Aqueous Al-Ion Supercapacitor with V2O5 Mesoporous Carbon Electrodes

Meng Tian; Ruihan Li; Chaofeng Liu; Donghui Long; Guozhong Cao

doi:10.1021/acsami.9b02030

Aqueous Al-Ion Supercapacitor with V₂O₅ Mesoporous Carbon Electrodes

ACS Appl Mater Interfaces. 2019 May 1;11(17):15573-15580. doi: 10.1021/acsami.9b02030. Epub 2019 Apr 18.

Authors

Meng Tian^{1

2}, Ruihan Li¹, Chaofeng Liu², Donghui Long^{1

3}, Guozhong Cao²

Affiliations

¹ State Key Laboratory of Chemical Engineering , East China University of Science and Technology , Shanghai 200237 , China.
² Department of Materials Science and Engineering , University of Washington , Seattle , Washington 98195 , United States.
³ Shanghai Key Laboratory of Multiphase Materials Chemical Engineering , East China University of Science and Technology , Shanghai 200237 , China.

PMID: 30965001
DOI: 10.1021/acsami.9b02030

Abstract

A high-performance, low-cost, aqueous Al-ion supercapacitor was fabricated based on nanostructured V₂O₅ impregnated mesoporous carbon microspheres (MCM/V₂O₅) electrodes and Al₂(SO₄)₃ electrolyte for efficient energy storage. MCM/V₂O₅ composites exhibit high dispersion of nanostructured V₂O₅ in a mesoporous carbon matrix, beneficial to fast reversible redox reactions with a short diffusion path. The corresponding capacitor illustrates the distinguishable redox behavior, most likely due to the Al³⁺ intercalation/deintercalation leading to the reduction/oxidation of V⁵⁺/V⁴⁺. It delivers a high-energy density of 18.0 Wh kg^-1 at 147 W kg^-1 and a long cycling lifespan with over 88% capacitance retention over 10 000 cycles. The competitive performance can be ascribed to the integration of the electric double layer capacitance provided from MCM with pseudocapacitance contributed by nanostructured V₂O₅. This work offers the possibilities of high-performance aqueous capacitors based on trivalent Al-ion as guest species, providing new directions for future development of supercapacitors.

Keywords: Al-ion capacitors; mesoporous carbon; pseudocapacitance; symmetric capacitors; vanadium pentoxide.