They are everywhere: in your pocket, in your car, in your hands, in your lap and even “in your face.” Lithium-ion batteries are in nearly every product that has become a staple of modern life, such as smartphones, tablets/notebook computers, digital cameras and headphones. They are in our transportation systems – trains, planes and automobiles. They are involved in our hobbies and recreation, including radio-controlled vehicles, hoverboards and e-bikes. They also show up in some of our vices, such as vaping and smoking e-cigarettes. Though we typically view the batteries and the products they power as innocuous, if something goes wrong it can go catastrophically wrong.