钙和铁共掺杂PrBaCo_(2)O_(5+δ)作为固体氧化物燃料电池阴极的研究

Research on Ca and Fe co-doped PrBaCo_(2)O_(5+δ)as a cathode material of solid oxide fuel cells

固体氧化物燃料电池(SOFC)作为一种高效的能量转化装置,具有广阔的应用前景。阴极的反应动力学和稳定性在SOFC中具有非常重要的意义。采用固相法合成了具有四方相的双钙钛矿结构的PrBa_(0.8)Ca_(0.2)Co_(1.5)Fe_(0.5)O_(5+δ)(PBCCF)。Ca离子和Fe离子的掺杂有效降低了PrBaCo_(2)O_(5+δ)的热膨胀系数。结构为PBCCF|GDC|SSZ|GDC|PBCCF的对称半电池在800℃时的极化阻抗为0.082Ω·cm^(2),表明PBCCF阴极在电化学反应过程中具有较高的催化活性。将PBCCF作为阴极丝网印刷在NiO-YSZ|YSZ|GDC结构的半电池(其中NiO-YSZ阳极支撑体和YSZ为电解质通过流延-叠层热压法制成,Gd_(0.2)Ce_(0.8)O_(1.9)(GDC)阻挡层通过丝网印刷法制成)上制备得到单电池,该电池在800℃时的功率密度可达1.0 W/cm^(2)。同时,单电池在60 h的短期稳定性测试中较为稳定。研究结果表明,PBCCF是一种非常有前景的SOFC阴极材料。

Solid oxide fuel cell(SOFC)is an efficient energy conversion device,which has demonstrated broad application prospects.The oxygen reduction reaction kinetics and stability of the cathode have been considered as two important factors of SOFC.Solid-state method is adopted to synthesize PrBa_(0.8)Ca_(0.2)Co_(1.5)Fe_(0.5)O_(5+δ)(PBCCF)with a tetragonal perovskite structure.The co-doping of Ca and Fe ions effectively reduces the thermal expansion coefficient of PrBaCo_(2)O_(5+δ).The polarization resistance of a symmetrical half cell with a structure of PBCCF|GDC|SSZ|GDC|PBCCF at 800℃is 0.082Ω·cm^(2),indicating that the PBCCF cathode has high activity in the electrochemical reaction process.A single cell is prepared based on a NiO-YSZ|YSZ|GDC structured half cell with screen-printed PBCCF cathode filaments.And the half cell is composited by NiO-YSZ anode support and YSZ electrolyte through tape casting-lamellating hot pressing method,as well as screen-printed Gd_(0.2)Ce_(0.8)O_(1.9)(GDC)barrier layers.The power density of the single cell can reach 1.0 W/cm^(2)at 800℃.In addition,the single cell also exhibits good short-term stability during the 60 h durability test.These results demonstrate that PBCCF is a very promising cathode material for SOFC.