@article{turgut_tuhin_toprakci_pasquinelli_spontak_toprakci_2018, title={Thermoplastic Elastomer Systems Containing Carbon Nanofibers as Soft Piezoresistive Sensors}, volume={3}, ISSN={["2470-1343"]}, DOI={10.1021/acsomega.8b01740}, abstractNote={Soft, wearable or printable strain sensors derived from conductive polymer nanocomposites (CPNs) are becoming increasingly ubiquitous in personal-care applications. Common elastomers employed in the fabrication of such piezoresistive CPNs frequently rely on chemically cross-linked polydiene or polysiloxane chemistry, thereby generating relatively inexpensive and reliable sensors that become solid waste upon application termination. Moreover, the shape anisotropy of the incorporated conductive nanoparticles can produce interesting electrical effects due to strain-induced spatial rearrangement. In this study, we investigate the morphological, mechanical, electrical, and electromechanical properties of CPNs generated from thermoplastic elastomer (TPE) triblock copolymer systems containing vapor-grown carbon nanofiber (CNF). Modulus-tunable TPE gels imbibed with a midblock-selective aliphatic oil exhibit well-behaved properties with increasing CNF content, but generally display nonlinear negative piezoresistance at different strain amplitudes and stretch rates due to nanofiber mobility upon CPN strain-cycling. In contrast, a neat TPE possessing low hard-block content yields a distinctive strain-reversible piezoresistive response, as well as low electrical hysteresis, upon cyclic deformation. Unlike their chemically cross-linked analogs, these physically cross-linked and thus environmentally benign CPNs are fully reprocessable by thermal and/or solvent means.}, number={10}, journal={ACS OMEGA}, author={Turgut, Ayse and Tuhin, Mohammad O. and Toprakci, Ozan and Pasquinelli, Melissa A. and Spontak, Richard J. and Toprakci, Hatice A. K.}, year={2018}, month={Oct}, pages={12648–12657} } @article{fu_padbury_toprakci_dirican_zhang_2018, title={Conductive textiles}, ISBN={["978-0-08-101273-4"]}, url={https://publons.com/publon/26924634/}, DOI={10.1016/b978-0-08-101273-4.00017-2}, abstractNote={With the rapid development of flexible electronics, conductive textiles are becoming important building blocks for wearables in broad applications. Different from conventional textiles, conductive textiles require fabrics to have a basic wearable function as well as electrical conductivity. Conductive textiles have been used in applications such as antistatic, electromagnetic (EM) shielding, and e-textiles. In this chapter, we introduce the fundamental principles of conductive textiles and review recent developments of advanced conductive coating technologies and their applications in antistatic, EM shielding, and e-textiles.}, journal={ENGINEERING OF HIGH-PERFORMANCE TEXTILES}, publisher={Elsevier}, author={Fu, K. and Padbury, R. and Toprakci, O. and Dirican, M. and Zhang, X.}, year={2018}, pages={305–334} } @misc{lee_yanilmaz_toprakci_fu_zhang_2014, title={A review of recent developments in membrane separators for rechargeable lithium-ion batteries}, volume={7}, ISSN={["1754-5706"]}, url={https://publons.com/publon/674379/}, DOI={10.1039/c4ee01432d}, abstractNote={The separator of a lithium-ion battery prevents the direct contact between the positive and negative electrodes while serving as the electrolyte reservoir to enable the transportation of lithium ions between the two electrodes.}, number={12}, journal={ENERGY & ENVIRONMENTAL SCIENCE}, publisher={Royal Society of Chemistry (RSC)}, author={Lee, Hun and Yanilmaz, Meltem and Toprakci, Ozan and Fu, Kun and Zhang, Xiangwu}, year={2014}, pages={3857–3886} } @article{lee_alcoutlabi_toprakci_xu_watson_zhang_2014, title={Preparation and characterization of electrospun nanofiber-coated membrane separators for lithium-ion batteries}, volume={18}, ISSN={["1433-0768"]}, url={https://publons.com/publon/674382/}, DOI={10.1007/s10008-014-2501-4}, number={9}, journal={JOURNAL OF SOLID STATE ELECTROCHEMISTRY}, publisher={Springer Nature}, author={Lee, Hun and Alcoutlabi, Mataz and Toprakci, Ozan and Xu, Guanjie and Watson, Jill V. and Zhang, Xiangwu}, year={2014}, month={Sep}, pages={2451–2458} } @inproceedings{li_fu_xue_toprakci_li_zhang_xu_lu_zhang_2013, title={Co3O4/carbon composite nanofibers for use as anode material in advanced lithium-ion batteries}, volume={1140}, url={https://publons.com/publon/7178343/}, DOI={10.1021/bk-2013-1140.ch003}, abstractNote={Co3O4/carbon composite nanofibers were prepared by a combination of electrospinning and carbonization methods using 10 - 30 nm and 30 - 50 nm