Prismatic batteries construction

Various types of cell and battery design and construction can be used in the nickel-zinc battery system. Cells have been built in both prismatic and cylindrical designs and both vented and sealed designs. However, most current commercial applications require the use of a sealed, maintenance-free design. A typical sealed prismatic battery is shown in Fig. 31.7. This type of construction can be used for a wide range of cell sizes and is particularly suited to larger capacity batteries (e.g. greater than 10 Ampere-hours). 

Lithium ion cells serve the smaU-sealed rechargeable battery market and compete mainly with the Ni-Cd and Ni-MH cells for the various applications. The Li-Ion cells are available in cylindrical and prismatic format as well as flat plate constructions. The cylindrical and prismatic constructions use a spiral-wrap cell core where the ceU case maintains pressure to hold and maintain compression on the anode, separator, and cathode. The lighter-weight polymer constructions utilize the adhesive nature of a polymer/laminate-based electrolyte to bond the anode to the cathode. 

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. 

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. 

Sealed nickel-metal hydride cells and batteries are constructed in cylindrical, button, and prismatic configurations, similar to those used for the sealed nickel-cadmium battery. 

FIGURE 29.2c Construction of a sealed prismatic nickel-metal hydride battery. 

Nickel-zinc batteries can be constructed in a variety of configurations such as prismatic or cylindrical cell designs. The specific cell or battery design will dictate the cell component configurations used. However, all cell designs have basic similarities in terms of the active materials used, the use of cell containers and covers, the use of metallic conductors and in the basic manufacturing techniques and application of these materials. 

Since the commercialization of Li-ion batteries by Sony in 1990, a broad array of variants has been introduced. One type, gel-polymer Li-ion batteries, utilizes the same active materials as products that employ liquid electrolytes, but in a different construction that enables the fabrication of cells with a thin form factor. Gel-polymer batteries, also referred to as polymer Li-ion batteries in the marketplace, are products where the microporous separator film used in conventional batteries is substituted by a layer of PVDF-HFP, or other polymer, impregnated with liquid electrolyte and the solid current collector foil is typically substituted with an open expanded metal current collector grid. In gel-polymer cells, the positive, separator, and negative layers are bound by the polymer, typically PVDF-HFP, and can be laminated together to form a monolithic device. Despite these differences, the active cell chemistry may remain identical to that in cylindrical or prismatic Li-ion batteries. 

The lithium iron sulfide battery operates at about 400 to 500°C using a fused halide eutectic electrolyte immobilized in the pores of a suitable separator. This battery displays a number of attractive featmes compared to the Na-S battery, including prismatic flat-plate constraction, ability to withstand numerous freeze-thaw cycles, cell failures in short-circuit conditions, ability to withstand overcharge, and low-cost materials and construction techniques. The major disadvantage is a somewhat lower performance. Although this battery is suitable for both EV and load-leveling applications, recent attention has focused on battery designs suitable for EV propulsion. ... 

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