2017. 09 – present: Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology, Sydney (UTS). (Postdoctoral research fellow)
2016. 08 – 2017. 08: Manufacturing Lindfield, Commonwealth Scientific and Industrial Research Organisation (CSIRO). (Joint program PhD candidate)
2013. 09 – 2017. 08: Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology, Sydney (UTS). (PhD candidate)
2012. 02 – 2013. 07: Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology, Sydney (UTS). (MSc)
2010. 10 – 2011. 07: Key Lab Organ Solids, Institute of Chemistry, Chinese Academy of Sciences (CAS). (Research Associate)
2007. 09- 2011. 07: School of Chemistry, Capital Normal University (CNU). (BSc)
Can supervise: YES
Functional organic materials (particular redox-enabled organic compounds) for lithium batteries including lithium-ion batteries and lithium-oxygen oxygen batteries
Zhang, J, Sade, H, Zhao, Y, Murdock, AT, Bendavid, A, Lellouche, J-P, Wang, G & Han, Z 2019, 'Conformal carbon coating on WS2 nanotubes for excellent electrochemical performance of lithium-ion batteries.', Nanotechnology, vol. 30, no. 3, pp. 035401-035401.View/Download from: UTS OPUS or Publisher's site
WS2 nanotubes with carbon coatings in a core-shell structure (i.e. WS2@C) are synthesized through a facile method based on the Lewis acid-activated thioglycosylation chemistry. The obtained WS2@C shows a conformal coverage of conductive amorphous carbon on the surface of WS2 after thermal treatment, with the thickness of carbon layer being controlled by adjusting the molar ratios of saccharide to nanotube during the synthesis process. When applied in lithium-ion batteries, the WS2@C structures show higher reversible capacity of 638 mAh g-1 at a current density of 500 mA g-1 and significantly improved cycling stability as compared to the pristine WS2 nanotubes. Post-mortem examinations of the electrode materials reveal that the carbon coatings could preserve the morphology of WS2 nanotubes and assist in forming stable solid electrolyte interface layers, leading to enhanced cycling stability. As such, the WS2@C structures show great potential in the application of lithium-ion batteries for achieving excellent electrochemical performances.
Zhang, J, Sun, B, Zhao, Y, Tkacheva, A, Liu, Z, Yan, K, Guo, X, McDonagh, AM, Shanmukaraj, D, Wang, C, Rojo, T, Armand, M, Peng, Z & Wang, G 2019, 'A versatile functionalized ionic liquid to boost the solution-mediated performances of lithium-oxygen batteries.', Nature communications, vol. 10, no. 1, p. 602.View/Download from: UTS OPUS or Publisher's site
Due to the high theoretical specific energy, the lithium-oxygen battery has been heralded as a promising energy storage system for applications such as electric vehicles. However, its large over-potentials during discharge-charge cycling lead to the formation of side-products, and short cycle life. Herein, we report an ionic liquid bearing the redox active 2,2,6,6-tetramethyl-1-piperidinyloxy moiety, which serves multiple functions as redox mediator, oxygen shuttle, lithium anode protector, as well as electrolyte solvent. The additive contributes a 33-fold increase of the discharge capacity in comparison to a pure ether-based electrolyte and lowers the over-potential to an exceptionally low value of 0.9 V. Meanwhile, its molecule facilitates smooth lithium plating/stripping, and promotes the formation of a stable solid electrolyte interface to suppress side-reactions. Moreover, the proportion of ionic liquid in the electrolyte influences the reaction mechanism, and a high proportion leads to the formation of amorphous lithium peroxide and a long cycling life (> 200 cycles). In particular, it enables an outstanding electrochemical performance when operated in air.
Guo, X, Zhang, J, Song, J, Wu, W, Liu, H & Wang, G 2018, 'MXene encapsulated titanium oxide nanospheres for ultra-stable and fast sodium storage', Energy Storage Materials, vol. 14, pp. 306-313.View/Download from: UTS OPUS or Publisher's site
© 2018 Sodium-ion batteries with high power density present tremendous potential for large-scale energy storage applications. However, it remains a big challenge to develop suitable anode materials for ultrafast and highly reversible sodium ion storage. Herein, for the first time, we report a novel strategy to fabricate highly conductive MXene Ti3C2Txencapsulated titanium oxide spheres (TiO2@Ti3C2Tx) as an excellent anode material for sodium-ion batteries. The MXene layers significantly improve the electronic conductivity of the whole electrode and protect the structural integrity of the TiO2spheres from electrochemical pulverization, which hence contributes to the formation of a stable solid-electrolyte interface. Meanwhile, the pseudocapacitance of the as-fabricated TiO2@Ti3C2Txcomposites enables high-rate capability and long cycle life in sodium-ion batteries. As a result, the hybrid electrode delivers a high reversible capacity of 116 mAh g-1at 960 mA g-1up to 5000 cycles. By coupling with a NaCrO2cathode, a prototype Na-ion full cell achieved a capacity of 103.4 mAh g-1at 960 mA g-1and an excellent cycling performance with 73.5% capacity retention after 1000 cycles.
