Disordered carbonaceous materials

Because of the variety of available carbons, a classification is inevitable. Most carbonaceous materials which are capable of reversible lithium intercalation can be classified roughly as graphitic and non-graphitic (disordered). 

As discussed in the next section, lithiated carbon electrodes are covered with surface films that influence and, in some cases, determine their electrochemical behavior (in terms of stability and reversibility). They are formed during the first intercalation process of the pristine materials, and their formation involves an irreversible consumption of charge that depends on the surface area of the carbons. This irreversible loss of capacity during the first intercalation/deintercalation cycle is common to all carbonaceous materials. However, several hard, disordered carbons exhibit additional irreversibility during the first cycle, in addition to that related to surface reactions with solution species and film formation. This additional irreversibility relates to consumption of lithium at sites of the disordered carbon, from which it cannot be electrochemically removed [346-351],... 

Table 9 Summary of Details on Several Types of Disordered, High Capacity Carbonaceous Materials Which Are Promising as Anodes for Novel Li Ion Batteries... 

FIGURE 26.12 Variation of reversible capacity of region III carbons with the probability of turbostratic disorder (P). (Reprinted with permission from J.R. Dahn, T. Zheng, Y. Liu, and J.S. Xue, Mechanisms for lithium insertion in carbonaceous materials. Science, 270, 590, 1995. Copyright 1995 AAAS.)... 

To date, all commercial Li-ion batteries use carbonaceous materials as the anode-active material. Fig. 3A shows the structural schematics of typical carbonaceous materials in the field. Among various carbonaceous materials, graphite and disordered carbons have been employed dominantly in Li-ion batteries. Graphite has a typical layered structure that consists of stacked graphene sheets with an ABAB. .. sequence... 

In this chapter we have summarized the fundamentals and recent advances in thermodynamic and kinetic approaches to lithium intercalation into, and deintercalation from, transition metals oxides and carbonaceous materials, and have also provided an overview of the major experimental techniques. First, the thermodynamics oflithium intercalation/deintercalation based on the lattice gas model with various approximations was analyzed. Lithium intercalation/deintercalation involving phase transformations, such as order-disorder transition or two-phase coexistence caused by strong interaction oflithium ions in the solid electrode, was clearly explained based on the lattice gas model, with the aid of computational methods. 

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