Key Issues Remaining to be Addressed

Intercalation-induced stress largely depends on the size of the particles and the cycling rate. It was shown that [24] the maximum tensile stress due to intercalation is on the order of 50 MPa for 5 pm (in radius) graphite electrode materials with a cychng rate of 5C. Simulations implemented on reahstic particle geometry reconstructed from 3D AFM imaging data [46] have shown that intercalation-induced stress could be as high as 110 MPa with a potential sweep rate of 0.5 mV 

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Extensive research has been directed toward optimizing the performance of Ni-cermet catalysts, electrolyte, and cathode, leading to development of intermediate SOFC. The key issue remained to be addressed is sulfur poisoning. Although sulfur poisoning has been a subject of extensive studies in heterogeneous catalysis, very limited work has been done on the development of sulfur-tolerant SOFC. 

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