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Lithium hybrid organic batteries are an energy storage device that combines lithium with an organic polymer. For example, polyaniline vanadium (V) oxide (PAni/V2O5) can be incorporated into the nitroxide-polymer lithium iron phosphate battery, PTMA/LiFePO4. Together, they improve the lithium ion intercalation capacity, cycle life, electrochemical performances, and conductivity of batteries. ==PAni/V2O5== Oxides, like V2O5, are used as cathodes in rechargeable lithium batteries. Crystalline V2O5 has a weaker rechargeability or cyclability than amorphous V2O5 because the crystal structure is damaged during discharge/charge cycles.〔Ng, S. H., Chew, S. Y., Wang, J., Wexler, D., Tournayre, Y., Konstantinov, K., & Liu, H. K. (2007). Synthesis and electrochemical properties of V 2 O 5 nanostructures prepared via a precipitation process for lithium-ion battery cathodes. Journal of Power Sources, 174(2), 1032-1035.〕 However, amorphous oxides, in particular the V2O5 xerogel, allows lithium ion to diffuse faster and thus have a better cyclability. Hybrid is formed by combining a conducting organic polymer (e.g. polyaniline) with an oxide (e.g. V2O5). V2O5 gels are prepared using the ion-exchange method.〔Liu, D., Liu, Y., Garcia, B. B., Zhang, Q., Pan, A., Jeong, Y. H., & Cao, G. (2009). V2O5 xerogel electrodes with much enhanced lithium-ion intercalation properties with N 2 annealing. Journal of Materials Chemistry, 19(46), 8789-8795. doi:10.1039/b914436f.〕 Vanadium (V) polymerizes aniline. Before synthesis of a hybrid battery, potentiometric titration of V2O5 gel with (NH4)2Fe(SO4)2 *6H2O is carried out; this determines the amount of V(V) present in the gel. Aniline solution is slowly added onto the V2O5 *nH2O gel. The following procedure is demonstrated in Figure 3. V2O5 is used because of its high specific capacity, high thermal stability, and high structural flexibility with lithium.〔Chao, D., Xia, X., Liu, J., Fan, Z., Ng, C. F., Lin, J., ... & Fan, H. J. (2014). A V2O5/Conductive‐Polymer Core/Shell Nanobelt Array on Three‐Dimensional Graphite Foam: A High‐Rate, Ultrastable, and Freestanding Cathode for Lithium‐Ion Batteries. Advanced Materials, 26(33), 5794-5800. doi:10.1002/adma.201400719.〕 Up to three moles of lithium ions can be added into the V2O5 lattice to create different structures.〔Swider-Lyons, K. E., Love, C. T., & Rolison, D. R. (2002). Improved lithium capacity of defective V2O5 materials. Solid State Ionics, 152, 99-104. doi:10.1016/S0167-2738(02)00350-8.〕 The structures created give the hybrid a long battery life. However, the intercalation capacity depends on the moderate electrical conductivity and low diffusion coefficient of the lithium ions in the vanadium oxide matrix.〔Li, G., Lu, Z., Huang, B., Huang, H., Xue, R., & Chen, L. (1995). An evaluation of lithium intercalation capacity into carbon by XRD parameters. Solid state ionics, 81(1), 15-18. doi:10.1016/0167-2738(95)00166-4.〕 Polyaniline is easily produced to have controlled structural and electronic properties.〔Molapo, K. M., Ndangili, P. M., Ajayi, R. F., Mbambisa, G., Mailu, S. M., Njomo, N., ... & Iwuoha, E. I. (2012). Electronics of conjugated polymers (I): polyaniline.International Journal of Electrochemical Science, 7(12).〕 Polyaniline eliminates the coordinated water of the V2O5 xerogel, so more lithium ions can be integrated into the structure. The organic part of the PAni/V2O5 hybrid degrades with the increase of temperature.〔Lira-Cantu, M., Gomez-Romero, P. (1999), The Organic-Inorganic Polyaniline/V2O5 System: Application as a High Capacity Hybrid Cathode for Rechargeable Lithium Batteries. Journal of the Electrochemical Society, 146(6): 2029-2033. doi:10.1149/1.1391886.〕 V(V) is reduced to V(IV), and aniline is oxidized to polyaniline.〔Lira-Cantu, M., Gomez-Romero, P. (1999), The Organic-Inorganic Polyaniline/V2O5 System: Application as a High Capacity Hybrid Cathode for Rechargeable Lithium Batteries. Journal of the Electrochemical Society, 146(6): 2029-2033. doi:10.1149/1.1391886.〕 Re-oxidizing V(IV) to a higher oxidation state of V(V) increases initial cell voltage and specific capacity. Since polyaniline is an electrochemically active component, it improves the specific charge of the hybrid material.〔Gvozdenović, M., Jugović, B., Stevanović, J., Trišović, T., & Grgur, B. (2011). Electrochemical Polymerization of Aniline. doi:10.5772/28293.〕 Combining polyaniline with V2O5 yields a larger specific charge difference. Thus, a greater total capacity contribution than V2O5 alone. Furthermore, the hybrid has a higher specific capacity than that of the V2O5 xerogel. Electrical conductivity is as high as 0.09 S/cm for 15 days.〔Park, K., Song, H., Kim, Y., Mho, S., Cho, W., and Yeo. I. (2009), Electrochemical Preparation and Characterization of V2O5 / Polyaniline composite Film Cathodes for Li Battery. Electrochimica Acta: Emerging Trends and Challenges in Electrochemistry, 55(27): 8023-8029. doi:10.1016/j.electacta.2009.12.047.〕 As a result, PAni/V2O5 hybrid is a conducting network and an electroactive material in the composites, which improves electrochemical behavior. It also prevents the irreversible structural changes made by redox cycling when the lithium ions enter the lattice. Moreover, this hybrid also has a high specific capacity and improved cyclability without capacity deterioration. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lithium hybrid organic battery」の詳細全文を読む スポンサード リンク
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