Reactivity and Safety Aspects of Carbonaceous Anodes used in Lithium-Ion Batteries — Correlation of Structural Parameters and Reactivity

Abstract

Among various alternative anode materials for rechargeable batteries, the carbonaceous anodes are the most promising as their capacity and rate capabilities can be tailored to satisfy specific applications [1–4]. Lithium can be intercalated into a large variety of carbonaceous materials’. Graphite anodes with high degree of crystallinity appears to be the most desirable candidate due to the high host capacity (Li/C₆), low and flat electrode potential profile similar to that of Li metal (0.01–0.02 V). The electrochemical process of lithium insertion and extraction from graphitic electrodes, however, has at least two major problems: first, the excessive electrolyte decomposition during the first lithiation process causing the irreversible capacity loss, and second, the formation of gaseous species which are detrimental to the performance of lithium cells and are considered hazardous as the majority of the gaseous species are flammable [5, 6]. Some of the gaseous species may also dissolve in the organic electrolyte and participate in parasitic reactions within the operating voltage of Li-ion cells.