Very cool– string batteries! Via Talk2myShirt:

In sewing, strings of various thickness and stiffness are used for piping, a type of trim inserted into a seam to define the edges or style lines of a garment or bag.

A team of researcher at LG Chem seems to add another function to the piping: they developed a Li-Ion battery in string form just a few millimeter thick, is bendable and can even be knotted without compromising it’s battery function.

The energy storage technology is based on Li-Ion chemistry just like conventional Li-Po batteries only twisted into a round, fine string instead in a flat, geometrical form factor.

Thin strands of nickel and tin coated copper wires form the anode. The researcher then spin the coated copper wires into metal yarn, wrap it around a rod to form a spring shape which functions as structural element of the string battery as well as the anode.