Co3O4 nanoparticles, respectively, and their potential use as the anode material in rechargeable lithium-ion batteries was investigated. The composite Co3O4/carbon nanofiber electrode containing 30 - 50 nm Co3O4 nanoparticles showed large reversible capacities and good cycleability with charge capacities of 677 and 545 mAh g-1 at the second and twentieth cycles, respectively. In contrast, the composite Co3O4/carbon nanofiber electrode containing 10 - 30 nm Co3O4 nanoparticles showed fast capacity fading during cycling due to severe nanoparticle aggregation. Results suggested that the good electrochemical performance of Co3O4/carbon nanofiber electrode containing 30 - 50 nm Co3O4 nanoparticles was ascribed to the combination of the properties of both Co3O4 nanoparticles (large Li storage capability) and carbon nanofiber matrix (long cycle life), and therefore this electrode material could be potentially used in high-energy rechargeable lithium-ion batteries.}, booktitle={Nanotechnology for sustainable energy}, author={Li, S. L. and Fu, K. and Xue, L. G. and Toprakci, O. and Li, Y. and Zhang, S. and Xu, G. J. and Lu, Y. and Zhang, Xiangwu}, year={2013}, pages={55–66} } @article{turhan_toprakci_2013, title={Comparison of high-volume instrument and advanced fiber information systems based on prediction performance of yarn properties using a radial basis function neural network}, volume={83}, number={2}, journal={Textile Research Journal}, author={Turhan, Y. and Toprakci, O.}, year={2013}, pages={130–147} } @article{li_xu_xue_zhang_yao_lu_toprakci_zhang_2013, title={Enhanced Rate Capability by Employing Carbon Nanotube-Loaded Electrospun Si/C Composite Nanofibers As Binder-Free Anodes}, volume={160}, ISSN={["1945-7111"]}, url={https://publons.com/publon/674380/}, DOI={10.1149/2.031304jes}, abstractNote={Si/C and Si/carbon nanotube (CNT)/C composite nanofibers were prepared by electrospinning and carbonization. The carbon nanofiber matrix can accommodate the volume change of Si nanoparticles and provide continuous pathways for efficient charge transport along the fiber axis. CNTs can improve the electronic conductivity and electrochemical performance of the composite nanofiber anodes. Results showed that many different types of connections between CNTs, Si nanoparticles and carbon matrix were formed. At a high current density of 300 mA g−1, after 30 cycles, the capacity of Si/CNT/C composite nanofiber anode was 44.3% higher than the anode without CNT and the C-rate performance of Si/CNT/C composite nanofiber anode was also superior to that of Si/C anode. It is, therefore, demonstrated that Si/CNT/C nanofibers are promising anode material with large capacities, good cycling stability, and good rate capability.}, number={3}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Li, Ying and Xu, Guanjie and Xue, Leigang and Zhang, Shu and Yao, Yingfang and Lu, Yao and Toprakci, Ozan and Zhang, Xiangwu}, year={2013}, pages={A528–A534} } @article{li_xu_yao_xue_zhang_lu_toprakci_zhang_2013, title={Improvement of cyclability of silicon-containing carbon nanofiber anodes for lithium-ion batteries by employing succinic anhydride as an electrolyte additive}, volume={17}, ISSN={["1433-0768"]}, url={https://publons.com/publon/674383/}, DOI={10.1007/s10008-013-2005-7}, number={5}, journal={JOURNAL OF SOLID STATE ELECTROCHEMISTRY}, author={Li, Ying and Xu, Guanjie and Yao, Yingfang and Xue, Leigang and Zhang, Shu and Lu, Yao and Toprakci, Ozan and Zhang, Xiangwu}, year={2013}, month={May}, pages={1393–1399} } @article{toprakci_toprakci_li_ji_xue_lee_zhang_zhang_2013, title={Synthesis and characterization of xLi(2)MnO(3) center dot (1-x)LiMn1/3Ni1/3Co1/3O2 composite cathode materials for rechargeable lithium-ion batteries}, volume={241}, ISSN={["0378-7753"]}, url={https://publons.com/publon/674386/}, DOI={10.1016/j.jpowsour.2013.04.155}, abstractNote={Various xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) cathode materials were prepared by the one-step sol–gel route. The structure of xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 composites was determined by X-ray diffraction analysis. The surface morphology and microstructure of xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 composites were characterized using scanning electron microscopy and transmission electron microscopy. Electrochemical performance of xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 composites was evaluated in terms of capacity, cycling performance and rate capability. Although the morphology and structure were found to be affected by the Li2MnO3 content, all composites showed an α-NaFeO2 structure with R3m space group. Electrochemical results showed that cells using 0.3Li2MnO3·0.7LiCo1/3Ni1/3Mn1/3O2 composites had good performance, in terms of large reversible capacity, prolonged cycling stability, and excellent rate capability.