Imagine a future in which our electrical gadgets are no
longer limited by plugs and external power sources.
This intriguing prospect is one of the reasons for the
current interest in building the capacity to store electrical energy directly
into a wide range of products, such as a laptop whose casing serves as its
battery, or an electric car powered by energy stored in its chassis, or a home
where the dry wall and siding store the electricity that runs the lights and
appliances.