Design and preparation of high-performance electrode materials, such as Si/C, Ge, Sn-based anode and TiO2, Ti4O7 anode in Lithium ion Batteries(LIBs), Sn-based anode in Sodium ion Batteries(NIBs), Cathode in Rechargeable Magnesium ion Batteries(RMBs) and Cathode in Aluminum ion Batteries(AIBs).
Design and preparation of defect states, surface modification, core-shell interface in nano-materials to achieve high performance of photovoltaic (dye-sensitized solar cells), and electrochemistry materials (LIBs, NIBs, RMBs and AIBs).
Tian, H, Shao, H, Chen, Y, Fang, X, Xiong, P, Sun, B, Notten, PHL & Wang, G 2019, 'Ultra-stable sodium metal-iodine batteries enabled by an in-situ solid electrolyte interphase', NANO ENERGY, vol. 57, pp. 692-702.View/Download from: UTS OPUS or Publisher's site
Chen, Y, Zhang, W, Zhou, D, Tian, H, Su, D, Wang, C, Stockdale, D, Kang, F, Li, B & Wang, G 2019, 'Co-Fe Mixed Metal Phosphide Nanocubes with Highly Interconnected-Pore Architecture as an Efficient Polysulfide Mediator for Lithium-Sulfur Batteries.', ACS nano, vol. 13, no. 4, pp. 4731-4741.View/Download from: UTS OPUS or Publisher's site
Lithium-sulfur (Li-S) batteries have been regarded as one of the most promising candidates for next-generation energy storage owing to their high energy density and low cost. However, the practical deployment of Li-S batteries has been largely impeded by the low conductivity of sulfur, the shuttle effect of polysulfides, and the low areal sulfur loading. Herein, we report the synthesis of uniform Co-Fe mixed metal phosphide (Co-Fe-P) nanocubes with highly interconnected-pore architecture to overcome the main bottlenecks of Li-S batteries. With the highly interconnected-pore architecture, inherently metallic conductivity, and polar characteristic, the Co-Fe-P nanocubes not only offer sufficient electrical contact to the insulating sulfur for high sulfur utilization and fast redox reaction kinetics but also provide abundant adsorption sites for trapping and catalyzing the conversion of lithium polysulfides to suppress the shuttle effect, which is verified by both the comprehensive experiments and density functional theory calculations. As a result, the sulfur-loaded Co-Fe-P (S@Co-Fe-P) nanocubes delivered a high discharge capacity of 1243 mAh g-1 at 0.1 C and excellent cycling stability for 500 cycles with an average capacity decay rate of only 0.043% per cycle at 1 C. Furthermore, the S@Co-Fe-P electrode showed a high areal capacity of 4.6 mAh cm-2 with superior stability when the sulfur loading was increased to 5.5 mg cm-2. More impressively, the prototype soft-package Li-S batteries based on S@Co-Fe-P cathodes also exhibited superior cycling stability with great flexibility, demonstrating their great potential for practical applications.
Tian, H, Wang, T, Zhang, F, Zhao, S, Wan, S, He, F & Wang, G 2018, 'Tunable porous carbon spheres for high-performance rechargeable batteries', JOURNAL OF MATERIALS CHEMISTRY A, vol. 6, no. 27, pp. 12816-12841.View/Download from: Publisher's site
Tian, H, Liang, Y, Repac, J, Zhang, S, Luo, C, Liou, SC, Wang, G, Ehrman, SH & Han, W 2018, 'Rational Design of Core-Shell-Structured Particles by a One-Step and Template-Free Process for High-Performance Lithium/Sodium-Ion Batteries', Journal of Physical Chemistry C, vol. 122, no. 39, pp. 22232-22240.View/Download from: UTS OPUS or Publisher's site
© 2018 American Chemical Society. Tin (Sn)-based materials are one of most promising candidates for rechargeable (Li+and Na+ion) batteries because of their high theoretical capacities (993 mAh/g for Li4.4Sn and 847 mAh/g for Na15Sn4) and reasonable working potentials. However, Sn-based anodes suffer from huge volume changes during cycling that hinder the applications in commercialized rechargeable batteries. Unique particle engineering to fabricate Sncore-carbonshell(Sn@C) particles has been shown to address or circumvent these problems. In this work, a distinct core-shell-structured Sn@C anode material has been successfully developed by using a one-step and template-free process (colloidal spray pyrolysis). A comprehensive analysis of chemical reaction kinetics of core-shell particles assists the product design to control the particle composition and structure by tuning the process variables, such as reaction temperature and cosolvent concentration. The unique Sn@C anode delivers a high capacity of 720 mAh/g after 300 cycles at 0.5C for lithium-ion batteries and a high capacity of >500 mAh/g at 0.2C for sodium-ion batteries. More importantly, this work advances the design of high-performance Sn@C composites for lithium/sodium-ion batteries in scalable process development, particle engineering, and material innovation.
