Bipolar Battery

Principally the construction of a bipolar battery is not size limited. The plates can be as large as needed with the possibility of any shape desired. Like in fuel cell systems battery plates can be built in m dimensions. This is an important aspect, because regular plate batteries are size limited by the current collector grids like the lead-acid automobil starter battery, which get unproportionally heavy at larger sizes and heavy loads. Generally we can expect energy... 

Bipolar electrodes are stacked to produce a battery of cells connected at the partitions. If the cells in a bipolar battery are not rigorously sealed around the edges, electrolyte leaks can provide a shunt current path between cells, which reduces the battery performance. Researchers continue to look at new materials and designs for commercial bipolar batteries. Recent work to develop bipolar batteries is discussed further in Future Development at the end of this article (Fig. 5.1). 

Fig. 5.1 Schematic of monopolar and bipolar battery designs [4] (Electrochemical Society approval obtained)...

Some scientists have designed fuel cells simultaneously using both liquid and gas (LG). This particular device uses a metallic envelope that is filled with air or oxygen and is dipped into an electrolyte fuel mixture. One side of the envelope is porous Ni and the other side is solid foil. The Ni acts as the air or oxygen electrode, and the catalyst-coated outside surface operates as a fuel electrode. The net result is that an array of such cells can produce a bipolar battery. Preliminary calculations indicate that a module composed of 80 cells could produce output power exceeding 750 watts (W). Higher module power can be obtained by deploying an increased number of cells. 

Figure 6.4 Structural details on a bipolar battery cell best suited for some applications.

A bipolar lead-acid battery eliminates grouping of positive and negative plates and the connections between cells. Bipolar battery construction shortens the current path between the positive and negative terminals of the battery, which reduces the battery s internal resistance to current flow and improves power delivery. The bipolar battery configuration is particularly suitable for high-voltage batteries because bipolar construction requires less space compared to conventional lead-acid batteries. 

Another potential advantage of the solid polymer battery is that the design lends itself to manufacture by automatic processes and the capability to be easily fabricated in a variety of shapes and forms. Very thin batteries for cell phones, PDAs and similar applications can be manufactured. At the other extreme, large thin plates can be manufactured and assembled in multiplate prismatic or bipolar batteries. 

FIGURE 41.14 Baseline and Advanced Low-Cost Seals for a molten-salt bipolar battery. (From Henriksen, et al. )... 

N. Papadakis et al., Performance of Rechargeable Lithium-Alloy/Metal Disulfide Pulse Power Bipolar Batteries, Proc. IEEE 35th Int. Power Sources Symp., Cherry Hill, N.J., June 22-25, 1992, p. 285. 

Bipolar batteries have been under development, using boiler plate pressure vessels. Design feasibility has been demonstrated, and the program is now being directed to design and demonstrate bipolar flight batteries for high power pulse applications. 

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