Sains Malaysiana 43(11)(2014): 1769–1774

Elektrolit Dwi Lapisan Sm_0.2Ce_0.8O_1.90 (SDC)/ Y_0.25Bi_0.75O_1.5 (YSB) untuk Sel Fuel

Oksida Pepejal Bersuhu Sederhana

(Sm_0.2Ce_0.8O_1.90 (SDC)/ Y_0.25Bi_0.75O_1.5 (YSB) Bilayered Electrolytes for Intermediate Solid

Oxide Fuel Cells)

DEDIKARNI PANUH, ANDANASTUTI MUCHTAR*, NORHAMIDI MUHAMAD,

EDY HERIANTO MAJLAN & WAN RAMLI WAN DAUD

Institut Sel Fuel, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor,Malaysia

Received: 22 November 2012/Accepted: 21 July 2014

ABSTRAK

Elektrolit dwi lapisan samarium terdop seria (SDC)/ytria terstabil bismut (YSB) dikaji adalah untuk menghasilkan sel fuel oksida pepejal bersuhu sederhana (IT-SOFC). Matlamat penyelidikan ialah mengkaji kesan suhu pengkalsinan terhadap penghasilan struktur elektrolit dwi lapisan SDC/YSB untuk IT-SOFC. Elektrolit dwi lapisan SDC dan YSB dihasilkan melalui kaedah sol-gel dan kaedah tindak balas keadaan pepejal. Serbuk SDC dikalsin pada suhu 800, 1000 dan 1200°C selama 5 jam dan serbuk YSB dikalsin pada suhu 550, 650 dan 750°C selama 2 jam. Analisis pembelauan sinar-X (XRD) mendapati serbuk SDC yang dihasilkan pada suhu 800-1200°C selama 5 jam mempunyai struktur Sm_0.2Ce_0.8O_1.90, manakala YSB mempunyai struktur Y0.25Bi0.75O1.5 pada suhu 750°C selama 2 jam. Peningkatan suhu pengkalsinan SDC pada suhu 800, 1000 dan 1200°C selama 5 jam menunjukkan peningkatan pada saiz hablur iaitu 42.4, 58.7 dan 79.9 nm. Peningkatan suhu pengkalsinan YSB sehingga suhu 750°C menyebabkan berlakunya perubahan struktur YSB daripada bentuk tetragon menjadi kiub fluorit dengan saiz hablur 28.86 nm. Hasil perbandingan ujian prestasi sel pada suhu pengoperasian sederhana (650°C), penggunaan elektrolit dwi lapisan (SDC/YSB) dengan suhu pengkalsinan SDC-1200°C dan YSB-750°C menghasilkan prestasi sel paling tinggi dengan ketumpatan kuasa 81.55 mW/cm2 dan ketumpatan arus 225.36 mA/cm₂.

Kata kunci: Elektrolit dwi lapisan; komposit; pengkalsinan; sol-gel

ABSTRACT

Bilayered electrolytes samarium doped ceria (SDC)/yttria stabilised bismuth (YSB) were investigated to develop intermediate temperature of solid oxide fuel cells (IT-SOFCs). The aim of this study was to investigate the effects of the calcination on the microstructure of SDC/YSB bilayered electrolytes in IT-SOFC. Bilayered electrolytes SDC and YSB were syntesised via sol-gel and a solid state reaction method. The SDC powders were calcined at 800, 1000 and 1200°C for 5 h whereas YSB powders were calcined at 550, 650 and 750°C for 2 h. The result from XRD showed that the SDC powder having a Sm_0.2Ce_0.8O_1.9 structure after the calcine at a temperature of 800 to 1200°C for 5 h and YSB having an Y0.25Bi0.75O1.5 structure at 750°C for 2 h. An increase in the calcination temperature on the SDC at 800, 1000 and 1200°C for 5 h caused an increased in crystalline size to 42.4, 58.7 and 79.9 nm, respectively. An increase in YSB calcination temperature to 750°C resulted in the transformation of YSB from tetragonal into cubic fluorite structure with a crystallite size of 28.86 nm. By comparing the results of cell performance test in intermediate operation temperature (650°C), bilayered electrolytes (SDC/YSB) with the calcination temperature SDC-1200°C and YSB-750°C showed the highest cell performance with power density 81.55 mW /cm2 and current density of 225.36 mA/cm₂.

Keywords: Bilayered electrolytes; calcination; composite; sol-gel

REFERENCES

Badwal, S.P.S. & Foger, K. 1996. Solid oxide electrolyte fuel cell review. Ceramics International 22: 257-265.