Meng, Z, Tan, X, Zhang, S, Ying, H, Yan, X, Tian, H, Wang, G & Han, W-Q 2018, 'Ultra-stable binder-free rechargeable Li/I2 batteries enabled by "Betadine'' chemical interaction', CHEMICAL COMMUNICATIONS, vol. 54, no. 87, pp. 12337-12340.View/Download from: Publisher's site
Liang, Y, Tian, H, Repac, J, Liou, SC, Chen, J, Han, W, Wang, C & Ehrman, S 2018, 'Colloidal spray pyrolysis: A new fabrication technology for nanostructured energy storage materials', Energy Storage Materials, vol. 13, pp. 8-18.View/Download from: UTS OPUS or Publisher's site
© 2017 Spray pyrolysis is a scalable process to fabricate functional particles as cathode/anode materials in rechargeable batteries from precursor solutions. However, one prerequisite of spray pyrolysis to achieve uniform particle-to-particle composition and structure is a stable precursor solution, restricting its usage to highly soluble salts. Otherwise, extremely acidic precursors are necessary to ease the uncontrollable hydrolysis of the salts and the subsequent precipitation. Moreover, strong reducing agents such as H2are also needed for complete solid-state reactions, introducing potential safety concerns. Herein, for the first time, we develop a novel process, colloidal spray pyrolysis (CSP), which can eliminate all the prerequisites simultaneously. Our process can generate particles directly from a multiphase precursor in mild processing conditions through in-situ solid-state reactions. The product structure and composition can be precisely designed based on aerosol dynamics and reaction kinetics. By applying CSP, Sn@C particles with three distinct interior nanostructures have been synthesized and evaluated as anodes for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The best performing Sn@C anode delivers 627.9 mAh/g at 2 C with capacity retention of 88.5% after 1500 cycles in LIBs and demonstrates superior rate capability for SIBs. This novel CSP process is promising in preparing electrode materials in LIBs and SIBs for future practical applications.
Zhang, S, Tan, X, Meng, Z, Tian, H, Xu, F & Han, WQ 2018, 'Naturally abundant high-performance rechargeable aluminum/iodine batteries based on conversion reaction chemistry', Journal of Materials Chemistry A, vol. 6, no. 21, pp. 9984-9996.View/Download from: UTS OPUS or Publisher's site
© 2018 The Royal Society of Chemistry. Rechargeable multivalent ion (Al3+, Mg2+ and Zn2+) batteries provide a viable alternative to lithium ion batteries because of the supply risk of lithium resources and safety concern. In this study, rechargeable metal-iodine batteries, particularly aluminum/iodine batteries, were fabricated with novel active carbon cloth/polyvinylpyrrolidone (ACC/PVPI) composite cathodes prepared via a facile solution-adsorption method combined with freeze-drying. The use of active carbon cloth (ACC) endows the composites superior electronic conductivity, and significantly decreases the weight of the electrode due to its function as a current collector. Hydrogen bonding interaction between PVP and iodine in PVPI guarantees the depression of the shuttle effect of polyiodide, thus lengthening the cycle life. The density functional theory (DFT) analysis shows that such shuttle depression occurs due to the hydrogen-bonded iodine species, and the relatively large formation energy hints at higher conversion reaction efficiency of Al ion batteries. These characteristics make the composites an ideal electrode in various metal ion batteries. To be specific, the Al/I2 battery with a distinct working potential window achieves a high capacity of 180.1 mA h g-1 at 0.2C and can remain stable after 500 cycles with a stable capacity of 127 mA h g-1 at 0.6C. Moreover, at higher current density of 1C, the battery delivers a capacity of 102.7 mA h g-1 for up to 1050 cycles. These above-mentioned characteristics of metal-iodine (Li, Mg and Al/I2) batteries, related electrochemical performance measurements and theoretical modeling analysis show that the rechargeable iodine-based batteries provide a promising direction in designing high-performance energy storage/transfer systems.
