Publications by authors named "Faxing Wang"

36 Publications

Facile assembly of layer-interlocked graphene heterostructures as flexible electrodes for Li-ion batteries.

Faraday Discuss 2021 Apr 8;227:321-331. Epub 2020 Dec 8.

Center for Advancing Electronics Dresden (cfaed), Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany.

Flexible electrodes with robust mechanical properties and high electrochemical performance are of significance for the practical implementation of flexible batteries. Here we demonstrate a general and straightforward co-assembly approach to prepare flexible electrodes, where electrochemically exfoliated graphene (EG) is exploited as the film former/conducting matrix and different binary metal oxides (LiTiO, LiCoO, LiMnO, LiFePO) are incorporated. The resultant EG-metal oxide hybrids exhibit a unique layer-interlocked structure, where the metal oxide is conformably wrapped by the highly flexible graphene. Due to numerous contact interphases generated between EG and the intercalated material, the hybrid films show high flexibility and can endure rolling, bending, folding and even twisting. When serving as the anode for Li-ion batteries, the freestanding EG-LiTiO hybrid presents a characteristic flat discharge plateau at 1.55 V (vs. Li/Li), indicating transformation of LiTiO to LiTiO. Small polarization, high rate capability and excellent cycling stability against mechanical bending are also demonstrated for the prepared EG-LiTiO hybrid. Finally, full cells composed of EG-LiTiO and EG-LiFePO hybrids show impressive cycling (98% capacity retention after 100 cycles at 1C) and rate performance (84% capacity retained at 2.5C). The straightforward co-assembly approach based on EG can be extended to other two-dimensional layered materials for constructing highly efficient flexible energy storage devices.
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http://dx.doi.org/10.1039/c9fd00120dDOI Listing
April 2021

Boosting Capacitive Sodium-Ion Storage in Electrochemically Exfoliated Graphite for Sodium-Ion Capacitors.

ACS Appl Mater Interfaces 2020 Nov 13;12(47):52635-52642. Epub 2020 Nov 13.

School of Energy Science and Engineering & Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816, Jiangsu Province, China.

Sodium (Na)-ion capacitors possess higher energy density than supercapacitors and higher power density than Na-ion batteries. However, kinetic mismatches between fast capacitive charge storage on the cathode and sluggish battery-type reactions on the anode lead to a poor charge/discharge rate capability and insufficient power output of Na-ion capacitors. Thus, developing suitable anode materials for Na-ion capacitors is urgently desirable. This work demonstrates an electrochemically exfoliated graphite (EEG) anode with enhanced capacitive charge storage, greatly boosting the Na-ion reaction kinetics of co-intercalation. The EEG anode shows a high reversible capacity of 109 mAh g and maintains a good capacity retention of 90% after 1000 cycles. The assembled Na-ion capacitor using the EEG anode can finish the charge/discharge process in less than 10 s, which achieves an ultrahigh power density of 17,500 W kg with an energy density of 17 Wh kg. The high capacitive contributions at both the anode and cathode contribute to the fast rate capability and high power output of the fabricated Na-ion capacitors. This work will promote the development of ultrafast charging sodium-ion storage devices.
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http://dx.doi.org/10.1021/acsami.0c14611DOI Listing
November 2020

Oligophenyls with Multiple Disulfide Bridges as Higher Homologues of Dibenzo[c,e][1,2]dithiin: Synthesis and Application in Lithium-Ion Batteries.

Chemistry 2020 Jun 5;26(36):8007-8011. Epub 2020 Jun 5.

Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.

Higher homologues of dibenzo[c,e][1,2]dithiin were synthesized from oligophenyls bearing multiple methylthio groups. Single-crystal X-ray analyses revealed their nonplanar structures and helical enantiomers of higher meta-congener 6. Such dibenzo[1,2]dithiin homologues are demonstrated to be applicable to lithium-ion batteries as cathode, displaying a high capacity of 118 mAh g at a current density of 50 mA g .
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http://dx.doi.org/10.1002/chem.202000728DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7383724PMC
June 2020

A Stimulus-Responsive Zinc-Iodine Battery with Smart Overcharge Self-Protection Function.

Adv Mater 2020 Apr 5;32(16):e2000287. Epub 2020 Mar 5.

Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, Dresden, 01069, Germany.

