The background description provided herein is for the purpose of generally presenting the context of the disclosure.
Electrochemical cells, often simply called batteries, are commonly used as electrical energy sources. Small batteries are especially useful in powering consumer products. Small batteries come in a variety of cell types. Common small battery cell types include AAA, AA, B, C, D, 9 V, CR2, and CR123A. Other types of small batteries known as button cells (also including wider cells sometimes referred to as coin cells) are frequently used to power a variety of products including but not limited to watches, cameras, calculators, key-less entry systems for vehicles and the like, laser pointers, glucometers, etc.
FIG. 1 illustrates the construction of a representative button cell 10 comprising a cathode 12 disposed within a cathode can 14 and an anode 16 disposed within an anode cup 18. A separator 20 physically separates and electronically insulates the anode 16 from the cathode 12. An insulating gasket 22 serves to seal the cell to prevent electrolyte loss and to prevent ingress of ambient atmospheric components into the cell and electronically insulate the cathode can 14 from the anode cup 18. Button cells usually have a long service life, for example, typically well over a year in continuous use in a wristwatch. In addition, most button cells have low self-discharge such that they hold their charge for relatively long times when not placed under load.
While button cell batteries are common in many portable consumer electronic devices, the size, shape, and appearance of these batteries, particularly coin cells having a diameter of 20 mm such as CR2016 lithium cells and CR2032 lithium cells, can pose dangers, particularly to infants, toddlers, and pets. These dangers can result in bodily harm, especially if the cell is swallowed unbeknownst to others around. And some of these button cell batteries can pose a relatively greater danger than others, which consumers may not fully appreciate. For example, 3 V coin cells batteries such as CR2016 3 V lithium cells and CR2032 3 V lithium cells, which are based on lithium-manganese dioxide chemistry, are sized such that they readily can become lodged in a human throat and thus cause electrolysis of body fluids and/or burning wet esophageal/organ tissue, for example, if swallowed. Of course, such batteries can also cause significant gastric distress if successfully swallowed.
USPTO Backgrounds
USPTO Backgrounds