Available Technology

Internal Short Circuit Device for Improved Lithium-Ion Battery Design

Energy storage cells (also referred to herein as "cells" or "batteries") sold for consumer use in portable electronic devices and other applications have occasional failure in the field. These cells have typically passed a wide variety of safety tests, such as those required by governmental shipping regulations and by other certification organizations, but fail after the cells have been in use over time (e.g., several months), even though there have been no other reported problems with the cells that fail. Regardless, these failures can result in the cells overheating, and in some cases, going into thermal runaway wherein the cell can ignite and burn. For example, these incidents have been reported in the media as "the burning laptop" and have resulted in the recall of millions of batteries. At least some of these failures have been attributed to a latent defect introduced during the cell manufacturing process that escapes detection during initial acceptance testing and results in an internal short circuit between the positive and negative components of a cell (electrodes or current collectors) after having been in use for some time. Due to the dormant nature of this flaw, battery manufacturers have found it difficult to precisely identify and study. NREL’s device introduces a latent flaw into a battery that may be activated to produce an ISC. NREL uses the ISC device to better understand the failure modes of Li-ion cells and to validate NREL’s abuse models. The device can be placed anywhere within the cell and can be used with both spirally wound and flat-plate cells containing any of the common Li-ion electrochemical systems. Producing a true internal short, the device is small compared to other shorting tools being developed by industry and does not rely on mechanically deforming the battery to activate the short, as do most of the other test methodologies. With the internal short in place, the battery can be used and cycled within normal operating conditions without activating the internal short device. This allows the battery to be aged prior to activation. The internal short produced by NREL’s device is consistent and is being developed as an analysis tool for battery manufacturers and other national laboratories as well as original equipment manufacturers (OEMs). This has broad-reaching applications as automakers bring electrified vehicles to market in larger numbers.
Abstract: 
Energy storage cells (also referred to herein as "cells" or "batteries") sold for consumer use in portable electronic devices and other applications have occasional failure in the field. These cells have typically passed a wide variety of safety tests, such as those required by governmental shipping regulations and by other certification organizations, but fail after the cells have been in use over time (e.g., several months), even though there have been no other reported...
Benefits: 
Enhanced energy storage safety -Easily integrated into existing batteries -Multiple methods for creating internal short
applications: 
Internal Laboratory Ref #: 
NREL ROI 10-46
Lab Representatives
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