Preparation of La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ film by pulse laser deposition (PLD) method on porous Ni–Fe metal substrate for CO₂ electrolysis

Preparation of metal supported La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ (LSGM) thin film cell for CO₂ electrolysis was studied and by using selective reduction method of NiO–NiFe₂O₄, it was found that porous Ni–Fe(9:1) based substrate with ca.30% porosity was successfully prepared without large volume change resulting in the successful preparation of LaGaO₃ dense thin film on metal substrate. By using Ce_0.8Sm_0.2O₂ (SDC) thin film, Ni diffusion from Ni–Fe substrate was prevented. CO₂ electrolysis was performed on the prepared LSGM/SDC on Ni–Fe porous substrate. When Sm_0.5Sr_0.5CoO₃ (SSC) anode was prepared by screen print method using SSC powder, sintering of SSC powder was significantly occurred resulting in the large IR loss and overpotential. In contrast, when SSC anode layer was deposited by PLD (30 min) after LSGM/ SDC layer deposition, tight contact between SSC anode and LSGM electrolyte film was obtained and the large CO₂ electrolysis current of 3 and 0.5 A/cm² were achieved at 973 and 773 K, respectively. Impedance analysis suggests that increased CO₂ electrolysis current was obtained by decreased IR loss and electrode overpotential.