Primary lithium batteries chemistry

One of the most common lithium primary battery chemistry is lithium sulfiir dioxide. It is lightweight and is used in a wide range of communications devices. The lithium sulfur dioxide battery provides power over a wide temperature range (-20 to +140° F) and has rather constant output until depleted. 

Batteries based on most combinations of the above types of solvent- lectrolytes and positive electrodes have been produced and tested. Naturallyt only a fraction have reached the stage of commercial manufacture but the wide variety of primary lithium batteries which have reached the market-place during the last 15 years is impressive. Table 10.7 seeks to illustrate the chemistry and performance as welt as the options as regards cells sizes and geometries for the most important lithium primary batteries now available for purchase. 

The term primary battery is used to describe any single use battery system. These include, amongst others, alkaline-manganese, zinc-carbon, lithium, mercuric oxide and zinc-air chemistries. Primary batteries are lightweight and convenient, relatively inexpensive and eonsequently are used by households throughout the world to power portable electrical and electronic devices, radios, torches, toys and a whole host of other every day appliances. 

While the development of primary cells with a lithium anode has been crowned by relatively fast success and such cells have filled their secure rank as power sources for portable devices for public and special purposes, the history of development of lithium rechargeable batteries was full of drama. Generally, the chemistry of secondary batteries in aprotic electrolytes is very close to the chemistry of primary ones. The same processes occur under discharge in both types of batteries anodic dissolution of lithium on the negative electrode and cathodic lithium insertion into the crystalline lattice of the positive electrode material. Electrode processes must occur in the reverse direction under charge of the secondary battery with a negative electrode of metallic lithium. Already at the end of the 1970s, positive electrode materials were found, on which cathodic insertion and anodic extraction of lithium occur practically reversibly. Examples of such compounds are titanium and molybdenum disulfides. 

Developed in the early 1970s, primary lithium batteries are the most energy-dense electrochemical cells made for watches, film cameras, medical devices, and military purposes. Lithium primary cells have a typical gravimetric density 250 Wh kg against only 150 Wh kg for Li-ion batteries. Various technologies that differ in chemistry and construction have been used to develop primary lithium batteries. In Table 2.4, they are classified into three groups, according to the form and the type of cathode and electrolyte used. Frost and Sullivan said that in 2009,... 

The semiconductive properties and tunnel structure of sulfide and transition-metal oxides led to the use of these materials in lithium power sources (Table 2.5). Several lithium-based chemistries were successfully applied to replace the prior system Zn/AgO and later the lithium-iodine batteries in implantable medical devices [59-61]. For example, Li//CuO, Li//V205, Li//CF and more recently Li// Ag2V40ii couples have been adopted to power cardiac pacemakers requiring less that 200 pW [62,63]. The lithium/carbon monofluoride (Li//CFJ primary cells are very attractive in several applications because of the double energy density with respect to the state-of-the-art LiZ/MnOa primary batteries (theoretically 2203 against 847 Wh kg ). 

As seen in the previous section there are numerous types of lithium batteries. In this section, we shall look at the generic hazards of primary (with liquid or solid cathode) and rechargeable batteries. There is much controversy over the reactivity of several individual chemistry types. It is the authors opinion that there are inherent hazards associated with any battery type or energy source and in most situations the hazards and size are directly related. In a similar scenario, lithium batteries in general cannot be categorized into being more or less hazardous than any other chemistry without knowing the exact type and size of the systems to be compared. 

Size, weight, capacity, and power density are the primary selection considerations for batteries in externally powered prosthetic design applications. The most popular types of rechargeable batteries in use in prosthetics today are nickel-cadmium (NiCd), nickel-metal-hydride (NiMH), and lithium-ion (Li-ion). Li-ion is fast becoming the chemistry of choice because of its high capacity-to-size (weight) ratio and low self-discharge characteristic. 

The primary molecular modeling methods that have been extensively applied to lithium battery electrolytes and electrode/electrolyte interfaces are molecular orbital calculations and molecular dynamics simulations. The former involves ab initio and density functional methods and will be referred to quanmm chemistry or QC... 

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