MrSeb writes: "LG Chem, a member of the LG conglomerate/chaebol and one of the largest chemical companies in the world, has devised a cable-type lithium-ion battery that’s just a few millimeters in diameter, and is flexible enough to be tied in knots, worn as a bracelet, or woven into textiles. The underlying chemistry of the cable-type battery is the same as the lithium-ion battery in your smartphone or laptop — there’s an anode, a lithium cobalt oxide (LCO) cathode, an electrolyte — but instead of being laminated together in layers, they’re twisted into a hollow, flexible, spring-like helix. flexible batteries have been created before — but they’ve all just standard, flat, laminated batteries made from sub-optimum materials, such as polymers. As such, as they have very low energy density, and they’re only bendy in the same way that a thin sheet of plastic is bendy. LG Chem’s cable-type batteries have the same voltage and energy density as your smartphone battery — but they’re thin and highly flexible to boot. LG Chem has already powered an iPod Shuffle for 10 hours using a knotted 25cm length of cable-type battery."