Study on the electrical properties of YSZ/YSZ-NiO electrolyte film at low temperature

The pulsed laser deposition (PLD) method was used to prepare YSZ electrolyte film on a porous NiO-YSZ anode substrate. Use XRD, SEM and RF impedance/material analyzer to characterize the phase structure, surface morphology and electrical properties of the multilayer film. The experimental results found that the minimum conductivity activation energy of YSZ electrolyte film is 0.86eV at 300-500℃, and the conductivity can reach 7.96×10-5 s/cm.

The solid oxide fuel cell (SOFC) is a highly efficient and clean energy conversion device, which is increasingly receiving wide attention due to its high efficiency, low pollution and many other advantages. The most important factor that determines the performance of SOFC is the ionic conductivity of the electrolyte material. At present, the most common and successful application in SOFC is the yttrium stabilized zirconia (YSZ) electrolyte. YSZ has good ionic conductivity and chemical stability at high temperature (≥900℃), so SOFC must be operated at high temperature (900-1000℃). Such a high operating temperature limits the selection range of electrode materials and greatly reduces the service life of SOFC and the long-term stability of battery materials. If the working temperature of the battery is reduced to 600-800°C (so-called medium temperature), or 300-500°C (low temperature), or even room temperature, the interaction between the battery components and the sintering degradation of the electrodes can be avoided, and the battery life can be extended, and the battery can be improved Efficiency and reduce production costs. Finding electrolytes with sufficiently high ionic conductivity at lower temperatures is an important topic in the current SOFC field.

In recent years, the main direction of research is to use thin film technology to reduce the operating temperature of SOFC electrolyte, and there have been great results in the medium temperature range of 500-700°C. Thin film electrolyte can also minimize ohmic loss and lower the operating temperature of the fuel cell. The conductivity of the 500nm thick YSZ thin film electrolyte obtained by the electrostatic spray deposition method by Bailly et al. is lower than that of the bulk material. Garbayo et al. studied the conductivity of the YSZ thin film electrolyte compared with the YSZ thick film with no support structure. Increased by an order of magnitude.

vacuum coating machine,pvd coating machine,pvd vacuum machine,vacuum ion coating machine,multi-arc ion coating machine

In this paper, a YSZ electrolyte film with a thickness of 600nm-1μm is prepared on a porous NiO-YSZ anode support substrate. The Vacuum Technology Network (http://www.chvacuum.com/) believes that this is a way to achieve as much as possible. Conductive thin film model of solid oxide fuel cell working at low temperature (300℃-500℃). It is found that in the low temperature range of 300℃-500℃, YSZ film has relatively large conductivity.

Mix NiO powder, YSZ powder and starch in a ratio of 5:5:2 wt.%, grind them with a ball mill for 48 hours, and hand-grind them with a mortar for 2 hours to make the three powders evenly mixed. Weigh several nano-sized powders, each 0.25g, and place them in an abrasive tool with a diameter of 13mm. Using a powder tablet press at an apparent pressure of 481 MPa, they are pressed into a disc with a diameter of 10mm and a thickness of 0.5mm. . The disc is sintered in a high temperature furnace at 1400 ℃ for 4 hours to make it densified, and the temperature rise and fall rate is 3 ℃/min. In this way, the green NiO–YSZ anode support is obtained.

vacuum coating machine,pvd coating machine,pvd vacuum machine,vacuum ion coating machine,multi-arc ion coating machine

The PLD-450 pulsed laser sputtering instrument produced by the Shenyang Scientific Instrument Factory of the Chinese Academy of Sciences is used. The chamber is equipped with four independent target positions. The laser is the COMPexPro201 pulsed excimer laser produced by Coherent Inc., the sputtering target The material uses high-purity YSZ target material (purity 99.999%). Fix the YSZ target and NiO–YSZ anode substrate on the corresponding sample holder, the distance between the substrate and the YSZ target is 5cm, the substrate temperature is set at 300-600℃, the oxygen partial pressure is set at 5Pa, the laser The working mode is constant voltage 26kV, the laser energy is 650-690mJ, the frequency is 10Hz, and the thickness of the film is controlled to 600nm-1μm by adjusting the laser energy and the number of pulses. For the convenience of discussion, the samples with different deposition temperatures are numbered as shown in Table 1.

vacuum coating machine,pvd coating machine,pvd vacuum machine,vacuum ion coating machine,multi-arc ion coating machine

The dense 8YSZ film was successfully deposited on the porous NiO-YSZ anode substrate by pulsed laser deposition, and the phase, surface morphology and electrical properties were tested and analyzed and the following conclusions were drawn:

(1) Using PLD technology, a dense thin film with a thickness of about 1 μm can be deposited on the porous NiO-YSZ anode substrate. When the substrate temperature is 500°C, the film has the best crystallinity. The film has a large equiaxed grain size, and the film has good crystallinity and is well attached to the NiO-YSZ anode substrate.

vacuum coating machine,pvd coating machine,pvd vacuum machine,vacuum ion coating machine,multi-arc ion coating machine

(2) The results of X-ray diffraction and electron microscopy show that the YSZ film deposited by laser sputtering grows preferentially in the (111) crystal orientation.

(3) The electrical performance test results show that at a higher temperature, the activation energy obtained by the test sample is 1.09 eV. At low temperature, the activation energy of the obtained YSZ film deposited on the NiO-YSZ substrate is 0.86 eV. The electrical conductivity tested under low temperature conditions is two orders of magnitude higher than that of the YSZ bulk material.

Founded in 2015,Zunhua Baorui Titanium Equipment Co.,Ltd. is a manufacturer specializing in pvd vacuum ion coating equipment. The company’s products mainly include large plate coating machine, large tube collating machine, tool coating machine and LOW-E glass production line. Mr.Wang baijiang ,general manager of the company ,has been engaged in vacuum coating industry for more than 30 years. He continuously improve production technology, improve product performance and devote himself to provide customers with better product experience and higher production efficiency.