Sun, B, Li, P, Zhang, J, Wang, D, Munroe, P, Wang, C, Notten, PHL & Wang, G 2018, 'Dendrite-Free Sodium-Metal Anodes for High-Energy Sodium-Metal Batteries.', Advanced materials (Deerfield Beach, Fla.), vol. 30, no. 29, pp. e1801334-e1801334.View/Download from: UTS OPUS or Publisher's site
Sodium (Na) metal is one of the most promising electrode materials for next-generation low-cost rechargeable batteries. However, the challenges caused by dendrite growth on Na metal anodes restrict practical applications of rechargeable Na metal batteries. Herein, a nitrogen and sulfur co-doped carbon nanotube (NSCNT) paper is used as the interlayer to control Na nucleation behavior and suppress the Na dendrite growth. The N- and S-containing functional groups on the carbon nanotubes induce the NSCNTs to be highly "sodiophilic," which can guide the initial Na nucleation and direct Na to distribute uniformly on the NSCNT paper. As a result, the Na-metal-based anode (Na/NSCNT anode) exhibits a dendrite-free morphology during repeated Na plating and striping and excellent cycling stability. As a proof of concept, it is also demonstrated that the electrochemical performance of sodium-oxygen (Na-O2 ) batteries using the Na/NSCNT anodes show significantly improved cycling performances compared with Na-O2 batteries with bare Na metal anodes. This work opens a new avenue for the development of next-generation high-energy-density sodium-metal batteries.
Song, J, Zhang, C, Guo, X, Zhang, J, Luo, L, Liu, H, Wang, F & Wang, G 2018, 'Entrapping polysulfides by using ultrathin hollow carbon sphere-functionalized separators in high-rate lithium-sulfur batteries', Journal of Materials Chemistry A, vol. 6, no. 34, pp. 16610-16616.View/Download from: UTS OPUS or Publisher's site
© 2018 The Royal Society of Chemistry. Lithium-sulfur batteries (LSBs) have been regarded as the most promising technology for next generation energy storage systems owing to their high energy density and low cost. However, the undesirable shuttle effect and low utilization of sulfur caused by dissolution and migration of polysulfide intermediates greatly restrict their practical application. Herein, we report a functional separator modified with novel ultrathin hollow carbon spheres (UHCSs) to improve the overall performance of LSBs and demonstrate for the first time that nonporous hollow structured carbon materials are ideal candidates for modifying the separator due to their unique properties. The ultrathin and nonporous shell of the coated UHCSs can act as a physical and a chemical barrier to effectively entrap lithium polysulfides owing to fewer diffusion sites. The UHCSs can also enhance the electron transfer for sulfur and accommodate the large volume change of sulfur as upper current collectors. When applying such UHCSs functionalized separators, the LSBs achieved a significantly improved electrochemical performance including a high capacity of 1346.3 mA h g-1 at 0.2C and high rate capability with a discharge capacity of 458 mA h g-1 even at 5C upon 1000 cycles.
Sun, B, Pompe, C, Dongmo, S, Zhang, J, Kretschmer, K, Schröder, D, Janek, J & Wang, G 2018, 'Challenges for Developing Rechargeable Room-Temperature Sodium Oxygen Batteries', Advanced Materials Technologies, vol. 3, no. 9.View/Download from: UTS OPUS or Publisher's site
© 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The development of high energy-density and low-cost energy storage devices requires new chemistry beyond the horizon of current state-of-the-art lithium-ion batteries. Recently, sodium/oxygen (Na/O2) batteries have attracted great attention as one possible battery type among the new generation of rechargeable batteries. They convince with superior energy density, a relatively simple cell reaction, and abundance of sodium. Research on Na/O2batteries has progressed quickly in recent years. However, a fundamental understanding underpinning the complex chemical/electrochemical side reactions is still insufficient, and many challenges remain unsolved for real practical applications. Herein, recent achievements and remaining issues for the development of rechargeable Na/O2batteries are summarized. The discussion focuses on cell reaction mechanisms as well as cathode materials, sodium anodes, and electrolytes as key components of this type of battery. Furthermore, perspectives for future research and technological advances of Na/O2batteries are outlined.