Boden, A., Di, J., Lagergren, C., Linbergh, G. & Wang, C.Y. 2007. Conductivity of SDC and (Li/Na)2CO3 composite electrolytes in reducing and oxidising atmospheres. Journal of Power Sources 172: 520-529.

Dedikarni, Andanastuti Muchtar, Norhamidi Muhamad, Edy Herianto Majlan & Wan Ramli Wan Daud. 2014. Fabrication of thin Ag-YSB composite cathode film for intermediate-temperature solid oxide fuel cells. Composites Part B: Engineering 58: 193-198.

Dedikarni, Andanastuti Muchtar, Norhamidi Muhamad & Wan Ramli Wan Daud. 2012. Kesan rawatan haba terhadap mikrostruktur katod berliang Ag_2O3-Bi_2O3 di atas substratum keluli tahan karat yang disediakan dengan kaedah pengecatan sluri. Sains Malaysiana41(1): 121-127.

Harwig, H.A. & Gerards, A.G. 1978. Electrical properties of the α, β, and δ phases of bismuth sesquioxide. Journal of Solid State Chemistry 26: 265-274.

Huang, H., Zhou, G. & Xie, Y. 2008. Electrochemical performances of Ag–(Bi_2O3)0.75(Y_2O3)0.25 composite cathodes. Journal of Alloys and Compounds 464: 322-326.

Inaba, H. & Tagawa, H. 1996. Ceria-based solid electrolytes. Solid State Ionics 83: 1-16.

Kakac, S., Pramuanjaroenkij, A. & Zhou, X.Y. 2007. A review of numerical modeling of solid oxide fuel cells. International Journal of Hydrogen Energy 32: 761-786.

Karaca, T., Alt?nçekiç, T.G. & Öksüzömer, M.F. 2010. Synthesis of nanocrystalline samarium-doped CeO2 (SDC) powders as a solid electrolyte by using a simple solvothermal route. Ceramics International 36: 1101-1107.

Kharton, V.V., Fiugueiredo, F.M., Navarro, L., Naumovich, E.N., Kovalevsky, A.V., Yaremchenco, A.A., Viskup, A.P., Carneiro, A., Marques, M.B. & Frade, J.R. 2001. Ceria-based materials for solid oxide fuel cells. Journal Materials Science 36: 1105-1117.

Noor Ashrina, A.H., Andanastuti Muchtar, Wan Ramli Wan Daud & Norhamidi Muhamad. 2009. Pencirian mikrostruktur katod La-Sr-Co-Fe-O bagi sel fuel oksida pejal bersuhu sederhana (IT-SOFC). Sains Malaysiana38: 857-861.

Prabhakar, S. & Nguyen, Q.M. 2004. Solid oxide fuel cells: Technology status. International Journal Applied Ceramic Technology 1: 5-15.

Srinivasan, R. & Bose, A.C. 2010. Structural properties of Sm3+ doped cerium oxide nanorods synthesized by hydrolysis

assisted co-precipitation method. Materials Letters 64: 1954-1956.

Verkerk, M.J. & Burggraaf, A.J. 1981. High oxygen ion conduction in sintered oxides of the Bi₂O₃-Dy₂O₃ system. Journal of the Electrochemical Society 128: 75-82.

Watanabe, A. & Kikuchi, T. 1986. Cubic-hexagonal transformation of yttria stabilized δ-bismuth sesquioxide, Bi₂-₂xY₂xO₃ (x=0.215-0.235). Solid State Ionics 21: 287-291.

Will, J., Mitterdorfer, A., Kleinlogel, C., Perednis, D. & Gauckler, L.J. 2000. Fabrication of thin electrolytes for second-generation solid oxide fuel cells. Solid State Ionics 131: 79-96.

Zhang, L., Li, L., Zhao, F., Chen, F. & Xia, C. 2011. Sm_0.2Ce_0.8O_1.9/ Y_0.25Bi_0.75O_1.5 bilayered electrolytes for low-temperature SOFCs with Ag-Y_0.25Bi_0.75O_1.5 composite cathodes. Solid State Ionics 192: 557-560.

Zhang, L., Xia, C., Zhao, F. & Chen, F. 2010. Thin film ceria– bismuth bilayer electrolytes for intermediate temperature solid oxide fuel cells with La_0.85Sr_0.15Mn_O3-δ–Y_0.25Bi_0.75O^1.5 cathodes. Materials Research Bulletin 45: 603-608.

*Corresponding author; email: muchtar@eng.ukm.my