高熵稳定双钙钛矿阴极材料SmBa(Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))_(2)O_(5+δ)的制备及性能优化

Stable High-Entropy Double Perovskite Cathode SmBa(Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))_(2)O_(5+δ)for Intermediate-Temperature Solid Oxide Fuel Cells

通过改进的自蔓延燃烧法合成制备高熵双钙钛矿SmBa(Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))_(2)O_(5+δ)(HE-SBC)阴极材料,并复合10%(摩尔分数)Gd_(2)O_(3)掺杂CeO_(2)(GDC)以优化性能。结果表明:通过B位高熵的方法可以显著减小Co离子由价态变化而引起的热膨胀,从而降低SmBaCo_(2)O_(5+δ)的热膨胀系数。在800℃,以氧化钇稳定氧化锆(YSZ)为电解质的HE-SBC对称电池的极化阻抗(R_(p))为1.04Ω·cm^(2),阳极支撑单电池的最高功率密度和R_(p)分别为683.53 m W/cm^(2)和0.46Ω·cm^(2)。进一步通过复合GDC(HE-SBC与GDC的质量比7:3)以增加三相界面提高HE-SBC的催化活性,在800℃HE-SBC-GDC复合阴极对称电池的极化阻抗仅为0.09Ω·cm^(2),且阳极支撑单电池的最高功率密度和R_(p)分别为838.66 m W/cm^(2)和0.12Ω·cm^(2)。

High-entropy double perovskite SmBa(Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))_(2)O_(5+δ)(HE-SBC)as a cathode material was prepared by a modified Pechini method,and the performance of HE-SBC with 10%(in mole fraction)Gd_(2)O_(3)-doped CeO_(2)(GDC)(HE-SBC-GDC)was optimized.The results show that the thermal expansion of Co ions caused by the change of valence state can be reduced due to the formation of high-entropy at B-site,thereby reducing the thermal expansion coefficient of SBC.The polarization impedance(R_(p))of the HE-SBC symmetrical cell with yttria-stabilized zirconia(YSZ)as an electrolyte is 1.04Ω·cm^(2)at 800℃and the maximum power density and R_(p)of the anode-supported single cell are 683.53 m W/cm^(2)and 0.46Ω·cm^(2),respectively.Furthermore,the catalytic activity of HE-SBC is improved by the addition of GDC[m(HE-SBC):m(GDC)=7:3]due to the enlarged three-phase interface.The polarization resistance of HE-SBC-GDC composite cathode symmetric cell is only 0.09Ω·cm^(2)at 800℃and the maximum power density and R_(p)of the anode-supported single cell are 838.66 m W/cm^(2)and 0.12Ω·cm^(2),respectively.