Aqueous Fuel Cell Using Specific Electrolyte

1 Aqueous Fuel Cell Using Specific Electrolyte 

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Like fuel cells, batteries using molten salt electrolytes offer high performance. Molten salts have very high electrical conductivity, which permits the use of high current densities. Likewise, molten salts permit the use of highly reactive electrode materials, which cannot be used in aqueous electrolytes. For these reasons, batteries with molten salts offer very high specific energy (>100 Wh/kg). To... 

FIGURE 21.1 Specific conductivities of electrolytes used in fuel cells in different temperature ranges. (Data from Spedding, P.L., J. Electrochem. Soc., 120, 1049, 1973 Horvath, A.L., Handbook of Aqueous Electrolyte Solutions, Ellis Horwood Ltd., Chichester, U.K., 1985 Brandon, N.P. et al., Annu. Rev. Mater. Res., 33, 183, 2003 Dimitrova, P. et al.. Solid State Ionics, 150, 115, 2002.)... 

DMFC offers a low-cost, portable, reliable fuel cell operating at moderate temperatures not exceeding 100°C and under one atmospheric pressure. It uses dissolved fuels, such as CH3OH, which are fairly inexpensive and available without any restriction. A dissolved fuel cell contains a mixture of the usual alkaline aqueous electrolyte and a soluble cheap fuel. The electrodes must show different specific catalyst activities to produce voltage. The cell must contain a highly... 

Jha dedicates a chapter specifically to fuel cells and describes the three distinct types of practical fuel cells, including those that use (1) aqueous electrolytes, (2) molten electrolytes, and (3) solid electrolytes. The fuel cell is an electricity generation system that combines an oxidation reaction and a reduction reaction. In a fuel cell, both the fuel and oxidant are added from an external source to react at two separate electrodes, whereas in a battery, the two separate electrodes are fuel and oxidant. Therefore, in the fuel cell in an energy conversion device, chemical energy... 

EFCs are electrochemical systems that consist of an anode, a cathode, and an electrolyte. Design of EFC prototypes was inspired by conventional batteries and fuel cells, but there are substantial differences that lead to completely new design concepts and requirements. Specifically, in contrast to conventional batteries, the oxidized substance in the EFC is not carried in the electrodes, but instead stored as a fuel. In contrast to conventional fuel cells, EFCs use highly selective enzymes in the anode and cathode reactions and they can operate without any membrane separation, in neutral aqueous electrolyte, and at room temperature and are capable to provide deep, or complete, fuel oxidation. 

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