Solid/electrolyte interphase properties

The alkali-metal/electrolyte interphase was named LI] the solid-electrolyte interphase (SEI). A good SEI must have the following properties ... 

We have seen that the idea of an electrode film system is useful for electrochemistry of molten salts including low-temperature ionic liquids. It is not restricted, however, to this field only. As an example, the protective layer on lithium metal in aprotic organic electrolytes could be mentioned. This layer, so-called solid electrolyte interphase (SEl), exhibits properties of a polyfunctional conductor with high ionic conductivity (Li ions are the carriers) and low electronic conductivity of semiconductive nature. Some peculiarities of film systems with semiconductive character of electronic conductivity are considered below. 

ProfatUova, 1. A. Kim, S.-S. Choi, N.-S., Enhanced thermal properties of the solid electrolyte interphase formed on graphite in an electrolyte with fluoroethylene carbonate, Electrochim. Acta 2009, 54, 4445 450. 

The layer formed instantaneously upon contact of the metal with the solution, consists of insoluble and partially soluble reduction products of electrolyte components. The thickness of the freshly formed layer is determined by the electron-tunneling range. The layer acts as an interphase between the metal and the solution and has the properties of a solid electrolyte with high electronic resistivity. For this reason it was called a solid-electrolyte interphase SEI. The batteries, consisting of SEI electrode, were called SEI batteries. ... 

In particular, tris(pentafluorophenyl) borane enables the improvement of the properties by forming stable sohd electrolyte interphase layers and suppressing a surface pulverization. The solid electrolyte interphase layers have been characterized by a variety of analytical tools, including SEM, EIS, and XPS (65). 

It has been suggested that in practical non-aqueous lithium battery systems the anode (Li or graphite) is always covered by a surface layer named the solid electrolyte interphase (SEI), 1-3 run thick, which is instantly formed by the reaction of the metal with the electrolyte. This film, which acts as an interphase between the metal and the solution, has the properties of a solid electrolyte. This layer has a corrosive effect and grows with the cycling life of the battery [52], Thermodynamic stability of a lithium cell requires the electrochemical potentials of electrodes a and Ec located within the energetic window of the electrolyte, which contrains the cell voltage Eq of th electrochemical ceU to ... 

The electrical double layer has also been investigated at the interface between two immiscible electrolyte solutions and at the solid electrolyte-electrolyte solution interface. Under certain conditions, the interface between two immiscible electrolyte solutions (ITIES) has the properties of an ideally polarized interphase. The dissolved electrolyte must have the following properties ... 

Abstract Recent advances in molecular modeling provide significant insight into electrolyte electrochemical and transport properties. The first part of the chapter discusses applications of quantum chemistry methods to determine electrolyte oxidative stability and oxidation-induced decomposition reactions. A link between the oxidation stability of model electrolyte clusters and the kinetics of oxidation reactions is established and compared with the results of linear sweep voltammetry measurements. The second part of the chapter focuses on applying molecular dynamics (MD) simulations and density functional theory to predict the structural and transport properties of liquid electrolytes and solid elecfiolyte interphase (SEI) model compounds the free energy profiles for Uthium desolvation from electrolytes and the behavior of electrolytes at charged electrodes and the electrolyte-SEl interface. 

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