中低温SOFC三维纳微网络复相阴极的可控构建与性能研究

本项目首次提出"三维纳微网络SOFC阴极结构"的概念，采用配位络合纺丝液静电纺丝制备纳米纤维LSCF和GDC，构建三维纳微网络结构的SOFC复相阴极。要获得纳米丝网络结构阴极的关键是其纳米丝形貌的耐高温性。本项目明确提出：纳米纤维显微结构不均匀及高温(800～1000℃)下易断裂的根本原因是电纺液的组分不均匀和不稳定。通过对电纺液中配体与金属离子的配位络合及其分子几何学对其螯合(配位)能力影响等的研究，阐明电纺液中异质键合的均匀形成等性质与纤维显微结构及纤维耐高温性间的关系。用LRS和FTIR表征凝胶纤维的分子结构，用DTA/TG、XRD、SEM和TEM等对凝胶和纳米纤维进行表征，制备具有纳微网络结构阴极的对称电池和单电池，进行电化学性能测试，揭示具有不同纳微网络结构的SOFC复（单）相阴极与其电化学性能间的关系及长期稳定性的规律。该项目对可商业化的中低温SOFC研究具有十分重要的意义。

The SOFC cathode with three dimensional nano(micro)-network is firstly pointed out in the project. Nano fiber LSCF and GDC are prepared by electrospinning and complexation sol-gel method, and then the three dimensional nano(micro)-network structure of SOFC composite cathode are formed. The key to obtain nano fiber structure of the cathode is to regulate the high temperature resistant of the morphology. The project showed that the main reason for the heterogeneity of the microstructure and easy-crack of nano fiber at 800~1000℃ was the chemical inhomogeneity and instability of the electrospinning solution. The effect of molecular geometry on the coordination and the ligand with metal cations complexation are investigated. The relation between the heterogeneity bonded uniformity of electrospinning solution, nano fiber microstructure and the temperature resistance of nano fiber are also illustrated. The molecular structure of the gel nano fiber is analyzed by LRS and FTIR. Moreover, the gel and nano fiber are characterized by DTA/TG, XRD, SEM and TEM. The symmetrical cell and single cell with nano(micro)-network structure cathode are prepared and tested. It indicate that the composite (or single phase) cathode with different nano(micro)-network structures has some relationships with electrochemical performance and long-stability.