Meng, Z, Tian, H, Zhang, S, Yan, X, Ying, H, He, W, Liang, C, Zhang, W, Hou, X & Han, W-Q 2018, 'Polyiodide-Shuttle Restricting Polymer Cathode for Rechargeable Lithium/Iodine Battery with Ultralong Cycle Life.', ACS applied materials & interfaces, vol. 10, no. 21, pp. 17933-17941.View/Download from: Publisher's site
Rechargeable lithium/iodine (Li/I2) batteries have attracted much attention because of their high gravimetric/volumetric energy densities, natural abundance and low cost. However, problems of the system, such as highly unstable iodine species under high temperature, their subsequent dissolution in electrolyte and continually reacting with lithium anode prevent the practical use of rechargeable Li/I2 cells. A polymer-iodine composite (polyvinylpyrrolidone-iodine) with high thermostability is employed as cathode material in rechargeable Li/I2 battery with an organic electrolyte. Because of the chemical interaction between polyvinylpyrrolidone (PVP) and polyiodide, most of the polyiodide in the cathode could be effectively trapped during charging/discharging. In-situ Raman observation revealed the evolution of iodine species in this system could be controlled during the process of I5- ↔ I3- ↔ I-. Herein, the Li/I2 battery delivered a high discharge capacity of 278 mAh g-1 at 0.2 C and exhibited a very low capacity decay rate of 0.019% per cycle for prolonged 1100 charge/discharge cycles at 2 C. More importantly, a high areal capacity of 4.1 mAh cm-2 was achieved for the electrode with high iodine loading of 21.2 mg cm-2. This work may inspire new approach to design the Li/I2 (or Li/polyiodide) system with long cycle life.
Tian, H, Guo, G-J, Geng, M, Zhang, Z, Zhang, M & Gao, K 2018, 'Effects of gas reservoir configuration and pore radius on shale gas nanoflow: A molecular dynamics study', JOURNAL OF CHEMICAL PHYSICS, vol. 148, no. 20.View/Download from: Publisher's site
Xiong, P, Zhang, X, Zhang, F, Yi, D, Zhang, J, Sun, B, Tian, H, Shanmukaraj, D, Rojo, T, Armand, M, Ma, R, Sasaki, T & Wang, G 2018, 'Two-Dimensional Unilamellar Cation-Deficient Metal Oxide Nanosheet Superlattices for High-Rate Sodium Ion Energy Storage.', ACS Nano, vol. 12, pp. 12337-12346.View/Download from: Publisher's site
Cation-deficient two-dimensional (2D) materials, especially atomically thin nanosheets, are highly promising electrode materials for electrochemical energy storage that undergo metal ion insertion reactions, yet they have rarely been achieved thus far. Here, we report a Ti-deficient 2D unilamellar lepidocrocite-type titanium oxide (Ti0.87O2) nanosheet superlattice for sodium storage. The superlattice composed of alternately restacked defective Ti0.87O2 and nitrogen-doped graphene monolayers exhibits an outstanding capacity of ∼490 mA h g-1 at 0.1 A g-1, an ultralong cycle life of more than 10000 cycles with ∼0.00058% capacity decay per cycle, and especially superior low-temperature performance (100 mA h g-1 at 12.8 A g-1 and -5 °C), presenting the best reported performance to date. A reversible Na+ ion intercalation mechanism without phase and structural change is verified by first-principles calculations and kinetics analysis. These results herald a promising strategy to utilize defective 2D materials for advanced energy storage applications.
