[1] Univ Teknol Petronas, Dept Elect & Elect Engn, Ctr Innovat Nanostruct & Nanodevices, Seri Iskandar, Perak, Malaysia
[2] Univ Teknol Petronas, Ctr Res Ion Liquids, Seri Iskandar, Perak, Malaysia
[3] Univ Teknol Petronas, Ctr Res Ion Liquids, Dept Fundamental & Appl Sci, Seri Iskandar, Perak, Malaysia
[4] Univ Malaya, Dept Chem, Kuala Lumpur, Malaysia
[5] Petr Nas Berhad, Grp Tech Solut Dept, Technol & Engn Div, Kuala Lumpur, Malaysia
[6] Univ Teknol Petronas, Dept Elect & Elect Engn, Seri Iskandar, Perak, Malaysia