Lithium insertion process

In 1995, West and Crespi studied the reversibility of the lithium insertion process in a polymer electrolyte Li/Ag2V4On cell, cycled between 2.2 and 3.5 V at 100°C... 

As Figure 14 shows, the combination of two lithium insertion materials (characterized by two different potentials of the lithium insertion process) yields a cell—the so-called rocking chair battery , after Armand [105] and Scrosati et al. [106]—in which during discharge lithium ions are released from the anode and travel through the electrolyte toward the cathode without variation in the composition of the... 

Intercalation-induced stresses have been modeled extensively in the Hterature. A one-dimensional model was proposed to estimate stress generation in the lithium insertion process in the spherical particles of a carbon anode [24] and an LiMn204 cathode [23]. In this model, displacement inside a particle is related to species flux by lattice velocity, and total concentration of species is related to the trace of the stress tensor by compressibihty. Species conservation equations and elasticity equations are also included. A two-dimensional porous electrode model was also proposed to predict electrochemicaUy induced stresses [30]. Following the model approach of diffusion-induced stress in metal oxidation and semiconductor doping [31-33], a model based on thermal stress analogy was proposed to simulate intercalation-induced stresses inside three-dimensional eUipsoidal particles [1]. This model was later extended to include the electrochemical kinetics at electrode particle surfaces [2]. This thermal stress analogy model was later adapted to include the effect of surface stress [34]. 

Composites of CuO nanotubes and Sn02 can be prepared by a simple solution-based method. During the first lithium insertion process, CuO is reduced to elemental Cu, and its nanotube structure is retained. In addition, the volume expansion of Sn02 is inhibited. Compared with pure Sn02, the composite shows markedly improved electrochemical performance. 

There are a large variety of carbonaceous materials that can interact with lithium ions in solutions and serve as Li insertion anodes in Li-ion batteries. The behavior of the lithium insertion processes into carbons in terms of capacity, stability, kinetics, and potential profile, depends very strongly on their 3D structure and morphology. Indeed, this chapter deals with the surface chemistry of electrodes, and hence, cannot deal in depth with structural aspects of carbonaceous materials. However, it was found and clearly demonstrated that the surface chemistry of carbons, and especially their surface film related stability, depends very strongly on their 3D structure. Therefore, in this section we deal with some structural aspects of carbonaceous materials. 

Doeff MM, Richardson TJ, Kepley L (1996) Lithium insertion processes of orthorhombic NaxMn02-based electrode materials. J Electrochem Soc 143 2507-2516... 

During electrochemical reduction (charge) of the carbon host, lithium cations from the electrolyte penetrate into the carbon and form a lithiated carbon Li rCn. The corresponding negative charges are accepted by the carbon host lattice. As for any other electrochemical insertion process, the prerequisite for the formation of lithiated carbons is a host material that exhibits mixed (electronic and ionic) conductance. 

Boron-containing carbons synthesized by co-pyrolysis of coal-tar pitch with pyridine-borane complex (series 25Bn) have already been considered as hosts for lithium insertion [4], Unlike the commercial graphites described above, the boron-doped carbon 25B2 (WUT) as received was not suitable for direct use in the cylindrical cell due to very large and hard particles. This feature makes the coating process very difficult. 

A promising EW may be obtained by combining tungsten trioxide, WO3, a well-known primary electrochromic electrode, which is coloured by the following lithium insertion-deinsertion process ... 

Lithium ion batteries use insertion processes for both the positive and negative electrodes, leading to the term rocking chair battery. The resulting transport of Li ions between the electrodes, usually... 

Lii+ rV308 has received considerable attention as a cathode material for secondary lithium batteries over the past few years. Lii+ rV308 has a layered framework suitable for reversible lithium intercalation processes that can allow up to four Li+ ions per formula unit to be inserted (i.e., xcan vary from 0 to... 

Table 3, which presents the various surface compounds formed on Li electrodes in the various solutions, together with reaction schemes 1-10, describes well the basic surface chemistry developed on the carbons. Similar results concerning the surface chemistry developed on carbons in alkyl carbonate mixtures have also been obtained by others [363-365], Hence, carbon electrodes are also solid electrolyte interface (SEI) electrodes, similar to lithium i.e., the overall insertion process of Li into the carbons requires the necessary step of Li ion... 

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