Tian, H, Zhang, S, Meng, Z, He, W & Han, W-Q 2017, 'Rechargeable Aluminum/Iodine Battery Redox Chemistry in Ionic Liquid Electrolyte', ACS Energy Letters, vol. 2, no. 5, pp. 1170-1176.View/Download from: UTS OPUS or Publisher's site
Rechargeable aluminum ion batteries (RABs) have attracted much attention because of their high charge density, low cost, and low flammability. However, the traditional cathodes used in RABs had limited intercalation ability of Al3+ ion, leading to a low capacity. We report for the first time a rechargeable aluminum/iodine (Al/I2) battery. The unique conversion reaction mechanism of the Al/I2 battery chemistry avoids the cathode material disintegration during repeated charge–discharge processes, and this system successfully suppresses the shuttle of dissolved polyiodide in ionic liquid because of the hydrogen-bonding interaction, resulting in a robust rechargeable RAB system. The rechargeable Al/I2 battery based on the I3–/I– redox chemistry is demonstrated to be highly reversible in Al3+ ion storage, providing a high capacity of >200 mAh g–1 at 0.2C and high stability for even over 150 cycles at 1C. This work provides a new insight into designing a RAB system based on redox chemistry.
Tian, H, Gao, T, Li, X, Wang, X, Luo, C, Fan, X, Yang, C, Suo, L, Ma, Z, Han, W & Wang, C 2017, 'High power rechargeable magnesium/iodine battery chemistry.', Nature Communications, vol. 8, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
Rechargeable magnesium batteries have attracted considerable attention because of their potential high energy density and low cost. However, their development has been severely hindered because of the lack of appropriate cathode materials. Here we report a rechargeable magnesium/iodine battery, in which the soluble iodine reacts with Mg2+ to form a soluble intermediate and then an insoluble final product magnesium iodide. The liquid-solid two-phase reaction pathway circumvents solid-state Mg2+ diffusion and ensures a large interfacial reaction area, leading to fast reaction kinetics and high reaction reversibility. As a result, the rechargeable magnesium/iodine battery shows a better rate capability (180 mAh g-1 at 0.5 C and 140 mAh g-1 at 1 C) and a higher energy density (∼400 Wh kg-1) than all other reported rechargeable magnesium batteries using intercalation cathodes. This study demonstrates that the liquid-solid two-phase reaction mechanism is promising in addressing the kinetic limitation of rechargeable magnesium batteries.
He, W, Tian, H, Zhang, S, Ying, H, Meng, Z & Han, W 2017, 'Scalable synthesis of Si/C anode enhanced by FeSix nanoparticles from low-cost ferrosilicon for lithium-ion batteries', Journal of Power Sources, vol. 353, pp. 270-276.View/Download from: UTS OPUS or Publisher's site
Silicon is considered as the most promising anode for advanced lithium-ion batteries (LIBs) due to the high theoretical capacity of 3579 mAh g−1, but the complex and high-cost preparation processes have limited it's widespread applications. So given the practical application, it's all the more important that we should prepare excellent electrochemical performance anodes with large scale and low cost. Here we present a scalable synthesis for preparing the cost-effective Si/C anode enhanced by FeSix nanoparticles (FSC) directly from the low-grade Ferrosilicon source (∼1000 $/t). The formation of the amorphous carbon layer and FeSix nanocrystalline (FeSi & FeSi2) can act as buffer layer to mechanically support the volume expansion change during cycling. The FSC anode exhibits a high initial capacity of 1489 mAh g−1 and a prolonged cycle performance with 86% capacity retention over 100 cycles at 500 mA g−1. Moreover, the FSC anode delivers an excellent rate performance of 450 mAh g−1 at 10 A g−1 due to the enhancement of the electrical conductivity by the amorphous carbon layer and the highly conductive FeSix nanocrystalline. This scalable and cost-effective method for preparing Si/C anode provides the promising application potentials in next generation energy storage systems.
