Giant nanomechanical energy storage capacity in twisted single-walled carbon nanotube ropes

Shigenori Utsumi; Sanjeev Kumar Ujjain; Satoshi Takahashi; Ryo Shimodomae; Tae Yamaura; Ryosuke Okuda; Ryuichiro Kobayashi; Oga Takahashi; Satoshi Miyazono; Naoki Kato; Keiichi Aburamoto; Yuta Hosoi; Preety Ahuja; Ayumi Furuse; Yuma Kawamata; Hayato Otsuka; Kazunori Fujisawa; Takuya Hayashi; David Tománek; Katsumi Kaneko

doi:10.1038/s41565-024-01645-x

Giant nanomechanical energy storage capacity in twisted single-walled carbon nanotube ropes

Nat Nanotechnol. 2024 Apr 16. doi: 10.1038/s41565-024-01645-x. Online ahead of print.

Authors

Shigenori Utsumi^#¹, Sanjeev Kumar Ujjain^#^{2

3}, Satoshi Takahashi¹, Ryo Shimodomae¹, Tae Yamaura¹, Ryosuke Okuda¹, Ryuichiro Kobayashi¹, Oga Takahashi¹, Satoshi Miyazono¹, Naoki Kato¹, Keiichi Aburamoto¹, Yuta Hosoi¹, Preety Ahuja^{2

3}, Ayumi Furuse², Yuma Kawamata^{2

4}, Hayato Otsuka², Kazunori Fujisawa⁵, Takuya Hayashi⁵, David Tománek^{6

7}, Katsumi Kaneko⁸

Affiliations

¹ Department of Mechanical and Electrical Engineering, Faculty of Engineering, Suwa University of Science, Chino, Japan.
² Research Initiative for Supra-Materials, Shinshu University, Nagano, Japan.
³ Center for Advanced Sensor Technology, University of Maryland Baltimore County, Baltimore, MD, USA.
⁴ Department of Science and Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
⁵ Department of Water Environment and Civil Engineering, Shinshu University, Nagano, Japan.
⁶ Physics and Astronomy Department, Michigan State University, East Lansing, MI, USA.
⁷ Department of Physics, University of Johannesburg, Johannesburg, South Africa.
⁸ Research Initiative for Supra-Materials, Shinshu University, Nagano, Japan. kkaneko@shinshu-u.ac.jp.

^# Contributed equally.

PMID: 38627470
DOI: 10.1038/s41565-024-01645-x

Abstract

A sustainable society requires high-energy storage devices characterized by lightness, compactness, a long life and superior safety, surpassing current battery and supercapacitor technologies. Single-walled carbon nanotubes (SWCNTs), which typically exhibit great toughness, have emerged as promising candidates for innovative energy storage solutions. Here we produced SWCNT ropes wrapped in thermoplastic polyurethane elastomers, and demonstrated experimentally that a twisted rope composed of these SWCNTs possesses the remarkable ability to reversibly store nanomechanical energy. Notably, the gravimetric energy density of these twisted ropes reaches up to 2.1 MJ kg^-1, exceeding the energy storage capacity of mechanical steel springs by over four orders of magnitude and surpassing advanced lithium-ion batteries by a factor of three. In contrast to chemical and electrochemical energy carriers, the nanomechanical energy stored in a twisted SWCNT rope is safe even in hostile environments. This energy does not deplete over time and is accessible at temperatures ranging from -60 to +100 °C.