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Metal-organic framework (MOF)-derived materials are attracting considerable attention because of the moldability in compositions and structures, enabling greater performances in diverse applications. However, the nanostructural control of multicomponent MOF-based complexes remains challenging due to the complexity of reaction mechanisms. Herein, we present a surface-induced self-nucleation-growth mechanism for the zeolitic imidazolate framework (ZIF) to prepare a new type of ZIF-8@SiO2 polyhedral nanoparticles. We discover that the Zn hydroxide moieties (Zn-OH) within ZIF-8 can trigger the hydrolysis of tetraethyl orthosilicate effectively on the ZIF-8 surface precisely, avoiding the formation of free orthosilicic acid (Si(OH)4) successfully. This is a pioneering work to elucidate the importance of MOF surface properties for preparing multicomponent materials. Then, a novel well-dispersed silicon hollow nanocage (H-Si@C) modified by the carbon was prepared after removal of the ZIF-8 and magnesiothermic reduction. The as-prepared H-Si@C demonstrates an overwhelmingly high lithium storage capability and extraordinary stability in lithium-ion batteries (LIBs), particularly the impressive performances when it was matched with the LiNi0.6Co0.2Mn0.2O2 cathode in a full cell. The MOF surface-induced self-nucleation-growth strategy is useful for preparing more multifunctional materials, while the study of lithium storage performances of the H-Si@C material is practical for LIB applications.

Lithium dendrite-free deposition is crucial to stabilizing lithium batteries, where the three-dimensional (3D) metal oxide nanoarrays demonstrate an impressive capability to suppress dendrite due to the spatial effect. Herein, we introduce a new insight into the ameliorated lithium plating process on 3D nanoarrays. As a paradigm, novel 3D Cu2O and Cu nanorod arrays were in situ designed on copper foil. We find that the dendrite and electrolyte decomposition can be mitigated effectively by Cu2O nanoarrays, while the battery failed fast when the Cu nanoarrays were used. We show that Li2O (i.e., formed in the lithiation of Cu2O) is critical to stabilizing the electrolyte; otherwise, the electrolyte would be decomposed seriously. Our viewpoint is further proved when we revisit the metal (oxide) nanoarrays reported before. Thus, we discovered the importance of electrolyte stability as a precondition for nanoarrays to suppress dendrite and/or achieve a reversible lithium plating/stripping for high-performance lithium batteries.

Four new tetrahydroanthracene derivatives (1, 3-5) and a known antibiotic, A-39183A (2), were discovered from the marine-sponge-derived actinomycete Streptomyces fumigatiscleroticus HDN10255. Their structures including absolute configurations were elucidated based upon MS and NMR spectroscopic data, ECD calculations, and biogenetic considerations. Compounds 2 and 4 showed considerable cytotoxicity with the best IC50 value of 1.8 μM against HeLa cells.

Creating new architectures combined with super diverse materials for achieving more excellent performances has attracted great attention recently. Herein, we introduce a novel dual metal (oxide) microsphere reinforced by vertically aligned carbon nanotubes (CNTs) and covered with a titanium oxide metal ion-transfer diffusion layer. The CNTs penetrate the oxide particles and buffer structural volume change while enhancing electrical conductivity. Meanwhile, the external TiO2-C shell serves as a transport pathway for mobile metal ions (e.g., Li+) and acts as a protective layer for the inner oxides by reducing the electrolyte/metal oxide interfacial area and minimizing side reactions. The proposed design is shown to significantly improve the stability and Coulombic efficiency (CE) of metal (oxide) anodes. For example, the as-prepared MnO-CNTs@TiO2-C microsphere demonstrates an extremely high capacity of 967 mA h g-1 after 200 cycles, where a CE as high as 99% is maintained. Even at a harsh rate of 5 A g-1 (ca. 5 C), a capacity of 389 mA h g-1 can be maintained for thousands of cycles. The proposed oxide anode design was combined with a nickel-rich cathode to make a full-cell battery that works at high voltage and exhibits impressive stability and life span.

