Cell design, zinc chloride

The name Leclanche cell is given to the familiar primary system consisting of a zinc anode, manganese dioxide cathode and an electrolyte of ammonium chloride and zinc chloride dissolved in water. The alternative designation zinc-carbon ceir is broader and includes the so-called zinc chloride system which, due to a different electrolyte composition, is characterized by a different discharge mechanism. The Leclanche cell may be written as... 

PERFORMANCE OF A CONVENTIONAL CELL DESIGN FOR ZINC CHLORIDE... 

Zinc-Carbon Battery. The Leclanche or zinc-carbon dry cell battery has existed for over 100 years and had been the most widely used of all the dry cell batteries because of its low cost, relatively good performance, and ready availability. Cells and batteries of many sizes and characteristics have been manufactured to meet the requirements of a wide variety of applications. Significant improvements in capacity and shelf life were made with this battery system in the period between 1945 and 1965 through the use of new materials (such as beneficiated manganese dioxide and zinc chloride electrolyte) and cell designs (such as the paper-lined cell). The low cost of the Leclanchd battery is a major attraction, but it has lost considerable market share, except in the developing countries, because of the newer primary batteries with superior performance characteristics. 

Industrial Heavy Duty. Application Low to intermediate-continuous and intermittent heavy-rate discharges low to moderate cost. This battery has generally replaced the industrial Leclanch6 heavy-duty battery. It is a true zinc-chloride cell and possesses the heavy-duty characteristics of the premium zinc chloride type. The cell electrolyte is zinc chloride however, some manufacturers may add small amounts of ammonium chloride. Natural manganese dioxide ore is used along with electrolytic manganese dioxide as the cathode. These cells use paper separators coated with cross-linked or modified starches, which enhance their stability in the electrolyte. Batteries of this formulation and design are competitive in cost to the Leclanche heavy-duty industrial batteries. They are recommended for heavy-duty applications where cost is an important consideration. This battery also exhibits a low le age characteristic. 

Similar to the concept described for the Oj-Hj cell system, the reductive activation of oxygen can be expected at the cathode in the presence of a suitable catalyst. On the basis of this zinc-air battery model, we have designed a number of catalytic systems from mixtures of zinc powder, carboxylic acid and various metal chlorides for oxygenations of alkanes and alkenes. In these catalytic systems, zinc powder works as the reductant as well as the electron conducting medium. The carboxylic acid works as a proton-conducting medium. Oxygen is reductively activated on the metal cations by protons from the carboxylic acid and electrons from zinc powder. 

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