}, journal={JOURNAL OF POWER SOURCES}, publisher={Elsevier BV}, author={Toprakci, Ozan and Toprakci, Hatice A. K. and Li, Ying and Ji, Liwen and Xue, Leigang and Lee, Hun and Zhang, Shu and Zhang, Xiangwu}, year={2013}, month={Nov}, pages={522–528} } @article{xue_zhang_li_lu_toprakci_xia_chen_hu_zhang_2013, title={Synthesis and properties of Li2MnO3-based cathode materials for lithium-ion batteries}, volume={577}, ISSN={["1873-4669"]}, url={https://publons.com/publon/674387/}, DOI={10.1016/j.jallcom.2013.07.029}, abstractNote={Lithium-ion batteries have been wildly used in various portable electronic devices and the application targets are currently moving from small-sized mobile devices to large-scale electric vehicles and grid energy storage. Therefore, lithium-ion batteries with higher energy densities are in urgent need. For high-energy cathodes, Li2MnO3–LiMO2 layered–layered (M = Mn, Co, Ni) materials are of significant interest due to their high specific capacities over wide operating potential windows. Here, three Li2MnO3-based cathode materials with α-NaFeO2 structure were prepared by a facile co-precipitation method and subsequent heat treatment. Among these three materials, 0.3Li2MnO3·0.5LiMn0.5Ni0.5O2·0.2LiCoO2 shows the best lithium storage capability. This cathode material is composed of uniform nanosized particles with diameters ranging from 100 to 200 nm, and it could be charged to a high cutoff potential to extract more lithium, resulting in a high capacity of 178 mAh g−1 between 2.0 and 4.6 V with almost no capacity loss over 100 cycles.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Xue, Leigang and Zhang, Shu and Li, Shuli and Lu, Yao and Toprakci, Ozan and Xia, Xin and Chen, Chen and Hu, Yi and Zhang, Xiangwu}, year={2013}, month={Nov}, pages={560–563} } @article{chakraborti_toprakci_yang_di spigna_franzon_ghosh_2012, title={A compact dielectric elastomer tubular actuator for refreshable Braille displays}, volume={179}, ISSN={["0924-4247"]}, DOI={10.1016/j.sna.2012.02.004}, abstractNote={Electroactive polymer actuators stimulated by appropriate levels of electric field are particularly attractive for human-assist devices such as Braille. The development of a full page refreshable Braille display is very important for the integration of the visually impaired into the new era of communication. In this paper, development of a compact dielectric elastomer actuator suitable for Braille application is reported. The actuators are fabricated from commercially available silicone tubes. The tube has been rendered mechanically anisotropic through asymmetric levels of applied pretension in circumferential and axial directions in order to direct the actuation strain in the axial direction of the actuator. Key performance parameters, such as displacement, force, and response time of the actuator are investigated. The test results demonstrate the potential of the compact, lightweight, and low cost dielectric elastomer as actuators for a refreshable full page Braille display.}, journal={SENSORS AND ACTUATORS A-PHYSICAL}, author={Chakraborti, P. and Toprakci, H. A. Karahan and Yang, P. and Di Spigna, N. and Franzon, P. and Ghosh, T.}, year={2012}, month={Jun}, pages={151–157} } @article{toprakci_toprakci_ji_xu_lin_zhang_2012, title={Carbon Nanotube-Loaded Electrospun LiFePO4/Carbon Composite Nanofibers As Stable and Binder-Free Cathodes for Rechargeable Lithium-Ion Batteries}, volume={4}, ISSN={["1944-8252"]}, url={https://publons.com/publon/674388/}, DOI={10.1021/am201527r}, abstractNote={LiFePO(4)/CNT/C composite nanofibers were synthesized by using a combination of electrospinning and sol-gel techniques. Polyacrylonitrile (PAN) was used as the electrospinning media and carbon source. Functionalized CNTs were used to increase the conductivity of the composite. LiFePO(4) precursor materials, PAN and functionalized CNTs were dissolved or dispersed in N,N-dimethylformamide separately and they were mixed before electrospinning. LiFePO(4) precursor/CNT/PAN composite nanofibers were then heat-treated to obtain LiFePO(4)/CNT/C composite nanofibers. Fourier transform infrared spectroscopy measurements were done to demonstrate the functionalization of CNTs. The structure of LiFePO(4)/CNT/C composite nanofibers was determined by X-ray diffraction analysis. The surface morphology and microstructure of LiFePO(4)/CNT/C composite nanofibers were characterized using scanning electron microscopy and transmission electron microscopy. Electrochemical performance of LiFePO(4)/CNT/C composite nanofibers was evaluated in coin-type cells. Functionalized CNTs were found to be well-dispersed in the carbonaceous matrix and increased the electrochemical performance of the composite nanofibers. As a result, cells using LiFePO(4)/CNT/C composite nanofibers have good performance, in terms of large capacity, extended cycle life, and good rate capability.