Scientists in the Korea Institute of Science and Technology (KIST) have worked with graphene and carbon nanotubes to develop a working lithium-ion battery that can be stretched by up to 50% without damage to any of the components. According to the scientists, the battery represents a significant step in the development of wearable or body-implantable electronic devices.
Rather than trying to add inherently stretchable materials such as rubber to the battery components, the group focused on creating an “accordion-like” structure, adding stretchability to materials that are not inherently stretchable. Using graphene and carbon nanotubes, the scientists were able to construct a honeycomb-shaped composite framework, which was then compressed inwardly like an accordion to impart the stretchable properties.
They then combined the electrodes with a gel electrolyte and stretchable packaging materials to create a working lithium-ion battery. The design demonstrated a capacity of 5.05 milliamp hours per square centimeter, maintaining 95.7% of this performance after 100 charge-discharge cycles. The battery also exhibited “superior electrochemical performance,” according to KIST, after 500 stretch-release cycles when the material was stretched up to 50%.
The university notes that all of the materials within the battery are active in the battery, with the stretchable properties added as a bonus. Jeong Gon Son, who led the research at KIST, says that he expects the stretchable design to “present a new paradigm in terms of stretchable energy storage systems for the further development of wearable and body-implantable electronic devices.”