Zhao, S, Sun, B, Yan, K, Zhang, J, Wang, C & Wang, G 2018, 'Aegis of Lithium-Rich Cathode Materials via Heterostructured LiAlF4 Coating for High-Performance Lithium-Ion Batteries.', ACS applied materials & interfaces, vol. 10, no. 39, pp. 33260-33268.View/Download from: Publisher's site
Lithium-rich oxides have been regarded as one of the most competitive cathode materials for next-generation lithium-ion batteries due to their high theoretical specific capacity and high discharge voltage. However, they are still far from being commercialized due to low rate capability and poor cycling stability. In this study, we propose a heterostructured LiAlF4 coating strategy to overcome those obstacles. The as-developed lithium-rich cathode material shows outstanding performance including a high reversible capacity (246 mA h g-1 at 0.1C), excellent rate capability (133 mA h g-1 at 5C), and ultralong cycling stability (3000 cycles). Comparing with those of pristine and AlF3-coated lithium-rich cathode materials, the enhanced performances can be attributed to the introduction of the lithium-ion-conductive nanolayer and the generation of nonbonding O n- species in the active material lattice, which enable rapid and effective lithium ion transport and diffusion. Our work provides a new strategy to develop high-performance lithium-rich cathode materials for high-energy-density lithium-ion batteries.
Zhao, Y, Zhang, J, Wu, W, Guo, X, Xiong, P, Liu, H & Wang, G 2018, 'Cobalt-doped MnO2 ultrathin nanosheets with abundant oxygen vacancies supported on functionalized carbon nanofibers for efficient oxygen evolution', Nano Energy, vol. 54, pp. 129-137.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier Ltd Developing low-cost and efficient catalysts for oxygen evolution reactions (OER) with both excellent activity and robust stability remains a great challenge. Herein, we report a facile spontaneous redox reaction to grow cobalt-doped MnO2 ultrathin nanosheets in situ with abundant oxygen vacancies vertically aligned on cobalt/nitrogen co-functionalized carbon nanofibers (Co-MnO2|OV) as an efficient OER catalyst. It is confirmed that metallic cobalt plays a critical role in the formation of long and ultrathin MnO2 nanosheets during the redox reaction. Furthermore, the cobalt ions doped into MnO2 significantly enhance the catalytic activity of MnO2 nanosheets. Benefiting from the collaborative advantages of doping strategy, fast charge transfer kinetics and strong synergistic coupling effects, Co-MnO2|OV composites exhibit an excellent catalytic activity and a good durability for electrochemical water oxidation, reaching 10 mA cm2 at an overpotential of 279 mV. According to the density functional theory (DFT) calculations, the enhanced catalytic activity mainly originates from a better conductivity and the decreased adsorption energy barrier of OH- on the O sites neighboring the doped Co and oxygen vacancies. Our findings suggest that the control over the structure and composition of the materials can achieve highly efficient oxygen evolution electrocatalysts.
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.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.
Zhang, J, Zhao, Y, Guo, X, Chen, C, Dong, CL, Liu, RS, Han, CP, Li, Y, Gogotsi, Y & Wang, G 2018, 'Single platinum atoms immobilized on an MXene as an efficient catalyst for the hydrogen evolution reaction', Nature Catalysis, vol. 1, no. 12, pp. 985-992.View/Download from: UTS OPUS or Publisher's site
© 2018, The Author(s), under exclusive licence to Springer Nature Limited. Single-atom catalysts offer a pathway to cost-efficient catalysis using the minimal amount of precious metals. However, preparing and keeping them stable during operation remains a challenge. Here we report the synthesis of double transition metal MXene nanosheets—Mo 2 TiC 2 T x , with abundant exposed basal planes and Mo vacancies in the outer layers—by electrochemical exfoliation, enabled by the interaction between protons and the surface functional groups of Mo 2 TiC 2 T x . The as-formed Mo vacancies are used to immobilize single Pt atoms, enhancing the MXene's catalytic activity for the hydrogen evolution reaction. The developed catalyst exhibits a high catalytic ability with low overpotentials of 30 and 77 mV to achieve 10 and 100 mA cm 2 and a mass activity about 40 times greater than the commercial platinum-on-carbon catalyst. The strong covalent interactions between positively charged Pt single atoms and the MXene contribute to the exceptional catalytic performance and stability.
Zhang, J, Sun, B, McDonagh, AM, Zhao, Y, Kretschmer, K, Guo, X & Wang, G 2017, 'A multi-functional gel co-polymer bridging liquid electrolyte and solid cathode nanoparticles: An efficient route to Li–O2batteries with improved performance', Energy Storage Materials, vol. 7, pp. 1-7.View/Download from: UTS OPUS or Publisher's site
© 2016 Lithium-oxygen (Li–O 2 ) batteries have the highest theoretical energy density amongst all rechargeable batteries and have attracted significant attention. However, large over-potentials originating from sluggish reaction kinetics often lead to low round-trip energy efficiency and short cycle life. We report here a novel multi-functional gel co-polymer that efficiently enhances the discharge and charge performances in Li–O 2 batteries by intimately connecting the liquid electrolyte and solid cathode nanoparti cles. On one hand, the co-polymer material, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate-co-methyl methacrylate) (P(TMA-MMA)), functions as a binder during the fabrication of the cathode and forms a gel polymer membrane to retain liquid electrolyte and to increase ionic conductivity. On the other hand, the TMA units, containing N–O radical groups that catalyse Li 2 O 2 formation and decomposition during charge and discharge cycles, are distributed throughout the polymer membrane. This allows more effective formation and decomposition of Li 2 O 2 than surface bound catalytic units. The combination of gelable MMA and catalytic TMA moieties enhances the interface between liquid electrolyte and solid cathode by functioning as a medium both to transport Li + (enhancing discharge process) and to carry electrons (reducing charge over-potential). Consequently, the optimized P(TMA-MMA) co-polymers provide exceptional electrochemical performance in Li–O 2 batteries.