}, number={3}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Toprakci, Ozan and Toprakci, Hatice A. K. and Ji, Liwen and Xu, Guanjie and Lin, Zhan and Zhang, Xiangwu}, year={2012}, month={Mar}, pages={1273–1280} } @article{li_lin_xu_yao_zhang_toprakci_alcoutlabi_zhang_2012, title={Electrochemical Performance of Carbon Nanofibers Containing an Enhanced Dispersion of Silicon Nanoparticles for Lithium-Ion Batteries by Employing Surfactants}, volume={1}, ISSN={["2162-8734"]}, url={https://publons.com/publon/674390/}, DOI={10.1149/2.002202eel}, abstractNote={Si/C composite nanofibers were prepared by electrospinning and carbonization. Two surfactants: cetyl trimethyl ammonium bromide (CTAB) and sodium dodecanoate (SD), were used to improve the dispersion of Si nanoparticles and the electrochemical performance. Results show that after 50 cycles, the discharge capacity of Si/C nanofibers does not have significant change after the addition of CTAB surfactant, however, the discharge capacity of Si/C nanofibers with SD surfactant is more than 20% higher than that without surfactant. It is demonstrated that employing SD surfactant is a simple and effective way to obtain Si/C nanofibers with large capacities and good cycling stability.}, number={2}, journal={ECS ELECTROCHEMISTRY LETTERS}, author={Li, Ying and Lin, Zhan and Xu, Guanjie and Yao, Yingfang and Zhang, Shu and Toprakci, Ozan and Alcoutlabi, Mataz and Zhang, Xiangwu}, year={2012}, pages={A31–A33} } @article{liang_cheng_zhao_zhang_sun_zhou_qiu_zhang_2012, title={High-capacity Li2Mn0.8Fe0.2SiO4/carbon composite nanofiber cathodes for lithium-ion batteries}, volume={213}, ISSN={["1873-2755"]}, url={https://doi.org/10.1016%2Fj.jpowsour.2013.04.019}, DOI={10.1016/j.jpowsour.2012.04.011}, abstractNote={Li2MnSiO4 has been considered as a promising cathode material with an extremely high theoretically capacity of 332 mAh g−1. However, due to its low intrinsic conductivity and poor structural stability, only about half of the theoretical capacity has been realized in practice and the capacity decays rapidly during cycling. To realize the high capacity and improve the cycling performance, Li2Mn0.8Fe0.2SiO4/carbon composite nanofibers were prepared by the combination of iron doping and electrospinning. X-ray diffraction, scanning electron microscope, and transmission electronic microscope were applied to characterize the Li2Mn0.8Fe0.2SiO4/carbon nanofibers. It was found that Li2Mn0.8Fe0.2SiO4 nanoparticles were embedded into continuous carbon nanofiber matrices, which formed free-standing porous mats that could be used as binder-free cathodes. The iron doping improved the conductivity and purity of the active material, and the carbon nanofiber matrix facilitated ion transfer and charge diffusion. As a result, Li2Mn0.8Fe0.2SiO4/carbon nanofiber cathodes showed promising improvement on reversible capacity and cycling performance.}, journal={JOURNAL OF POWER SOURCES}, publisher={Elsevier BV}, author={Liang, Yinzheng and Cheng, Sichen and Zhao, Jianmeng and Zhang, Changhuan and Sun, Shiyuan and Zhou, Nanting and Qiu, Yiping and Zhang, Xiangwu}, year={2012}, month={Sep}, pages={10–15} } @article{toprakci_toprakci_ji_lin_gu_zhang_2012, title={LiFePO4 nanoparticles encapsulated in graphene-containing carbon nanofibers for use as energy storage materials}, volume={4}, ISSN={["1941-7012"]}, url={https://publons.com/publon/674392/}, DOI={10.1063/1.3690936}, abstractNote={LiFePO4/graphene/C composite nanofibers, in which LiFePO4 nanoparticles were encapsulated in graphene-containing carbon nanofiber matrix, were synthesized by using a combination of electrospinning and sol-gel techniques. Polyacrylonitrile (PAN) was used as the electrospinning media and the carbon source. Graphene was incorporated in order to increase the conductivity of the composite. PAN was dissolved in N,N–dimethylformamide (DMF). LiFePO4 precursor and graphene were dispersed in DMF separately and were mixed with PAN solution before electrospinning. Electrospun fibers were heat-treated to obtain LiFePO4/graphene/C composite nanofibers. The