The development of rechargeable batteries beyond 300 Wh kg–1 for electric vehicles remains challenging, where low-capacity electrode materials (especially a graphite anode, 372 Ah kg–1) remain the ...

Structural design and/or carbon modification are the most important strategies to improve the performance of materials in many applications, where metal (oxide)-based anode design attracts great attention in metal ion batteries due to their high capacities. However, achieving these two goals within one-step remains challenging due to the lower cost and higher efficiency needed to satisfy the demand in practical application. Herein, we report a new approach for the crystal reconstruction of metal oxides by acetylene treatment, in which a hierarchical binary oxide decorated with carbon (i.e., Mn2Mo3O8@C) is introduced. The mechanism of constructing unique monocrystalline hexagonal nanoplates and uniform carbon coating is discussed in detail. Benefiting from the uniqueness of structure and composition, the Mn2Mo3O8@C demonstrates an extremely high lithium storage capacity of 890 mA h g-1 and good rate capacities at 20 A g-1 over 1000 cycles. In addition, the high rate capabilities and long cycle lifespan are further confirmed when the Mn2Mo3O8@C anode is matched with the nickel-rich layered oxide cathode. This study not only introduces a new binary oxide anode with high performances in lithium (ion) batteries but also presents a convenient methodology to design more advanced functional materials.

New hierarchical hollow SiO2 spheres (HHSs) decorated with metal nanoparticles (i.e., Co, Co–HHS) were designed using an in situ self-assembly approach. The Co nanoparticles were found to have a catalytic effect on (de-)lithiation of SiO2 and hence in storing lithium. Then, an extremely high capacity of 932 mA h g−1 and good cycling stability for more than 1000 cycles were demonstrated in the corresponding lithium battery. In addition, the lithium-ion full batteries of the Co–HHS versus lithium layered oxide cathode (e.g., LiNi1/3Co1/3Mn1/3O2, NCM333) were introduced and showed good performance, demonstrating the promising application of the Co–HHS, in particular for pursuing high-energy-density batteries.

A simple and low-cost polymer-aided sol–gel method was developed to prepare γ-Al2O3 protective layers for LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode materials. The selected polyvinyl alcohol polymer additive not only facilitates the formation of a uniform and thin γ-Al2O3 layer on the irregular and rough cathode particle surface to protect it from corrosion but also serves as a pore-forming agent to generate micropores in the film after sintering to allow fast transport of lithium ions, which guaranteed the excellent and stable battery performance at high working voltage. Detailed studies in the full battery mode showed that the leached corrosion species from the cathode had a more profound harmful effect to the graphite anode, which seemed to be the dominating factor that caused the battery performance decay.

We demonstrate a novel strategy to enhance sulfur loading and rate performance for Li–S battery by synchronously coupling a nanostructured cathode with an antifouling separator via a facile electrostatic self-assembly approach. The assembly of two dimensional (2D) MXene and positively charged 1D CNT-Polyethyleneimine was observed to controllably address the key issues of sluggish ionic transport, and produce an integrate cathode with dynamic crosslinking network. Moreover, an antifouling separator is proposed by this strategy for the first time, which features well-organized inter-lamellar porosity, dual polarity and high conductivity. The antifouling separator is found to play a pivotal role in: 1) low-order polysulfide activation, 2) high rate cyclability, and 3) Li dendrites inhibition. Our integrated design realizes a long-term capacity of 980 mAh g−1 at 5 mA cm−2 over 500 cycles (sulfur loading: 2.6 mg cm−2). Furthermore, a flexible self-assembled cathode with high loading (5.8 mg cm−2) and superb mechanical strength (13 MPa), demonstrates an appealing areal capacity of 7.1 mAh cm−2 and rate performance at nearly 10 mA cm−2.

