Batteries dimensions

A concept of power supply can always be made on the basis of an efficient description of a battery s application. However, to fulfill the above-mentioned requirements, it is advisable to plan the battery dimensions based on principles which may be described as optimizing temperature factors. This method departs from the premise that any battery, which is not subject to impermissible heating under prescribed load, is bound to exhibit the necessary efficiency and service life, i.e. to have the desired operating reliability. The temperature of the electrolyte would ideally display a constant value, merely being dependent on the ambient temperature in the driverless industrial truck, which is itself only subject to minor fluctuations. The temperature of the electrolyte would in this way be directly related to normal ambient temperature. If this were to fall drastically in winter, additional measures would of course have to be taken to raise the temperature of the electrolyte. 

It is imperative that only the latest version of each standard be used. Due to the periodic revision of these standards, only the latest version can be relied upon to provide reliable enforceable specifications of battery dimensions, terminals, marking, general design features, conditions of electrical testing for performance verification, mechanical tests, test sequences, safety, shipment, storage, use, and disposal. 

Product (capacity) Internal res. of fuUy charged battery mil 25°C Nominal short circuit current for charged battery Dimensions Weight lb. (kg)... 

The dimensions of these wooden supports will be determined by the battery jar. The position of the holes and slots should be arranged so that the tubes may be spaced at convenient distanees as shown in Fig. 4. 

Typical dimensions for the /5-alumina electrolyte tube are 380 mm long, with an outer diameter of 28 mm, and a wall thickness of 1.5 mm. A typical battery for automotive power might contain 980 of such cells (20 modules each of 49 cells) and have an open-circuit voltage of lOOV. Capacity exceeds. 50 kWh. The cells operate at an optimum temperature of 300-350°C (to ensure that the sodium polysulfides remain molten and that the /5-alumina solid electrolyte has an adequate Na" " ion conductivity). This means that the cells must be thermally insulated to reduce wasteful loss of heat atjd to maintain the electrodes molten even when not in operation. Such a system is about one-fifth of the weight of an equivalent lead-acid traction battery and has a similar life ( 1000 cycles). 

Figure 31. The construction, shape and dimensions of the 2CR5 lithium-manganese dioxide battery for fully automatic cameras.

Figure 11. Px 10 S bundle battery details are given in the text. Dimensions are in inches.

The microporosity is also important for this application, in order not to allow shorts through the backweb during battery life. Bottom shorts are avoided by a mud room of sufficient dimensions, and side shorts by plastic edge protectors on the... 

The maximum values of electric power and unit output of electrochemical cells vary within wide limits. The total current load admitted by individual electrolyzers for the electrochemical production of various materials in plant or pilot installations (their capacity) is between 10 A and 200 kA, while the current loads that can be sustained by different types of battery (their current ratings) are between 10 A and 20 kA. Corresponding differences exist in the linear dimensions of the electrodes (between 5 mm and 3 m) as well as in the overall mass and size of the reactors. 

As to anodes, in most of the research work a generously dimensioned sheet of lithium metal has been used. Such an electrode is rather irreversible, but this is not noticed when a large excess of lithium is employed. Li-Al alloys and carbon materials inserting lithium cathodically during recharging can be used as anodes in nonaqueous solutions. Zinc has been used in polymer batteries with aqueous electrolyte (on the basis of polyaniline). 

The aerosol distributions are calculated in terms of a single mode, without attempting to resolve them into a major large mode and a minor very small (unattached) mode. The unattached mode is very much smaller in diameter (of molecular cluster dimensions) than the major mode of the aerosol and in underground mines its peak height is very small. To resolve such a mode would require more than the three diffusion batteries used for the measurements. 

Parallel developments in the physical chemistry of surfaces have also proceeded rapidly during the same period. An extensive battery of new spectroscopic and microscopic techniques have brought analysis and even observation down to the molecular and atomic ideal of seeing and manipulating these ultimate units of chemistry. Much of the driving force for these advances has come from the microelectronics industry, where the ability towards mass production of microstructures approaching nanometer dimensions is proceeding with remarkable speed and success. 

It has been known for some time that lithium can be intercalated between the carbon layers in graphite by chemical reaction at a high temperature. Mori et al. (1989) have reported that lithium can be electrochemically intercalated into carbon formed by thermal decomposition to form LiCg. Sony has used the carbon from the thermal decomposition of polymers such as furfuryl alcohol resin. In Fig. 11.23, the discharge curve for a cylindrical cell with the dimensions (f) 20 mm x 50 mm is shown, where the current is 0.2 A. The energy density for a cutoff voltage of 3.7 V is 219 W h 1 which is about two times higher than that of Ni-Cd cells. The capacity loss with cycle number is only 30% after 1200 cycles. This is not a lithium battery in the spirit of those described in Section 11.2. 

An excihng new scientific direction emerged in the 1980s and 1990s for exploring molecular sieves as advanced solid state materials. In a 1989 review, Ozin et al. [88] speculated that zeolites (molecular sieves) as microporous molecular electronic materials with nanometer dimension window, channel and cavity architecture represent a new fronher of solid state chemistry with great opportunihes for innovahve research and development . The applicahons described or envisioned included molecular electronics, quantum dots/chains, zeolite electrodes, batteries, non-linear ophcal materials and chemical sensors. More recently there have been significant research reports on the use of zeolites as low k dielectric materials for microprocessors [89]. 

For any battery applications, the separator should have uniform pore distribution to avoid performance losses arising from nonuniform current densities. The submicrometer pore dimensions are critical for preventing internal shorts between the anode and the cathode of the lithium-ion cell, particularly since these separators tend to be as thin as 25 /[Pg.192]

A calculation of the power requirements of the smart dust mote underscores our point that the present generation of batteries cannot effectively power this device. Thin-film batteries are among the most advanced of the lithium battery systems, with a capability to scale down to dimensions on the same order of magnitude as the cubic millimeter of the dust mote. 3 The energy density for the thin-film system is 2 J mm , which matches or exceeds standard lithium ion systems, such as those that power laptop computers. A key design requirement for the smart dust mote is that the power consumption cannot exceed 10 juW. If the dust mote uses this power continuously over a day, it will consume 1 J. 

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