| Today, energy and environmental protection have become issues of common concern around the world. Oxide ceramic membrane materials have attracted much attention for their great potential applications in the chemical, metallurgy, energy, environmental protection and other areas. As the ceramic hollow fiber membrane has a small diameter, a thin wall and very large effective membrane area per unit volume, it has been studied extensively in recent years. This thesis mainly investigates the permeation performance of the ceramic hollow fiber membranes for oxygen or hydrogen separation, and the electrochemical properties of hollow fiber solid oxide fuel cells.Chapter 1 is the literature review. It briefly describes the definition and classification of membranes, as well as the preparation and applications of ceramic hollow fiber membranes. The research progress and problems of ceramic hollow fiber membranes are also intensively discussed.In Chapter 2, dense dual phase composite Bi1.5Y0.3Sm0.2O3-La0.8Sr0.2MnO3-δhollow fiber membrane was fabricated by the combined phase inversion/sintering technique. The hollow fiber membrane possessed an asymmetric structure. A finger-like porous structure was present on the inner side and a denser structure on the outer side of the hollow fiber membrane. An oxygen permeation flux 3.9×10-7 mol cm-2 s-1 was obtained at 850℃under a gradient of air/helium. The oxygen permeation flux increases with the helium sweeping rate, the length of the hollow fiber and the oxygen partial pressure on the feed side increasing. The oxygen permeation process was simulated by a plug flow model in combination with the Wagner theory. The simulation results were in fair agreement with the measured permeation data.In Chapter 3, the hydrogen permeation performance of Ni-BaZr0.1Ce0.7Y0.2O3-δdual phase composite metal-ceramic hollow fiber membrane was investigated. NiO-BZCY composite powders were prepared by the nitrate-citric method with one step. The as-prepared NiO-BZCY hollow fiber precursors were sintered in reducing atmosphere to get Ni-BZCY metal ceramic membrane. The hollow fiber membrane has a "sandwich" structure:finger-like structures were formed near both the inner and outer walls, but a sponge-like layer occured at the center of the fiber. The hydrogen permeation flux of the hollow fiber membrane increases with the hydrogen flow rate on the feed side and the argon sweeping rate increasing. As formation of BaCO3 in the membrane, the hydrogen permeation flux of the hollow fiber membrane is not larger than that of disc-shaped membrane with relative high thickness. Therefore, in order to increase the fiber membrane separation performance, the formation of BaCO3 must be inhibited.In Chapter 4, an anode hollow fiber of diameter 1.7 mm has been successfully fabricated using the phase inversion technique. The Ni-YSZ anode layer possesses large finger-like pores on both sides of the hollow-fiber membrane, which provides a convenient channel for transporting the fuel gas to the electrolyte. A 12-μm-thick dense YSZ electrolyte membrane was successfully coated on the anode hollow-fiber by vacuum assisted coating and co-sintering method. The three-point bending strength of sintered NiO-YSZ/YSZ hollow fiber may reach up to 118.3 MPa. However, after reduction by hydrogen gas, the mechanical strength of the resulted Ni-YSZ/YSZ hollow fiber would be reduced noticeably. The open circuit voltage (OCV) values are greater than 1.01 V and the maximum power densities reach 124, 287,377 mW cm-2 at 600,700 and 800℃, respectively, using wet H2 (～3%H2O) as fuel and static air as oxidant gas. As a result of high packing densities, this kind of anode-supported hollow-fiber SOFCs has a high potential for practical applications.In Chapter 5, an YSZ hollow fiber used for electrolyte membrane of SOFC has been prepared by the phase inversion and sintering method. The nickel anode was deposited into the YSZ electrolyte membrane from nickel nitrate solution. Appropriate sintering temperature can make nickel deposited into the finger-like pores near inner surface of the YSZ electrolyte membrane more effectively. The anode adheres very well to the electrolyte membrane, which can significantly reduce the ionic resistance. The maximum power densities of 28,78, and 146 mW cm-2 are achieved at 600,700 and 800℃, respectively. With further optimization of the electrolyte and anode layers, more improvements on output power of SOFC may be expected. In addition, the YSZ electrolyte-supported hollow fiber SOFC shows a high mechanical strength throughout the measurement process, which is beneficial for practical applications in the future.In Chapter 6, the low-frequency internal friction Q-1 and relative shear modulus M of La2Cu1-xNixO4+δ(0≤x≤1) compounds were measured. La2Cu1-xNixO4+δcompounds have an orthorhombic K2NiF4 structure. The unit cell parameters a and b slightly increase, whereas it is contrary for c with the nickel content increasing and the excess oxygenδincreases from 0.0132 to 0.1250. For x<0.005, there are two relaxation internal friction peaks around 200 and 250 K, which is due to the hopping of single interstitial O atoms and O pairs, respectively. The peak at low temperature is invisible for 0.015≤x≤1 and the peak height at high temperature decreases suddenly with the nickel content increasing at x≈0.2 (δ≈0.046), indicating the existence 3D ordering of interstitial oxygen. Moreover, the temperatures of O-T phase transition for La2Cu1-xNixO4+δdecrease with increasing the nickel content.In Chapter 7, the researches presented in this dissertation are evaluated and future work concerning the development of ceramic hollow fiber membranes is discussed.
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