Disclosed is a method for manufacturing electrodes (100) for electrochemical devices such as batteries and capacitors in which a viscous polysiloxane polymer electrolyte (116) is incorporated into the slurry of materials forming the electrode (100). The optional addition of protective additives (218) to the slurry is also disclosed. A follow-on vacuum impregnation step (228) is disclosed to further improve penetration and wetting by the electrolyte (116).