Kretschmer, K, Sun, B, Zhang, J, Xie, X, Liu, H & Wang, G 2017, '3D Interconnected Carbon Fiber Network-Enabled Ultralong Life Na3 V2 (PO4 )3 @Carbon Paper Cathode for Sodium-Ion Batteries.', Small, vol. 13, no. 9.View/Download from: UTS OPUS or Publisher's site
Sodium-ion batteries (NIBs) are an emerging technology, which can meet increasing demands for large-scale energy storage. One of the most promising cathode material candidates for sodium-ion batteries is Na3 V2 (PO4 )3 due to its high capacity, thermal stability, and sodium (Na) Superionic Conductor 3D (NASICON)-type framework. In this work, the authors have significantly improved electrochemical performance and cycling stability of Na3 V2 (PO4 )3 by introducing a 3D interconnected conductive network in the form of carbon fiber derived from ordinary paper towel. The free-standing Na3 V2 (PO4 )3 -carbon paper (Na3 V2 (PO4 )3 @CP) hybrid electrodes do not require a metallic current collector, polymeric binder, or conducting additives to function as a cathode material in an NIB system. The Na3 V2 (PO4 )3 @CP cathode demonstrates extraordinary long term cycling stability for 30 000 deep charge-discharge cycles at a current density of 2.5 mA cm(-2) . Such outstanding cycling stability can meet the stringent requirements for renewable energy storage.
Zhang, J, Sun, B, Zhao, Y, Kretschmer, K & Wang, G 2017, 'Modified Tetrathiafulvalene as an Organic Conductor for Improving Performances of Li-O2 Batteries.', Angewandte Chemie, vol. 56, no. 29, pp. 8505-8509.View/Download from: UTS OPUS or Publisher's site
Large over-potentials owing to the sluggish kinetics of battery reactions have always been the drawbacks of Li-O2 batteries, which lead to short cycle life. Although redox mediators have been intensively investigated to overcome this issue, side-reactions are generally induced by the solvated nature of redox mediators. Herein, we report an alternative method to achieve more efficient utilization of tetrathiafulvalene (TTF) in Li-O2 batteries. By coordinating TTF+ with LiCl during charging, an organic conductor TTF+ Clx- precipitate covers Li2 O2 to provide an additional electron-transfer pathway on the surface, which can significantly reduce the charge over-potential, improve the energy efficiency of Li-O2 batteries, and eliminate side-reactions between the lithium metal anode and TTF+ . When a porous graphene electrode is used, the Li-O2 battery combined with TTF and LiCl shows an outstanding performance and prolonged cycle life.
Zhang, J, Sun, B, Zhao, Y, Kretschmer, K & Wang, G 2017, 'Modified Tetrathiafulvalene as an Organic Conductor for Improving Performances of LiO 2 Batteries', Angewandte Chemie, vol. 129, no. 29, pp. 8625-8629.View/Download from: UTS OPUS or Publisher's site
Large overpotentials owing to the sluggish kinetics of battery reactions have always been the drawbacks of LiO2 batteries, which lead to short cycle life. Although redox mediators have been intensively investigated to overcome this issue, sidereactions are generally induced by the solvated nature of redox mediators. Herein, we report an alternative method to achieve more efficient utilization of tetrathiafulvalene (TTF) in LiO2 batteries. By coordinating TTF+ with LiCl during charging, an organic conductor TTF+Clx precipitate covers Li2O2 to provide an additional electrontransfer pathway on the surface, which can significantly reduce the charge overpotential, improve the energy efficiency of LiO2 batteries, and eliminate sidereactions between the lithium metal anode and TTF+. When a porous graphene electrode is used, the LiO2 battery combined with TTF and LiCl shows an outstanding performance and prolonged cycle life.