He, W, Liang, Y, Tian, H, Zhang, S, Meng, Z & Han, W-Q 2017, 'A facile in situ synthesis of nanocrystal-FeSi-embedded Si/SiO x anode for long-cycle-life lithium ion batteries', Energy Storage Materials, vol. 8, pp. 119-126.View/Download from: UTS OPUS or Publisher's site
A cost-effective, environmentally friendly and industrialized method of using low-grade sources to prepare high-performance anode material for lithium ion batteries (LIBs) with high energy density and long cycle life is both appealing and challenging. Herein, we present a low-cost, scalable and controllable approach for preparing unique sub-micrometer core-shell structure nanocrystal-FeSi-embedded Si/SiOx (FSO) anode material directly from a low-grade Fe-Si alloy. The sub-micrometer FSO anode materials are controlled by in-situ reaction of the Fe-Si-O in the Fe-Si alloy according to the phase diagram. The XRD and Rietveld refinement results indicate that when the treatment temperature increase, (i) FeSi phase appears together with Si and FeSi2, and then (ii) Fe3Si phase appears together with Si and FeSi. Most importantly, benefited from the formation of the amorphous SiOx as buffer layer and self-conductive nanocrystal-FeSi as a robust skeleton to mechanically support the large volume change of Si during cycling, the sub-micrometer core-shell structure FSO anode exhibits a high capacity (931.3 mA h g−1) at 50 mA g−1 and a prolonged cycle performance with 86% capacity retention over 1000 cycles at 1 A g−1. The full cell with prelithiated FSO as the anode and commercial LiCoO2 as the cathode delivers a high energy density of 467.5 W h kg−1 at the 0.05 C. This work provides a promising route for commercial production of high-performance Si/SiOx-based anode materials in LIBs.
He, W, Tian, H, Wang, X, Xin, F & Han, W 2015, 'Three-dimensional interconnected network GeOx/multi-walled CNT composite spheres as high-performance anodes for lithium ion batteries', JOURNAL OF MATERIALS CHEMISTRY A, vol. 3, no. 38, pp. 19393-19401.View/Download from: Publisher's site
Xin, F-X, Tian, H-J, Wang, X-L, Xu, W, Zheng, W-G & Han, W-Q 2015, 'Enhanced Electrochemical Performance of Fe0.74Sn5@Reduced Graphene Oxide Nanocomposite Anodes for Both Li-Ion and Na-Ion Batteries', ACS APPLIED MATERIALS & INTERFACES, vol. 7, no. 15, pp. 7912-7919.View/Download from: Publisher's site
He, W, Tian, H, Xin, F & Han, W 2015, 'Scalable fabrication of micro-sized bulk porous Si from Fe-Si alloy as a high performance anode for lithium-ion batteries', JOURNAL OF MATERIALS CHEMISTRY A, vol. 3, no. 35, pp. 17956-17962.View/Download from: Publisher's site
Xin, F, Wang, X, Bai, J, Wen, W, Tian, H, Wang, C & Han, W 2015, 'A lithiation/delithiation mechanism of monodispersed MSn5 (M = Fe, Co and FeCo) nanospheres', JOURNAL OF MATERIALS CHEMISTRY A, vol. 3, no. 13, pp. 7170-7178.View/Download from: Publisher's site
Ying, H, Tian, H, Meng, Z & Han, W 2015, 'TinO2n-1 Series Compounds-Properties, Preparation Methods and Applications', PROGRESS IN CHEMISTRY, vol. 27, no. 4, pp. 361-372.View/Download from: Publisher's site
Tian, H, Xin, F, Wang, X, He, W & Han, W 2015, 'High capacity group-IV elements (Si, Ge, Sn) based anodes for lithium-ion batteries', Journal of Materiomics, vol. 1, no. 3, pp. 153-169.View/Download from: Publisher's site