Zinc-iodine aqueous batteries (ZIABs) are highly attractive for grid-scale energy storage due to their high theoretical capacities, environmental friendliness, and intrinsic non-flammability. However, because of the close redox potential of Zn stripping/platting and hydrogen evolution, slight overcharge of ZIABs would induce drastic side reactions, serious safety concerns, and battery failure. A novel type of stimulus-responsive zinc-iodine aqueous battery (SR-ZIAB) with fast overcharge self-protection ability is demonstrated by employing a smart pH-responsive electrolyte. Operando spectroelectrochemical characterizations reveal that the battery failure mechanism of ZIABs during overcharge arises from the increase of electrolyte pH induced by hydrogen evolution as well as the consequent irreversible formation of insulating ZnO at anode and soluble Zn(IO ) at cathode. Under overcharge conditions, the designed SR-ZIABs can be rapidly switched off with capacity degrading to 6% of the initial capacity, thereby avoiding continuous battery damage. Importantly, SR-ZIABs can be switched on with nearly 100% of capacity recovery by re-adjusting the electrolyte pH. This work will inspire the development of aqueous Zn batteries with smart self-protection ability in the overcharge state.
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http://dx.doi.org/10.1002/adma.202000287DOI Listing
April 2020

Fully Conjugated Phthalocyanine Copper Metal-Organic Frameworks for Sodium-Iodine Batteries with Long-Time-Cycling Durability.

Adv Mater 2020 Jan 9;32(4):e1905361. Epub 2019 Dec 9.

Center for Advancing Electronics Dresden (cfaed) and Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

Rechargeable sodium-iodine (Na-I ) batteries are attracting growing attention for grid-scale energy storage due to their abundant resources, low cost, environmental friendliness, high theoretical capacity (211 mAh g ), and excellent electrochemical reversibility. Nevertheless, the practical application of Na-I batteries is severely hindered by their poor cycle stability owing to the serious dissolution of polyiodide in the electrolyte during charge/discharge processes. Herein, the atomic modulation of metal-bis(dihydroxy) species in a fully conjugated phthalocyanine copper metal-organic framework (MOF) for suppression of polyiodide dissolution toward long-time cycling Na-I batteries is demonstrated. The Fe [(2,3,9,10,16,17,23,24-octahydroxy phthalocyaninato)Cu] MOF composited with I (Fe -O -PcCu/I ) serves as a cathode for a Na-I battery exhibiting a stable specific capacity of 150 mAh g after 3200 cycles and outperforming the state-of-the-art cathodes for Na-I batteries. Operando spectroelectrochemical and electrochemical kinetics analyses together with density functional theory calculations reveal that the square planar iron-bis(dihydroxy) (Fe-O ) species in Fe -O -PcCu are responsible for the binding of polyiodide to restrain its dissolution into electrolyte. Besides the monovalent Na-I batteries in organic electrolytes, the Fe -O -PcCu/I cathode also operates stably in other metal-I batteries like aqueous multivalent Zn-I batteries. Thus, this work offers a new strategy for designing stable cathode materials toward high-performance metal-iodine batteries.
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http://dx.doi.org/10.1002/adma.201905361DOI Listing
January 2020

A High-Voltage, Dendrite-Free, and Durable Zn-Graphite Battery.

Adv Mater 2020 Jan 1;32(4):e1905681. Epub 2019 Dec 1.

Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

The intrinsic advantages of metallic Zn, like high theoretical capacity (820 mAh g ), high abundance, low toxicity, and high safety have driven the recent booming development of rechargeable Zn batteries. However, the lack of high-voltage electrolyte and cathode materials restricts the cell voltage mostly to below 2 V. Moreover, dendrite formation and the poor rechargeability of the Zn anode hinder the long-term operation of Zn batteries. Here a high-voltage and durable Zn-graphite battery, which is enabled by a LiPF -containing hybrid electrolyte, is reported. The presence of LiPF efficiently suppresses the anodic oxidation of Zn electrolyte and leads to a super-wide electrochemical stability window of 4 V (vs Zn/Zn ). Both dendrite-free Zn plating/stripping and reversible dual-anion intercalation into the graphite cathode are realized in the hybrid electrolyte. The resultant Zn-graphite battery performs stably at a high voltage of 2.8 V with a record midpoint discharge voltage of 2.2 V. After 2000 cycles at a high charge-discharge rate, high capacity retention of 97.5% is achieved with ≈100% Coulombic efficiency.
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http://dx.doi.org/10.1002/adma.201905681DOI Listing
January 2020

Boosting electrocatalytic N reduction to NH on β-FeOOH by fluorine doping.

