Battery assembly

Battery assembly using cylindrical cells varies, and ceU-to-ceU connections are spot welded after using either flat tabs or cup tabs. CeU-to-ceU insulation is effected either by using plastic cell jackets (shrink-on) or by inserting cells in plastic modules with each cell occupj-ing its own cavity. 

Silver electrodes prepared by any of the three methods are almost always subjected to a sintering operation prior to cell or battery assembly. 

The subsequent procedures, formation, washing, drying, and battery assembly are similar to those described above. 

This operation is also performed using machines. The cured plates are fed into the parting machine by mechanical means. The plates are parted in the machine and then collected when the operation is completed manually. The parted plates are thereafter stacked for use in battery assembly. More rejects are also generated in this section as well as some lead dust. The ventilation system in this area ensures that the lead dust generated is removed from the work area and discharged into the atmosphere through a baghouse filter. 

The main fields of application for this battery chemistry include portable TVs, radio receivers, lamps, flashlights, electric shavers, barrier lightning, instruments, batteries for portable rechargers, emergency power supplies, small refrigerators, power sources for tourists, hunters, geologists, shepherds and so on. Parameters of some batteries, assembled from the modules, are summarized in Table 4. 

Fig. 12.3 Fabrication of the nanocomposite paper units for battery, (a) Schematic of the battery assembled by using nanocomposite film units. The nanocomposite unit comprises LiPF6 electrolyte and multiwalled carbon nanotube (MWNT) embedded inside cellulose paper. A thin extra layer of cellulose covers the top of the MWNT array. Ti/Au thin film deposited on the exposed MWNT acts as a current collector. In the battery, a thin Li electrode film is added onto the nanocomposite, (b) Cross-sectional SEM image of the nanocomposite paper showing MWNT protruding from the cel-lulose-RTIL ([bmlm] [Cl]) thin films (scale bar, 2pm). The schematic displays the partial exposure of MWNT. A supercapacitor is prepared by putting two sheets of nanocomposite paper together at the cellulose exposed side and using the MWNTs on the external surfaces as electrodes, (c) Photographs of the nanocomposite units demonstrating mechanical flexibility. Flat sheet (top), partially rolled (middle), and completely rolled up inside a capillary (bottom) are shown (See Color Plates)...

Fig. 12.3 Fabrication of the nanocomposite paper units for battery, (a) Schematic of the battery assembled by using nanocomposite film units. The nanocomposite unit comprises LiPF6 electrolyte and multiwalled carbon nanotube (MWNT) embedded inside cellulose paper. A thin extra layer of cellulose covers the top of the MWNT array. Ti/Au thin film deposited on the exposed MWNT acts as a current collector. In the battery, a thin Li electrode film is added onto the nanocomposite.

Early experiments with planar electrodes (Figure 16a) lead to car battery assemblies of radiating walls, where the reaction mixture is circulating in between the lamps (Figure 16b) [60-62]. 

Fig. 8.11 Charge-discharge characteristics for a Li-FeS2 cell at 450°C, Battery assembled in uncharged state. Current = 5 A. (By permission of Academic Press as Fig. 8,10.)...

Another feature of AGM separators is their compressibility. With compression of the plate and separator stack, this AGM property guarantees good plate-separator contact, even if the plates are not perfectly smooth. Also, battery assembly is facilitated since the stack can be easily inserted into the cell after compression to a thickness lower than the cell dimension. An undesirable result of the compressibility is that the AGM separator does not exert sufficient resistance against expansion of the positive plate during battery cycle-life. This expansion is particularly prevalent in deep-cycle applications and can cause the battery to suffer premature capacity loss (PCL) via reduced inter-particle conductivity — a phenomenon known as PCL-2 [7]. In the literature, two additional characteristics, which are related to the PCL-2 failure mode, are discussed, namely, AGM separators shrink when first wetted with electrolyte and their fibres can be crushed at high pressure levels [8-10]. These features result in a loss of separator resilience, i.e., a lessening of the ability to display a reversible spring effect. 

The architecture of the soft hybrid battery is described in Fig. 11.16. The contactor in this representation is denoted as outside the battery system, but it could be incorporated as part of the battery assembly. This representation also includes a battery controller within the battery assembly that may actually be physically located outside the battery box or even as shared space on another... 

Battery assembly. Dried plates are stacked in active blocks, so that positive and negative plates alternate with separators in between. Plates of like polarity are interconnected into semi-blocks by welding together through the plate lugs. The active blocks are then introduced into battery containers, the cells are connected and the batteries are covered with lids and tested for air-tightness. The vents are closed to eliminate access of air from the surroundings, and the batteries are packed and ready for delivery. 

Batteries intended to be used within 2 or 3 months after manufacture are produced with lead—ealeium—tin alloys, filled with electrolyte and ready for use. In this case, the technological scheme in Fig. 2.52 is modified. The tank formation and plate drying steps are eliminated and plate curing is followed by battery assembly, the formation process being completed in the battery itself. 

Sivakkumar, S., Kim, D.-W., 2007. Polyanfline/carbon nano tube composite cathode for rechargeable lithium polymer batteries assembled with gel polymer electrolyte. J. Electrochem. Soc. 154, A134-A139. 

Separators must have a longtime chemical and mechanical stability in the battery environment. They must be sufficiently elastic so as not to break down in the course of battery assembling and be shockproof. In addition, they must be inexpensive, simple in manufacture, with reproducible properties in large-scale production. An ideal separator must introduce only a minimum resistance to ionic current. The conductance attenuation coefficient varies from 1.1 to 1.6 for simple spacers and from 2 to 8 for porous and ultra porous varieties, reaching 15 only in exceptional cases. Depending on the battery type and function, separators either fill the whole electrode gap or only a part of it. In the latter case electrode surface is in free contact with the free liquid electrolyte, which is sometimes essential for sheet-shaped separators to have several rips in order to ensure a gap between them and the electrodes. 

Naoi, K., A. Ishijima, and T. Osaka. 1987. An improvement of battery performance of lithium batteries assembled with a polypyrrole cathode formed electrochemically with the aid of a nitrile rubber insulating film. J Electroanal Chem 217 (1) 203. 

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