Zhao, Y, Zhang, J, Guo, X, Fan, H, Wu, W, Liu, H & Wang, G 2017, 'Fe3C@nitrogen doped CNT arrays aligned on nitrogen functionalized carbon nanofibers as highly efficient catalysts for the oxygen evolution reaction', Journal of Materials Chemistry A, vol. 5, no. 37, pp. 19672-19679.View/Download from: UTS OPUS or Publisher's site
© 2017 The Royal Society of Chemistry. Fe 3 C based catalysts are found to be one of the most promising electrocatalysts for the oxygen evolution reaction (OER). Herein, we report on a nanoarchitectured material composed of Fe 3 C nanoparticles encapsulated at the tip of nitrogen-enriched carbon nanotubes (NCNTs), which are aligned on one dimensional (1D) nitrogen-doped carbon nanofibers (Fe 3 C@NCNTs-NCNFs) by a scalable electrospinning technique, as a high performance OER catalyst. The unique 3D hierarchical architecture of Fe 3 C@NCNTs-NCNFs leads to highly exposed active sites, enhanced electron transfer properties and strong synergistic coupled effects. Fe 3 C@NCNTs-NCNFs exhibit an outstanding catalytic performance with a high current density (10 mA cm -2 at an overpotential of 284 mV), a low Tafel slope (56 mV dec -1 ), a low charge transfer resistance and strong durability in 1 M KOH solution. The electrochemical evaluation demonstrates that the Fe 3 C@NCNTs-NCNF composite is a promising electrocatalyst for the OER in alkaline solution.
Wang, Y, Kretschmer, K, Zhang, J, Mondal, AK, Guo, X & Wang, G 2016, 'Organic sodium terephthalate@graphene hybrid anode materials for sodium-ion batteries', RSC ADVANCES, vol. 6, no. 62, pp. S7098-S7102.View/Download from: UTS OPUS or Publisher's site
Guo, X, Sun, B, Zhang, J, Liu, H & Wang, G 2016, 'Ruthenium decorated hierarchically ordered macro-mesoporous carbon for lithium oxygen batteries', JOURNAL OF MATERIALS CHEMISTRY A, vol. 4, no. 25, pp. 9774-9780.View/Download from: Publisher's site
Zhao, Y, Zhang, J, Li, K, Ao, Z, Wang, C, Liu, H, Sun, K & Wang, G 2016, 'Electrospun cobalt embedded porous nitrogen doped carbon nanofibers as an efficient catalyst for water splitting', JOURNAL OF MATERIALS CHEMISTRY A, vol. 4, no. 33, pp. 12818-12824.View/Download from: Publisher's site
Zhang, J, Sun, B, Xie, X, Zhao, Y & Wang, G 2016, 'A Bifunctional Organic Redox Catalyst for Rechargeable Lithium-Oxygen Batteries with Enhanced Performances', ADVANCED SCIENCE, vol. 3, no. 4.View/Download from: UTS OPUS or Publisher's site
Xie, X, Su, D, Zhang, J, Chen, S, Mondal, AK & Wang, G 2015, 'A comparative investigation on the effects of nitrogen-doping into graphene on enhancing the electrochemical performance of SnO2/graphene for sodium-ion batteries.', Nanoscale, vol. 7, no. 7, pp. 3164-3172.View/Download from: UTS OPUS or Publisher's site
SnO2/nitrogen-doped graphene nanohybrids have been synthesized by an in situ hydrothermal method, during which the formation of SnO2 nanocrystals and nitrogen doping of graphene occur simultaneously. The as-prepared SnO2/nitrogen-doped graphene nanohybrids exhibit enhanced electrochemical performance for sodium-ion batteries compared to SnO2/graphene nanocomposites. A systematic comparison between SnO2/nitrogen-doped graphene nanohybrids and the SnO2/graphene counterpart as anode materials for sodium-ion batteries has been conducted. The comparison is in a reasonable framework, where SnO2/nitrogen-doped graphene nanohybrids and the SnO2/graphene counterpart have the same SnO2 ratio, similar SnO2 crystallinity and particle size, close surface area and pore size. The results clearly manifest that the improved electron transfer efficiency of SnO2/nitrogen-doped graphene due to nitrogen-doping plays a more important role than the increased electro-active sites within graphene network in enhancing the electro-activity of SnO2/nitrogen-doped graphene nanohybrids compared to the SnO2/graphene counterpart. In contrast to the previous reports which often ascribe the enhanced electro-activity of nitrogen-doped graphene based composites to two nitrogen-doping effects (improving the electron transfer efficiency and increasing electro-active sites within graphene networks) in one single declaration, this work is expected to provide more specific information for understanding the effects of nitrogen-doping into graphene on improving the electrochemical performance of graphene based composites.
