Primary electrochemical cells

Graham, R. W., ed. (1981). Primary Electrochemical Cell Technology Advances Since 1977. Park Ridge, NJ Noyes Data Corporation. 

Explain the differences between a primary electrochemical cell—one that is not rechargeable—and a storage cell (for example, the lead storage battery), which is rechargeable. 

Manganese dioxide, Mn02, (MDO) is a widely used as material in primary electrochemical cells. It is the positive electrode of the zinc-MnOa cell, invented in 1866 by the French engineer Georges-Lionel Leclanche [11]. Li-MnOa battery was developed by Sanyo in 1975 [12] as low-power supplies for watches, calculators and memory backups. The poor cyclability of MDOs observed at that time [13] has been improved by preparing composite dimensional manganese oxides (CDMOs) for the development of flat-type secondary batteries. Table 6.2 lists the chemical formula of selected Li-Mn-O compounds used in Li batteries. 

There are two major types of electrochemical cells primary batteries and secondaiy, or storage, batteries. Primary hatteiy construction allows for only one continuous or intermittent discharge secondary hattei y construction, on the other hand, allows for recharging as well. Since the charging process is the... 

The "classical" Leclanche cell uses zinc sheet formed into a cylindrical can serving simultaneously as the anode and as the cell container (AB1C1). The cathode is a mixture of Mn02 and graphite wrapped into a piece of separator and contacted by a central carbon rod. The can dissolves slowly when the cell is not in use and faster when the cell delivers electrical energy. The reaction following the primary electrochemical zinc dissolution [Eq. (19)] leads, in the case of an ammonium chloride electrolyte, to a zinc diammine cation ... 

The majority of electrochemical cells to have been constructed are based on PEO, PAN, or PVdF [101]. Recently, the Yuasa Corporation have commercialized solid polymer electrolyte batteries, primarily for use in devices such as smart cards, ID cards, etc. To date, the batteries which have been manufactured and marketed are primary lithium batteries based on a plasticized polymer electrolyte, but a similar secondary battery is expected [120]. 

Most of the methods we have described so far give the activity of the solvent. Often the activity of the solute is of equal or greater importance. This is especially true of electrolyte solutions where the activity of the ionic solute is of primary interest, and in Chapter 9, we will describe methods that employ electrochemical cells to obtain ionic activities directly. We will conclude this chapter with a discussion of methods based on the Gibbs-Duhem equation that allow one to calculate activities of one component if the activities of the other are known as a function of composition. 

One spare electrochemical cell stack is installed in the primary anolyte circuit. Manual intervention is required to connect the spare cell stack and disconnect a faulty cell stack. Five spare cell stacks are kept in storage, allowing replacement of all primary or secondary electrochemical cell stacks (but not both at once) in the case of common-mode failure, e.g., severe blockage. The inventory of spare cell stacks was not deemed necessary to cover common-mode failure of both primary and polishing (secondary) electrochemical cells, because their anolyte circuits are separate and the catholyte circuit is much less likely to be the source of failure (AEA, 2001a). 

Early electrochemical processes for the oxidation of alcohols to ketones or carboxylic acids used platinum or lead dioxide anodes, usually with dilute sulphuric acid as electrolyte. A divided cell is only necessary in the oxidation of primary alcohols to carboxylic acids if (he substrate possesses an unsaturated function, which could be reduced at the cathode [1,2]. Lead dioxide is the better anode material and satisfactory yields of the carboxylic acid have been obtained from oxidation of primary alcohols up to hexanol [3]. Aldehydes are intermediates in these reactions. Volatile aldehydes can be removed from the electrochemical cell in a... 

Much of the recent research in solid state chemistry is related to the ionic conductivity properties of solids, and new electrochemical cells and devices are being developed that contain solid, instead of liquid, electrolytes. Solid-state batteries are potentially useful because they can perform over a wide temperature range, they have a long shelf life, it is possible to make them very small, and they are spill-proof We use batteries all the time—to start cars, in toys, watches, cardiac pacemakers, and so on. Increasingly we need lightweight, small but powerful batteries for a variety of uses such as computer memory chips, laptop computers, and mobile phones. Once a primary battery has discharged, the reaction cannot be reversed and it has to be thrown away, so there is also interest in solid electrolytes in the production of secondary or storage batteries, which are reversible because once the chemical reaction has taken place the reactant concentrations can be... 

Discussion of general operation of conductometric sensors can begin by analyzing Fig. 8.1. Once again we realize that the electrochemical cell is a complex arrangement of resistances and capacitances. The primary interaction between the sample and the sensor involves the selective layer the sensory information is... 

Abstract The primary method for pH is based on the measurement of the potential difference of an electrochemical cell containing a platinum hydrogen electrode and a silver/silver chloride reference electrode, often called a Harned cell. Assumptions must be made to relate the operation of this cell to the thermodynamic definition of pH. National metrology institutes use the primary method to assign pH values to a limited number of primary standards (PS). The required comparability of pH can be ensured only if the buffers used for the calibration of pH meter-electrode assemblies are traceable to... 

The primary method for pH is based on the measurement of the potential difference of the electrochemical cell without a liquid junction involving a selected buffer solution, a platinum hydrogen gas electrode and a silver/silver chloride reference electrode, often also referred to as a Harned cell. 

The purity value of this salt is assigned by a coulo-metric method, which is one of the potentially primary methods for amount of substance determination, according to the CCQM. The principle of this method is as follows given an analyte dissolved in a solution, both the solution and the analyte contained in an electrochemical cell, the amount of electrical charge required to perform a chemical reaction in which the analyte of interest can be converted in another compound, is directly proportional to the amount of substance of this analyte. 

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