Krishnakant Tiwari , Chen-Hao Wang , Bih-Show Lou , Aknachew Mebreku Demeku , Igamcha Moirangthem , Shiqi Wang , Ismail Rahmadtulloh , Chaur-Jeng Wang , Wenyi Huo , Jyh-Wei Lee
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引用次数: 0
Abstract
High entropy alloy oxides (HEAOs) are a novel class of materials stabilized through configurational entropy, and they are anticipated to exhibit remarkable electrochemical properties. Here, we report the preparation of oxygen-rich amorphous VNbMoTaWOx HEAO thin films deposited on the surface of graphite felt (GF) electrode using a novel HiPIMS deposition technique intended for application in vanadium redox flow batteries (VRFBs). The modified GF electrode, featuring a 154 nm thick HEAO coating on the GF surface with an O/W ratio of 8.35, designated H#50, demonstrated superior electrocatalytic performance towards the VO2+/VO2+ redox couple, achieving energy efficiency values of 81.40 % at 100 mA cm−2 and 71.40 % at 160 mA cm−2. This represents a 7.70 % and 17.30 % improvement, respectively, over the uncoated GF electrode. The uniformly dispersed refractory metal, V, Nb, Mo, Ta, and W cations in the thin film, along with the optimal thickness, enable faster electron and ion transportation without obstructing the pores of GF. The diverse metal ions contribute to multiple oxidation states and abundant oxygen vacancies, which enhance the electroactive sites for the VO2+/VO2+ redox reaction. Additionally, this approach demonstrates remarkable cycling stability over 200 cycles. Utilizing HiPIMS technology, this innovative method offers a fast and efficient way to develop high-performance VRFB electrodes with strong potential for industrial-scale applications.
高熵合金氧化物(HEAOs)是一类通过构型熵稳定的新型材料,有望表现出优异的电化学性能。本文报道了一种新型HiPIMS沉积技术在石墨毡(GF)电极表面沉积富氧无定形VNbMoTaWOx HEAO薄膜,有望应用于钒氧化还原液流电池(vrfb)。在GF表面包覆154nm厚的HEAO层,O/W比为8.35 (H#50),对VO2+/VO2+氧化还原对表现出优异的电催化性能,在100 mA cm - 2和160 mA cm - 2下的能量效率分别达到81.40%和71.40%。与未涂覆的GF电极相比,这分别提高了7.70%和17.30%。薄膜中均匀分布的难熔金属、V、Nb、Mo、Ta和W阳离子,以及最佳厚度,使电子和离子传输速度更快,而不会阻碍GF的孔隙。不同的金属离子有助于形成多种氧化态和丰富的氧空位,从而增强了VO2+/VO2+氧化还原反应的电活性位点。此外,该方法在200次循环中表现出显著的循环稳定性。利用HiPIMS技术,这种创新的方法提供了一种快速有效的方法来开发具有工业规模应用潜力的高性能VRFB电极。
期刊介绍:
The Journal of Power Sources is a publication catering to researchers and technologists interested in various aspects of the science, technology, and applications of electrochemical power sources. It covers original research and reviews on primary and secondary batteries, fuel cells, supercapacitors, and photo-electrochemical cells.
Topics considered include the research, development and applications of nanomaterials and novel componentry for these devices. Examples of applications of these electrochemical power sources include:
• Portable electronics
• Electric and Hybrid Electric Vehicles
• Uninterruptible Power Supply (UPS) systems
• Storage of renewable energy
• Satellites and deep space probes
• Boats and ships, drones and aircrafts
• Wearable energy storage systems