Electrical deposition efficiency

II. Ease of electrical connection Here the main problem is that of efficient electrical current collection, ideally with only two electrical leads entering the reactor and without an excessive number of interconnects, as in fuel cells. This is because the competitor of an electrochemically promoted chemical reactor is not a fuel cell but a classical chemical reactor. The main breakthrough here is the recent discovery of bipolar or wireless NEMCA,8 11 i.e. electrochemical promotion induced on catalyst films deposited on a solid electrolyte but not directly connected to an electronic conductor (wire). 

A well-distributed deposition of Pt/C nanocatalyst and Nafion ionomer on bofh hydrophilic and hydrophobic carbon-based electrodes has been successfully obfained using a Pt/C concentration of 1.0 g/L, an electrical field of 300 V/cm, and a deposition time of 5 minutes [118]. The deposition of Pt/C nanocatalysts and Nafion solution via the electrophoretic process gives rise to higher deposition efficiency and a uniform distribution of catalyst and Nafion ionomer on the PEMFC electrodes. 

Equations (33) - (35) are taken from Tardos et al (23), and are based on a low Reynold s number analysis. Eqn. (33) is the result of a "best-fit" of the theoretically computed values taken from Figure 7 of that same work. Similarly, Eqn. (36) for the electrical deposition, is obtained from a "best-fit" of the theoretically computed values taken from Figure 3 of Tardos and Pfeffer (21). Note that if the particle and collector charges are of the same sign, the electrical deposition efficiency becomes the negative of Eqn. (36). Consistent with the flow field models used in the development of Eqns. (33) - (36), the velocity employed is an assembly averaged velocity for each phase. For the multi-phase situation that exists in the fluidized bed, this is given by the superficial or empty-tower velocity divided by the phase volume fraction, ... 

Electrostatic spraying of powders is now a commercial reality. Golovoy (6) cites particle size, spherical particle shape, and electrical surface resistivity of the powder blend as important factors in deposition efficiency. 

Preliminary experimenu suggest that an adherent vacuum-sputtered carbon film can be deposited on gold-electroded PVDF elements at a temperature below the depolariza-lion temperature. Thus, the combined goab of efficient electrical insulation, impermeability lo blood fluids, flexibility and fatigue resistance, and minimum interaction with surroundings cells may be achieved for inqrtaniable devices. 

Lithium deposited on an anode during a charge is chemically active and reacts with organic electrolytes after deposition. Then, the lithium is consumed during cycling. The cycling efficiency (percent) of a lithium anode (Eff) is basically defined by Eq. (1) [23], where Qp is the amount of electricity needed to plate lithium and <2S is the amount of electricity needed to strip all the plated lithium. As Eff is less than 100 percent, an excess of lithium is included in a practical rechargeable cell to compensate for the consumed lithium. 

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