Ultra-thin sealed lead-acid batteries
The structure and performance of the world's first ultra-thin sealed lead-acid batteries are described. The batteries are 0.65 mm thick, the thinnest ever achieved, and are made possible by a new electrode structure. In a conventional battery, the separator is sandwiched between the positive and negative electrodes. In the new battery structure, however, the positive electrode, electrolyte, and negative electrode are arranged on the same plane. Movement of the battery reaction sites during charge/discharge is parallel to the main surface of the electrode. Consequently, the new battery structure offers significant advantages in regard to life performance. Batteries utilizing this new structure have a long life of over 400 cycles, and good performance of the charge/discharge characteristics. In addition, a variety of different batteries can be manufactured using screen patterns. By using the techniques described above, the thickness of a sealed lead-acid battery can be reduced to less than one seventh of that of a conventional one, without performance degradation.<<ETX>>
Distinctive features of thin‐layer sealed lead‐acid storage batteries with comb‐shaped plates
We fabricated 2.5-mm thick lead-acid cells with comb-shaped electrodes, sealed with laminated sheets, and estimated their performance. Some of the cells showed above 500 mAh of an initial capacity and one of them were cycled over 140 times till the capacity decreased to a half of the initial capacity. The initial capacity was affected strongly by viscosity of electrolyte gel filled in the cells. Utilization of electrode active materials and electrolyte was more than 20% and 55%, respectively, in the cells showed above 500 mAh of initial capacity. Cycle life was influenced mainly by cathode degradation and electrolyte drying out. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(11): 60–67, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1138
UV-B radiometry and dosimetry for solar measurements.
Biologically effective irradiance or dose of solar UV radiation was determined using a spectroradiometer, two broadband radiometers and two types of passive UV-dosimeters. The absolute erythema irradiance and the actinic irradiance were calculated from the solar spectrum measured with the spectroradiometer. It was demonstrated that the erythema irradiance is proportional to the actinic irradiance of solar radiation. The erythema irradiance was also determined using the two broadband radiometers which utilize a filter transmitting erythema spectra. Personal UV-dosimeters such as polysulphone and CR-39 were used to determine the erythema dose for a selected period of time. These results were used to estimate the accuracy of the broadband radiometers and UV-dosimeters. It was found that the results obtained from the broadband radiometers deviate from the absolute erythema irradiance by less than 20% during clear days between the hours of 11:00 and 13:00 Eastern Standard Time (EST) in Australia. The assessment of the erythema dose using passive dosimeters such as polysulphone and CR-39 could introduce an error as high as 40% if the calibration was not performed before undertaking experimental measurements.