Mining Contract: Evaluating the Inherent Safety of Li-ion Batteries in Portable Electronics Used in Underground Mine Environments
This contract aims to provide a better understanding of the potential risk of lithium-ion (Li-ion) batteries as an ignition source in an underground mine environment contaminated by methane-air mixtures. The inherent safety of representative Li-ion cells will be studied and experimentally evaluated as a function of cathode and anode chemistry, electrolyte solvent, and state-of-charge; under crush, over-charge, or over-discharge abuse conditions.
Contract Status & Impact
This contract is ongoing.
Li-ion batteries have become one of the most popular types of rechargeable battery for portable electronics. Li-ion technology provides enhanced energy storage capabilities that lengthen device runtime, shorten the recharge time, and extend the life of the battery. Beyond consumer electronics, Li-ion batteries are now growing in popularity for usage in underground mine safety equipment such as cap lamps, hand-held gas detectors, hand tools, and communications and tracking devices. Li-ion batteries also have well-known thermal runaway safety concerns. There have been numerous reported thermal failures of Li-ion battery-powered equipment, including equipment approved as permissible by the Mine Safety and Health Administration (MSHA). MSHA has issued a Program Information Bulletin regarding safety precautions for charging of Li-ion or lithium polymer batteries. With the tendency for Li-ion battery chemistries to undergo thermal runaway—creating a potential ignition source in a mine—it is important that the use of different Li-ion battery chemistries be evaluated as a means for eliminating this hazard.
Under this contract, the University of Kentucky is evaluating the inherent safety of Li-ion batteries used in portable electronics for underground mine applications. The potential ignition hazard of commercially available cells will be evaluated as a function of cathode and anode chemistry, electrolyte solvent, and state-of-charge. Experiments will involve cell crush, over-charge, or over-discharge abuse conditions in an environment contaminated with a 6.5% methane-air atmosphere. Initial efforts have focused on the design and assembly of test fixtures, and acquiring representative Li-ion cells.
Data collected for this study will be used to evaluate the risk for ignition hazards, to develop recommendations for selecting appropriate battery chemistries, and to establish safe maintenance and operating procedures for portable devices using Li-ion batteries.