© 2015 The Chinese Ceramic Society Tremendous efforts have been devoted to replace commercial graphite anode (372 mAh g−1) by group IV elements (Si, Ge, Sn) based-materials with high capacities in lithium-ion batteries (LIBs). The use of these materials is hampered by the pulverization of these particles due to the high volumetric change during lithiation and delithiation cycles, which leads to particles pulverization and destabilization of solid electrolyte interphase (SEI) films. These problems result in fast capacity fading and low Coulombic efficiency. Nanostructured materials show significant improvements in rate capability and cyclability due to their high surface-to-volume ratio, reduced Li+ diffusion length, and increased freedom associated with the volume change during cycling. However, the nanostructured active materials with high ratio of surface-to-volume increase the irreversible capacity due to the formation of more SEI films. Although the nanostructured materials active materials keep relatively stable during repeated cycles of lithiation/delithiation process, the SEI film continually breaks/reforms, lowing the Coulombic efficiency. Meanwhile, the high-cost, low Coulombic efficiency and low tapping density limit the commercialization of the nanostructured electrode materials. Therefore, it is urgent to find solutions which could take advantage of both long cycle life of nanomaterials within the group IV elements (Si, Ge, Sn) and high volumetric/gravimetric capacity of micro-materials in the group IV as well as elements (Si, Ge, Sn). This report presents an overview of the recently developed strategies for improving the group IV elements (Si, Ge, Sn)-based anodes performances in LIBs to provide a further insight understanding in designing novel anodes.
Tian, H, Xin, F, Tan, X & Han, W 2014, 'High lithium electroactivity of boron-doped hierarchical rutile submicrosphere TiO2', JOURNAL OF MATERIALS CHEMISTRY A, vol. 2, no. 27, pp. 10599-10606.View/Download from: Publisher's site
Cai, M, Pan, X, Liu, W, Sheng, J, Fang, X, Zhang, C, Huo, Z, Tian, H, Xiao, S & Dai, S 2013, 'Multiple adsorption of tributyl phosphate molecule at the dyed-TiO2/electrolyte interface to suppress the charge recombination in dye-sensitized solar cell', JOURNAL OF MATERIALS CHEMISTRY A, vol. 1, no. 15, pp. 4885-4892.View/Download from: Publisher's site
Tian, H, Hu, L, Zhang, C, Mo, L, Li, W, Sheng, J & Dai, S 2012, 'Superior energy band structure and retarded charge recombination for Anatase N, B codoped nano-crystalline TiO2 anodes in dye-sensitized solar cells', JOURNAL OF MATERIALS CHEMISTRY, vol. 22, no. 18, pp. 9123-9130.View/Download from: Publisher's site
Sheng, J, Hu, L, Mo, L, Li, W, Tian, H & Dai, S 2012, 'A multistep attachment process: Transformation of titanate nanotubes into nanoribbons', SCIENCE CHINA-CHEMISTRY, vol. 55, no. 3, pp. 368-372.View/Download from: Publisher's site
Zhang, C, Huang, Y, Chen, S, Tian, H, Mo, L, Hu, L, Huo, Z, Kong, F, Ma, Y & Dai, S 2012, 'Photoelectrochemical Analysis of the Dyed TiO2/Electrolyte Interface in Long-Term Stability of Dye-Sensitized Solar Cells', JOURNAL OF PHYSICAL CHEMISTRY C, vol. 116, no. 37, pp. 19807-19813.View/Download from: Publisher's site
Zhang, C, Chen, S, Tian, H, Huang, Y, Huo, Z, Dai, S, Kong, F & Sui, Y 2011, 'Experimental Investigation of Back Electron Transfer and Band Edge Shift in Dyed TiO2 Electrodes', JOURNAL OF PHYSICAL CHEMISTRY C, vol. 115, no. 17, pp. 8653-8657.View/Download from: Publisher's site
Tian, H, Hu, L, Li, W, Sheng, J, Xu, S & Dai, S 2011, 'A facile synthesis of anatase N,B codoped TiO2 anodes for improved-performance dye-sensitized solar cells', JOURNAL OF MATERIALS CHEMISTRY, vol. 21, no. 20, pp. 7074-7077.View/Download from: Publisher's site