Surface modification of a cathode (e.g., lithium layered oxide, NCM) has become ever more important in lithium-ion batteries, particularly for pursuing higher energy densities and safety at high voltage. This is because structural degradation of the cathode can be mitigated significantly. Herein, an organic complex is introduced for metal phosphate (e.g., AlPO4) modification through a new film-forming process in nonaqueous solution. This general strategy overcomes the challenge of nonuniform coating in current precipitation methods and then opens a new avenue toward ultrathin surface modification on a molecular scale. As one example, as-prepared AlPO4-coated NCM exhibits much improved structural and electrochemical stability; meanwhile, thermal runaway can be suppressed significantly in overcharged cells using the modified NCM, demonstrating higher and reliable safety features. The great improvements benefit from the uniform and ultrathin AlPO4 coating, which inhibits the collapse and conversion of the la...

Four new tetrahydroanthracene derivatives (

Sodium-ion batteries are promising alternatives for lithium-ion batteries due to their lower cost caused by global sodium availability. However, the low Coulombic efficiency (CE) of the sodium metal plating/stripping process represents a serious issue for the Na anode, which hinders achieving a higher energy density. Herein, we report that the Na

Rechargeable lithium-ion batteries (LIBs) dominate the energy market, from electronic devices to electric vehicles, but pursuing greater energy density remains challenging owing to the limited electrode capacity. Although increasing the cut-off voltage of LIBs (>4.4 V vs. Li/Li+ ) can enhance the energy density, the aggravated electrolyte decomposition always leads to a severe capacity fading and/or expiry of the battery. Herein, a new durable electrolyte is reported for high-voltage LIBs. The designed electrolyte is composed of mixed linear alkyl carbonate solvent with certain cyclic carbonate additives, in which use of the ethylene carbonate (EC) co-solvent was successfully avoided to suppress the electrolyte decomposition. As a result, an extremely high cycling stability, rate capability, and high-temperature storage performance were demonstrated in the case of a graphite|LiNi0.6 Co0.2 Mn0.2 O2 (NCM622) battery at 4.45 V when this electrolyte was used. The good compatibility of the electrolyte with the graphite anode and the mitigated structural degradation of the NCM622 cathode are responsible for the high performance at high potentials above 4.4 V. This work presents a promising application of high-voltage electrolytes for pursuing high energy LIBs and provides a straightforward guide to study the electrodes/electrolyte interface for higher stability.

Sulfurized polyacrylonitrile (SPAN) is the most promising cathode for next-generation lithium–sulfur (Li–S) batteries due to the much improved stability. However, the molecular structure and reaction mechanism have not yet been fully understood. Herein, we present a new take on the structure and mechanism to interpret the electrochemical behaviors. We find that the thiyl radical is generated after the cleavage of the S–S bond in molecules in the first cycle, and then a conjugative structure can be formed due to electron delocalization of the thiyl radical on the pyridine backbone. The conjugative structure can react with lithium ions through a lithium coupled electron transfer process and form an ion-coordination bond reversibly. This could be the real reason for the superior lithium storage capability, in which the lithium polysulfide may not be formed. This study refreshes current knowledge of SPAN in Li–S batteries. In addition, the structural analysis is applicable to analyze the current organic catho...

The pursuit of increased energy density and longer lifespan lithium-ion batteries (LIBs) is urgently needed to satisfy a dramatically increased demand in the energy market. Currently, metal-oxide-based anodes are being intensively studied due to their higher capacities over current graphite anodes. This work introduces a sustainable strategy to construct a metal-oxide-based anode with high capacity and an extremely long lifecycle, in which the features of bioinspired architectures and heteroatom doping can contribute greatly to increased performances. In detail, 1D tubelike metal oxide (e.g., MnO) coated on an N-doped carbon framework (i.e. MnO/N-C) has been designed by using the naturally abundant and renewable Metaplexis japonica fibers (MJFs) as the biotemplate and heteroatom source. Benefiting from the uniqueness of structure and compositions, as-prepared MnO/N-C demonstrates extremely high rate capacities of 951, 777, 497, and 435 mAh g-1 at the rates of 0.5, 2, 4, and 5 Ag-1 , respectively, with a good stability of more than 1000 cycles. It was found that the electrochemical performances are superior to most previous MnO-based anodes, in which the faster kinetics of conversion due to the advantage of the ion/electron transportation and morphological evolution has been verified. It is hoped that the concept of bioinspired architectures with heteroatom doping can be applied in wider applications for increased capability.

