With the launch of wearable devices and smartphones that require a high capacity of electricity such as foldable phones and 5G phones, the interest in batteries is increasing and various battery types are under development. For example, flexible batteries embedded in a mobile watch band or wireless power sharing batteries that have developed from wireless charging. However, there is currently no manufacturing process for a battery that produces thousands of milliamp Hour (mAh) with the capacity to be foldable. Recently, a research team from Korea developed a monolithic electrode that can replace heavy copper collectors and enabled development of such a flexible battery with high capacity.