Improved performance and stability of low-temperature, molten-carbonate fuel cells using a cathode with atomic layer deposited ZrO2

Molten-carbonate fuel cells (MCFCs) are high-temperature fuel cell systems that typically operate at approximately 650 °C. Due to their high operating temperature, the thermal degradation of MCFC components limits the lifetime of the MCFC. Therefore, lowering the operating temperature is an effective way to reduce thermal degradation. However, the electrochemical reaction on the cathode also becomes slower as the operational temperature decreases. To improve the performance and stability, atomic layer deposition (ALD) of ZrO2 on the cathode is proposed. ALD produces a uniform, thin coating with precise thickness control. Therefore, nano-coating can be performed via ALD without affecting the porous structure of the cathode. The uniform ZrO2 coating donates electrons to NiO due to the low electronegativity of Zr. The electron-rich environment of NiO improves the cell performance by providing electrons for the oxygen reduction reaction. Also, the single cell using ZrO2-coated cathode demonstrates improved stability compared to the uncoated cathode cell due to the inhibition of NiO sintering by the ZrO2 coating layer.