Bacterial esterases and lipases, especially extremozymes attract increasing attention due to various advantages both in good properties and wide applications. In the present study, a cold-adapted, alkali-stable and highly salt-tolerant esterase (Est700) was cloned from Bacillus licheniformis, expressed and purified with a molecular mass of 25 kDa. The optimal temperature of Est700 was 30 °C, with 35% maximal activity retaining at 0 °C. Its optimal pH was 8.0 and showed high stability at pH 5.0–11.0. Noticeably, Est700 was highly activated by 3.5 M NaCl and the extent of this activation is much stronger than that of currently reported halophilic ones. It was also stable in 5 M NaCl with no activity loss. High salt concentrations changed the secondary structure and folding properties of Est700 with formation of more α-helix and less β-sheet domains. With salt incubation, its melting temperature was estimated to be 57.2 °C, which is 12.8 °C higher than that of native one. Interestingly, Est700 lacks the acidic surface that is considered essential for enzyme stability at high salinity. However, it has a mainly positive surface electrostatic potential, which is probably different from most reported halotolerant esterases. These multiple properties make Est700 a valuable candidate in both basic research and industrial applications.

The high capacity of Li-rich layered cathode materials have attracted great attention for the greater energy density lithium ion (Li-ion) batteries, but the understanding of knowledge associated with electrochemical behaviours are still needed to improve their performances further. In this study, different amount of Co content is designed in Li-rich layered compounds (0.5Li2MnO3·0.5LiMn0.5-xNi0.5-xCo2xO2, 0 ≤ x ≤ 0.2), and the stepwise electrochemical activation process is applied to explore the features. We discover that the substitution of Co3+ ions can accelerate the electrochemical activation of Li2MnO3 component, and the Co-doped compound delivers much higher capacities even they suffer an apparent voltage decay comparing to the Co-free one. Besides, a fast metal ions migration exists (e.g., from the metastable tetrahedral site to the lower energy cubic site) in initial dozens of cycles (e.g., 30 cycles at 0.1C); thereafter, they likely return to the original octahedral site, as demonstrated in the voltage decay and hysteresis analysis.

Graphite anodes are not stable in most noncarbonate solvents (e.g., ether, sulfoxide, sulfone) upon Li ion intercalation, known as an urgent issue in present Li ions and next-generation Li–S and Li–O2 batteries for storage of Li ions within the anode for safety features. The solid electrolyte interphase (SEI) is commonly believed to be decisive for stabilizing the graphite anode. However, here we find that the solvation structure of the Li ions, determined by the electrolyte composition including lithium salts, solvents, and additives, plays a more dominant role than SEI in graphite anode stability. The Li ion intercalation desired for battery operation competes with the undesired Li+–solvent co-insertion, leading to graphite exfoliation. The increase in organic lithium salt LiN(SO2CF3)2 concentration or, more effectively, the addition of LiNO3 lowers the interaction strength between Li+ and solvents, suppressing the graphite exfoliation caused by Li+–solvent co-insertion. Our findings refresh the knowled...

The development of versatile strategies to create new structured materials via heteroatom doping has become a fascinating research topic owing to their fantastic properties, while the popular metal–organic framework opens promising avenues for the design of diverse architectures. Herein, an intriguing type of spherical N-doped porous carbon (i.e., N–C) particles containing numerous Co3O4 nanocrystals (i.e., Co3O4/N–C) is introduced, in which the Zn–Co based Prussian blue analogue acts as a sacrificial template and carbon source, while the volatilization of zinc and oxidation of Co produce rich pores and form highly active Co3O4 nanocrystals. The resultant Co3O4/N–C particles have an extremely high lithium storage capacity of 1255 mA h g−1 and excellent rate capability even at a current of 2000 mA g−1. Their long cycle life of over 500 cycles at 1000 mA g−1 with a high capacity of 798 mA h g−1 further demonstrates their prominent properties. Our kinetic analysis reveals that the high performances of Co3O4/N–C beyond the theoretical values mainly stem from the active Co3O4 nanocrystals, fast diffusion of lithium ions within its structure and its pseudocapacitive behaviors. Furthermore, the Co3O4/N–C particles also demonstrate impressive stability and rate capabilities in a lithium-ion battery versus a cathode of lithium layered oxide even at high voltage conditions.