Chem Commun (Camb) 2019 Apr 18;55(27):3987-3990. Epub 2019 Mar 18.

Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, Sichuan, China. and Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China.

As the cheapest and one of the most abundant transition metals, Fe is not only involved in nitrogenases for biological N fixation but is also extensively utilized in the Haber-Bosch process for industrial-scale NH synthesis. However, the application of Fe-based electrocatalysts for ambient N-to-NH conversion still requires exploration of effective strategies to boost the catalytic performances for simultaneously achieving a large NH yield and a high Faradaic efficiency (FE). Here, we report that the ambient electrocatalytic N reduction activity of a β-FeOOH nanorod can be greatly improved by fluorine doping. When tested at -0.60 V vs. reversible hydrogen electrode (RHE) in 0.5 M LiClO, such a β-FeO(OH,F) nanorod obtains an optimal NH yield (42.38 μg h mg) and FE (9.02%), much higher than those of pristine β-FeOOH (10.01 μg h mg, 2.16%). Density functional theory calculations reveal that the enhancement in activity originates from the lower reaction energy barrier (0.24 eV) of the nanorod than that of β-FeOOH (0.59 eV).
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http://dx.doi.org/10.1039/c9cc00647hDOI Listing
April 2019

Zn-Ion Hybrid Micro-Supercapacitors with Ultrahigh Areal Energy Density and Long-Term Durability.

Adv Mater 2019 Jan 27;31(3):e1806005. Epub 2018 Nov 27.

Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstr. 4, 01069, Dresden, Germany.

On-chip micro-supercapacitors (MSCs), as promising power candidates for microdevices, typically exhibit high power density, large charge/discharge rates, and long cycling lifetimes. However, as for most reported MSCs, the unsatisfactory areal energy density (<10 µWh cm ) still hinders their practical applications. Herein, a new-type Zn-ion hybrid MSC with ultrahigh areal energy density and long-term durability is demonstrated. Benefiting from fast ion adsorption/desorption on the capacitor-type activated-carbon cathode and reversible Zn stripping/plating on the battery-type electrodeposited Zn-nanosheet anode, the fabricated Zn-ion hybrid MSCs exhibit remarkable areal capacitance of 1297 mF cm at 0.16 mA cm (259.4 F g at a current density of 0.05 A g ), landmark areal energy density (115.4 µWh cm at 0.16 mW cm ), and a superb cycling stability without noticeable decay after 10 000 cycles. This work will inspire the fabrication and development of new high-performance microenergy devices based on novel device design.
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http://dx.doi.org/10.1002/adma.201806005DOI Listing
January 2019

Aqueous Dual-Ion Battery Based on a Hematite Anode with Exposed {1 0 4} Facets.

ChemSusChem 2018 Dec 9;11(24):4269-4274. Epub 2018 Nov 9.

Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

The aqueous rechargeable lithium battery (ARLB) is one of the most promising devices for large-scale grid applications. Currently, a key issue for ARLBs is to develop promising anode materials with favorable electrochemical performances. Here, for the first time, we demonstrate an aqueous battery that utilizes the reversible redox reaction with hydroxide ions (OH ) in the hematite (Fe O ) anode and a commercial Li ion intercalation compound in neutral solution as the cathode. The fabricated aqueous battery displays a reversible capacity of 92 mAh g . The morphology of the used Fe O anode with exposed {1 0 4} facets for this aqueous battery is unique and attractive. Importantly, with the dual-pH neutral-alkaline hybrid electrolyte, many excellent anode materials that previously could only work in alkaline electrolytes can now be successfully combined with commercial cathodes in neutral solutions, which may significantly enrich the range of anode materials for ARLBs. In addition, the reported battery configuration can be extended to other aqueous batteries beyond Li-ion ones with lower cost.
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http://dx.doi.org/10.1002/cssc.201801918DOI Listing
December 2018

Fluoride-Free Synthesis of Two-Dimensional Titanium Carbide (MXene) Using A Binary Aqueous System.

Angew Chem Int Ed Engl 2018 Nov 24;57(47):15491-15495. Epub 2018 Oct 24.

Chair of Molecular Functional Materials and Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Mommsenstraße 4, 01069, Dresden, Germany.

