This book describes a body of work whose ultimate goal is to optimize the design of microbatteries. It focuses on the fundamental properties of the structure and atomic diffusion in glassy materials which optimize the properties of the electrolyte. Experimental results and their phenomenological description of lithium borate glasses are extensively covered. Other chapters discuss the effects of barriers between the electrodes and the electrolyte and the book culminates with a description of actual progress in making applications of these materials to batteries, sensors and other devices.