This study is based on our iGEM (international genetically engineered machine) 2019 competition project in which an in vitro model was established to simulate the human monitoring and regulation of blood glucose level using the “liver-on-a-chip” and a genetically engineered bacterium capable of producing proinsulin efficiently. The microfluidic device is able to accommodate cellular chassis loaded with biological parts for diabetic treatment. In addition, electrochemical biosensors were designed to detect the differential glucose concentration from the both chambers of the organ chip. The model can test different chemicals and organs, when the components in the channels and cells are altered. We have thus accomplished an in vitro model of how the proinsulin generated by engineered bacteria works on liver cells. In the near future, our research paradigm will be shifted to bacterial implantation in the human intestines to replace pancreas for the automatic secretion of insulin for diabetic patients.

A new synergistic lithium ion solvation structure effect tailored by mixed organic/inorganic lithium salts is introduced to mitigate the growth of lithium-dendrites. A uniform lithium plating, lower polarization and higher coulombic efficiency are confirmed by lithium plating/stripping. The effect of different solvation structures was analyzed by Raman spectroscopy and simulations. Then, a reliable lithium–sulfur full battery with high performance over hundreds of cycles was configured.

Multi-dimensional metal oxides have attracted great attention in diverse applications due to their intriguing performances. However, their structural design remains challenging, particularly that based on organic chelation chemistry. Although metal-organic complexes with different architectures have been reported, their structure formation mechanisms are not well understood because of the complex chelation processes. Herein, we introduce a new metal-organic coordination strategy to construct metal-decorated (Ni, Co, Mn) Mo-based complexes ranging from 2D nanopetals to 3D microflowers. The chelating process of the metal-organic complex can be tuned by a surfactant, giving rise to different structures, and then a further metal can be appended. Thus, different metal (oxide)-decorated MoO

Creating new nanostructured materials inspired by biomaterials is one of the most fascinating topics owing to their fantastic properties. Herein, we synthesize a new hollow aurilave-like carbon using the natural spores of Lycoperdon Boavista (SLBs) as hard-template, where the heteroatom of nitrogen and oxygen can be in-situ doped simultaneously. The hollow N/O-co-doped carbon (HNOC) has a high specific surface area and is rich in defects, enabling high performances in sodium-ion batteries (SIBs) and supercapacitors (SCs). A high sodium storage capacity of 246 and 107 mAh g−1 with superior stability over 1000 cycles can be achieved at the rates of 0.1 and 2 A g−1, respectively. Besides, the high rate capacity of 260 F g−1 at 5 A g−1 and extraordinary cycling stability over 10,000 cycles are also demonstrated in SCs. The great features of HNOC are further studied versus Na3V2(PO4)3 cathode in a sodium ion full battery, where the excellent stability and span life are both confirmed. We hope this newly-designed carbon material could complement the structure-related properties in electrochemistry, and also the presented synthetic strategy can be widely extended for designing more functional materials with greater capabilities.