structure of LiFePO4/graphene/C composite nanofibers was determined by X–ray diffraction analysis. The surface morphology and microstructure of LiFePO4/graphene/C composite nanofibers were characterized using scanning electron microscopy and transmission electron microscopy. Electrochemical performance of LiFePO4/graphene/C composite nanofibers was evaluated in coin-type cells. Graphene flakes were found to be well-dispersed in the carbonaceous matrix and increased the electrochemical performance of the composite nanofibers. As a result, cells containing LiFePO4/graphene/C composite nanofiber cathodes showed good electrochemical performance, in terms of capacity, cycle life, and rate capability.}, number={1}, journal={JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY}, author={Toprakci, Ozan and Toprakci, Hatice A. K. and Ji, Liwen and Lin, Zhan and Gu, Renpeng and Zhang, Xiangwu}, year={2012}, month={Jan} } @article{fu_xue_yildiz_li_lee_li_xu_zhou_bradford_zhang_et al._2013, title={Si/C composite nanofibers with stable electric conductive network for use as durable lithium-ion battery anode}, volume={2}, ISSN={["2211-3282"]}, url={https://publons.com/publon/674385/}, DOI={10.1016/j.nanoen.2012.11.001}, abstractNote={High-energy anode materials have attracted significant attention because of their potential applications in large-scale energy storage devices. However, they often suffer from rapid capacity fading due to the pulverization of the electrode and the breakdown of electric conductive network caused by the large volume changes of active material upon repeated lithium insertion and extraction. In this work, a new electrode composed of Si/C composite nanofibers was prepared, aiming at the improvement of cycling performance of Si anodes through the establishment of a stable electric conductive network for Si during cycling. By electrospinning, a three-dimensional network of carbon nanofibers, which possesses good elasticity to maintain the structure integrity and stable electric conductive network, is formed; by carbon coating, all Si nanoparticles are tightly bonded with carbon fibers to form a stable electric conductive pathway for electrode reactions. The nanofiber structure and the carbon coating on Si, combined with the binder, lead to a stable network structure that can accommodate the huge volume change of Si during the repeated volume expansion and contraction, thus resulting in excellent cycling performance.}, number={3}, journal={NANO ENERGY}, publisher={Elsevier BV}, author={Fu, Kun and Xue, Leigang and Yildiz, Ozkan and Li, Shuli and Lee, Hun and Li, Ying and Xu, Guanjie and Zhou, Lan and Bradford, Philip D. and Zhang, Xiangwu and et al.}, year={2013}, month={May}, pages={361–367} } @article{li_guo_ji_lin_xu_liang_zhang_toprakci_hu_alcoutlabi_et al._2013, title={Structure control and performance improvement of carbon nanofibers containing a dispersion of silicon nanoparticles for energy storage}, volume={51}, ISSN={["1873-3891"]}, url={https://publons.com/publon/674384/}, DOI={10.1016/j.carbon.2012.08.027}, abstractNote={Si/C composite nanofibers were prepared by electrospinning and carbonization using polyacrylonitrile (PAN) as the spinning medium and carbon precursor. The nanofibers were used as lithium-ion battery anodes to combine the advantages of carbon (long cycle life) and silicon (high storage capacity) materials. The effects of Si particle size, Si content, and carbonization temperature on the structure and electrochemical performance of the anodes were investigated. Results show that anodes made from a 15 wt.% Si/PAN precursor with a Si particle size of 30–50 nm and carbonization temperature of 800 °C exhibit the best performance in terms of high capacity and stable cycling behavior. It is demonstrated that with careful structure control, Si/C composite nanofiber anodes are a promising material for next-generation lithium-ion batteries.}, journal={CARBON}, author={Li, Ying and Guo, Bingkun and Ji, Liwen and Lin, Zhan and Xu, Guanjie and Liang, Yinzheng and Zhang, Shu and Toprakci, Ozan and Hu, Yi and Alcoutlabi, Mataz and et al.