Hydrogen Absorption in Spherical Particles

Very often H absorption is studied in practical powdered materials (e.g., in NiMH batteries) that consist of spherical particles for which a finite-length spherical diffusion treatment must be used [287-289]. In this case the diffusion Eq. (7.56) must be written for the spherical diffusion, as in Eq. (4.91)  

Proceeding as in Sect. 4.6.2, the mass transfer impedance is described as 

The preceding theory may be extended to other intercalation reactions, e.g., in lithium batteries. It has also been extended to bilayers [295, 296]. 

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