Xie, X, Ao, Z, Su, D, Zhang, J & Wang, G 2015, 'MoS2/graphene composite anodes with enhanced performance for sodium-ion batteries: The role of the two-dimensional heterointerface', Advanced Functional Materials, vol. 25, no. 9, pp. 1393-1403.View/Download from: Publisher's site
© 2015 Wiley-VCH Verlag GmbH & Co. KGaA. Graphene has been widely used as conformal nanobuilding blocks to improve the electrochemical performance of layered metal sulfides (MoS2, WS2, SnS, and SnS2) as anode materials for sodium-ion batteries. However, it still lacks in-depth understanding of the synergistic effect between these layered sulfides and graphene, which contributes to the enhanced electroactivity for sodium-ion batteries. Here, MoS2/reduced graphene oxide (RGO) nanocomposites with intimate two-dimensional heterointerfaces are prepared by a facile one-pot hydrothermal method. The heterointerfacial area can be effectively tuned by changing the ratio of MoS2 to RGO. When used as anode materials for sodium-ion batteries, the synergistic effect contributing to the enhanced reversible capacity of MoS2/RGO nanocomposites is closely related with the heterointerfacial area. The computational results demonstrate that Na prefers to be adsorbed on MoS2 in the MoS2/RGO heterostructure rather than intercalate into the MoS2/RGO heterointerface. Interestingly, the MoS2/RGO heterointerfaces can significantly increase the electronic conductivity of MoS2, store more Na ions, while maintaining the high diffusion mobility of Na atoms on MoS2 surface and high electron transfer efficiency from Na to MoS2. It is expected that the efforts to establish the correlation between the two-dimensional heterointerface and the electrochemical sodium-ion storage performance offer fundamental understanding for the rational design of layered metal sulfides/graphene composites as high-performance electrode materials for sodium-ion batteries.
Xie, X, Kretschmer, K, Zhang, J, Sun, B, Su, D & Wang, G 2015, 'Sn@CNT nanopillars grown perpendicularly on carbon paper: A novel free-standing anode for sodium ion batteries', NANO ENERGY, vol. 13, pp. 208-217.View/Download from: UTS OPUS or Publisher's site
Zhang, J, Sun, B, Xie, X, Kretschmer, K & Wang, G 2015, 'Enhancement of stability for lithium oxygen batteries by employing electrolytes gelled by poly(vinylidene fluoride-co-hexafluoropropylene) and tetraethylene glycol dimethyl ether', Electrochimica Acta, vol. 183, pp. 56-62.View/Download from: UTS OPUS or Publisher's site
© 2015 Elsevier Ltd. Free-standing gel polymer electrolytes with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix plasticized with tetraethylene glycol dimethyl ether (TEGDME) were prepared and investigated. The as-prepared gel polymer electrolytes exhibited large operating window and acceptable ionic conductivity. When applied in lithium oxygen batteries, the gel polymer electrolyte could support a high initial discharge capacity of 2988mAhg-1 when a carbon black electrode without catalyst was used as cathode. Furthermore, the battery with gel polymer electrolyte can last at least 50 cycles in the fixed capacity cycling, displaying an excellent stability. Detailed study reveals that the gelling process is essential for the cycling stability enhancement. With excellent electrochemical properties, the free-standing gel polymer electrolyte presented in this investigation has great application potentials in long-life lithium oxygen batteries.
Zhao, Y, Xie, X, Zhang, J, Liu, H, Ahn, HJ, Sun, K & Wang, G 2015, 'MoS2 Nanosheets Supported on 3D Graphene Aerogel as a Highly Efficient Catalyst for Hydrogen Evolution.', Chemistry (Weinheim an der Bergstrasse, Germany), vol. 21, no. 45, pp. 15908-15913.View/Download from: Publisher's site
The development of efficient catalysts for electrochemical hydrogen evolution is essential for energy conversion technologies. Molybdenum disulfide (MoS2 ) has emerged as a promising electrocatalyst for hydrogen evolution reaction, and its performance greatly depends on its exposed edge sites and conductivity. Layered MoS2 nanosheets supported on a 3D graphene aerogel network (GA-MoS2 ) exhibit significant catalytic activity in hydrogen evolution. The GA-MoS2 composite displays a unique 3D architecture with large active surface areas, leading to high catalytic performance with low overpotential, high current density, and good stability.
Su, D, Zhang, J, Dou, S & Wang, G 2015, 'Polypyrrole hollow nanospheres: stable cathode materials for sodium-ion batteries.', Chemical communications (Cambridge, England), vol. 51, no. 89, pp. 16092-16095.View/Download from: UTS OPUS or Publisher's site
Hollow polypyrrole (PPy) nanospheres with high sodium storage capacity as cathode materials for Na-ion batteries were reported. PPy hollow nanospheres demonstrated high current rate capacity and good cyclability. It was revealed by electrochemical testing and DFT calculation that the as-prepared PPy hollow nanospheres participate in reversible doping/de-doping reactions.
Mondal, AK, Su, D, Chen, S, Zhang, J, Ung, A & Wang, G 2014, 'Microwave-assisted synthesis of spherical -Ni(OH)2 superstructures for electrochemical capacitors with excellent cycling stability', Chemical Physics Letters, vol. 610-611, pp. 115-120.View/Download from: UTS OPUS or Publisher's site
A novel single-step microwave-assisted process has been developed to synthesize spherical -Ni(OH)2 superstructures without using any templates. Structure characterizations show that the spherical -Ni(OH)2 composed of twisted nanosheets was obtained. The electrochemical properties of the as-prepared materials were evaluated by cyclic voltammetry and chronopotentiometry technology in 2 M KOH solution. Due to the unique morphology, the prepared -Ni(OH)2 electrode displays a high specific capacitance of 2147 F g-1 at a discharge current of 1 A g-1 and outstanding cycling stability (99.5% capacitance retained after 2000 cycles), suggesting its potential application as an efficient electrode material for high-performance electrochemical capacitors. © 2014 Elsevier B.V.
