Honeycomb graphene creates stretchable battery for wearables

Technology News | May 4, 2020

By Nick Flaherty

A team at the Photo-Electronic Hybrids Research Centre at the Korea Institute of Science and Technology (KIST) have built a high-capacity, stretchable battery based on lithium ion electrodes and electrolytes.

The microscale reentrant-honeycomb shaped, graphene-based electrode is characterized has an accordion-like stretchability. A stretchable gel electrolyte and stretchable separator are also developed for all-component stretchable full cells. This can be used for wearable applications.

The stretchable battery was developed by fabricating a structurally stretchable electrode consisting solely of electrode materials and then assembling with stretchable gel electrolyte and stretchable packaging, says Dr. Jeong Gon Son. The honeycomb framwork consists of a 2D layer of graphene, which serves as an curtain, and carbon nanotubes, which formed a nano-size rope. This framework acts like an accordion using a radial compression process.

The electrodes developed by the research team do not contain any materials typically used for stretchability, such as rubber, that do not provide energy storage. Instead, all of the materials are used for energy storage and charge transport. This provides an energy storage capacity of 5.05 mAh/cm² that is as high as existing non-stretchable batteries. This can stretch up to 50 percent of its length under 500 cycles, with a long term stability of 95.7 percent after 100 cycles in air conditions.

“The stretchable battery developed through this research is expected to present a new paradigm in term of stretchable energy storage systems for the further development of wearable and body-implantable electronic devices” said Dr Son.

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