Structural capacitors are composite structures that function as energy storage capacitors. Parallel plate-type capacitors have the advantage of high voltage resistance, but are limited by low capacitance. An electric ...Structural capacitors are composite structures that function as energy storage capacitors. Parallel plate-type capacitors have the advantage of high voltage resistance, but are limited by low capacitance. An electric double-layer capacitor with a composite structure using a solid polymer electrolyte matrix with a glass fiber fabric separator has recently been developed. However, the solid polymer electrolyte caused the capacitor to possess high internal resistance. In the present study, a new design of supercapacitor using a form core sandwich with high water retention is proposed and experimentally investigated. Activated carbon sheets are used as electrodes on the form core sandwich to make a supercapacitor. Woven carbon fabric is used as lead wires of the supercapacitor. The resulting supercapacitor displays a low surface resistance of 810 Ωcm2 and high areal capacitance of 520 mF/cm2.展开更多
Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmissio...Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmission electron microscope, and energy dispersive spectroscopy （EDS）. As the milling time extends, the dielectric constant of the ceramics increases, whereas the temperature coefficient of capacitance at 125℃ drops quickly. The changes in dielectric properties are considered relevant to the microstructure evolution caused by the milling process. Defects on the surface of BaTiO3 particles increase because of the effects of milling process, which will make it easier for additives to diffuse into the interior grains. As the milling time increases, the shell region gets thicker and the core region gets smaller; however, EDS results show that the chemical inhomogeneity between grain core and grain shell becomes weaker.展开更多
Output voltage is an important performance characteristic of planar insulating core transformer (PICT).In PICT magnetic cores are insulated from their neighboring magnetic cores by solid insulating materials.Solid ins...Output voltage is an important performance characteristic of planar insulating core transformer (PICT).In PICT magnetic cores are insulated from their neighboring magnetic cores by solid insulating materials.Solid insulating materials can increase leakage flux.This results in a low generated voltage in secondary coils,especially on the upper stages.Connecting flux compensation capacitors to secondary coils can compensate the flux loss.Design equations to calculate the flux compensation capacitors value and relevant simulation by CST and Protel software were presented.Simulation results of an actual PICT showed that output voltage increased by 19% after being connected to flux compensation capacitors and the voltage on every stage was equally distributed.Results of simulation were consistent with the following experimental test,which revealed that flux compensation capacitors were effective.展开更多
Structural capacitors are composite structures that function as energy storage capacitors. An electric double-layer capacitor with a composite structure using a solid polymer electrolyte matrix with a glass fiber fabr...Structural capacitors are composite structures that function as energy storage capacitors. An electric double-layer capacitor with a composite structure using a solid polymer electrolyte matrix with a glass fiber fabric separator has recently been developed. In the present study, new foam core sandwich structure is adopted and the effect of the degree of cure is experimentally investigated. Carbon fiber fabric cloth is used as electrodes, and the polystyrene foam core is used as separator. Material system of Poly Ethylene Glycol DiGlycidyl Ether (PEGDGE) with Lithium bisTriFluoromethane Sulfonyl Imide (LiTFSI) and hardener of TriEthylene TetrAmine (TETA) is adopted as ion-conductive polymer matrix. The effect of the cure degree is experimentally investigated by using 100% cure degree, 70% cure degree and 0% cure degree specimens. As a result, the polystyrene foam-core sandwich system is proved to be effective, but the capacitance is not enough because of the lack of surface area of the carbon fiber electrodes. As the remained TETA impedes the movement of Li<sup>+</sup> cation in the solid polymer by means of the segment-motion-assisted diffusion process, the low degree of cure causes small capacitance with this material system.展开更多
文摘Structural capacitors are composite structures that function as energy storage capacitors. Parallel plate-type capacitors have the advantage of high voltage resistance, but are limited by low capacitance. An electric double-layer capacitor with a composite structure using a solid polymer electrolyte matrix with a glass fiber fabric separator has recently been developed. However, the solid polymer electrolyte caused the capacitor to possess high internal resistance. In the present study, a new design of supercapacitor using a form core sandwich with high water retention is proposed and experimentally investigated. Activated carbon sheets are used as electrodes on the form core sandwich to make a supercapacitor. Woven carbon fabric is used as lead wires of the supercapacitor. The resulting supercapacitor displays a low surface resistance of 810 Ωcm2 and high areal capacitance of 520 mF/cm2.
基金supported by the National Science fund for Distinguished Young Scholars (No.50625204)the National Natural Science Foundation of China (Science Fund for Creative Research Groups)(No.50621201)+1 种基金the Major State Basic Research Development Program of China (No.2009CB623301)the National High-Tech Research and Development Program of China (No.2006AA03Z0428), and Samsung Electro-Mechanics Co., Ltd.
文摘Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmission electron microscope, and energy dispersive spectroscopy （EDS）. As the milling time extends, the dielectric constant of the ceramics increases, whereas the temperature coefficient of capacitance at 125℃ drops quickly. The changes in dielectric properties are considered relevant to the microstructure evolution caused by the milling process. Defects on the surface of BaTiO3 particles increase because of the effects of milling process, which will make it easier for additives to diffuse into the interior grains. As the milling time increases, the shell region gets thicker and the core region gets smaller; however, EDS results show that the chemical inhomogeneity between grain core and grain shell becomes weaker.
文摘Output voltage is an important performance characteristic of planar insulating core transformer (PICT).In PICT magnetic cores are insulated from their neighboring magnetic cores by solid insulating materials.Solid insulating materials can increase leakage flux.This results in a low generated voltage in secondary coils,especially on the upper stages.Connecting flux compensation capacitors to secondary coils can compensate the flux loss.Design equations to calculate the flux compensation capacitors value and relevant simulation by CST and Protel software were presented.Simulation results of an actual PICT showed that output voltage increased by 19% after being connected to flux compensation capacitors and the voltage on every stage was equally distributed.Results of simulation were consistent with the following experimental test,which revealed that flux compensation capacitors were effective.
文摘Structural capacitors are composite structures that function as energy storage capacitors. An electric double-layer capacitor with a composite structure using a solid polymer electrolyte matrix with a glass fiber fabric separator has recently been developed. In the present study, new foam core sandwich structure is adopted and the effect of the degree of cure is experimentally investigated. Carbon fiber fabric cloth is used as electrodes, and the polystyrene foam core is used as separator. Material system of Poly Ethylene Glycol DiGlycidyl Ether (PEGDGE) with Lithium bisTriFluoromethane Sulfonyl Imide (LiTFSI) and hardener of TriEthylene TetrAmine (TETA) is adopted as ion-conductive polymer matrix. The effect of the cure degree is experimentally investigated by using 100% cure degree, 70% cure degree and 0% cure degree specimens. As a result, the polystyrene foam-core sandwich system is proved to be effective, but the capacitance is not enough because of the lack of surface area of the carbon fiber electrodes. As the remained TETA impedes the movement of Li<sup>+</sup> cation in the solid polymer by means of the segment-motion-assisted diffusion process, the low degree of cure causes small capacitance with this material system.