Xie, X, Su, D, Sun, B, Zhang, J, Wang, C & Wang, G 2014, 'Synthesis of Single-Crystalline Spinel LiMn2O4 Nanorods for Lithium-Ion Batteries with High Rate Capability and Long Cycle Life', CHEMISTRY-A EUROPEAN JOURNAL, vol. 20, no. 51, pp. 17125-17131.View/Download from: UTS OPUS or Publisher's site
Zhang, J, Chen, S, Xie, X, Kretschmer, K, Huang, X, Sun, B & Wang, G 2014, 'Porous poly(vinylidene fluoride-co-hexafluoropropylene) polymer membrane with sandwich-like architecture for highly safe lithium ion batteries', JOURNAL OF MEMBRANE SCIENCE, vol. 472, pp. 133-140.View/Download from: UTS OPUS or Publisher's site
Chen, S, Huang, X, Sun, B, Zhang, J, Liu, H & Wang, G 2014, 'Multi-shelled hollow carbon nanospheres for lithium–sulfur batteries with superior performances', J. Mater. Chem. A, vol. 2, no. 38, pp. 16199-16207.View/Download from: UTS OPUS or Publisher's site
Zhang, J, Sun, B, Huang, X, Chen, S & Wang, G 2014, 'Honeycomb-like porous gel polymer electrolyte membrane for lithium ion batteries with enhanced safety', Scientific Reports, vol. 4, pp. 1-7.View/Download from: UTS OPUS or Publisher's site
Lithium ion batteries have shown great potential in applications as power sources for electric vehicles and
large-scale energy storage. However, the direct uses of flammable organic liquid electrolyte with commercial
separator induce serious safety problems including the risk of fire and explosion. Herein, we report the
development of poly(vinylidene difluoride-co-hexafluoropropylene) polymer membranes with multi-sized
honeycomb-like porous architectures. The as-prepared polymer electrolyte membranes contain porosity as
high as 78%, which leads to the high electrolyte uptake of 86.2 wt%. The PVDF-HFP gel polymer electrolyte
membranes exhibited a high ionic conductivity of 1.03 mS cm21 at room temperature, which is much higher
than that of commercial polymer membranes. Moreover, the as-obtained gel polymer membranes are also
thermally stable up to 3506C and non-combustible in fire (fire-proof). When applied in lithium ion batteries
with LiFePO4 as cathode materials, the gel polymer electrolyte demonstrated excellent electrochemical
performances. This investigation indicates that PVDF-HFP gel polymer membranes could be potentially
applicable for high power lithium ion batteries with the features of high safety, low cost and good
Sun, B, Huang, X, Chen, S, Zhang, J & Wang, G 2014, 'An optimized LiNO3/DMSO electrolyte for high-performance rechargeable LiO2 batteries', RSC Advances, vol. 4, pp. 11115-11120.View/Download from: UTS OPUS or Publisher's site
Finding stable electrolytes is essential to address the poor cycling capability of current rechargeable non-aqueous LiO2 batteries. An optimized dimethyl sulfoxide (DMSO) based electrolyte using lithium nitrate (LiNO3) as the lithium salt has been first investigated for rechargeable LiO2 batteries. The charge over-potential of LiO2 batteries with LiNO3/DMSO electrolyte is 0.42 V lower than that of batteries with LiClO4/DMSO electrolyte. The LiO2 batteries with LiNO3/DMSO electrolyte also showed excellent high C-rate performance and good cycling stability.
Sun, B, Huang, X, Chen, S, Zhao, Y, Zhang, J, Munroe, P & Wang, G 2014, 'Hierarchical macroporous/mesoporous NiCo2O4 nanosheets as cathode catalysts for rechargeable Li-O2 batteries', Journal of Materials Chemistry A, vol. 2, pp. 12053-12059.View/Download from: UTS OPUS or Publisher's site
The key factor to improve the electrochemical performance of Li-O2 batteries is to find bi-functional cathode catalysts to promote the oxygen reduction and evolution reactions. Despite tremendous effects, developing cathode catalysts with high activity remains a great challenge. Herein, we report the synthesis of hierarchical macroporous/mesoporous NiCo2O4 nanosheets as an effective cathode catalyst for Li-O2 batteries. The hierarchical porous catalyst was synthesized by a hydrothermal method, followed by low temperature calcination. SEM and TEM observations clearly present that the as-prepared NiCo2O4 nanosheets showed a hierarchical porous structure with mesopores distributed through the surface of NiCo2O4 nanosheets and macropores formed between the crumpled nanosheets. When investigating as the cathode catalyst in Li-O2 batteries, the as-prepared NiCo2O4 nanosheets exhibited higher reversible capacity, lower charge/discharge overpotential, and better cycling stability than those of pristine carbon black. The enhanced electrochemical performance of NiCo2O4 nanosheets should be attributed not only to the high catalytic activity of NiCo2O4 towards oxygen reduction reaction and oxygen evolution reaction, but also to the novel hierarchical porous structure of NiCo2O4.
