Gassing current

The enclosed area of the curve is a measure of the reversible charge delivery capacity of the electrode. For fast current pulses, a different measurement method is used to determine the charge injection limits without gassing. Current pulses are applied and the voltage over two electrodes is monitored just below the gassing limits (Fig. 24). Once having passed the extensive in vitro testing, the electrodes were tested in chronic animal experiments. 

Another gassing current calculation approach for PV applications was developed by Filler et al. [25]. Cnrrent is usually small in PV applications and gassing is the major loss during charging therefore, the Butler-Volmer equation can be modified and normalized to define the gassing current ... 

The gassing current is actually based on the difference between u and... 

A more appropriate battery for transportation applications is probably a nickel-iron or nickel-metal hydride battery. These batteries are not as susceptible to heat and gassing as lead-acid batteries, so they can better withstand high current or high voltage charges that can dramatically shorten charging time. 

With this method, control equipment is simple and inexpensive and it is straightforward to calculate the charge delivered. However, if high currents are used, problems are encountered with batteries which have porous electrode structures because of non-uniform current distribution, and severe gassing may occur towards the end of the charge. At low current,... 

Current US primary energy consumption is about 102 exajoules (EJ) (97 Quads) and is expected to increase to >137 EJ (130 Quads) by 2020. Transportation fuels produced from oil are projected to account for nearly one-third of the projected energy use by 2020, with nearly 68% of the oil imported from unstable and/or unfriendly countries, resulting in a trade imbalance of more than 206 billion (US in 2001). Additionally, the use of fossil fuels for transportation and electricity is a significant contributor of greenhouse gasses such as carbon dioxide, nitrogen oxides, and carbon monoxide (1-4). 

However, that is observed only within the range of the so-called safe voltage window of operation - for alkaline aqueous electrolytes it covers the range of l,12-l,24v, and depends on material purity and current density. Exceeding this voltage causes gassing, electrode swelling and loss of electric contact between particles in the electrode volume. 

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