Two-dimensional (2D) titanium carbide (Ti C ) is emerging as an important member of the MXene family. However, fluoride-based synthetic procedures remain an impediment to the practical applications of this promising class of materials. Here we demonstrate an efficient fluoride-free etching method based on the anodic corrosion of titanium aluminium carbide (Ti AlC ) in a binary aqueous electrolyte. The dissolution of aluminium followed by in situ intercalation of ammonium hydroxide results in the extraction of carbide flakes (Ti C T , T=O, OH) with sizes up to 18.6 μm and high yield (over 90 %) of mono- and bilayers. All-solid-state supercapacitor based on exfoliated sheets exhibits high areal and volumetric capacitances of 220 mF cm and 439 F cm , respectively, at a scan rate of 10 mV s , superior to those of LiF/HCl-etched MXenes. Our strategy paves a safe way to the scalable synthesis and application of MXene materials.
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http://dx.doi.org/10.1002/anie.201809662DOI Listing
November 2018

WS-Graphite Dual-Ion Batteries.

Nano Lett 2018 11 11;18(11):7155-7164. Epub 2018 Oct 11.

Graphene Labs , Istituto Italiano di Tecnologia , via Morego 30 , 16163 Genova , Italy.

A novel WS-graphite dual-ion battery (DIB) is developed by combining a conventional graphite cathode and a high-capacity few-layer WS-flake anode. The WS flakes are produced by exploiting wet-jet milling (WJM) exfoliation, which allows large-scale and free-material loss production (i.e., volume up to 8 L h at concentration of 10 g L and exfoliation yield of 100%) of few-layer WS flakes in dispersion. The WS anodes enable DIBs, based on hexafluorophosphate (PF) and lithium (Li) ions, to achieve charge-specific capacities of 457, 438, 421, 403, 295, and 169 mAh g at current rates of 0.1, 0.2, 0.3, 0.4, 0.8, and 1.0 A g, respectively, outperforming conventional DIBs. The WS-based DIBs operate in the 0 to 4 V cell voltage range, thus extending the operating voltage window of conventional WS-based Li-ion batteries (LIBs). These results demonstrate a new route toward the exploitation of WS, and possibly other transition-metal dichalcogenides, for the development of next-generation energy-storage devices.
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http://dx.doi.org/10.1021/acs.nanolett.8b03227DOI Listing
November 2018

Two-dimensional materials for miniaturized energy storage devices: from individual devices to smart integrated systems.

Chem Soc Rev 2018 Oct;47(19):7426-7451

Department of Chemistry and Food Chemistry & Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany.

Nowadays, the increasing requirements of portable, implantable, and wearable electronics have greatly stimulated the development of miniaturized energy storage devices (MESDs). Electrochemically active materials and microfabrication techniques are two indispensable parts in MESDs. Particularly, the architecture design of microelectrode arrays is beneficial to the accessibility of two-dimensional (2D) active materials. Therefore, this study reviews the recent advancements in microbatteries and microsupercapacitors based on electrochemically active 2D materials. Emerging microfabrication strategies enable the precise control over the thickness, homogeneity, structure, and dimension in miniaturized devices, which offer tremendous opportunities for achieving both high energy and power densities. Furthermore, smart functions and integrated systems are discussed in detail in light of the emergence of intelligent and interactive modes. Finally, future developments, opportunities, and urgent challenges related to 2D materials, device fabrications, smart responsive designs, and microdevice integrations are provided.
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http://dx.doi.org/10.1039/c8cs00561cDOI Listing
October 2018

Cobalt-Based Metal-Organic Framework Nanoarrays as Bifunctional Oxygen Electrocatalysts for Rechargeable Zn-Air Batteries.

Chemistry 2018 Dec 30;24(69):18413-18418. Epub 2018 Oct 30.

Center for Advancing Electronics Dresden (Cfaed) and Department of, Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

Owing to their high theoretical energy density, environmental benign character, and low cost, rechargeable Zn-air batteries have emerged as an attractive energy technology. Unfortunately, their energy efficiency is seriously plagued by sluggish oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) that alternately occurs on air electrodes. Herein, we demonstrate Co-based metal-organic framework (Co(bpdc)(H O) (bpdc=biphenyl -4, 4'-dicarboxylic acid), Co-MOF) arrays as novel bifunctional oxygen electrocatalysts. The Co-MOF is in situ constructed on a three-dimensional graphite foam (GF) through a hydrothermal reaction. In a 1 m KOH aqueous solution, the resultant Co-MOF/GF exhibits an OER overpotential of only ≈220 mV at 10 mA cm , which is much lower than those for Ir/C and previously reported noble metal-free electrocatalysts. In conjunction with its ORR half-wave potential of 0.7 V (vs. RHE), the Co-MOF/GF manifests a greatly decreased potential gap of ≈0.75 V in comparison with Pt/C-Ir/C couple and previously reported bifunctional oxygen electrocatalysts. Furthermore, an assembled rechargeable zinc-air battery using Co-MOF electrocatalyst in an air electrode delivers a maximum power density of 86.2 mW cm and superior charge-discharge performance. Microscopic, spectroscopic and electrochemical analyses prove that the initial Co-MOF is transformed into Co-oxyhydroxides during the OER and ORR process, which essentially serve as bifunctional active centers.
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http://dx.doi.org/10.1002/chem.201804339DOI Listing
December 2018