}, year={2013}, month={Jan}, pages={185–194} } @article{ji_toprakci_alcoutlabi_yao_li_zhang_guo_lin_zhang_2012, title={alpha-Fe2O3 Nanoparticle-Loaded Carbon Nanofibers as Stable and High-Capacity Anodes for Rechargeable Lithium-Ion Batteries}, volume={4}, ISSN={["1944-8244"]}, url={https://publons.com/publon/674393/}, DOI={10.1021/am300333s}, abstractNote={α-Fe(2)O(3) nanoparticle-loaded carbon nanofiber composites were fabricated via electrospinning FeCl(3)·6H(2)O salt-polyacrylonitrile precursors in N,N-dimethylformamide solvent and the subsequent carbonization in inert gas. Scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and elemental analysis were used to study the morphology and composition of α-Fe(2)O(3)-carbon nanofiber composites. It was indicated that α-Fe(2)O(3) nanoparticles with an average size of about 20 nm have a homogeneous dispersion along the carbon nanofiber surface. The resultant α-Fe(2)O(3)-carbon nanofiber composites were used directly as the anode material in rechargeable lithium half cells, and their electrochemical performance was evaluated. The results indicated that these α-Fe(2)O(3)-carbon nanofiber composites have high reversible capacity, good capacity retention, and acceptable rate capability when used as anode materials for rechargeable lithium-ion batteries.}, number={5}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Ji, Liwen and Toprakci, Ozan and Alcoutlabi, Mataz and Yao, Yingfang and Li, Ying and Zhang, Shu and Guo, Bingkun and Lin, Zhan and Zhang, Xiangwu}, year={2012}, month={May}, pages={2672–2679} } @article{bonino_ji_lin_toprakci_zhang_khan_2011, title={Electrospun Carbon-Tin Oxide Composite Nanofibers for Use as Lithium Ion Battery Anodes}, volume={3}, ISSN={["1944-8252"]}, url={https://publons.com/publon/674395/}, DOI={10.1021/am2004015}, abstractNote={Composite carbon-tin oxide (C-SnO(2)) nanofibers are prepared by two methods and evaluated as anodes in lithium-ion battery half cells. Such an approach complements the long cycle life of carbon with the high lithium storage capacity of tin oxide. In addition, the high surface-to-volume ratio of the nanofibers improves the accessibility for lithium intercalation as compared to graphite-based anodes, while eliminating the need for binders or conductive additives. The composite nanofibrous anodes have first discharge capacities of 788 mAh g(-1) at 50 mA g(-1) current density, which are greater than pure carbon nanofiber anodes, as well as the theoretical capacity of graphite (372 mAh g(-1)), the traditional anode material. In the first protocol to fabricate the C-SnO(2) composites, tin sulfate is directly incorporated within polyacrylonitrile (PAN) nanofibers by electrospinning. During a thermal treatment the tin salt is converted to tin oxide and the polymer is carbonized, yielding carbon-SnO(2) nanofibers. In the second approach, we soak the nanofiber mats in tin sulfate solutions prior to the final thermal treatment, thereby loading the outer surfaces with SnO(2) nanoparticles and raising the tin content from 1.9 to 8.6 wt %. Energy-dispersive spectroscopy and X-ray diffraction analyses confirm the formation of conversion of tin sulfate to tin oxide. Furthermore, analysis with Raman spectroscopy reveals that the additional salt soak treatment from the second fabrication approach increases in the disorder of the carbon structure, as compared to the first approach. We also discuss the performance of our C-SnO(2) compared with its theoretical capacity and other nanofiber electrode composites previously reported in the literature.}, number={7}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Bonino, Christopher A. and Ji, Liwen and Lin, Zhan and Toprakci, Ozan and Zhang, Xiangwu and Khan, Saad A.}, year={2011}, month={Jul}, pages={2534–2542} } @misc{zhang_ji_toprakci_liang_alcoutlabi_2011, title={Electrospun Nanofiber-Based Anodes, Cathodes, and Separators for Advanced Lithium-Ion Batteries}, volume={51}, ISSN={["1558-3716"]}, url={https://publons.com/publon/674396/}, DOI={10.1080/15583724.2011.593390}, abstractNote={Novel nanofiber technologies present the opportunity to design new materials for advanced rechargeable lithium-ion batteries. Among the various existing energy storage technologies, rechargeable lithium-ion batteries are considered as effective solution to the increasing need for high-energy electrochemical power sources. This review addresses using electrospinning technology to develop novel composite nanofibers which can be used as anodes, cathodes, and separators for lithium-ion batteries. The discussion focuses on the preparation, structure, and performance of silicon/carbon (Si/C) nanofiber anodes, lithium iron phosphate/carbon (LiFePO4/C) nanofiber cathodes, and lithium lanthanum titanate oxide/polyacrylonitrile (LLTO/PAN) nanofiber separators. Si/C nanofiber anodes have the advantages of both carbon (long cycle life) and Si (high lithium-storage capacity). LiFePO4/C nanofiber cathodes show good electrochemical performance including satisfactory capacity and good cycling stability. LLTO/PAN nanofiber separators have large electrolyte uptake, high ionic conductivity, and low interfacial resistance with lithium, which increase the capacity and improve the cycling stability of lithium-ion cells. These results demonstrate that electrospinning is a promising approach to prepare high-performance nanofiber anodes, nanofiber cathodes, and nanofiber separators that can potentially replace currently-used lithium-ion battery materials.