Accession Number:

ADA440426

Title:

Failure Model for a Leaking Nickel-Hydrogen Cell

Descriptive Note:

Technical rept.

Corporate Author:

AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS

Personal Author(s):

Report Date:

2005-08-30

Pagination or Media Count:

19.0

Abstract:

A model has been developed and used to analyze the loss of capacity and dry out of nickel-hydrogen cells as a result of pressure vessel leaks. This analysis has allowed a number of conclusions to be drawn about the behavior of nickel-hydrogen cells with leaks Cells that are repeatedly cycled may not lose all capacity by leaking their hydrogen. There is a leak size threshold at 1-2.5 um below which nickel-hydrogen cells will not dry out by gas. There is a leak size threshold at 0.1-0.2 um below which it will be difficult to identify the rate of capacity loss as differing significantly from normal wear-related capacity loss rates. Pre-existing leaks smaller than about 0.1 um cannot be detected by typical leak detection methods. Leak latency can occur if pre-existing subthreshold leaks grow in size during the cell operation.

Subject Categories:

  • Electrochemical Energy Storage

Distribution Statement:

APPROVED FOR PUBLIC RELEASE