Polarity-Switchable Symmetric Graphite Batteries with High Energy and High Power Densities.

Adv Mater 2018 Sep 22;30(39):e1802949. Epub 2018 Aug 22.

Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

Multifunctional batteries with enhanced safety performance have received considerable attention for their applications at extreme conditions. However, few batteries can endure a mix-up of battery polarity during charging, a common wrong operation of rechargeable batteries. Herein, a polarity-switchable battery based on the switchable intercalation feature of graphite is demonstrated. The unique redox-amphoteric intercalation behavior of graphite allows a reversible switching of graphite between anode and cathode, thus enabling polarity-switchable symmetric graphite batteries. The large potential gap between anion and cation intercalation delivers a high midpoint device voltage (≈average voltage) of ≈4.5 V. Further, both the graphite anode and cathode are kinetically activated during the polarity switching. Consequently, polarity-switchable symmetric graphite batteries exhibit a remarkable cycling stability (96% capacity retention after 500 cycles), a high power density of 8.66 kW kg , and a high energy density of 227 Wh kg (calculated based on the total weight of active materials in both anode and cathode), which are superior to other symmetric batteries and recently reported dual-graphite or dual-carbon batteries. This work will inspire the development of new multifunctional energy-storage devices based on novel materials and electrolyte systems.
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http://dx.doi.org/10.1002/adma.201802949DOI Listing
September 2018

A Dual-Stimuli-Responsive Sodium-Bromine Battery with Ultrahigh Energy Density.

Adv Mater 2018 Jun 30;30(23):e1800028. Epub 2018 Apr 30.

Chair of Molecular Functional Materials, School of Science, Technische Universität Dresden, Mommsenstrasse 4, 01069, Dresden, Germany.

Stimuli-responsive energy storage devices have emerged for the fast-growing popularity of intelligent electronics. However, all previously reported stimuli-responsive energy storage devices have rather low energy densities (<250 Wh kg ) and single stimuli-response, which seriously limit their application scopes in intelligent electronics. Herein, a dual-stimuli-responsive sodium-bromine (Na//Br ) battery featuring ultrahigh energy density, electrochromic effect, and fast thermal response is demonstrated. Remarkably, the fabricated Na//Br battery exhibits a large operating voltage of 3.3 V and an energy density up to 760 Wh kg , which outperforms those for the state-of-the-art stimuli-responsive electrochemical energy storage devices. This work offers a promising approach for designing multi-stimuli-responsive and high-energy rechargeable batteries without sacrificing the electrochemical performance.
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http://dx.doi.org/10.1002/adma.201800028DOI Listing
June 2018

Dual-Graphene Rechargeable Sodium Battery.

Small 2017 12 27;13(47). Epub 2017 Oct 27.

Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

Sodium (Na) ion batteries are attracting increasing attention for use in various electrical applications. However, the electrochemical behaviors, particularly the working voltages, of Na ion batteries are substantially lower than those of lithium (Li) ion batteries. Worse, the state-of-the-art Na ion battery cannot meet the demand of miniaturized in modern electronics. Here, we demonstrate that electrochemically exfoliated graphene (EG) nanosheets can reversibly store (PF ) anions, yielding high charging and discharging voltages of 4.7 and 4.3 V vs. Na /Na, respectively. The dual-graphene rechargeable Na battery fabricated using EG as both the positive and negative electrodes provided the highest operating voltage among all Na ion full cells reported to date, together with a maximum energy density of 250 Wh kg . Notably, the dual-graphene rechargeable Na microbattery exhibited an areal capacity of 35 μAh cm with stable cycling behavior. This study offers an efficient option for the development of novel rechargeable microbatteries with ultra-high operating voltage and high energy density.
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http://dx.doi.org/10.1002/smll.201702449DOI Listing
December 2017

Latest advances in supercapacitors: from new electrode materials to novel device designs.

