本篇以分子動力模擬的方法研究溫度對於高分子電解質Li(CF3SO3)/聚乙二醇與LiN(CF3SO2)2/聚乙二醇之離子擴散、導電、配位及集結之影響，並與文獻上的實驗值比對。模擬之聚合物為兩端以OH基結尾之聚乙二醇（poly(ethylene glycol)，簡稱PEG），其分子量為400 g/mol。模擬之條件參考Johansson等人之實驗參數，於乙醚氧原子數：鋰離子數（O：Li）為10：1，溫度為323、333及353 K下進行。

　　模擬所得之鋰離子、陰離子及高分子之擴散速率隨溫度之上升而遞增；其中鋰離子與高分子之運動，由於配位的關係，相互偶合，故其擴散速率非常接近。模擬之擴散係數值以LiN(CF3SO2)2PEG系統與實驗值最為接近。模擬結果顯示，鋰離子周圍第一殼層內之氧原子數約為5.4，與實驗值相符。高溫有利於鋰離子與PEG之氧原子配位，但低溫則有利於其與陰離子之配位。對於Li(CF3SO3)PEG系統而言，與鋰離子配位之氧原子數以來自於PEG者居多，此結果與鋰鹽為LiN(CF3SO2)2時相反。鋰離子周圍之陰離子數在前者為2，後者為3，顯示後者形成離子對或離子群之機率較大。

　　Molecular dynamics simulation have been used to study the temperature effects on the ionic diffusion, conductivity, coordination, and aggregation in polyelectrolytes Li(CF3SO3)/poly(ethylene glycol) and LiN(CF3SO2)2/poly(ethylene glycol). The simulations are examined against the experimental data from the literature. The polymer under study is hydroxyl-terminated poly(ethylene glycol)(PEG), with a MW of 400 g/mol. Simulations were conducted with O:Li (the ratio for the number of the ether oxygen to that of lithium ion) = 10:1 at 323, 333 and 353 K to mimic the experiment of Johansson et al.

　　The simulated diffusion coefficients of Li+, anion, and polymer increase with temperature. Since the motions of the lithium ion and polymer are, owing to coordination, strongly coupled, their diffusion coefficients are quite similar. The simulated diffusion coefficients agree well with experimental values, especially for LiN(CF3SO2)2PEG system. It is known that the number of oxygen atoms in the first coordination sphere of the lithium ion is about 5.4, which is in accord with experiment. The higher temperature facilitates the coordination of lithium ion with the oxygen atom of PEG, but Li+ coordination with anion is favored at low temperature. For the Li(CF3SO3)PEG, most of the oxygen atoms that coordinate with Li+ come from PEG. But the result is reversed when the salt is changed to LiN(CF3SO2)2. The number of anions around the Li+ ion in about 2 for the former, but 3 for the latter, which indicates that the probability to form ion pair or ion aggregate is higher for the latter.

[1] Wright, P. V. and Fenton, D. E. Polymer 1973, 14, 589.

[2] Wright, P. V. Br. Poly. J. 1975, 7, 319.

[3] Armand, M. B. and Duclot, M. J. Patent 1978 No.0013199.

[4] Armand, M. B.; Chabagno, J. M. and Duclot, M. J. Fast Ion Transport in Solids (Eds Vashishta, Mundy and Shenoy) North Holland 1979.

[5] Shriver, D. F.; Dupon, R.; Papke, B. L.; Ratner, M. A. and Whitmore D. H. J. Am. Chem. Soc. 1982, 104, 6247.

[6] Gray, F. M. Solid Polymer Electrolytes Fundamentals and Technological Applications, VCH Publisher, NY 1991.

[7] Lightfoot, P,; Mechta, M. A. and Bruce, P. G. Science 1993, 262, 883

[8] Huang, W. and Frech, R. Solid state Ionics 1994, 72, 103.

[9] Chintapalli, S. and Frech, R. Electrochim. Acta 1995, 40, 2093.

[10] Huang, W.; Frech, R.; Johansson, P. and Lindgren, J. Electrochim. Acta 1995, 40, 2147.

[11] Williamson, M. J.; Southall J. P.; Hubbard, H. V. S.; Davies, G. R. and Ward, I. M. Polymer 1999, 40, 3945.

[12] Palma, A.; Pasquarello, A.; Ciccotti, G. and Car, R. J. Chem. Phys. 1998, 23, 9933.

[13] Borodin, O. and Smith, G. D. J. Phys. Chem. B 2001, 105, 3329.

[14] 郭人華, “Molecular Simulations of the Ion Conductivity and Diffusion in Polyethylene Oxide/Electrolyte Solutions”, 國立成功大學碩士 2002.

[15] 魏至偉, “Dependence of ionic association on polymer chain length in poly(ethylene oxide)-LiCF3SO3 complexes : a molecular dynamics study”, 國立成功大學碩士論文 2002.

[16] Johansson, A.; Goholl, A. and Tegenfeldt, J. Polymer 1996, 37, 1387.

[17] Teodora, D. N. and Suter, U. W. Macromolecules 1985, 18, 1206.

[18] Baskir, J. N. and Suter, U. W. Macromolecules 1988, 21, 1877.

[19] Discover user guide part 1, Biosym/MSI Technologies 1996, V 4.0.

[20] Ratner, M. “Polymer electrolyte Reviews-1”, Elsevier Applied Science, London 1987, p. 173.

[21] Zimm, B. H. J. Chem. Phys. 1953, 21, 934.

[22] Zimm, B. H. and Lundberg, J. L. J. Phys. Chem. 1956, 60, 425.

[23] Lundberg, J. L. J. Macromol. Sci. 1969, B3, 693.

[24] Haile, J. L. “Molecular Dynamics Simulation”, New York 1992, p. 293.

[25] Shi, J. and Vincent, C. A. Solid State Ionics 1993, 60, 11.

[26] Rose, P. E. J. Chem. Phys. 1953, 21, 1272.

[27] Zimm, B. H. J. Chem. Phys. 1956, 24, 269.

[28] Hayamizu, K. and Akiba, E. J. Chem. Phys. 2002, 117, 5929.

[29] Bernson, A. and Lindgren, J. Polymer 1994, 35, 4842.

[30] Hyun, J. K.; Dong, H.; Rhodes, C. P.; Frech, R. and Wheeler, R. A. J. Phys. Chem. B 2001, 105, 3329.

[31] Torell, L. M.; Jacobsson, P.; Sidebottom, D. and Petersen, G. Solid State Ionics 1992, 53-56, 1037.