Carbon modification is one of the most important strategies to boost the performance of the material in many applications, where the carbon modified metal (oxide) anode gains great attention in metal-ion batteries due to their high capacity and improved stability. However, a close-knit carbon coating through an efficient and cost-effective approach remains challenging for satisfying the demand in practical application. Herein, a new in-situ self-catalytic approach by acetylene treatment is presented, in which a tunable graphitized carbon layer can be knitted on the metal (oxide) directly to produce many kinds of core-shell structured metal (oxide)@C hybrid materials. The in-situ triggering mechanism of forming graphitized carbon is discussed in detail using the model of MnO. Then, we find that the as-prepared MnO@C exhibits an extremely high lithium storage capacity of 1077 mAh g−1 and good rate capacities at 10 A g−1 over 500 cycles. In addition, a new full battery of MnO@C || LiNi0.8Co0.1Mn0.1O2 is constructed, where the high capacity retention of 73.1% at 0.5C over 250 cycles is well confirmed. This study not only opens a new avenue to prepare more carbon decorated functional materials but also explores the potential applications of metal (oxide)-based materials for high-performance rechargeable batteries.

This work is supported by the National Natural Science Foundation of China (21978281, 21975250) and National Key R&D Program of China (SQ2017YFE9128100). The authors also thank the Independent Research Project of the State Key Laboratory of Rare Earth Resources Utilization (110005R086), Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. The research was also supported by King Abdullah University of Science and Technology (KAUST).

In this study, highly dispersive spherical Li-rich solid solution (Li1.2Mn0.54Ni0.13Co0.13O2) particles are successfully synthesized by a co-precipitation method. Then these particles are treated with aluminum nitrates ethanol solution at 80 degrees C. The treatment can extract lithium (Li2O) from the Li2MnO3 component in the composite of Li1.2Mn0.54Ni0.13Co0.13O2. Simultaneously, a thin layer of Al2O3 can be precipitated on the surface of the electrode particles via direct thermal decomposition of aluminum nitrates. After treatment, the first-cycle coulombic efficiency of the electrode increases from 72.1% to 93.6%, meanwhile it shows a superior cycling stability at 100 mAg(-1) with a discharge capacity of around 220 mAh g(-1) and retention of 92.5% after 100 cycles, which is much higher than that of the pristine electrode (83.2%). Even at a high current density of 2 A g(-1) (10 C), the discharge capacity could still achieve and well maintain as high as 140 mAh g(-1). (C) 2013 Elsevier Ltd. All rights reserved.

In this work, we have developed a new method to grow NiO nanomaterials on the surface of graphene nanosheets (GNSs). The morphologies of NiO nanomaterials grown on GNSs could be tailored by trace amounts of water introduced into the mixed solvents of CO2-expanded ethanol (CE). Small and uniform Ni-salt nanoparticles (Ni-salt-NPs) were grown on the surface of graphene oxide (GO) through the decomposition of nickel nitrate directly in CE. However, when trace amounts of water were introduced into the mixed solvents, Ni-salt nanoflakes arrays (Ni-salt-NFAs) were grown on the surface of GO with almost perpendicular direction. After thermal treatment in N2 atmosphere, these Ni-salt @GO composites were converted to NiO@GNSs composites. The forming mechanisms of the NiO-NPs@GNSs and NiO-NFAs@GNSs were discussed by series comparative experiments. The presence of the trace amounts of water affected the chemical composition and structure of the precursors formed in CE and the growth behaviors on the surface of GNSs. When used as anode materials for lithium-ion batteries, the NiO-NPs@GNSs composite exhibited better cycle and rate performance compared with the NiO-NFAs@GNSs.

Li(Mn 1/3 Ni 1/3 Co 1/3 )O 2 cathode materials were fabricated by a hydroxide precursor method. Al 2 O 3 was coated on the surface of the Li(Mn 1/3 Ni 1/3 Co 1/3 )O 2 through a simple and effective one-step electrostatic self-assembly method. In the coating process, a NHCO 3 -H 2 CO 3 buffer was formed spontaneously when CO 2 was introduced into the NaAlO 2 solution. Compared with bare Li(Mn 1/3 M 1/3 Co 1/3 )O 2 , the surface-modified samples exhibited better cycling performance, rate capability and rate capability retention. The Al 2 O 3 -coated Li(Mn 1/3 Ni 1/3 Co 1/3 )O 2 electrodes delivered a discharge capacity of about 115 mAh·g −1 at 2 A·g −1 , but only 84 mAh·g −1 for the bare one. The capacity retention of the Al 2 O 3 -coated Li(Mn 1/3 Ni 1/3 Co 1/3 )O 2 was 90.7% after 50 cycles, about 30% higher than that of the pristine one.