Chem Soc Rev 2017 Nov;46(22):6816-6854

School of Energy Science and Engineering, and Institute for Advanced Materials, Nanjing Tech University, Nanjing 211816, Jiangsu Province, China.

Notably, many significant breakthroughs for a new generation of supercapacitors have been reported in recent years, related to theoretical understanding, material synthesis and device designs. Herein, we summarize the state-of-the-art progress toward mechanisms, new materials, and novel device designs for supercapacitors. Firstly, fundamental understanding of the mechanism is mainly focused on the relationship between the structural properties of electrode materials and their electrochemical performances based on some in situ characterization techniques and simulations. Secondly, some emerging electrode materials are discussed, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), MXenes, metal nitrides, black phosphorus, LaMnO, and RbAgI/graphite. Thirdly, the device innovations for the next generation of supercapacitors are provided successively, mainly emphasizing flow supercapacitors, alternating current (AC) line-filtering supercapacitors, redox electrolyte enhanced supercapacitors, metal ion hybrid supercapacitors, micro-supercapacitors (fiber, plane and three-dimensional) and multifunctional supercapacitors including electrochromic supercapacitors, self-healing supercapacitors, piezoelectric supercapacitors, shape-memory supercapacitors, thermal self-protective supercapacitors, thermal self-charging supercapacitors, and photo self-charging supercapacitors. Finally, the future developments and key technical challenges are highlighted regarding further research in this thriving field.
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http://dx.doi.org/10.1039/c7cs00205jDOI Listing
November 2017

A high-capacity dual core-shell structured [email protected]@PPy nanocomposite anode for advanced aqueous rechargeable lithium batteries.

Nanoscale 2017 Aug;9(31):11004-11011

College of Science, National Research Center of Engineering Technology for Utilization of Functional Ingredients from botanica, College of Agronomy, Hunan Agricultural University, Changsha, 410128, China.

Anode materials with high capacity for aqueous rechargeable lithium batteries (ARLBs) are very rarely reported. Here we found that a dual core-shell structured [email protected]@PPy nanocomposite prepared by us shows excellent electrochemical performance. Its initial discharge capacity in a saturated LiAc aqueous electrolyte is very high, which is up to 481 mA h g based on the weight of the composite and 879 mA h g based on the sulfur content. It shows excellent rate capability. When nanotube LiMnO is used as a cathode, the assembled ARLB can deliver an energy density of 110 Wh kg based on two electrodes and show excellent cycling. These results show great promise for the practical application of ARLBs.
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http://dx.doi.org/10.1039/c7nr03602gDOI Listing
August 2017

A novel enzymatic method for synthesis of glycopeptides carrying natural eukaryotic N-glycans.

Chem Commun (Camb) 2017 Aug;53(65):9075-9077

State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, P. R. China.

A novel enzymatic approach was developed for facile production of glycopeptides carrying natural eukaryotic N-glycans. In this approach, peptides can be GlcNAcylated at one or two natural N-glycosylation sites via two-step enzymatic reactions catalyzed by an evolved N-glycosyltransferase (ApNGT) and a glucosamine N-acetyltransferase (GlmA), respectively. The resulting GlcNAc-peptides were further modified by an endo-β-N-acetylglucosaminidase M mutant (EndoM) to generate glycopeptides. In three steps of enzymatic catalysis, glycopeptides carrying complex-type N-glycans can be efficiently synthesized.
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http://dx.doi.org/10.1039/c7cc04362gDOI Listing
August 2017

Production of homogeneous glycoprotein with multisite modifications by an engineered -glycosyltransferase mutant.

J Biol Chem 2017 05 5;292(21):8856-8863. Epub 2017 Apr 5.

