Metallic heterostructure solid oxide fuel cells with robust performance output and durability

Metallic heterostructure solid oxide fuel cells, which hold promising application prospects at low operating temperatures (≤500 ℃), have demonstrated enhanced ionic conductivity and high-performance output. However, the robustness of their performance and durability remains unclear for industrialization. Here, we delve into the robustness of performance output and durability of metallic heterostructure solid oxide fuel cells using CeO₂/Li_xCoO₂ (x = 0.75, 1) electrolytes, adopting both density functional theory (DFT) calculations and experimental verifications. The CeO₂/Li_xCoO₂ (x = 0.75, 1) heterostructures are prepared by unsophisticated solid-state reaction. The DFT calculations reveal that the O-2p and Co-3d orbitals pass through the Fermi level, indicating the successful construction of the CeO₂/Li_xCoO₂ (x = 0.75, 1) metallic heterostructures. Under two conditions: no lithium vacancies and up to 25 % lithium vacancies, single cells with CeO₂/LiCoO₂ and CeO₂/Li_0.75CoO₂ electrolytes achieve high performance outputs of 781.3 mW·cm⁻² and 703.1 mW·cm⁻² at 500 ℃. They also exhibit enhanced ionic conductivities of 0.335 S·cm⁻¹ and 0.327 S·cm⁻¹, and durability of 80 h and 40 h, respectively. These results demonstrate that metallic heterostructure solid oxide fuel cells possess robust performance and durability. This work clarifies that the metallic heterostructure solid oxide fuel cells with the features of material adaptability and flexibility are capable of maintaining robust performance output and durability at low operating temperatures (≤500 ℃), which supply a novel and dependable option for energy utilization and conversion devices.