Sheng, J, Hu, L, Xu, S, Mo, L, Tian, H & Dai, S 2011, 'A Study on Formation of Titanium Oxide Nanoribbons', JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, vol. 11, no. 11, pp. 9924-9927.View/Download from: Publisher's site
Sheng, J, Hu, L, Li, W, Mo, L, Tian, H & Dai, S 2011, 'Formation of single-crystalline rutile TiO2 splitting microspheres for dye-sensitized solar cells', SOLAR ENERGY, vol. 85, no. 11, pp. 2697-2703.View/Download from: Publisher's site
Tian, H, Hu, L, Zhang, C, Chen, S, Sheng, J, Mo, L, Liu, W & Dai, S 2011, 'Enhanced photovoltaic performance of dye-sensitized solar cells using a highly crystallized mesoporous TiO2 electrode modified by boron doping', JOURNAL OF MATERIALS CHEMISTRY, vol. 21, no. 3, pp. 863-868.View/Download from: Publisher's site
Zhang, C, Chen, S, Mo, L, Huang, Y, Tian, H, Hu, L, Huo, Z, Dai, S, Kong, F & Pan, X 2011, 'Charge Recombination and Band-Edge Shift in the Dye-Sensitized Mg2+-Doped TiO2 Solar Cells', JOURNAL OF PHYSICAL CHEMISTRY C, vol. 115, no. 33, pp. 16418-16424.View/Download from: Publisher's site
Sheng, J, Hu, L, Xu, S, Liu, W, Mo, L, Tian, H & Dai, S 2011, 'Characteristics of dye-sensitized solar cells based on the TiO2 nanotube/nanoparticle composite electrodes', JOURNAL OF MATERIALS CHEMISTRY, vol. 21, no. 14, pp. 5457-5463.View/Download from: Publisher's site
Xu, S, Hu, L, Sheng, J, Kou, D, Tian, H & Dai, S 2011, 'Electron transportation and optical properties of microstructure TiO 2 films: Applied in dye-sensitized solar cells', Frontiers of Optoelectronics in China, vol. 4, no. 1, pp. 72-79.View/Download from: Publisher's site
Micro-structure of TiO 2 films in dye-sensitized solar cells (DSSCs) can affect light absorption and electron transportation that impact on the characteristics of currentvoltage (J-V). In this paper, films with different surface area, pore size and porosity were obtained by adding different ratio of ethyl cellulose (Ec-S) to pastes, and a photo-electric conversion efficiency (η) of 7. 55% with a short-circuit current density (J sc ) of 16. 81 mA·cm -2 was obtained when the ratio of Ec-S was 10:5. BET results showed that film with this optimum ratio had the most suitable pore size and surface area for good properties of photovoltaic, which had a low reflectivity and high transmission rate, and the efficiency of light utilization was improved. Moreover, measurements by intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS) implied that the electron transport time (τ d ) increased as the content of Ec-S increased, which was related to the larger surface area. Results of steady-state cyclic voltammetry indicated that diffusion-limited current density (J lim ) of I 3- in TiO 2 film increased with its porosity, which revealed that the transportation of redox mediators in the electrolyte was speeded up. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.
Tian, H, Hu, L, Zhang, C, Liu, W, Huang, Y, Mo, L, Guo, L, Sheng, J & Dai, S 2010, 'Retarded Charge Recombination in Dye-Sensitized Nitrogen-Doped TiO2 Solar Cells', JOURNAL OF PHYSICAL CHEMISTRY C, vol. 114, no. 3, pp. 1627-1632.View/Download from: Publisher's site
Liu, W, Kou, D, Cai, M, Hu, L, Sheng, J, Tian, H, Jiang, N & Dai, S 2010, 'The Intrinsic Relation between the Dynamic Response and Surface Passivation in Dye-Sensitized Solar Cells Based on Different Electrolytes', JOURNAL OF PHYSICAL CHEMISTRY C, vol. 114, no. 21, pp. 9965-9969.View/Download from: Publisher's site