From the State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China and

Naturally occurring -glycoproteins exhibit glycoform heterogeneity with respect to -glycan sequon occupancy (macroheterogeneity) and glycan structure (microheterogeneity). However, access to well-defined glycoproteins is always important for both basic research and therapeutic purposes. As a result, there has been a substantial effort to identify and understand the catalytic properties of -glycosyltransferases, enzymes that install the first glycan on the protein chain. In this study we found that ApNGT, a newly discovered cytoplasmic -glycosyltransferase from , has strict selectivity toward the residues around the Asn of -glycosylation sequon by screening a small library of synthetic peptides. The inherent stringency was subsequently demonstrated to be closely associated with a critical residue (Gln-469) of ApNGT which we propose hinders the access of bulky residues surrounding the occupied Asn into the active site. Site-saturated mutagenesis revealed that the introduction of small hydrophobic residues at the site cannot only weaken the stringency of ApNGT but can also contribute to enormous improvement of glycosylation efficiency against both short peptides and proteins. We then employed the most efficient mutant (Q469A) other than the wild-type ApNGT to produce a homogeneous glycoprotein carrying multiple (up to 10) -glycans, demonstrating that this construct is a promising biocatalyst for potentially addressing the issue of macroheterogeneity in glycoprotein preparation.
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http://dx.doi.org/10.1074/jbc.M117.777383DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5448120PMC
May 2017

Soft-Template Construction of 3D Macroporous Polypyrrole Scaffolds.

Small 2017 04 1;13(14). Epub 2017 Feb 1.

Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

A bottom-up approach toward 3D hierarchical macroporous polypyrrole aerogels is demonstrated via soft template-directed synthesis and self-assembly of ultrathin polypyrrole nanosheets in solution, which present interconnected macropores, ultrathin walls, and large specific surface areas, thereby exhibiting a high capacity, satisfactory rate capability, and excellent cycling stability for Na-ion storage.
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http://dx.doi.org/10.1002/smll.201604099DOI Listing
April 2017

Persulfurated Coronene: A New Generation of "Sulflower".

J Am Chem Soc 2017 02 2;139(6):2168-2171. Epub 2017 Feb 2.

Department of Chemistry and Food Chemistry, Center for Advancing Electronics Dresden, Technische Universität Dresden , 01062 Dresden, Germany.

We report the first synthesis of a persulfurated polycyclic aromatic hydrocarbon (PAH) as a next-generation "sulflower." In this novel PAH, disulfide units establish an all-sulfur periphery around a coronene core. The structure, electronic properties, and redox behavior were investigated by microscopic, spectroscopic and electrochemical methods and supported by density functional theory. The sulfur-rich character of persulfurated coronene renders it a promising cathode material for lithium-sulfur batteries, displaying a high capacity of 520 mAh g after 120 cycles at 0.6 C with a high-capacity retention of 90%.
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http://dx.doi.org/10.1021/jacs.6b12630DOI Listing
February 2017

Stimulus-Responsive Micro-Supercapacitors with Ultrahigh Energy Density and Reversible Electrochromic Window.

Adv Mater 2017 Feb 6;29(7). Epub 2016 Dec 6.

Center for Advancing Electronics Dresden (cfaed) and Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

Stimulus-responsive micro-supercapacitors (SR-MSCs) with ultrahigh volumetric energy density and reversible electrochromic effect are successfully fabricated by employing a vanadium pentoxide and electrochemical exfoliated graphene-based hybrid nanopaper and viologen as electrode and stimulus-responsive material, respectively. The fabricated high-performance SR-MSCs offer new opportunities for intuitively observing the working state of energy devices without the aid of extra equipment and techniques.
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http://dx.doi.org/10.1002/adma.201604491DOI Listing
February 2017

A Quasi-Solid-State Li-Ion Capacitor Based on Porous TiO Hollow Microspheres Wrapped with Graphene Nanosheets.

Small 2016 Dec 29;12(45):6207-6213. Epub 2016 Sep 29.

Laboratory of Advanced Materials, Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China.

The quasi-solid-state Li-ion capacitor is demonstrated with graphene nanosheets prepared by an electrochemical exfoliation as the positive electrode and the porous TiO hollow microspheres wrapped with the same graphene nanosheets as the negative electrode, using a Li-ion conducting gel polymer electrolyte. This device may be the key to bridging the gap between conventional lithium-ion batteries and supercapacitors, meanwhile meeting the safety demands of electronic devices.
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http://dx.doi.org/10.1002/smll.201602331DOI Listing
December 2016

Dual-Template Synthesis of 2D Mesoporous Polypyrrole Nanosheets with Controlled Pore Size.

Adv Mater 2016 Oct 8;28(38):8365-8370. Epub 2016 Aug 8.

Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.

