Title: Electrodes with Electrodeposited Water-excluding Polymer Coating Enable High-Voltage Aqueous Supercapacitors

Abstract

Aqueous supercapacitors are powerful energy sources, but they are limited by energy density that is much lower than lithium-ion batteries. Since raising the voltage beyond the thermodynamic potential for water splitting (1.23 V) can boost the energy density, there has been much effort on water-stabilizing salvation additives such as Li ₂ SO ₄ that can provide an aqueous electrolyte capable of withstanding ~1.8 V. Guided by the first-principles calculations that reveal water can promote hydrogen and oxygen evolution reactions, here, we pursue a new strategy of covering the electrode with a dense electroplated polymerized polyacrylic acid, which is an electron insulator but a proton conductor and proton reservoir. The combined effect of salvation and coating expands the electrochemical window throughout pH 3 to pH 10 to 2.4 V for both fast and slow proton-mediated redox reactions. This allows activated carbon to quadruple the energy density, a kilogram of nitrogen-doped graphene to provide 127 Watt-hour, and both to have improved endurance because of suppression of water-mediated corrosion. Therefore, aqueous supercapacitors can now achieve energy densities quite comparable to that of a lithium-ion battery, but at 100 times the charging/discharging speed and cycle durability.

Authors:

Dong, Wujie ^[1]; Lin, Tianquan ^[2]; Huang, Jian ^[2]; Wang, Yuan ^[2]; Zhang, Zhichao ^[3]; Wang, Xin ^[1]; Yuan, Xiaotao ^[1]; Lin, Jie ^[2]; Chen, I-Wei  ^[3];

• Search DOE PAGES for author "Chen, I-Wei"
• Search DOE PAGES for ORCID "0000-0002-4045-4467"

Huang, Fuqiang  ^[4]

• Search DOE PAGES for author "Huang, Fuqiang"
• Search DOE PAGES for ORCID "0000-0001-8334-6522"

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+ Show Author Affiliations

1. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
2. State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
3. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
4. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China

Publication Date:

Fri Oct 09 00:00:00 EDT 2020

Sponsoring Org.:

USDOE

OSTI Identifier:

1909322

Grant/Contract Number:  

FG02-11ER46814; SC0007064

Resource Type:

Published Article

Journal Name:

Research

Additional Journal Information:

Journal Name: Research Journal Volume: 2020; Journal ID: ISSN 2639-5274

Publisher:

American Association for the Advancement of Science (AAAS)

Country of Publication:

United States

Language:

English