Nickel metal hydride batteries are now an established technology, being used in a wide range of applications. One problem that has been identified with the technology is the poor high rate capability of these batteries, and therefore in a number of circumstances nickel cadmium batteries are still the preferred energy source. One option to resolve this problem has been to surface treat the materials with platinum group metals. This treatment produces cells that show great promise in applications such as the power tool, industrial and automotive markets. The current work describes the surface treatment of metal hydride electrode alloys with a wider variety of platinum metal combinations to assess the rate performance of these materials at ambient and near-zero temperatures. It is observed that the treatment improves the activity of the cells at low temperatures, supporting the view that the surface energy of the electrode alloy is a strong contender as the rate-determining feature of these materials. In addition to this conclusion, the data suggest that these cells would withstand the harsh constraints when used as an automotive starter battery. (C) 2002 Elsevier Science BY All rights reserved.
- platinum group metal
- low temperature