Interface Resistance of an SOFC Cathode with a Pr1-xTbxO2-d Active Layer

We investigated the use of Pr1-xTbxO2-d (x=0.0-1.0) material for active layer in SOFC cathode. Pr1-xTbxO2-d (x=0.0-1.0) in single-phase fluorite structure were successfully synthesized. They are solid solution of Pr6O11 and Tb4O7. When the x is between 0.3 and 0.6, the phase transition between room temperature and 800oC were eliminated Coin cells with GDC electrolyte and Pr1-xTbxO2-d (x=0.0-1.0) active layer and LaNi0.6Fe0.4O3 (LNF) current collecting layer were made to clarify the effect of this active layer. The interface resistance of these cathodes was measured with an AC impedance method at 800oC. The cathodes withPr1-xTbxO2-d (for all composition) active layer performed better than that of reference cathode, which has no active layer (consisting only LNF layer).

Impact of Li3BO3 Addition on Solid Electrode-Solid Electrolyte Interface in All-Solid-State Batteries

All-solid-state lithium-ion batteries raise the issue of high resistance at the interface between solid electrolyte and electrode materials that needs to be addressed. The article investigates the effect of a low-melting Li3BO3 additive introduced into LiCoO2- and Li4Ti5O12-based composite electrodes on the interface resistance with a Li7La3Zr2O12 solid electrolyte. According to DSC analysis, interaction in the studied mixtures with Li3BO3 begins at 768 and 725 °C for LiCoO2 and Li4Ti5O12, respectively. The resistance of half-cells with different contents of Li3BO3 additive after heating at 700 and 720 °C was studied by impedance spectroscopy in the temperature range of 25–340 °C. It was established that the introduction of 5 wt% Li3BO3 into LiCoO2 and heat treatment at 720 °C led to the greatest decrease in the interface resistance from 260 to 40 Ω cm2 at 300 °C in comparison with pure LiCoO2. An SEM study demonstrated that the addition of the low-melting component to electrode mass gave better contact with ceramics. It was shown that an increase in the annealing temperature of unmodified cells with Li4Ti5O12 led to a decrease in the interface resistance. It was found that the interface resistance between composite anodes and solid electrolyte had lower values compared to Li4Ti5O12|Li7La3Zr2O12 half-cells. It was established that the resistance of cells with the Li4Ti5O12/Li3BO3 composite anode annealed at 720 °C decreased from 97.2 (x = 0) to 7.0 kΩ cm2 (x = 5 wt% Li3BO3) at 150 °C.