Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate

This study investigated the electrochemical properties of supercapacitors by pre-modifying thick birch biochar monoliths with FeCl<sub>3</sub> or C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> solutions prior to wood pyrolysis. The pre-modification introduc...

Full description

Saved in:
Bibliographic Details
Main Authors: Ziyue Song, Tianjie Feng, Donald W. Kirk, Charles Q. Jia
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Batteries
Subjects:
Online Access:https://www.mdpi.com/2313-0105/11/2/47
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849719304829796352
author Ziyue Song
Tianjie Feng
Donald W. Kirk
Charles Q. Jia
author_facet Ziyue Song
Tianjie Feng
Donald W. Kirk
Charles Q. Jia
author_sort Ziyue Song
collection DOAJ
description This study investigated the electrochemical properties of supercapacitors by pre-modifying thick birch biochar monoliths with FeCl<sub>3</sub> or C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> solutions prior to wood pyrolysis. The pre-modification introduced iron species to the surface, promoting the specific surface area, charge-stored species, and surface functionalities, which enhanced the gravimetric capacitance. X-ray diffraction confirmed the successful loading of Fe<sub>3</sub>O<sub>4</sub> and Fe. SEM implied the wider distribution of iron-rich particulates and porous carbon via self-pyrolysis on the biochar surface modified with 1.0 M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub>. Contact angle measurements demonstrated the enhanced wettability of the biochar surfaces following pre-modification, with the C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub>-modified samples exhibiting superior wettability compared to the other groups. The gravimetric capacitance of the supercapacitor was dramatically promoted and reached 210 F/g and 219 F/g, respectively, when modified with 1.0M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> and 1.0 M FeCl<sub>3</sub> at a 5 mA/g current density. Compared to the birch biochar modified with 1.0 M FeCl<sub>3</sub>, the 1.0 M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> had a higher current response peak and capacitive behavior in the CV analysis, demonstrated better ion diffusion capacity, and had lower charge-transfer resistance in the EIS results. But, a slight irreversible process on the electrode of the 1.0 M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> group led to a lower level of the supercapacitor capacitance retention. The results using ferric solution pre-impregnation show how iron species doping can improve capacitance behavior, providing a feasible scheme for the modification of thick biochar monolith.
format Article
id doaj-art-04169cbd1d9345048e8d23776dc0f7ea
institution DOAJ
issn 2313-0105
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series Batteries
spelling doaj-art-04169cbd1d9345048e8d23776dc0f7ea2025-08-20T03:12:10ZengMDPI AGBatteries2313-01052025-01-011124710.3390/batteries11020047Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric CitrateZiyue Song0Tianjie Feng1Donald W. Kirk2Charles Q. Jia3The Green Technology Lab, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, CanadaThe Green Technology Lab, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, CanadaThe Green Technology Lab, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, CanadaThe Green Technology Lab, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, CanadaThis study investigated the electrochemical properties of supercapacitors by pre-modifying thick birch biochar monoliths with FeCl<sub>3</sub> or C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> solutions prior to wood pyrolysis. The pre-modification introduced iron species to the surface, promoting the specific surface area, charge-stored species, and surface functionalities, which enhanced the gravimetric capacitance. X-ray diffraction confirmed the successful loading of Fe<sub>3</sub>O<sub>4</sub> and Fe. SEM implied the wider distribution of iron-rich particulates and porous carbon via self-pyrolysis on the biochar surface modified with 1.0 M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub>. Contact angle measurements demonstrated the enhanced wettability of the biochar surfaces following pre-modification, with the C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub>-modified samples exhibiting superior wettability compared to the other groups. The gravimetric capacitance of the supercapacitor was dramatically promoted and reached 210 F/g and 219 F/g, respectively, when modified with 1.0M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> and 1.0 M FeCl<sub>3</sub> at a 5 mA/g current density. Compared to the birch biochar modified with 1.0 M FeCl<sub>3</sub>, the 1.0 M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> had a higher current response peak and capacitive behavior in the CV analysis, demonstrated better ion diffusion capacity, and had lower charge-transfer resistance in the EIS results. But, a slight irreversible process on the electrode of the 1.0 M C<sub>6</sub>H<sub>5</sub>FeO<sub>7</sub> group led to a lower level of the supercapacitor capacitance retention. The results using ferric solution pre-impregnation show how iron species doping can improve capacitance behavior, providing a feasible scheme for the modification of thick biochar monolith.https://www.mdpi.com/2313-0105/11/2/47biochar monolithsupercapacitorsferric chlorideferric citrateiron species
spellingShingle Ziyue Song
Tianjie Feng
Donald W. Kirk
Charles Q. Jia
Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate
Batteries
biochar monolith
supercapacitors
ferric chloride
ferric citrate
iron species
title Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate
title_full Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate
title_fullStr Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate
title_full_unstemmed Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate
title_short Electrochemical Performance of Pre-Modified Birch Biochar Monolith Supercapacitors by Ferric Chloride and Ferric Citrate
title_sort electrochemical performance of pre modified birch biochar monolith supercapacitors by ferric chloride and ferric citrate
topic biochar monolith
supercapacitors
ferric chloride
ferric citrate
iron species
url https://www.mdpi.com/2313-0105/11/2/47
work_keys_str_mv AT ziyuesong electrochemicalperformanceofpremodifiedbirchbiocharmonolithsupercapacitorsbyferricchlorideandferriccitrate
AT tianjiefeng electrochemicalperformanceofpremodifiedbirchbiocharmonolithsupercapacitorsbyferricchlorideandferriccitrate
AT donaldwkirk electrochemicalperformanceofpremodifiedbirchbiocharmonolithsupercapacitorsbyferricchlorideandferriccitrate
AT charlesqjia electrochemicalperformanceofpremodifiedbirchbiocharmonolithsupercapacitorsbyferricchlorideandferriccitrate