Battery technology performance

Manufacturers often feel compelled to be very vague about how well a battery will perform because of the uncertainty about how the batteiy will be used. Technology manufacturers invest heavily m marketing research before deciding what type of batteiy to provide with a new product. Sometimes it is a clear-cut decision other times there is no one best choice for all potential users. Perhaps the most important issue is whether a product will be used continuously or intermittently. For instance, selecting a battery for a DVD player is much easier than a cellular phone. The DVD player is likely to be used continuously by... 

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. 

The popularity of EVs did not last. By the 1920s, the performance of ICE vehicles improved dramatically, and the earlier major drawbacks had been solved. Ironically, the replacement of the dangerous hand crank -with a battei y-powered electric starter was a major innovation accelerating ICE vehicle sales at the expense of EV sales. At the same time, there were no concurrent solutions to the limitations of battery technology for EVs that addressed the demand to drive faster and farther. 

Table 3. Typical performance characteristics of various rechargeable battery technologies...

Modeling has become an important tool in developing new battery technology as well as for improving the performance of existing commercial systems. Models based on engineering principles of current distribution and fundamental electrochemical reaction parameters can predict the behavior of porous... 

Figure 1 Juxtaposes the energy fields of these three potential product definitions with that of conventional primary battery technology. The data on the energy densities for the battery product definitions were adopted from a recent technology review. The expected energy performance figures for biofuel cells...

Most battery systems employ carbon materials in one form or another, as noted in Table 10.1. The use of carbon materials in batteries stretches across a wide spectrum of battery technologies. The variety of carbon runs the gamut from bituminous materials, used to seal carbon-zinc and carbon black powders in lead acid batteries, to high performance synthetic graphites, used as active materials in lithium-ion cells. The largest use is as a conductive diluent to enhance the performance of cathode materials. In many instances, it is used as a conductive diluent for poorly conducting cathode materials where carbon blacks, such as acetylene black, are preferred. It is essential that... 

Consuming patterns have over recent years seen a dramatic increase in the use of portable equipment for entertainment and work (such as music and video players, laptop computers and mobile phones with multi-functionality). This has increased the demand for batteries, but at the same time found limitations of the battery technology that seem difficult to avoid even with increasing conversion efficiencies. Fuel cells with small-scale stores are an obvious solution to these problems, because the technical performance is already far beyond that of batteries (e.g., operating a state-of-the-art laptop computer for a few days rather than a few hours). The difference between these otherwise similar technologies is the external storage of chemicals for a fuel cell versus the internal storage in batteries. 

Zinc/air batteries are produced in button shape. Their energy density at 20 °C is 340 Wh kg-1, which is the highest energy density of the primary battery technologies (see Table 2) however, their applications are limited because their performance is not independent on the environmental conditions (because oxygen is obtained from the environment). Their nominal voltage is 1.5 V, which is comparable with other battery technologies (see Table 2). 

Another approach to consistent power delivery from renewable sources is to consider the use of supercapacitors placed between the renewable power source and the electrolyzer. These may or may not be viable, and we have not yet researched this possibility. Supercapacitors are basically a cross between capacitor and battery technology. They use electrodes, and a liquid or organic electrolyte, but they store energy by static charge rather than by electrochemical means. They can be cycled millions of times, and have a recharge time of seconds. Supercapacitors might also be viable to enhance peak load performance on the fuel cell end. 

---