Diffusion battery design

Raes, F., and A. Reineking, A New Diffusion Battery Design for the Measurement of Sub-20 nm Aerosol Particles The Diffusion Carrousel, Atmos. Environ., 19, 385-388 (1985). 

Three reviews describing applications of diffusion denuders have been published. The doctoral dissertation of Ferm (31) reflects considerable experience with single-tube denuders for the measurement of a variety of species. The review by Ali et al. (32) is extensive it provides an excellent historical and theoretical background and summarizes the literature based on the type of analyte gas determined. The focus of the most recent review, by Cheng (19), is diffusion batteries used for size discrimination of aerosols as well as diffusion denuders. Various physical designs are discussed in some detail in that review. 

These results can be applied to deposition in sampling tubes and to the design of the diffusion battery, a device used to measure the particle size of submicron aerosols. The... 

Starved electrolyte battery — A -> battery with minimum amount of -> electrolyte. The electrolyte in starved electrolyte cells or batteries exists in the porous structure of the - electrodes and absorbed in the separator, so it contains little or no free fluid electrolytic solution. This type of batteries is used in certain constructions of sealed - lead-acid and -> nickel-cadmium batteries that rely on gas diffusion and recombination on the electrodes during charging or overcharging in order to maintain maintenance-free conditions, and to suppress pressure buildup. Starved electrolyte batteries benefit from larger - energy density due to the reduced amount of electrolyte. This design may suffer from poor heat dissipation compared with -> flooded batteries, thus for high power applications this point has to be taken into account. 

The important design difference between VRLA and flooded lead-acid batteries is the partially saturated condition of the plates and separator in VRLA products. As noted earlier, the diffusion rates for oxygen and hydrogen are lO times greater... 

Diffusion potential is also created between the electrolyte concentrations near the positive and the negative battery plates on charge and discharge [10]. A certain period of time is needed to equalize the H2SO4 concentration between the two plates before measuring the EMF of the cell. The duration of this time period depends on the particular cell design. 

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