganese oxide-carbon nano composite formed by coating the carbon material with the lithium manganese oxide at a thickness of several nm. There is provided a manufacturing apparatus capable of coating the carbon material with the lithium manganese oxide at a thickness of several nm.
摘要:
A method for the synthesis of nanocomposites is provided. The method comprises the steps of mixing carbon nanotubes with a urea solution to form urea/carbon nanotube composites (first step), mixing the urea/carbon nanotube composites with a solution of a metal oxide or hydroxide precursor to prepare a precursor solution (second step), and hydrolyzing the urea in the precursor solution to form a metal oxide or hydroxide coating on the carbon nanotubes (third step). Further provided are nanocomposites synthesized by the method. In the nanocomposites, a metal oxide or hydroxide is coated to a uniform thickness in the nanometer range on porous carbon nanotubes. Advantageously, the thickness of the coating can be easily regulated by controlling the urea content of urea/carbon nanotube composites as precursors. In addition, the nanocomposites are nanometer-sized powders and have high electrical conductivity and large specific surface area. Therefore, the nanocomposites are useful as electrode active materials for electrochemical capacitors, including pseudo capacitors and electrochemical double layer capacitors, lithium secondary batteries, and polymer batteries. Further provided is a capacitor comprising the nanocomposites.