高效稳定耐硫纳米纤维型层状钙钛矿阳极的构建及其性能研究

In this project, the transition metals such as Cu, Fe, Co or its alloy and perovskite oxides are used to replace the commercial Ni-based perovskite anode material to solve the deactivation of anode carbon and sulfur poisoning caused by the diversity of fuel gas in Solid Oxide Fuel Cells (SOFCs). To improve the anti-carbon and sulfur tolerance characteristics of anode materials, a series of the B-site transition metals and their oxides nanoparticles in-situ growth on the layered perovskite composites anode T/TOx-PrBaMn2-x(Tx)O5+δ (T, transition metal) nanofiber were prepared by electrospinning and reducing atmosphere controlling steps. Both anti-carbon and sulfur resistance of this anode material are obviously improved by our former work. Based on this results, we will evaluate the best preparation method of metal particles excluded from fiber-type layered perovskite by in-situ and off-line characterization techniques. The precipitation regularity of transition metal, its evolution in different fuel atmospheres and the synergistic catalysis effect between nanoparticles and fiber perovskite will be analyzed. Revealing the mechanism of the interaction between the oxygen species/ oxygen vacancy and the battery stability. Further, we will study the relationship between the structure and catalytic efficiency of this composites anode and its catalysis mechanism. To continuously promote the development process of low-cost and high-performance perovskite anode materials.

本项目针对碳氢燃料中SOFC阳极积碳和硫毒害的失活问题，基于已知的过渡金属(T)及其合金(Cu、Fe、Co等)，或具有钙钛矿结构的电极，能够替代现有商业化的Ni基阳极，实现阳极材料抗积碳、耐硫的特性。突破现有钙钛矿阳极材料的研究思路，以提高阳极高效稳定等特征为目的，采用静电纺丝技术、原位析出等方法，制备出B位过渡金属及其氧化物纳米颗粒析出的纤维层状钙钛矿复合阳极材料T/TOx-PrBaMn2-x(Tx)O5+δ。前期结果表明该复合阳极的抗积碳硫性能明显提高。在此基础上探明基于纤维型层状钙钛矿与其B位析出金属颗粒的最佳制备方法；过渡金属的析出规律及其在不同燃料气氛中的演化规律；解析纳米颗粒与纤维钙钛矿之间的协同催化作用。揭示该复合阳极的氧物种与氧空位在电池稳定性提升中的作用机制。进一步揭示该类型材料的结构与催化效率关系及其抗硫抗积碳机制，不断推进低成本高性能的钙钛矿阳极材料的研发进程。

开发高效、廉价、稳定性好的低维纳米纤维复合电极有利于新能源领域的发展。本项目基于单钙钛矿、双钙钛矿、相变型（气氛条件下单双互转）钙钛矿，三种典型的钙钛矿氧化物，为提高该类型阳极电导率、活性、稳定性等提出了较深入和完整的研究体系，分以下三个层面：（1）钙钛矿材料本征属性的设计和优化，获得其组成和相结构对体相传导性能的影响规律；（2）低维纳米复合阳极的构建，阐明表界面高效传导和纳米效应的协同催化优势；（3）复合阳极与电解质的连接新工艺开发，实现低温条件下纳米阳极与电解质的界面构筑。以此建立从形貌构建、结构演变、到电化学性能的提升之间的关联性。该研究内容涉及低温相变、析出、拓扑交换等科学过程的辨析，静电纺丝技术、计算模拟、原位拉曼等先进科学技术的应用。本项目的开展将为实现高催化活性、低成本、稳定性好的复合阳极材料规模化应用奠定科学依据和材料基础。