Rational molecular design of polymeric materials toward efficient triboelectric energy harvesting. (December 2019)

• Record Type: Journal Article
• Authors: Lee, Jong Hyeok; Kim, Kyung Hoon; Choi, Moonkang; Jeon, Jisoo; Yoon, Hyeok Jun; Choi, Jinhyeok; Lee, Young-Seak; Lee, Minbaek; Wie, Jeong Jae
• Is Part Of: Nano energy. Volume 66(2019)
• Publication Date: 2019-12
• Subjects: Triboelectric energy harvesting -- Electron affinity -- Hypervalency -- Yellow chemistry -- Inverse vulcanization -- Surface modification; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2019.104158
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: In the periodic table, halogenic elements have a larger electron affinity (EA = −270~−349 kJ/mol) than any other group, allowing them to accommodate extra electrons for triboelectric energy harvesting. However, because halogenic elements are not homopolymerizable, carbon (EA = −122 kJ/mol)-based polymers (i.e. PTFE, PVDF) are often employed for structural use and mechanical integrity at the expense of reduced electron affinity, intrinsically sacrificing triboelectric energy harvesting. Herein, we report the first example of triboelectric energy harvesting with sulfur backbone-based inorganic polymers synthesized via inverse-vulcanization process of elemental sulfur, a by-product of petroleum refining process. Fluorinated polymeric sulfur demonstrated 6-fold and 3-fold increase in triboelectric energy outputs in voltage and currents respectively in comparison with commercial PTFE film. Such high energy harvesting was achieved by high electron affinity of sulfur (−200 kJ/mol) and by its hypervalency via expanded-octet which provided coordination of two additional bonds with halogens compared to carbon. The triboelectric open-circuit voltage output reached 1366 V and demonstrated direct powering of 630 LEDs under the minimal force of ~30 N. This yellow chemistry-based molecular engineering paves a way for a new class of triboelectric materials toward low-cost, eco-friendly, and scalable triboelectric energy harvesting applications. Graphical abstract: Image 1 Highlights: First report on triboelectric properties derived from sulfur-backbone based polymers. Fluorinated polymeric sulfur is obtained through inverse vulcanization and surface fluorination. Extremely negative triboelectric material is designed based on sulfur's high electron affinity and hypervalency. Fluorinated polymeric sulfur demonstrated a 6-fold and 3-fold increase in voltage and current outputs in comparison to PTFE.