Ni、Cu共浸渍的LSCM-GDC复合阴极性能研究

固体氧化物电解池可以清洁、高效地将电能和热能转化为化学能,在新能源领域具有广阔的应用前景。La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-δ(LSCM)具有较好的高温稳定性,但离子电导率相对较低,在电解过程中电催化性能不足。本文将LSCM与具有较高离子导电性的Ce_0.8Gd_0.2O_2-δ(GDC)复配构造复合电极,并以共负载的形式在复合电极中浸渍纳米Ni、Cu金属催化剂提高电极的水蒸气吸附和转化能力,Ni、Cu共负载能够同时保留单一Ni或Cu负载对电极电解机制的改善。结果表明,Ni、Cu共负载相比于单一Ni或Cu负载电极在还原性气氛下具有更高的电化学性能,在还原性气氛和800 ℃工作温度下,镍铜质量比2∶8的负载电极在-0.1 V过电位下的电流密度可达到2.36 A·cm^-2,极化阻抗为0.92 Ω·cm²。

Properties of LSCM-GDC Composite Cathode Impregnatedwith Ni and Cu

Solid oxide electrolysis cell can cleanly and efficiently convert electric and thermal energy into chemical energy, which has broad application prospects in the new energy field. La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-δ (LSCM) has high temperature stability and is one of hotspots in the research of solid oxide electrolysis cell cathode materials. However, the relatively low ionic conductivity of LSCM results in insufficient electrocatalytic performance during electrolysis. In this paper, Ce_0.8Gd_0.2O_2-δ (GDC) with high ionic conductivity was composited on the basis of LSCM to construct a composite electrode, and Ni and Cu were impregnated into the composite electrode as metal catalysts to improve the water vapor adsorption and conversion capacity of the electrode. Ni, Cu co-loaded can keep single Ni or Cu loaded at the same time to improve the electrode electrolysis mechanism. The results show that compared with single Ni or Cu impregnation cathodes, the electrode with Ni and Cu co-impregnation has higher electrochemical performance under reducing atmosphere. The electrochemical performance of the electrode under reducing atmosphere at 800 ℃ is better than that under oxidizing atmosphere. The electrode with the nickel-copper mass ratio of 2∶8 has the best performance among the Ni, Cu-loaded cathodes, which current density reaches 2.36 A·cm^-2 at -0.1 V overpotential, and the polarization resistance is 0.92 Ω·cm².