Comprehensive study on lithium-ion battery cathode LiNixCoyMn1-x-yO2 as an air electrode for protonic ceramic fuel cells

The protonic ceramic fuel cells (PCFCs) exhibits a remarkable high-energy conversion efficiency and significant application potential at low temperatures. In this context, the layered ternary lithium-ion batteries (LIB) material, LiNixCoyMn1-x-yO2 (LNCM), is explored as a potential cathode for PCFCs. Utilizing density functional theory (DFT) calculations, we have conducted a comprehensive analysis of oxygen vacancies, hydration energy, density of states, and other pertinent properties to evaluate these ternary materials. Both theoretical and experimental findings suggest that LiNi0.5Co0.2Mn0.3O2 (LNCM523) may offer the optimal performance as a PCFCs cathode. Notably, after calcination in air at 700 degrees C for 100 h, LNCM523 displayed no phase transition or the emergence of new phases. The impedance of LNCM523, measured on a BaZr0.1Ce0.7Y0.1Yb0.1O3-delta (BZCYYb) electrolyte, is 0.225 52 cm2 at 650 degrees C. At this temperature, the peak power density of the single cell reaches 355 mW cm- 2. Moreover, during a 100-h stability test conducted at 550 degrees C, the output performance of the single cell remained unaltered. In electrolysis mode, at 650 degrees C and 1.3 V, the current density for electrolysis water attained 1.75 A cm- 2. Based on these promising results, LNCM emerges as a viable cathode candidate for PCFCs.