Hi everyone

I am learning the modeling of lithium-ion battery, and I found the expression of current density of electrolyte in Eq. (A-2) of ref[1] as the picture attached below.

It said this equation was derived in this book (ref[2]), but I can not find the derivation procedure in that book.

So please help me to understand how to derive this equation.

Thank you very much.

Qingran

Reference

[1] Doyle M, Newman J, Gozdz A S, et al. Comparison of modeling predictions with experimental data from plastic lithium ion cells[J]. Journal of the Electrochemical Society, 1996, 143(6): 1890-1903

[2] Newman J. Electrochemical Systems. Prentice-Hall, Englewood Cliffs, NJ (1991)