Primary aqueous cells

With the continuing development of portable electric and electronic equipment, demand for small primary aqueous electrolyte cells continues to expand and a growth rate in world production in the range of 6-12% per annum has been maintained over the past 25 years. It is estimated that there is now an annual consumption averaging 8-15 cells per person in the Western developed countries. 

By far the largest sector of the battery industry worldwide is based on the lead-acid aqueous cell whose dominance is due to a combination of low cost, versatility and the excellent reversibility of the electrochemical system, Lead-acid cells have extensive use both as portable power sources for vehicle service and traction, and in stationary applications ranging from small emergency supplies to load levelling systems. In terms of sales, the lead-acid battery occupies over 50% of the entire primary and secondary market, with an estimated value of 100 billion per annum before retail mark-up. 

The zinc-silver oxide couple has been known for over 100 years and forms one of the highest energy aqueous cells. The theoretical energy density is 300 Wh/kg (1400 Wh/dm3) and practical values in the range 40-110 Wh/ kg (116-320 Wh/dm3) have been achieved. Primary cells were considered briefly in Chapter 3. 

Primary lithium cells compare favorably with cells with aqueous electrolytes because of their very good shelf life in other words, very low self-discharge. The best shelf life is characteristic for lithium iodine cells, in which the capacity loss under storage for 10 years at the temperature of 40°C does not exceed 10% The guaranteed shelf life (under due conditions) of lithium cells with other electrochemical systems is... 

Primary lifhium cells use a lithium-metal anode and a nonaqueous electrolyte having a larger window than the 1.23 eV of an aqueous electrolyte. Both liquid and solid Li -ion electrolytes can be used. 

The development of primary lithium batteries for implantable medical devices was a big advance that enabled devices to operate more reliably and longer. Lithium is the lightest metal and has the most negative reduction potential. When combined with any number of positive electrode materials, the result is cells with high energy densities compared to aqueous cells. Most lithium cells have an initial open circuit voltage between 1.8 and 3.9 V, compared to 1.2-1.6 V for most aqueous cells. 

Leclanch6 and alkaline cells with aqueous electrolytes, but also in primary lithium cells with organic electrolytes. The y - MnOj structure consists of inter-grown domains of -Mn02 and... 

Zinc/carbon and alkaline/manganese cells are primary battery systems lead, nickel/cadmium, and nickel/metal hydride accumulators are secondary batteries with aqueous electrolyte solutions. Their per-... 

It is so universally applied that it may be found in combination with metal oxide cathodes (e.g., HgO, AgO, NiOOH, Mn02), with catalytically active oxygen electrodes, and with inert cathodes using aqueous halide or ferricyanide solutions as active materials ("zinc-flow" or "redox" batteries). The cell (battery) sizes vary from small button cells for hearing aids or watches up to kilowatt-hour modules for electric vehicles (electrotraction). Primary and storage batteries exist in all categories except that of flow-batteries, where only storage types are found. Acidic, neutral, and alkaline electrolytes are used as well. The (simplified) half-cell reaction for the zinc electrode is the same in all electrolytes ... 

Aqueous polysulflde solutions have been widely investigated as primary electrolytes in photoelectrochemical solar cells (PEC Chap. 5). The complexity of these solutions arising from the overlap of multiple chemical equilibria is well... 

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