| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 73897 | Microporous and Mesoporous Materials | 2012 | 7 Pages |
Walnut shell-based activated carbons (WS-ACs) were prepared by chemical activation with KOH and used as an electrode material for electrical double layer capacitors (EDLCs). The WS-AC samples were characterized before and after ball milling for 8 h to assess their electrochemical characteristics as carbon electrodes for EDLCs. Nitrogen adsorption analyses showed that the Brunauer–Emmett–Teller (BET) surface areas of the WS-ACs were decreased to approximately 10% of their original value after ball milling. However, their capacitances were slightly increased and their other electrochemical properties such as impedance and charge/discharge stability were improved. Pore size distribution analysis revealed that whereas most of the micropores were destroyed, a considerable number of mesopores in the size range of 2–10 nm were formed by ball milling. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis confirmed a 10% increase in the graphite content after ball milling.
Graphical abstractPore size distribution and specific capacitances of WS-1/4 before and after ball milling.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Walnut shell-based activated carbons (ACs) are prepared by KOH activation. ► The prepared ACs are ball milled to fabricate EDLC electrodes. ► The electrochemical properties of ball milled ACs are considerably improved. ► Nitrogen adsorption and XPS analyses clarify properties of activated carbons. ► The formation of mesopores and graphitic sites are main reasons for improvement.
