Electrochemistry in Nonaqueous Solutions || Use of Nonaqueous Solutions in Modern Electrochemical Technologies

✍ Scribed by Izutsu, Kosuke

• Publisher: Wiley-VCH Verlag GmbH & Co. KGaA
• Year: 2009
• Tongue: German
• Weight: 313 KB
• Edition: 2nd, Revised and Enlarged
• Category: Article
• ISBN: 3527323902
• DOI: 10.1002/9783527629152.ch12

✦ Synopsis

Recently, applications of nonaqueous solutions are increasing in the field of modern electrochemical technologies. In this chapter, examples of such applications of nonaqueous solutions are outlined. The technological aspects of nonaqueous electrochemistry have been dealt with in books [1] and review articles [2].

12.1 Batteries Using Nonaqueous Solutions -Lithium Batteries (a) Primary lithium batteries [1] Primary lithium batteries, which are commercially available since 1970s, are still used as power sources for cameras, watches, calculators and various other portable electronic devices. As a typical example, the schematic diagram of the coin-type Li/MnO 2 battery is shown in Figure 12.1. It consists of an anode (negative electrode), a cathode (positive electrode), an electrolyte solution and a porous separator. The anode is Li metal, the cathode is MnO 2 and the electrolyte solution is $1 M LiClO 4 or Li(SO 3 CF 3 ) in a nearly 1: 1 mixture of propylene carbonate (PC) and 1,2-dimethoxyethane (DME). The porous separator is an unwoven cloth of polyolefins (e.g. polypropylene). The voltage of this cell is about 3.0 V and the reactions during the discharge are as follows:

At the anode, metallic lithium dissolves as lithium ion (Li þ ) and at the cathode, Li þ diffuses into the crystal lattice of manganese dioxide. Electrolyte solutions of various aprotic organic solvents are used in primary lithium batteries. Among the organic solvents are alkyl carbonates (PC (e r ¼ 64.4), ethylene carbonate (EC, 89.6 40 C ), dimethyl carbonate (DMC, 3.1), diethyl carbonate (DEC, 2.8)), ethers (DME (7.2), tetrahydrofuran (THF, 7.4), 2-Me-THF (6.2), 1,3-dioxolane (DIOX, 7.1)) and esters (methyl formate (MF, 8.5 20 C ), g-BL