The work is typically divided into volumes (Ionics, Electrodics, and later additions on specific applications), covering the discipline from the bottom up.
If you are seeking the work (i.e., the intellectual content) rather than a free file, consider purchasing a second-hand physical copy, checking WorldCat for nearby libraries, or buying the newer editions (e.g., Modern Electrochemistry 2A and 2B by Bockris, Reddy, and Gamboa-Aldeco, which are still in print).