Superconducting electrode capacitor based on double-sided YBCO thin film for wireless power transfer applications

摘要

A high-temperature superconducting (HTS) electrode capacitor (HTS capacitor) has been reported for the first time in the form of a superconductor-insulator-superconductor structure. Double-sided HTS thin film might be inherently suitable for the raw material choice of an HTS capacitor. In terms of electrode material, HTS thin film has a much lower surface resistance than normal conductors, and, as a dielectric medium, its substrate generally has a larger dielectric constant but a smaller loss tangent than the dielectric layers of some conventional capacitors. Thus, it is possible to fabricate a high-quality capacitor based on double-sided HTS thin film. This type of HTS capacitor could play a role in wireless power transfer (WPT) technology, since the WPT efficiency depends on the quality factors of both the coil and capacitor. Numerous studies have been performed to optimize the WPT system with HTS coil. In contrast, we develop an HTS capacitor based on double-sided YBCO film for WPT applications and investigate its effect on the WPT system. It is found that the HTS capacitor can provide a high quality factor, enhance WPT efficiency, and work normally with an HTS coil at 77 K, avoiding the dilemma between an HTS coil and a normal capacitor.