}, number={3}, journal={POLYMER REVIEWS}, author={Zhang, Xiangwu and Ji, Liwen and Toprakci, Ozan and Liang, Yinzheng and Alcoutlabi, Mataz}, year={2011}, pages={239–264} } @article{ji_lin_alcoutlabi_toprakci_yao_xu_li_zhang_2012, title={Electrospun carbon nanofibers decorated with various amounts of electrochemically-inert nickel nanoparticles for use as high-performance energy storage materials}, volume={2}, ISSN={["2046-2069"]}, url={https://publons.com/publon/674391/}, DOI={10.1039/c1ra00676b}, abstractNote={Carbon nanofibers decorated with various amounts of electrochemically-inert metallic nickel nanoparticles are synthesized through electrospinning and carbonization processes. The morphology and composition of Ni nanoparticles in carbon nanofibers are controlled by preparing different nanofiber precursors. The lithium-ion battery performance evaluations indicated that the content of electrochemically-inert Ni nanoparticles in carbon nanofibers has a great influence on the final electrochemical performance. For example, at certain Ni contents, these composite nanofibers display excellent electrochemical performance, such as high reversible capacities, good capacity retention, and excellent rate performance, when directly used as binder-free anodes for rechargeable lithium-ion batteries. However, when the Ni content is too low or too high, the corresponding electrodes show low reversible capacities although they still have good reversibility and rate performance.}, number={1}, journal={RSC ADVANCES}, author={Ji, Liwen and Lin, Zhan and Alcoutlabi, Mataz and Toprakci, Ozan and Yao, Yingfang and Xu, Guanjie and Li, Shuli and Zhang, Xiangwu}, year={2012}, pages={192–198} } @article{alcoutlabi_ji_guo_li_li_zhang_toprakci_zhang_2011, title={Electrospun nanofibers for energy storage}, volume={11}, number={6}, journal={AATCC Review}, author={Alcoutlabi, M. and Ji, L. W. and Guo, B. K. and Li, S. L. and Li, Y. and Zhang, S. and Toprakci, O. and Zhang, X. W.}, year={2011}, pages={45–51} } @article{toprakci_ji_lin_toprakci_zhang_2011, title={Fabrication and electrochemical characteristics of electrospun LiFePO4/carbon composite fibers for lithium-ion batteries}, volume={196}, ISSN={["1873-2755"]}, url={https://publons.com/publon/674397/}, DOI={10.1016/j.jpowsour.2011.04.031}, abstractNote={LiFePO4/C composite fibers were synthesized by using a combination of electrospinning and sol–gel techniques. Polyacrylonitrile (PAN) was used as an electrospinning media and a carbon source. LiFePO4 precursor materials and PAN were dissolved in N,N-dimethylformamide separately and they were mixed before electrospinning. LiFePO4 precursor/PAN fibers were heat treated, during which LiFePO4 precursor transformed to energy-storage LiFePO4 material and PAN was converted to carbon. The surface morphology and microstructure of the obtained LiFePO4/C composite fibers were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental dispersive spectroscopy (EDS). XRD measurements were also carried out in order to determine the structure of LiFePO4/C composite fibers. Electrochemical performance of LiFePO4/carbon composite fibers was evaluated in coin-type cells. Carbon content and heat treatment conditions (such as stabilization temperature, calcination/carbonization temperature, calcination/carbonization time, etc.) were optimized in terms of electrochemical performance.}, number={18}, journal={JOURNAL OF POWER SOURCES}, author={Toprakci, Ozan and Ji, Liwen and Lin, Zhan and Toprakci, Hatice A. K. and Zhang, Xiangwu}, year={2011}, month={Sep}, pages={7692–7699} } @article{lin_ji_toprakci_krause_zhang_2010, title={Electrospun carbon nanofiber-supported Pt-Pd alloy composites for oxygen reduction}, volume={25}, ISSN={["2044-5326"]}, url={https://publons.com/publon/674398/}, DOI={10.1557/jmr.2010.0163}, abstractNote={Carbon nanofiber-supported Pt–Pd alloy composites were prepared by co-electrodepositing Pt–Pd alloy nanoparticles directly onto electrospun carbon nanofibers. The morphology and size of Pt–Pd alloy nanoparticles were controlled by the surface treatment of carbon nanofibers and the electrodeposition duration time. Scanning electron microscopy/energy dispersive spectrometer (SEM)/(EDS) and x-ray photoelectron spectroscopy (XPS) were used to study the composition of Pt–Pd alloy on the composites, and the co-electrodeposition mechanism of Pt–Pd alloy was investigated. The resultant Pt–Pd/carbon nanofiber composites were characterized by running cyclic voltammograms in oxygen-saturated 0.1 M HClO4 at 25 °C to study their electrocatalytic ability to reduce oxygen. Results show that Pt–Pd/carbon nanofiber composites possess good performance in the electrocatalytic reduction of oxygen. Among all Pt–Pd/carbon nanofibers prepared, the nanofiber composite with a Pt–Pd loading of 0.90 mg/cm2 has the highest electrocatalytic activity by catalyst mass.