The first synergistic dual-template self-assembly approach is presented for bottom-up construction of 2D mesoporous polypyrrole nanosheets based on different supramolecular assemblies, which feature a double-layered architecture, controlled pore sizes, ultrathin thickness, and large surface area. The unique structure rends them with superior reversible discharge capability, rate performance, and stable cyclability when serving as the cathode materials for Na-ion batteries.
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http://dx.doi.org/10.1002/adma.201603036DOI Listing
October 2016

Electrode materials with tailored facets for electrochemical energy storage.

Nanoscale Horiz 2016 Jul 29;1(4):272-289. Epub 2016 Feb 29.

College of Energy and Institute for Electrochemical Energy Storage, Nanjing Tech University, Jiangsu Province, Nanjing 211816, China.

In recent years, the design and morphological control of crystals with tailored facets have become hot spots in the field of electrochemical energy storage devices. For electrode materials, morphologies play important roles in their activities because their shapes determine how many facets of specific orientation are exposed and therefore available for surface reactions. This review focuses on the strategies for crystal facet control and the unusual electrochemical properties of electrode materials bound by tailored facets. Here, electrode materials with tailored facets include transition metal oxides such as SnO, CoO, NiO, CuO, and MnO, elementary substances such as Si and Au, and intercalation compounds such as LiTiO, LiCoO, LiMnO, LiFePO, and NaMnO for various applications of Li-ion batteries, aqueous rechargeable lithium batteries, Na-ion batteries, Li-O batteries and supercapacitors. How these electrode materials with tailored facets affect their electrochemical properties is discussed. Finally, research opportunities as well as the challenges in this emerging research frontier are highlighted.
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http://dx.doi.org/10.1039/c5nh00116aDOI Listing
July 2016

An Aqueous Rechargeable Zn//Co3 O4 Battery with High Energy Density and Good Cycling Behavior.

Adv Mater 2016 Jun 27;28(24):4904-11. Epub 2016 Apr 27.

College of Energy and Institute for Advance Materials, Nanjing Tech University, Nanjing, 211816, Jiangsu Province, China.

An aqueous rechargeable Zn//Co3 O4 battery is demonstrated with [email protected] fibers and Co3 O4 @Ni foam as the negative and positive electrodes, respectively, using an electrolyte of 1 m KOH and 10 × 10(-3) m Zn(Ac)2 . It can operate at a cell voltage as high as 1.78 V with an energy density of 241 W h kg(-1) and presents excellent cycling. The battery is also assembled into a flexible shape, which can be applied in flexible or wearable devices requiring high energy.
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http://dx.doi.org/10.1002/adma.201505370DOI Listing
June 2016

Aqueous Rechargeable Zinc/Aluminum Ion Battery with Good Cycling Performance.

ACS Appl Mater Interfaces 2016 Apr 31;8(14):9022-9. Epub 2016 Mar 31.

College of Energy, Institute for Electrochemical Storage, and Institute for Advanced Materials, Nanjing Tech University , Nanjing, Jiangsu 211816, People's Republic of China.

Developing rechargeable batteries with low cost is critically needed for the application in large-scale stationary energy storage systems. Here, an aqueous rechargeable zinc//aluminum ion battery is reported on the basis of zinc as the negative electrode and ultrathin graphite nanosheets as the positive electrode in an aqueous Al2(SO4)3/Zn(CHCOO)2 electrolyte. The positive electrode material was prepared through a simple electrochemically expanded method in aqueous solution. The cost for the aqueous electrolyte together with the Zn negative electrode is low, and their raw materials are abundant. The average working voltage of this aqueous rechargeable battery is 1.0 V, which is higher than those of most rechargeable Al ion batteries in an ionic liquid electrolyte. It could also be rapidly charged within 2 min while maintaining a high capacity. Moreover, its cycling behavior is also very good, with capacity retention of nearly 94% after 200 cycles.
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http://dx.doi.org/10.1021/acsami.5b06142DOI Listing
April 2016

A Quasi-Solid-State Sodium-Ion Capacitor with High Energy Density.

Adv Mater 2015 Nov 30;27(43):6962-8. Epub 2015 Sep 30.

College of Energy and Institute for Advanced Materials, Nanjing Tech University, Jiangsu Province, Nanjing, 211816, China.

A quasi-solid-state sodium-ion capacitor is demonstrated with nanoporous disordered carbon and macroporous graphene as the negative and positive electrodes, respectively, using a sodium-ion-conducting gel polymer electrolyte. It can operate at a cell voltage as high as 4.2 V with an energy density of record high 168 W h kg(-1).
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http://dx.doi.org/10.1002/adma.201503097DOI Listing
November 2015