Engineering high-entropy oxide on reduced graphene oxide as a highly stable and efficient electrocatalyst for vanadium redox flow batteries
以還原氧化石墨烯負載高熵氧化物作為高度穩定且高效的釩氧化還原液流電池觸媒
📄 英文摘要
Efficient catalysts are essential for vanadium redox flow batteries (VRFBs), a key technology for large-scale energy storage. We report a high-entropy oxide of (CeMoBiWZrLa)O₂ supported by reduced graphene oxide ((CeMoBiWZrLa)O₂/rGO) as a composite catalyst for enhanced VRFB performance. The composite, synthesized via a hydrothermal reduction process, consists of dispersed HEO nanoparticles anchored on rGO sheets, which enhances electrolyte wettability and improves performance by enabling faster kinetics and more efficient ion transport. Moreover, the high configurational entropy, abundant oxygen vacancies, and inherent mechanical stability of HEO synergistically facilitate ion desorption, ensuring long-term durability. In-situ Raman spectroscopy reveals M–OH and C–OH₂⁺ intermediates, confirming accelerated redox kinetics in acidic electrolytes. The HEO/rGO-modified HGF electrode achieves energy efficiencies of 85.75% and 80.22% at 80 and 120 mA cm⁻² (improvements of 7.44% and 13.36%, respectively), with excellent stability over 300 cycles.
📄 中文摘要
高效觸媒對於作為大規模儲能關鍵技術的釩氧化還原液流電池（VRFBs）至關重要。本研究報告一種高熵氧化物 (CeMoBiWZrLa)O₂ 負載於還原氧化石墨烯上的複合觸媒（(CeMoBiWZrLa)O₂/rGO），用於提升 VRFB 性能。此複合材料透過水熱還原法合成，由錨定於 rGO 片上的分散 HEO 奈米粒子組成，增強了電解質浸潤性，並透過更快的動力學與更有效的離子傳輸提升性能。此外，HEO 的高組態熵、豐富氧空位與固有機械穩定性協同促進離子脫附，確保長期耐久性。In-situ Raman 光譜揭示了 M–OH 與 C–OH₂⁺ 中間產物，確認了在酸性電解質中加速的氧化還原動力學。HEO/rGO 改質的 HGF electrode 在 80 與 120 mA cm⁻² 下分別達到了 85.75% 與 80.22% 的能量效率（分別提升 7.44% 與 13.36%），並在 300 次循環中展現出色的穩定性。
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