Enhancing the performance and long-term stability of layered structure Li1-xNaxNi0.80Co0.15Al0.05O2-δ via Na-doped strategy for solid oxide fuel cells

The LiNi 0.8 0 Co 0.15 Al 0.05 O 2-δ (LNCA) electrode exhibits better catalytic activity in low-temperature solid oxide fuel cells (LT-SOFCs). However, LNCA still faces some challenges in commercialization due to poor stability, scarcity of lithium resources, and high costs. Here, Na-doped LNCA electrode not only enriches oxygen vacancies and prolongs long-term stability, but also maintains a layered structure and reduces costs. At 550 °C, under the optimal ratio of L 0.85 Na 0.15 NCA electrode, the maximum power density (MPD) of a single cell reaches 1147 mW cm −2 with an open circuit voltage (OCV) of 1.13 V and a polarization impedance (R p ) of 0.21 Ω cm 2 , which is 30.6% higher than the single cell power (878 mW cm −2 ) of the Na-undoped LNCA electrode. The cell maintained long-term stability for 108 h at a constant current density of 156.25 mA cm −2 and a voltage of about 0.9 V. The results indicate that Na-doped LNCA is an effective strategy to improve the electrochemical performance of LNCA and long-term stability of cell.