Self-templated hollow nanospheres of B-site engineered non-stoichiometric perovskite for supercapacitive energy storage via anion-intercalation mechanism

Self-templated hollow nanospheres of B-site engineered non-stoichiometric perovskite for supercapacitive energy storage via anion-intercalation mechanism

Energy storage

Supercapacitor

Mass spectrometry

Ions

Electrolytes

Storage (materials)

Potassium hydroxide

Electrochemical electrodes

Fluorine compounds

Perovskite

Cyclic voltammetry

Nanospheres

The continual increase in energy demand and inconsistent supply have attracted attention towards sustainable energy storage/conversion devices, such as electrochemical capacitors with high energy densities and power densities. Perovskite oxides have received significant attention as anion-intercalation electrode materials for electrochemical capacitors. In this study, hollow nanospheres of non-stoichiometric cubic perovskite fluorides, KNi1xCoxF3 (x = 0.2

= 0.33) (KNCF-0.2) have been synthesized using a localized Ostwald ripening. The electrochemical performance of the non-stoichiometric perovskite has been studied in an aqueous 3 M KOH electrolyte to categorically investigate the fluorine-vacancy-mediated charge storage capabilities. High capacities up to 198.55 mA h g1 or 714.8 C g1 (equivalent to 1435 F g1) have been obtained through oxygen anion-intercalation mechanism (peroxide pathway, O-). The results have been validated using ICP (inductively coupled plasma mass spectrometry) analysis and cyclic voltammetry. An asymmetric supercapacitor device has been fabricated by coupling KNCF-0.2 with activated carbon to deliver a high energy density of 40 W h kg1 as well as excellent cycling stability of 98% for 10,000 cycles. The special attributes of hollow-spherical, non-stoichiometric perovskite (KNCF-0.2) have exhibited immense promise for their usability as anion-intercalation type electrodes in supercapacitors. 2021 Elsevier Inc.

600

Journal of Colloid and Interface Science

2021

Iqbal, Sarmad

Mady, Amr Hussein

Kim, Young-Il

Javed, Umer

Shafi, P.Muhammed

Nguyen, Van Quang

Hussain, Iftikhar

Tuma, Dirk

Shim, Jae-Jin

729-739

journalArticle

219797

10.1016/j.jcis.2021.03.147