Date Published: January 03, 2018
Publisher: John Wiley and Sons Inc.
Author(s): Huiwu Long, Wen Zeng, Hua Wang, Mengmeng Qian, Yanhong Liang, Zhongchang Wang.
Aqueous sodium‐ion battery of low cost, inherent safety, and environmental benignity holds substantial promise for new‐generation energy storage applications. However, the narrow potential window of water and the enlarged ionic radius because of hydration restrict the selection of electrode materials used in the aqueous electrolyte. Here, inspired by the efficient redox reaction of biomolecules during cellular energy metabolism, a proof of concept is proposed that the redox‐active biomolecule alizarin can act as a novel electrode material for the aqueous sodium‐ion battery. It is demonstrated that the specific capacity of the self‐assembled alizarin nanowires can reach as high as 233.1 mA h g−1, surpassing the majority of anodes ever utilized in the aqueous sodium‐ion batteries. Paired with biocompatible and biodegradable polypyrrole, this full battery system shows excellent sodium storage ability and flexibility, indicating its potential applications in wearable electronics and biointegrated devices. It is also shown that the electrochemical properties of electrodes can be tailored by manipulating naturally occurring 9,10‐anthroquinones with various substituent groups, which broadens application prospect of biomolecules in aqueous sodium‐ion batteries.
Sample Preparation and Characterization: In a typical synthesis process, 60 mg alizarin (Acros, purity 97%) was dissolved in 180 mL acetone, which was subsequently dropped into deionized water of different volumes under magnet stirring condition. The precipitation was eventually collected by centrifugation and dried at 50 °C overnight. Morphology of alizarin was observed by a field‐emission SEM (JSM‐7600F, JEOL) at a working voltage of 5 kV, and the Fourier transform infrared spectroscopy spectra were measured on a Nicolet iN10 spectrophotometer using transmission mode. DFT calculations were conducted using the Gaussian 09 software. A total of five geometries were optimized for each molecule by employing the restricted B3LYP hybrid functional and 6–311+G(d,p) basis set. The molecular orbital of each molecule, e.g., HOMO and LUMO energies, was analyzed.
The authors declare no conflict of interest.