Lithium–Sulfur Battery Electrolytes

Book chapter, 2017

The electrolyte is at the very heart of any battery concept physically, but more and more also mentally amongst battery researchers and developers. This is largely due to the growing insight that many problems related to overall efficiency, life-length, and safety often originate in the electrolyte. This is perhaps even more a truth for the Lithium-Sulfur (Li–S) battery technology and hence large efforts are today focused on novel Li–S battery electrolytes — materials as well as concepts. In this chapter we will start by summarizing the similarities and differences in demands and design as compared to the Li-ion battery (LIB) technology, as the latter is more familiar to most readers. We then move to two large sections of liquid and solid electrolytes, respectively, outlining the materials and methods used. In each of the sections we point to a few specific topics and how these are researched today, keeping the comparison with the LIB as a way to more easily understand the unique features/issues/problems that electrolytes for Li–S batteries are facing. The chapter is made at a level and limited to a scope where the open literature is sufficient and plentiful, but of course studying the patent literature and gaining the hidden industry know-how may definitively extend the scope for the interested reader. Overall we hope that after reading this chapter, armed with a basic knowledge of the types of electrolytes and the materials presently in use in Li–S batteries, it will be easier for the reader to understand the needs, limitations, problems, but also the possibilities. This should finally open for suggestions of how to rationally improve the electrolytes with in the end enhanced performance of future Li–S batteries.