Coulombic/energy efficiency

The overall lattice energies of ionic solids, as treated by the Born-Eande or Kaputin-sldi equations, thus depends on (i) the product of the net ion charges, (ii) ion-ion separation, and (iii) pacldng efficiency of the ions (reflected in the Madelung constant, M, in the Coulombic energy term). Thus, low-melting salts should be most... 

The use of periodic boundary conditions also allows for an efficient evaluation of the ion-ion interaction. Ewald developed a method to compute the Coulomb energy associated with long range ion-ion interactions in solids. The Coulomb energy due to interactions between an ion at position R2 and an array of ions positioned at Rj+i is given by... 

The efficiency of the methods outlined above has been tested by calculating the intermolecular Coulomb energies and forces for a series of water boxes (64,128,256, 512 and 1024) under periodic boundary conditions [15, 62], The electron density of each monomer is expanded on five sites (atomic positions and bond mid-points) using two standard ABSs, A2 and PI.These sets were used to fit QM density of a single water molecule obtained at the B3LYP/6-31G level. We have previously shown that the A1 fitted density has an 8% RMS force error with respect to the corresponding ab initio results. In the case of PI, this error is reduced to around 2% [15, 16], Table 6-1 shows the results for the 5 water boxes using both ABSs (Table 6-7). 

Grebenyuk et al. (1998) suggested another method to assess the membrane stability against fouling. It was based on the ratio between the overall energy consumption (L) and Coulomb s efficiency (lie) during a real ED process to that observed in ideally nonfouled (Kf) or modified (Ks) membranes. 

The energy efficiency of the EV battery is <50%. The major cause of coulombic inefficiency (10-30%) is the chemical reaction of zinc with dissolved chlorine. Thanks to kinetic inhibitions, only about 1% inefficiency (over the complete cycle) derives from the evolution of hydrogen and carbon oxides. The latter derive from... 

Two types of efficiency measurement are generally performed on MFCs coulombic efficiency (CE) and energy efficiency (EE). 

An efficient numerical method, developed and used in [43,90- 92] for the computation of the Coulomb energy of 3D systems with 2D periodicity has been shown in [93] practically equivalent to the above described methods based on the use of the Ewald sum for 3D systems with 3D periodicity. 

A separator was not required for this kind of battery. Average coulombic and energy efficiencies were up to 96% and 86%, respectively [57]. Over 1,000 cycles were achieved in a small laboratory cell. Zinc deposition from an alkaline zincate solution has been also investigated [58], and results show that zinc deposition on the cadmium substrate is better than other materials, for example, Cu, Pb. On the cadmium-coating electrode, electroplating behavior was simple and facilitated the discharge of zinc. 

The Coulombic efficiency of ESs, defined as the ratio of the discharge current to the charging current, can be expected to approach 100% even at high currents. In practical use, the charge and discharge current values are controlled to be the same, so the Columbic efficiency equals 100%. This efficiency applies to fhe currenf, and does not directly correspond to high energy efficiency. 

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