Chen, S, Huang, X, Liu, H, Sun, B, Yeoh, W, Li, K, Zhang, J & Wang, G 2014, '3D Hyperbranched Hollow Carbon Nanorod Architectures for High-Performance Lithium-Sulfur Batteries', Advanced Energy Materials, vol. 4, p. 1301761.View/Download from: UTS OPUS or Publisher's site
Lithium-sulfur batteries have been plagued for a long time by low Coulombic efficiency, fast capacity loss, and poor high rate performance. Here, the synthesis of 3D hyperbranched hollow carbon nanorod encapsulated sulfur nanocomposites as cathode materials for lithium-sulfur batteries is reported. The sulfur nanocomposite cathodes deliver a high specific capacity of 1378 mAh g-1 at a 0.1C current rate and exhibit stable cycling performance. The as-prepared sulfur nanocomposites also achieve excellent high rate capacities and cyclability, such as 990 mAh g -1 at 1C, 861 mAh g -1 at 5C, and 663 mAh g -1 at 10C, extending to more than 500 cycles. The superior electrochemical performance are ascribed to the unique 3D hyperbranched hollow carbon nanorod architectures and high length/radius aspect ratio of the carbon nanorods, which can effectively prevent the dissolution of polysulfi des, decrease self-discharge, and confi ne the volume expansion on cycling. High capacity, excellent high-rate performance, and long cycle life render the as-developed sulfur/carbon nanorod nanocomposites a promising cathode material for lithium-sulfur batteries.
Xie, X, Su, D, Chen, S, Zhang, J, Dou, S & Wang, G 2014, 'SnS2 Nanoplatelet@Graphene Nanocomposites as High-Capacity Anode Materials for Sodium-Ion Batteries', Chemistry An Asian Journal, vol. 9, pp. 1611-1617.View/Download from: Publisher's site
Na-ion batteries have been attracting intensive investigations as a possible alternative to Li-ion batteries. Herein, we report the synthesis of SnS2 nanoplatelet@graphene nanocomposites by using a morphology-controlled hydrothermal method. The asprepared SnS2/graphene nanocomposites present a unique two-dimensional platelet-on-sheet nanoarchitecture, which has been identified by scanning and transmission electron microscopy. When applied as the anode material for Na-ion batteries, the SnS2/graphene nanosheets achieved a high reversible specific sodium-ion storage capacity of 725 mAhg1, stable cyclability, and an enhanced high-rate capability. The improved electrochemical performance for reversible sodium-ion storage could be ascribed to the synergistic effects of the SnS2 nanoplatelet/graphene nanosheets as an integrated hybrid nanoarchitecture, in which the graphene nanosheets provide electronic conductivity and cushion for the active SnS2 nanoplatelets during Na-ion insertion and extraction processes.
Zhang, J, Sun, B, Ahn, H, Wang, C & Wang, G 2013, 'Conducting polymer-doped polyprrrole as an effective cathode catalyst for Li-O2 batteries', Materials Research Bulletin, vol. 48, no. 12, pp. 4979-4983.View/Download from: UTS OPUS or Publisher's site
Polypyrrole conducting polymers with different dopants have been synthesized and applied as the cathode catalyst in Li-O2 batteries. Polypyrrole polymers exhibited an effective catalytic activity towards oxygen reduction in lithium oxygen batteries. It was discovered that dopant significantly influenced the electrochemical performance of polypyrrole. The polypyrrole doped with Cl- demonstrated higher capacity and more stable cyclability than that doped with ClO4-. Polypyrrole conducting polymers also exhibited higher capacity and better cycling performance than that of carbon black catalysts.
Sun, B, Zhang, J, Munroe, P, Ahn, H & Wang, G 2013, 'Hierarchical NiCo2O4 nanorods as an efficient cathode catalyst for rechargeable non-aqueous Li-O2 batteries', Electrochemistry Communications, vol. 31, pp. 88-91.View/Download from: UTS OPUS or Publisher's site
NiCo2O4 nanorods were synthesized by a hydrothermal method followed by low temperature calcination. FESEM and TEM analyses confirmed that the as-prepared materials consist of a hierarchical nanorod structure. When applied as cathode catalysts in rechargeable LiO2 batteries, NiCo2O4 nanorods exhibited a superior catalytic activity, including low charge over-potential, high discharge capacity and high-rate capability.