Preparation Of SDC Buffer PLD And Its Effect On Electrochemical Properties Of Battery

Medium-temperature solid oxide fuel cells（600℃-800℃）is a kind of all-solid-state power generation device which can directly convert chemical energy into electrical energy.It has attracted wide attention because of its clean and efficient advantages.Electrolyte is an important part of IT-SOFC,so the production of a better electrolyte can effectively improve the output characteristics of IT-SOFC,which can solve the problem of the increase of polarization impedance caused by the decrease of temperature.It plays a vital role in the development of IT-SOFC.The(BiO_1.5)_0.88(DyO_1.5)_0.08（WO₃）_0.04（8DY4WSB）electrolyte material was prepared by solid phase method.A layer of Sm_0.2Ce_0.8O_1.9（SDC）film was sputtered on 8DY4WSB electrolyte sheet as buffer layer by pulsed laser deposition technology.The effects of sputtering energy and sputtering times on the properties of SDC buffer films were studied as the preparation conditions of PLD.And the electrochemical performance of symmetrical semi-battery supported by 8DY4WSB electrolyte sheet is affected by SDC buffer layer.In addition,compared with classic SOFC,the Bi₂O₃-based electrolyte prepared in the experiment has an obvious effect on improving the conductivity of the battery.The 8DY4WSB electrolyte was prepared by solid phase method and sintered at 700℃,800℃,850℃and 890℃.It can be seen from the XRD diagram that the optimum sintering temperature of the electrolyte is 890℃.At this time,there is no miscellaneous peak,and the phase is good.And the Archimedes test results showed that the density of 8DY4WSB electrolytes was more than 99%.By testing the XRD diagram of SDC-8DY4WSB complex,it can be seen that SDC and8DY4WSB maintain their respective phase structure,which proves that the two materials have good chemical compatibility.Experiments using SrCo_0.8Ti_0.15Nb_0.05O_3-δ（sintering temperature is 1150℃）for the production of the cathode electrolyte supported symmetric batteries.Comparing the AC impedance values of symmetrical semi-battery with sputtering energy of 400 mJ and 500 mJ,it can be seen that the impedance at 500 mJ is less than that at 400 mJ.By comparing different sputtering number（15 k,25 k and 35 k）found that the impedance decreases with the decrease of sputtering times.In the experiment,the minimum impedance is about 0.0807Ω·cm2,which has good conductivity.At this time,the sputtering energy is 500 mJ,the sputtering times are 15 k,and the test temperature is 800℃.In conclusion,SDC buffer layer sputtered on 8DY4WSB electrolyte sheet can improve the conductivity of electrolyte in order to avoid reactions between substances.