Ion insertion anodic

Table 2. Commercially available rechargeable coin-type cells with lithium-ion inserted anodes...

An Alternative to the Lithium-Metal Anode (Lithium-Ion Inserted Anodes)... 

Recently, lithium-ion inserted compounds have been investigated as new anodes. These compounds have the possibility of... 

The thermodynamic properties of magnesium make it a natural choice for use as an anode material in rechargeable batteries, as it may provide a considerably higher energy density than the commonly used lead-acid and nickel-cadmium systems, while in contrast to Pb and Cd, magnesium is inexpensive, environmentally friendly, and safe to handle. However, the development of Mg-ion batteries has so far been limited by the kinetics of Mg " " diffusion and the lack of suitable electrolytes. Actually, in spite of an expected general similarity between the processes of Li and Mg ion insertion into inorganic host materials, most of the compounds that exhibit fast and reversible Li ion insertion perform very poorly in Mg " ions. Hence, there... 

Kumar TP, Ramesh R, Lin YY, Fey GTK (2004) Tin-filled carbon nanotubes as insertion anode materials for lithium-ion batteries. Electrochemistry Communications 6 520-525. 

The electrochemical insertion process includes - charge transfer (red-ox reaction) by electrons and ions and -> diffusion of ions in the host to theirs sites. The inserted species can be cations (upon cathodic polarization), anions (upon anodic polarization), atoms, and molecules. Insertion of ions can be accompanied by co-insertion of solvent molecules from the -> solvation shell of the ions, which are dragged to the host together with the ions as the electrical field is applied. Insertion electrodes are highly important for the filed of - Li batteries, as most of the electrodes used in Li/Li-ion batteries are in fact insertion electrodes. Thereby, this entry concentrates mainly on Li ion insertion electrodes. 

Interestingly, theoretical CVs for reversible electrochemical processes involving ion insertion solids, when the concentration of electrolyte is sufficiently high, are essentially identical to those predicted for reversible charge transfer processes between species in solution (Lovric et al., 1998). Then, the median potential, taken as the half-sum of the cathodic and anodic peak potentials, is equal to the formal potential in Equation (2.5). When the electrolyte concentration is low, the voltammetric peaks vanish and the median potential is given by (Lovric et al., 1998) ... 

Aravindan, V., J. Sundaramurthy, A. Jain et al. 2014. Unveiling TiNbjO, as an insertion anode for lithium ion capacitors with high energy and power density. ChemSusChem 7 1858-1863. 

Hahn, R., Ghicov,A,Tsuchiya, H.,Macak,]. M., Munoz,A G.,and Schmuki, P. [2007]. Lithium-ion insertion in anodic Ti02 nanotubes resulting in high electrochromic contrast. 5 International Conference on Porous Semiconductors — Science and Technology. Physica Status SolidiA —Applications and Materials Science., 204, pp. 1281-1285. 

Figure 7.17 (a) Charge-discharge curves and (b) cychc performance for the SnO MWCNT Sn02 PPy anode at 100 mA gb (c) schematic illustration of the volume change during the Li-ion insertion/extraction process. Panels are reproduced with permission [111]. Copyright 2011, Elsevier. 

The significant improvement of capacity and cyclability of conjugated-polymer-based anode materials has been well described above in silicon and tin oxide, which often suffer the low electronic conductivity and especially the huge volumetric change during Li-ion insertion/extraction reaction. As for other anode materials, such as Fe O [112], NiO [113], TiO [114], and MoS [115], the similar functionalities were also demonstrated. 

The mechanism is, however, more complicated than simply the anion X entering the polymer during anodic polarization and leaving it upon the cathodic one, as cation motion can also be involved [2]. Conducting polymers are thus a class of ion-insertion electrochromic materials that act during an electrochromic process as mixed electronic and ionic conductors. 

A typical example of anodic ECMs is iridium oxide which may be rapidly and reversibly coloured in aqueous solutions containing sulphuric acid. The exact type and mechanism of the ion insertion process in this oxide are still uncertain [17]. In aqueous H2SO4, the most commonly used electrolyte, two mechanisms have been proposed, i.e. a cation mechanism involving coloration via proton extraction ... 

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