Novel High-Energy-Density Rechargeable Hybrid Sodium-Air Cell with Acidic Electrolyte

Yao Kang; Fengmei Su; Qingkai Zhang; Feng Liang; Keegan R Adair; Kunfeng Chen; Dongfeng Xue; Katsuro Hayashi; Shan Cecilia Cao; Hossein Yadegari; Xueliang Sun

doi:10.1021/acsami.8b04278

Novel High-Energy-Density Rechargeable Hybrid Sodium-Air Cell with Acidic Electrolyte

ACS Appl Mater Interfaces. 2018 Jul 18;10(28):23748-23756. doi: 10.1021/acsami.8b04278. Epub 2018 Jul 2.

Authors

Yao Kang, Fengmei Su, Qingkai Zhang, Feng Liang, Keegan R Adair¹, Kunfeng Chen², Dongfeng Xue², Katsuro Hayashi³, Shan Cecilia Cao⁴, Hossein Yadegari¹, Xueliang Sun¹

Affiliations

¹ Department of Mechanical and Materials Engineering , University of Western Ontario , London , Ontario N6A 5B9 , Canada.
² State Key Laboratory of Rare Earth Resources Utilization , Chinese Academy of Sciences , Changchun 130022 , China.
³ Department of Applied Chemistry, Faculty of Engineering , Kyushu University , Fukuoka 819-0395 , Japan.
⁴ Department of Material Science and Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States.

PMID: 29932623
DOI: 10.1021/acsami.8b04278

Abstract

Low-cost, high-energy-density, and highly efficient devices for energy storage have long been desired in our society. Herein, a novel high-energy-density hybrid sodium-air cell was fabricated successfully on the basis of acidic catholytes. Such a hybrid sodium-air cell possess a high theoretical voltage of 3.94 V, capacity of 1121 mAh g^-1, and energy density of 4418 Wh kg^-1. First, the buffering effect of an acidic solution was demonstrated, which provides relatively long and stable cell discharge behaviors. Second, the catholytes of hybrid sodium-air cells were optimized systematically from the solutions of 0.1 M H₃PO₄ + 0.1 M Na₂SO₄ to 0.1 M HAc + 0.1 M NaAc and it was found that the cells with 0.1 M H₃PO₄ + 0.1 M Na₂SO₄ displayed a maximum power density of 34.9 mW cm^-2. The cell with 0.1 M H₃PO₄ + 0.1 M Na₂SO₄ displayed higher discharge capacity of 896 mAh g^-1. Moreover, the fabricated acidic hybrid sodium-air cells exhibited stable cycling performance in ambient air and they delivered a low voltage gap around 0.3 V when the current density is 0.13 mA cm^-2, leading to a high energy efficiency up to 90%. Therefore, the present study provides new opportunities to develop highly cost-effective energy storage technologies.

Keywords: acetic acid; electrochemical performance; electrolyte; phosphoric acid; sodium−air cell.