Battery selection, secondary batteries

B. Chemical transport selectivity 42 Nanomaterials in Secondary Battery Research and Development 48... 

In considering the selection of anodes for high energy density (HED) storage (or secondary) batteries (SB), we note that there are some 19 metals whose free-energy density (TED) of reaction with oxidants such as O2, Cl2, and F2 are higher than those of Zn with the same oxidants. Most of these metals react violently with water. The remainder are passivated by water. Therefore other electrolytes must be considered for these metals, based on non-aqueous, molten salt, or solid-state ionic conductors. Much experimental work has been carried out during the last two decades on primary and secondary batteries based on anhydrous electrolytes, aimed at utilization of the active metals. 

Owing to possible future restrictions that could preclude the testing of samples with all five toxicity tests, we evaluated the index response with a reduced battery of toxicity tests. The basic rule for the selection of tests in a reduced battery was to maintain one primary producer, one primary consumer and a secondary consumer. The test combinations of two selected reduced batteries were Hydra, Daphnia and Lactuca tests (H-D-L) and Hydra, Daphnia and S. capricornutum (H-D-S) tests... 

Physicochemical properties of ILs can be changed by variation of the component ions. There are important studies to achieve ILs having excellent properties such as low Tm, low viscosity, high ionic conductivity and wide electrochemical potential windows. It is generally understood that ILs are difficult to apply as electrolyte solution substituents because they contain a large number of ions which cannot work as carrier ions for electrochemical devices such as secondary batteries. Therefore, structural design of ions for particular applications is important for ILs. Selective ion conduction is one of the attractive and challenging tasks for IL science. 

In the last few decades, conductive polymers have found exciting new relevance in non-rechargeable (primary) and rechargeable (secondary) batteries for electrical storage. Besides high electrical conductivity, conductive polymers have high selectivity to electrode reaction, low catalytic activity towards side-reactions, sufficient mechanical strength, fabricability, costs etc. 

Schottky barrier, 16-19 Schulz, 6-2, 6-6 SCL regime, 19-3 SCLC model, 16-9, 16-639 SCLC, 16-9, 16-19 Screw direction, 3-5-3-7, 3-8, 3-10 SDWs-(TMTSF)2PFg, 16-14-16-15 Secondary battery, 8-73-8-77 Secondary dopants for PEDT PSS, 10-9 Secondary growth, 7-7-7-11 Selected area electron diffraction, 17-32 Self-assembled monolayer (SAM), 8-55-8-56,... 

In the secondary-battery area, it is the drive to develop electric vehicles competitive with gasoline driven ones that has stimulated investment in research and development. This has covered a broad spectrum from improved lead-acid battery to a large selection of new chemical power sources. 

Nickel/metal hydride (Ni/MH) battery is a secondary battery using hydrogen storage alloy for the negative electrode, Ni(OH)2 for the positive electrode, and alkaline solution for the electrolyte. Polypropylene nonwoven fabric is usually selected for the separator. The theoretical voltage is about 1.32 V, and the operating voltage is about 1.2 V which is almost the same as that of Ni/Cd battery [1]. The Ni/MH battery has been put to practical use for portable electric equipments in 1990 and for HEV (hybrid electric vehicle) in 1997 [2, 3]. 

Table 16.1 shows a selection of the most important applications. Primary button cells normally cover the load range from pA to mA. The mA range can be covered by primary and by secondary cells. For heavy loads in the A range mostly secondary batteries are chosen. 

Table 6.7 illustrates the selection of primary and secondary batteries. As the power requirements of the application increase (going from the bottom of the list to the top) and the size of the battery becomes larger, the trend for the battery-of-choice shifts from the primary to the secondary battery. The primary battery dominates in the lower power applications and where a long service life is required, such as smoke detectors, implants and memory backup. 

For example, separators for secondary batteries and supercapacitors separate the cathode and anode to prevent shorting, while in flow batteries and fuel cells, an ideal separator should selectively control the mass transportation in the cell. 

The first choice to be made is whether a primary or secondary battery is required. Usually, there is no doubt about the requirement in this respect. We shall therefore proceed to a discussion of the selection of the particular type of primary or secondary battery required for the application in mind. 

With data of this type, it is possible to make a start in the process of selecting a suitable type of secondary battery to meet a particular application. However, as discussed in Section 2.1 on primary batteries, many other considerations would apply in making the final selection. 

In conclusion, it can be said regarding the battery selection process, whether primary or secondary batteries are being considered, that the design engineer is faced with many commercial portable power systems in a wide variety of models. The battery selection process cannot therefore be reduced to an exact science. Seldom does any one battery system meet all the requirements Ta a given application. The selec-lion of a battery is further complicated by the fact that the performance characteristics of battery systems vary with temperature, current drain, service schedules, etc. Consequently the selection process usually involves a trade-off or compromise between battery requirements and battery system characteristics. 

Manganese dioxide, Mn02, (MDO) is a widely used as material in primary electrochemical cells. It is the positive electrode of the zinc-MnOa cell, invented in 1866 by the French engineer Georges-Lionel Leclanche [11]. Li-MnOa battery was developed by Sanyo in 1975 [12] as low-power supplies for watches, calculators and memory backups. The poor cyclability of MDOs observed at that time [13] has been improved by preparing composite dimensional manganese oxides (CDMOs) for the development of flat-type secondary batteries. Table 6.2 lists the chemical formula of selected Li-Mn-O compounds used in Li batteries. 

Instrument Power - Instrument power failures are evaluated on a basis similar to that described for a power failure. Included in the normal considerations for PR sizing should be the failure of power supply to all instruments in and controlled from a single bus bar. Reliability feahires should include secondary selective power supply to control rooms, with emergency generator or battery backup for critical instruments and control computers. Critical controls should be able to continue operation independently of control computers. 

---