Bobbin batteries

D-size bobbin battery at +25°C. (b) Operating (plateau) voltage of the same battery as a function of temperature at various drain rates. (Ref. 23.)... 

FIGURE 14.19 Discharge characteristics of Ii/SOCl2 cylindrical D-size bobbin battery at IdST . (From Ref. 24.)... 

FIGURE 14.21 Service life of Li/SOClj cylindrical high-capacity bobbin batteries to 2.0 volt cut-off. 

FIGURE 14.23 Li/SOClj cylindrical AA-size bobbin batteries—minimum voltage vs. load after 2-year storage at 25°C (a) standard construction (b) with loading on lithium anode. 

FIGURE 14.39 Cross-sectional view of Li /MnOj bobbin battery. Courtesy of Duracell, Inc.)... 

The performance of the Li/MnOj cylindrical bobbin battery at temperatures from -20 to 60°C is shown in Fig. 14.50. Operation of the coin-type and cylindrieal bobbin eleetrode batteries at the lower temperatures is limited to the lower diseharge rates. 

FIGURE 14.48 Discharge characteristics of li/MnOj cylindrical bobbin battery (850-mAh size) at 20°C. a) Discharge tune in hours, (fc) Discharge time in days. Courtesy ofDuracell, Inc.)... 

Figure 1. The design principle of a cylindrical Zn-carbon (Leclanche) cell [21. I, Zinccan 2, separator MnO, bobbin (Reproduced by courtesy of Varta Battery AG).

Dry cells have been well-known for over 100 years and form the technical basis of today s modern dry cell industry. Zinc carbon cells are the most widely used of all the primary batteries worldwide because of their low cost, availability, and acceptability in various situations. The two major separator types ever used or in use are gelled paste and paper coated with cereal or other gelling agents such as methyl-cellulose. The paste type is dispensed into the zinc can, and the preformed bobbin is inserted, pushing the paste up the can walls between the zinc and the bobbin. A typical paste electrolyte uses zinc chloride, ammonium chloride, water, and starch or flour as the gelling agents. The coated-paper type uses a special paper coated with flour, starch, regenerated cellulose. 

The model 2/3A batteiy is a cylindrically shaped bobbin-type battery, 1.6 cm in diameter and 5 cm long. The battery is a solid cathode type with a nominal 3.0 volt rating. It has low to moderate power capability. The battery is not pressurized and doesn t need a hermetic seal. It is generally used for portable electronic equipment, photographic equipment, watches, calculators, etc. Lifetimes of up to 10 years are obtained. 

The cylindrical cells use a jellyroll construction similar to that already described for Li-FeS2 cells (Fig. 1). However, the cathode is typically thicker and embedded into a stainless steel Exmet screen rather than coated onto foil. Specialty versions of cylindrical cells using a bobbin construction are also manufactured these cells have higher capacity, but can only discharge at very low drain rates. Miniature cells use much of the same materials, but the electrodes are punched out and stacked together with a disk of separator material (Fig. 8). The 9 V battery uses a system of three unit cells wired in series using folded electrodes and a common case (Fig. 9). 

Most primary or dry cells with aqueous electrolytes employ single, thick electrodes arranged in parallel or concentric configurations. Typical battery configurations are categorized as cylindrical, bobbins, buttons, or coin cells. Some primary cells are made in prismatic and thin, flat constructions to achieve the lowest volume. These form factors yield poor energy density and power capacity levels. 

Fabrication of a battery or a cell determines how the device will function and how much it will cost to construct it. Several primary cells with aqueous electrolytes seem to use a single electrodes arranged in parallel or concentric configuration. Specific construction of this type of cell includes cylindrical or bobbin button, and coin. Small secondary cells use a wound or jelly roll construction feature, in which long thin electrodes are wound into a cylinder and placed in a metallic housing or container. This particular cell construction yields higher power density, but it... 

The LiMnOj battery is the most popular lithium battery, and it is produced worldwide by more than 14 manufacturers. The battery cells are available in a wide range of sizes, shapes, and capacities. Types of construction features for this battery include coin shape, cylindrical bobbin, cylindrical wound, cylindrical D cell configuration, and prismatic feature. Performance characteristics of commercially available LiMn204 rechargeable batteries are summarized in Table 8.2. 

The bobbin usually contains ratios of manganese dioxide to powdered carbon from 3 1 to as much as 11 1 by weight. Also, 1 1 ratios have been used in batteries for photoflash applications where high pulses of current are more important than capacity. 

Experimental work on Al/MnOj primary or dry batteries was concentrated on the D-size cylindrical battery using a construction similar to the one used for the Mg/Mn02 battery (Fig. 9.3). The most successful anodes were made of a duplex metal sheet consisting of two different aluminum alloys. The inner, thicker layer was more electrochemically active, leaving the outer layer intact in the event of pitting of the inner layer. The cathode bobbin consisted of manganese dioxide and acetylene black, wetted with the electrolyte. Aqueous solutions of aluminum or chromium chloride, containing a chromate inhibitor, were the most satisfactory electrolytes. 

Low rate Bobbin in cy- 3.6 3.5-3.3 590 1100 Medium Flat Cylindical batteries... 

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