Thermal Mathematical Modeling of a Multicell Common Pressure Vessel Nickel‐Hydrogen Battery

Abstract

2781cal response. This is certainly the case for the above system since the Li~NiOx/WQ eleetroehromic cell can be cycled several thousand times with about 50% change in optical transmission. 23 Some concern could still be addressed to the charge-discharge rates since they directly influence the device's response time. However, for most applications, response times of the order of one or few seconds are appropriate and thus even materials with relatively slow lithium diffusion rates are still acceptable, providing they offer the required optical properties.Therefore, the first generation rocking chair batteries, proposed in the early eighties as novel lithium, low-rate reehargeable systems capable of offering long cycle life, 3 have indeed found continued interest. So, the old concept does hold. The question is whether the new concepts for rocking chair batteries, proposed as alternatives to highenergy, high-power lithium and nickel-cadmium batteries, 13't4 will eventually find their way in the competitive portable power source market.

Three‐dimensionai temperature and current distribution in a battery module

“…The work by Lee et al (1986) also focused on calculating transient, 3-D temperature profiles but did not account for the influence of temperature on physical properties. The transient, 2-D model by Kim et al (1992) for a cylindrically symmetric battery treated temperature-dependent thermal properties, but the heat genera-tion rate (resulting from the passage of current) was specified as a model input. Evans (1993, 1994) provide 2-D analyses of lithium-polymer batteries subject to constant physical properties.…”

Thermal-Electrochemical Modeling of Battery Systems

“…Subject to proper boundary conditions, Eq. 1 and its various simplified forms have been solved to obtain the temperature distribution in lead-acid, [14][15][16] nickel-hydrogen, 17 lithium-polymer, [18][19][20][21] and lithium-ion 8,22 battery modules, with a single cell as the minimum REV. When the lumped-parameter approach is applicable (cf.…”

Modeling of a Nickel-Hydrogen Cell: Phase Reactions in the Nickel Active Material

“…This indicates that endothermic heat effects of the cell reactions dominate. As the cell approaches overcharge, the cell temperature rapidly increases because more and more input energy is wasted on the side reactions, e.g., the oxygen evolution on the nickel electrode and the oxygen reduction on the platinum elec- 150 kJ/mol ⌬E a, 4 10 kJ/mol ⌬E a, 5 10 kJ/mol ⌬E a, 6 10 kJ/mol ⌬E a, 7 10 kJ/mol ⌬E a, 8 10 kJ/mol a The parameters that have no source listed are assumed values.…”

“…This may significantly affect cell performance. 4,5 To investigate such possibilities, the heat transfer in the radial direction of the cell stack is modeled, as given by the following governing equations…”