Ultrathin Thin-Film Battery Thinner Than Hair... Expectations for 'Electronic Skin'

Developed Micro Supercapacitor

[Asia Economy Reporter Junho Hwang] An ultrathin energy storage device thinner than a strand of hair has been developed. This device maintains its performance even when folded like paper and retains almost the same storage capacity after 1000 charge and discharge cycles. The research team expects that, through further studies, this energy storage device can be applied to various wearable devices such as electronic skin.

Professor Seongwon Lee's research team at Daegu Gyeongbuk Institute of Science and Technology announced on the 23rd that they have developed an ultrathin energy storage device capable of supplying power stably even under physical stress. The related research results were recently published in the international journal Nano Energy.

Micro Supercapacitor Fabrication Method

This device is composed of a thin film with a total thickness of about 23 micrometers (μm). This is half the thickness of a hair strand, which is about 40 micrometers (μm). The device has a storage capacity performance of 7.91 millifarads (mF/cm2) per unit area. It maintains almost the same storage capacity even after 1000 charge and discharge cycles. It is physically very flexible, making it suitable for various applications.

The research team implemented this device using a mass production method that applies graphene ink as an active electrode through a spray solution process. Instead of the conventional spray process that sprays ink vertically, they used a spray process that sprays at a 45-degree angle, achieving more than 30% higher energy storage efficiency per unit area compared to the existing method.

Physical Stability Data of Small Devices

Professor Seongwon Lee said, "Through this research, we developed a supercapacitor that is thinner than conventional batteries or supercapacitors and guarantees strong adhesion and durability even on curved surfaces like skin. However, the total energy storage capacity is still somewhat lower compared to existing batteries, so we plan to continue related research."

He added, "I think it will take about 3 to 5 years to commercialize this device. Although the efficiency per unit area and volume is excellent, the total energy capacity is insufficient compared to existing batteries, so research is needed to compensate for this and reduce the energy consumption of the operating devices."