Page | 003 1.0 PURPOSE
The intent of this guideline is to provide users of lithium-ion (Li-ion) and lithium
polymer (LiPo) cells and battery packs with enough information to safety handle
them under normal and emergency conditions.
Caution must be taken in Li-ion battery storage, use, management, and disposal due
to the potential for fire and injury if these batteries are misused or damaged. There
have been several incidents at MIT and other universities involving Li-ion and LiPo
batteries. At MIT these incidents were related to batteries left on chargers for
extended times, unattended charging, incompatible chargers, cheap knock-off
batteries and shorts from improperly wired or isolated connections.
2.0 BACKGROUND
Batteries are classified as primary or secondary. Primary batteries irreversibly transform
chemical energy to electrical energy. When the initial supply of reactants is exhausted,
energy cannot be readily restored to the battery by electrical means. Alkaline and lithium-
metal batteries are examples of primary batteries. Primary lithium batteries are briefly
discussed in this guidance but since these batteries contain lithium metal, a water reactive
material, the handling recommendations, in an emergency situation, for these batteries are
different from Li-ion/LiPo.
Secondary batteries can be recharged; that is, they can have their chemical reactions
reversed by supplying electrical energy to (charging) the cell. Secondary batteries age during
each cycle so they are not indefinitely rechargeable. Prior to the widespread introduction of
Li-ion batteries, lead acid, nickel-cadmium and nickel-metal-hydride were the most common
types of secondary batteries.
Li-ion/LiPo batteries have emerged in recent years as the most popular secondary batteries
due to advantages that include light weight, higher energy density, low memory effect and
longer life span. They provide a compact and powerful energy source for MIT research
projects and Remote Controlled (RC) vehicles requiring electrical energy. With this
technology, lithium-ions are stored in the anode (negative electrode), and transported
during the discharge to the cathode (positive electrode) in a flammable organic electrolyte.
The materials used are graphite for the anode and a metal oxide for the cathode.
Li-ion batteries are used in battery packs for portable laptops, power tools and many other
devices requiring electrical power. LiPo are commonly seen in applications like RC vehicles
where their relatively light weight and high current draw, are an advantage. Since both
battery types have similar chemistries they require similar care in charging and handling to
avoid unsafe situations.
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