}, number={7}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Lin, Zhan and Ji, Liwen and Toprakci, Ozan and Krause, Wendy and Zhang, Xiangwu}, year={2010}, month={Jul}, pages={1329–1335} } @article{toprakci_toprakci_ji_zhang_2010, title={Fabrication and electrochemical characteristics of LiFePO4 powders for lithium-Ion batteries}, url={https://publons.com/publon/674400/}, DOI={10.14356/kona.2010008}, abstractNote={Novel powder fabrication technologies provide opportunities to develop high-performance, low-cost cathode materials for rechargeable lithium-ion batteries. Among various energy storage technologies, rechargeable lithium-ion batteries have been considered as effective solution to the increasing need for high-energy density electrochemical power sources. Rechargeable lithium-ion batteries offer energy densities 2 - 3 times and power densities 5 - 6 times higher than conventional Ni-Cd and NiMH batteries, and as a result, they weigh less and take less space for a given energy delivery. However, the use of lithium-ion batteries in many large applications such as electric vehicles and storage devices for future power grids is hindered by the poor thermal stability, relatively high toxicity, and high cost of lithium cobalt oxide (LiCoO2) powders, which are currently used as the cathode material in commercial lithium-ion batteries. Recently, lithium iron phosphate (LiFePO4) powders have become a favorable cathode material for lithium-ion batteries because of their low cost, high discharge potential (ar ound 3.4 V versus Li/Li + ), large specific capacity (170 mAh/g), good thermal stability, and high abundance with the environmentally benign and safe nature. As a result, there is a huge demand for the production of high-performance LiFePO4 powders. However, LiFePO4 also has its own limitation such as low conductivity (~10 -9 S/cm), which results in poor rate capability. This can be addressed by modifying the powder structure using novel fabrication technologies. This paper presents an overview of recent advances in the fabrication of high-performance LiFePO4 powders for lithium-ion batteries. The LiFePO4 powder fabrication methods covered include: solid-state synthesis, mechanochemical activation, carbothermal reduction, microwave heating, hydrothermal synthesis, sol-gel synthesis, spray pyrolysis, co-precipitation, microemulsion drying, and others. The impacts of these fabrication methods on the structure and performance of LiFePO4 powders are discussed. In addition, the improvement of the conductivity of LiFePO4 powders through novel powder technologies}, number={28}, journal={Kona Powder and Particle Journal}, author={Toprakci, O. and Toprakci, H. A. K. and Ji, L. W. and Zhang, Xiangwu}, year={2010}, pages={50–73} } @article{ji_lin_li_li_liang_toprakci_shi_zhang_2010, title={Formation and characterization of core-sheath nanofibers through electrospinning and surface-initiated polymerization}, volume={51}, ISSN={["1873-2291"]}, url={https://publons.com/publon/674399/}, DOI={10.1016/j.polymer.2010.07.042}, abstractNote={Novel core-sheath nanofibers, composed of polyacrylonitrile (PAN) core and polypyrrole (PPy) sheath with clear boundary between them, were fabricated by electrospinning PAN/FeCl3·6H2O bicomponent nanofibers and the subsequent surface-initiated polymerization in a pyrrole-containing solution. By adjusting the concentration of FeCl3·6H2O, the surface morphology of PPy sheath changed from isolated agglomerates or clusters to relatively uniform thin-film structure. Thermal properties of PAN-PPy core-sheath nanofibers were also characterized. Results indicated that the PPy sheath played a role of inhibitor and retarded the complex chemical reactions of PAN during the carbonization process.}, number={19}, journal={POLYMER}, author={Ji, Liwen and Lin, Zhan and Li, Ying and Li, Shuli and Liang, Yinzheng and Toprakci, Ozan and Shi, Quan and Zhang, Xiangwu}, year={2010}, month={Sep}, pages={4368–4374} }