5. Electrolytes and passivation layers

Electrolyte is a medium that enables movement of lithium ions between negative and positive electrode materials. The performance of a LiB can be influenced by the nature of electrolyte and its physicochemical and electrochemical properties. Most common li-quid electrolytes used in lithium-ion batteries are composed of a lithium salt, one or more non-aqueous, aprotic organic solvent, and additives. There are several important specifications for salt and solvent. The lithium salts should contain monovalent anions that exhibit a high dissociation degree and moderate size to ensure high mobility. The electrolyte should be chemically stable and non-corrosive with respect to the current collectors, have low reactivity towards the battery components, low toxicity and high safety. The electrolyte formulation depends on the type of positive and negative electrode materials, as well as on the specific...