Byung Hun Oh

Cable‐Type Flexible Lithium Ion Battery Based on Hollow Multi‐Helix Electrodes

An important focus in product design is the creation of practical and aesthetic devices. In portable electronics, in particular, the limiting factor is often the shape of the battery; indeed, removal of this battery restriction would constitute a disruptive technology that could open up a path for design innovation. [ 1 ] However, despite the development of smaller, thinner, and lighter batteries, the existing battery technology is still far from realizing such design fl exibility, mainly owing to the fi xed shapes, i.e., cylindrical, prismatic, or pouch shape. [ 2 ] Hence, there is increasing recognition of the need for a new concept that would permit various product designs previously impossible with traditional technologies. To this end, fl exible batteries are considered a promising solution, owing to their potential to adapt to mechanical stress and accordingly change shape. Furthermore, the progress made in fl exible electronics such as roll-up displays and wearable electronics would receive a strong stimulus with the development of bendable/twistable batteries. [ 3 ] Several recent studies of energy conversion devices have focused on the development of fl exible batteries or supercapacitors [ 4–7 ] using soft materials such as poly mer electrolytes, [ 8 ] nanometer-sized active materials, [ 9–14 ]