The invention and successful commercialization of lithium-ion batteries revolutionized our lives in the 21st century. Now more than ever, we rely on electrical energy efficiently packed in these tiny electrochemical devices to drive our cars, to stay connected with our co-workers, friends and families, and to calculate, process and store astronomical amounts of information. In these tiny devices, the electrons and ions flow in various directions via different predesigned pathways to capture or release the energy, and to do so reversibly thousands of times. Such processes rely on various components that are well synchronized to work with each other.

However, the invention of lithium-ion batteries was blessed by certain fortuitous factors. When the engineers at Asahi Kasei and Sony put the individual components (anode, cathode and electrolyte) together and assembled the first prototype lithium-ion battery, the scientific principles governing these processes were not completely understood. Thanks to the intensive research efforts during the past three decades, gradually we started to understand how the energy is stored and released in the lattices of the anode and cathode, how the ions and electrons transport in the bulk electrolytes and across interfaces and how the irreversible chemistries initiate, grow, terminate and eventually ensure the reversibility of reactions occurring far away from thermodynamical equilibria. However, many questions still remain unanswered.

Electrolytes, their interfaces with both electrodes and their interactions with these electrodes play the key roles in determining the reversibility of these reactions. Understanding the composite and convoluted phenomena and behaviors of ion solvation, ion transport, charge transfer and sacrificial electrolyte–electrode reactions at the molecular level will allow us to design the next generation of electrochemical energy storage devices with higher power and energy than lithium-ion batteries. Despite such importance, however, there has not been a book that systematically summarizes the knowledge of electrolytes and interfaces. While the books by Bockris, Bard and Faulkner and also Newman all provided solid foundations of basic electrochemistry, ionics and electrodics, there was a gap between these and the practical electrolytes, interfaces and interphases that we are seeing in advanced battery systems.

This book by Kang Xu serves as a link between these fundamental books and the practical electrolyte systems that we deal with in today’s battery research. It systematically summarizes all related knowledge of electrolyte materials, ion solvation and transport, charge transfer, interfacial science and interphasial chemistry, from classical understanding to state-of-the-art studies. It is an excellent textbook for those just entering the field of battery chemistry and materials research, and an excellent desktop reference for researchers in the field.

Khalil Amine

Argonne National Laboratory, USA