Vented batteries, nickel-cadmium battery

In Japan, the Furukawa Battery Co., Ltd. industrialized a sintered-type vented nickel-cadmium battery for airplane starting in 1955. The Furukawa Battery Co., Ltd. started mass production of the vented-type nickel-cadmium secondary battery and a sealed nickel-cadmium secondary battery for industrial use in 1962 and developed the same to the fields, such as aircrafts. 

Figure 1.14 Heat generation during charge and discharge of a vented nickel/cadmium battery. Charging with constant current I5 (5 hour rate) until 1.65 V/ceU is reached. Discharge also with I5.

The specific heat Csatt of a battery depends on its specific design, but the different systems do not vary too much. In batteries with aqueous electrolyte, the content of water is of great importance due to its high specific heat. The specific heat of customary vented lead-acid batteries is slightly above lkj kg K while the corresponding value of VRLA batteries is in the range of 0.7 to 0.9 kJ kg K As the specific heat of a vented nickel/cadmium battery with sintered electrodes the value 1.25Jkg is reported (9), while that of the sealed version is... 

In narrowly spaced vented nickel/cadmium batteries, cellophane occasionally is used as an ion-conducting foil to prevent direct gas flow between the electrodes. 

During charging, water decomposition can only be critical as a heat source, when the cell voltage considerably exceeds 1.48 V (= Ucai for water decomposition). As a result, vented nickel/cadmium batteries can be charged at quite high rates without suffering heat problems. But in the sealed version, the internal oxygen cycle can cause serious thermal problems (cf. Fig. 1.15). 

Of the conventional secondary systems, the nickel-iron and the vented pocket-type nickel-cadmium batteries are best with regard to cycle life and total lifetime. The nickel-hydrogen battery developed mainly for aerospace applications, has demonstrated very long cycle life under shallow depth of discharge. The lead-acid batteries do not match the performance of the best alkaline batteries. The pasted cells have the shortest life of the lead-acid cells the best cycle life is obtained with the tubular design, and the Plante design has the best lifetime. 

TABLE 26.4 Market Segments and Applications for Vented Industrial Nickel-Cadmium Batteries... 

In portable applications were batteries are exposed to temperature extremes or rough handling, nickel-cadmium batteries are used for signal lamps, hand lamps, search lights, and portable instmments. Vented spillproof batteries are used in large devices, whereas sealed nickel-cadmium batteries dominate the smaller ones (see Chap. 27). 

Baker C., and M. Beu ekatien, Proc. SAE Power Systems Conf, San Diego, CA, Oct 31-Nov. 2, 2000. FNC Vented Nickel-Cadmium Batteries, Hoppecke Batterien. 

VENTED SINTERED-PLATE NICKEL-CADMIUM BATTERIES ... 

VENTED SBMTERED-PLATE NICKEL-CADMIUM BATTERIES 21.1... 

Typical average values for the energy and power densities of the vented sintered-plate nickel-cadmium battery at 25°C are shown in Table 27.2. 

TABLE 27.2 Energy and Power Characteristics of Vented Srntered-Plate Nickel-Cadmium Battery (Single Cell Basis)... 

FIGURE 27.12 Service life of typical vented sintered-plate nickel-cadmium battery (gravimetric) at 25°C. 

Charging of the vented sintered nickel-cadmium battery following its discharge in cyclic use, has four significant objectives. These may be stated as follows ... 

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