Lithium anode reserve batteries

AMBIEINTT-TEMPERATURE LITHIUM ANODE RESERVE BATTERIES... 

Lithium anode reserve batteries are basically composed of three major components ... 

TABLE 20.1 Typical Characteristics of Lithium Anode Reserve Batteries... 

MulticeU Bipolar Construction with Single-Activator Reservoir. Lithium anode reserve batteries, using bipolar constraction, are relatively few in number and always developed for specific applications. The bipolar constraction—one component used as hotii the anode collector of one cell and the cathode collector of the next cell in the stack— is not unique to the lithium reserve battery, but an adaptation of techniques used in other types of batteries. There are several advantages of the bipolar constraction ... 

More recently, spin-dependent liquid-electrolyte reserve batteries employing lithium anodes have been developed. The most promising system is that in which thionyl chloride serves in the dual role of electrolyte carrier and active cathodic depolarizer (see Chap. 20). The accepted cell reaction for this system is... 

The use of lithium metal as an anode in reserve batteries provides a significant energy advantage over the traditional reserve batteries because of the high potential and low equivalent weight (3.86 Ah/g) of lithium. A lithium reserve battery can operate at a voltage close to twice that of the conventional aqueous types. Due to the reactivity of lithium in aqueous electrolytes, with the exception of the special lithium-water and lithium-air batteries (see Sec. 38.6), lithium batteries must use a nonaqueous electrolyte with which hthium is non-reactive. 

In the selection of a lithium anode electrochemical system for packaging into a reserve battery, besides such important considerations as physical properties of the electrolyte solution and performance as a function of the discharge conditions, factors such as the stability of the electrolyte and the compatibility of the electrolyte with the materials of construction of the electrolyte reservoir are of special importance. 

The basic cell structure of this system consists of a lithium anode, a microporous polypropylene film separator, and a cathode that is usually composed of 90% V2O5 and 10% graphite, on a weight basis. When it is used in a reserve battery, the prevalent electrolyte is 2M LiAsFg + 0.4M LiBp4 in methyl formate (MF) because of its excellent stability during long-term... 

Several types of primary batteries have been developed that use lithium-metal anodes and solid cathodes. This entry reviews the more common commercial systems, namely Li-FeS2, Li-MnOa, and Li-CFx- Readers are referred to the relevant sections for information on Li-V20s and Li-Ag2V40ii cells that are used for reserve and medical battery applications, respectively. There has been a wide range of cathodes developed in the laboratory and also marketed for specialty applications [1], but most have never been produced commercially. (Li-CuO cells were made for some military applications [2], but production was discontinued in the mid-1990s). Before going into details on the aforementioned three types mostly used in consumer applications, we will cover the main characteristics that they have in common. 

Lithium batteries use nonaqueous solvents for the electrolyte because of the reactivity of lithium in aqueous solutions. Organic solvents such as acetonitrile, propylene carbonate, and dimethoxyethane and inorganic solvents such as thionyl chloride are typically employed. A compatible solute is added to provide the necessary electrolyte conductivity. (Solid-state and molten-salt electrolytes are also used in some other primary and reserve lithium cells see Chaps. 15, 20, and 21.) Many different materials were considered for the active cathode material sulfur dioxide, manganese dioxide, iron disulfide, and carbon monofluoride are now in common use. The term lithium battery, therefore, applies to many different types of chemistries, each using lithium as the anode but differing in cathode material, electrolyte, and chemistry as well as in design and other physical and mechanical features. 

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