Hydrides batteries

Hydrogen-storage alloys (18,19) are commercially available from several companies in the United States, Japan, and Europe. A commercial use has been developed in rechargeable nickel—metal hydride batteries which are superior to nickel—cadmium batteries by virtue of improved capacity and elimination of the toxic metal cadmium (see BATTERIES, SECONDARYCELLS-ALKALINe). Other uses are expected to develop in nonpolluting internal combustion engines and fuel cells (qv), heat pumps and refrigerators, and electric utility peak-load shaving. 

H. Ogawa, M. Ikoma, H. Kawano, and I. Matsumoto, "Metal Hydride Electrode for High Energy Density Sealed Nickel—Metal Hydride Battery," Proceedings of the 16th International Power Sources Conference, UK, 1988. 

Lithium-Ion Cells. Lithium-ion cells and the newer alternative, lithium-ion-polymer, can usually run much longer on a charge than comparable-size Nicad and nickel-metal hydride batteries. Usually is the keyword here since it depends on the battery s application. If the product using the battery requires low levels of sustained current, the lithium battery will perform very well however, for high-power technology, lithium cells do not perform as well as Nicad or nickel-metal hydride batteries. 

A more appropriate battery for transportation applications is probably a nickel-iron or nickel-metal hydride battery. These batteries are not as susceptible to heat and gassing as lead-acid batteries, so they can better withstand high current or high voltage charges that can dramatically shorten charging time. 

GM began offering more expensive nickel-metal hydride batteries as an option. These batteries extended the range to 75 to 130 miles, but also took slightly longer to recharge. 

Secondary batteries can be electrically charged, and these batteries can offer savings in costs and resources. Recently, lithium-ion and nickel-metal hydride batteries have been developed, and are used with the other secondary batteries, such as nickel-cadmium, lead-acid, and coin-type lithium secondary batteries. 

The variety of practical batteries has increased during the last 20 years. Applications for traditional and new practical battery systems are increasing, and the market for lithium-ion batteries and nickel-metal hydride batteries has grown remarkably. This chapter deals with consumer-type batteries, which have developed relatively recently. 

Batteries using an alkaline solution for electrolyte are commonly called alkaline batteries. They are high-power owing to the high conductivity of the alkaline solution. Alkaline batteries include primary batteries, typical of which are alkaline-manganese batteries, and secondary batteries, typical of which are nickel-cadmium and nickel-metal hydride batteries. These batteries are widely used. 

Nickel-metal hydride batteries contain a nickel electrode similar to that used in nickel-cadmium batteries as the positive... 

The nickel-metal hydride battery comes in two shapes cylindrical and prismatic. The internal structure of the cylindrical battery is shown in Fig. 18. It consists of positive and negative electrode sheets wrapped within the battery, with... 

Figure 20 shows the charge-discharge characteristics of the AA-size nickel-metal hydride battery in comparison with the nickel-cadmium battery produced by Sanyo Electric. Its capacity density is 1.5 to 1.8 higher than that of nickel-cadmium batteries. 

The discharge voltage of nickel-metal hydride batteries is almost the same as that of nickel-cadmium batteries. 

The outstanding characteristics of the nickel-metal hydride battery are as follows ... 

Since nickel-metal hydride batteries were commercialized in 1990, they have become increasingly popular as a power source for computers, cellular phones, electric shavers, and other products. 

Figure 25 shows nickel-metal hydrides batteries that have been improved by using the technique mentioned above. 

Figure 25. Nickel-metal hydride batteries manufactured by new technology.

Nickel hydroxides have been used as the active material in the positive electrodes of several alkaline batteries for over century [1], These materials continue to attract much attention because of the commercial importance of nickel-cadmium and nickel-metal hydride batteries. In addition to being the cathode active material in nickel-metal hydride batteries, Ni(OH)2 is an important corrosion product of the anode during cycling. There are several reviews of work in the field [2-10],... 

In normal battery operation several electrochemical reactions occur on the nickel hydroxide electrode. These are the redox reactions of the active material, oxygen evolution, and in the case of nickel-hydrogen and nickel-metal hydride batteries, hydrogen oxidation. In addition there are parasitic reactions such as the corrosion of nickel current collector materials and the oxidation of organic materials from separators. The initial reaction in the corrosion process is the conversion of Ni to Ni(OH)2. 

M. Ikoma, S. Hamada. N. Morishita, Y. Ho-shina, K. Ohta, T. Kimura, Proc Symp on Hydrogen and Metal Hydride Batteries (Eds. P. D. Bennet, T. Sakai), The electrochemical Society, Pennington, NJ, 1996, 94-27, p. 370. 

The metal in a nickel metal hydride battery is usually a complex alloy of several metals, such as Cr. Ni, Co, V, Ti, Fe, and Zr. 

Battery technology continues to advance at a steady pace. Lithium batteries and nickel-metal-hydride batteries are now commonplace. These new rechargeable batteries eliminate the need for toxic cadmium and store more energy per unit mass. The detailed chemistry that underlies the newest advances in battery technology involves principles that are beyond the scope of an introductory course. 

High-power lithium-ion batteries are promising alternatives to the nickel metal hydride batteries which are currently used for energy storage in hybrid electric vehicles (HEVs). Currently, Li(Ni,Co)02-based materials are the most widely studied cathode materials for the high-power lithium-ion batteries [1-4]. Although Li(Ni,Co)02-based materials meet the initial power requirement for the HEY application, however, it has been reported that they... 

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