To optimize the electrolyte is one of the most important directions to take in order to improve the Li/S battery in terms of performance - especially cell cyclability, rate capability, safety, and life-span. In this review we examine the state of the art for different choices of electrolytes; concepts, design, and materials, and how the resulting chemical and physical properties of the electrolyte affect the overall Li/S battery performance. The objective is to create an overall assessment of electrolytes in use at present and to provide a thorough basis for rational selection of future electrolytes for Li/S batteries. (C) 2014 Elsevier B.V. All rights reserved.