Gregory Salitra

Li-ion battery technology has become very important in recent years as these batteries show great promise as power sources that can lead us to the electric vehicle (EV) revolution. The development of new materials for Li-ion batteries is the focus of research in prominent groups in the field of materials science throughout the world. Li-ion batteries can be considered to be the most impressive success story of modern electrochemistry in the last two decades. They power most of today's portable devices, and seem to overcome the psychological barriers against the use of such high energy density devices on a larger scale for more demanding applications, such as EV. Since this field is advancing rapidly and attracting an increasing number of researchers, it is important to provide current and timely updates of this constantly changing technology. In this review, we describe the key aspects of Li-ion batteries: the basic science behind their operation, the most relevant components, anodes, cathodes, electrolyte solutions, as well as important future directions for R&D of advanced Li-ion batteries for demanding use, such as EV and load-leveling applications.

Li(metal)–sulfur (Li–S) systems are among the rechargeable batteries of the highest possible energy density due to the high capacity of both electrodes. The surface chemistry developed on Li electrodes in electrolyte solutions for Li–S batteries was rigorously studied using Fourier transform infrared and X-ray photoelectron spectroscopies. A special methodology was developed for handling the highly reactive Li samples. It was possible to analyze the contribution of solvents such as 1-3 dioxolane, the electrolyte , polysulfide , and additives to protective surface films that are formed on the Li electrodes. The role of as a critical component whose presence in solutions prevents a shuttle mechanism that limits the capacity of the sulfur electrodes is discussed and explained herein.

A route for the preparation of binder-free sulfur-carbon cathodes is developed for lithium sulfur batteries. The method is based on the impregnation of elemental sulfur into the micropores of activated carbon fibers. These electrodes demonstrate good electrochemical performance at high current density attributed to the uniform dispersion of sulfur inside the carbon fiber.

The development and commercialization of Li ion batteries during recent decades is one of the great successes of modern electrochemistry. The increasing reliability of Li ion batteries makes them natural candidates as power sources for electric vehicles. However, their current energy density, which can reach an average of 200 Wh kg −1 on the single cell level, limits the possible driving range of electric cars propelled by Li‐ion batteries. Thereby, there is a strong driving force to develop power sources technologies beyond Li‐ion batteries that will mark breakthroughs in energy density capabilities. Li‐sulfur batteries have high theoretical energy density that can revolutionize electrochemical propulsion capability. Consequently, in recent years there has been much work throughout the world related to these systems. The scope of work on this topic justifies frequent publications of review articles that summarize recent extensive work and provide guidelines and direction for focused future work. Here, a comprehensive, systematic work related to Li‐sulfur battery systems is described, beginning with the Li anode challenges, carbon‐encapsulated sulfur cathodes, and various kinds of relevant electrolyte solutions. Based on the work described and parallel recent studies by other groups, important and comprehensive guidelines for further research and development efforts in this field are provided.