In this work, we report a facile method for the synthesis of a Co3O4–functionalized carbon nanotube (Co3O4–f-CNT) composite via the growth of Co3O4 nanoparticles on the surface of functionalized carbon nanotubes (f-CNTs) by thermal decomposition of cobalt nitrate hexahydrate in ethanol. The composite consists of 13% carbon nanotubes and 87% Co3O4 nanoparticles by weight, and all the Co3O4 particles grew compactly along the carbon nanotube axis with a highly uniform dispersion. When used as an anode material for rechargeable lithium ion batteries, the composite manifested high capacities and excellent cycling performance at high and low current rates. The discharge capacity was 719 mA h g−1 at the 2nd cycle and 776 mA h g−1 at the 100th cycle. Even at a current density of 1 A g−1, the specific capacity still remained at about 600 mA h g−1. This superior electrochemical performance was attributed to the unique nanostructure of the composite. Because almost all of the Co3O4 nanoparticles were immobilized on the surface of f-CNTs, physical aggregation of nanoparticles was avoided during the charge–discharge processes. Furthermore, the good mechanical flexibility of f-CNTs can readily alleviate the massive volume expansion/shrinkage associated with a conversion reaction electrode. Finally, f-CNTs are highly conductive matrices for electrons due to their high conductivity, which can shorten the diffusion path for electrons.

Development of flexible and freestanding electrode is fascinating for lithium-sulfur (Li-S) batteries to enable higher gravimetric energy density and wider potential applications. However, the lithium polysulfides shuttle effect remains challenging and leads to a severe capacity fading. Here, we study the sulfur cathode prepared via phase inversion method with polyethersulfone (PES) polymeric binder and the coupling strategy of the electrode with polysulfide-modified electrolyte to enhance the cells performance. The flexible/freestanding electrode was successfully prepared by the efficient and straight forward method, even it is possible for massive production of electrodes with various size. The resultant polymeric networks in the electrode can effectively trap the soluble polysulfides owing to the higher hydrophilicity and stronger affinity of PES than that with the routine polyvinylidene fluoride (PVDF) binder. Furthermore, we show a two-fold enhancement of the cell performance by coupling the electrode with polysulfide-modified electrolyte, giving an improved capacity of 1141 mAh g-1, lower polarization of 192 mV and more stable capacity retention with 100% Coulombic efficiency over 100 cycles at 0.25C. The advantages of favored strategy are further demonstrated in lithium-ion sulfur full battery with lithiated graphite anode, which demonstrates much improved performance than those previously reported. This work successfully introduces an efficient strategy for flexible/freestanding electrodes and enlightens the importance of coupling strategy to enhance the performances of Li-S batteries. Figure 1. (a) Digital photographs of the as-prepared composite via phase inversion method. (b) Cycle performance of half-cells using 2-layer PES-CNT-S and PVDF-CNT-S cathodes with polysulfide(PS)-free electrolyte and polysulfide(PS)-modified electrolyte at 0.25C. REFERENCES W. Wahyudi, Z. Cao, P. Kumar, M. Li, Y. Wu, M. N. Hedhili, T. D. Anthopoulos, L. Cavallo, L. J. Li, J. Ming, Adv. Funct. Mater., 2018, 28 (34), 1802244. J. Ming, Z. Cao, W. Wahyudi, M. Li, P. Kumar, Y. Wu, J.-Y. Hwang, M. N. Hedhili, L. Cavallo, Y.-K. Sun, L. J. Li, ACS Energy Lett., 2018, 3 (2), 335-340. W. Wang, Z. Cao, G. A. Elia, Y. Wu, W. Wahyudi, E. Abou-Hamad, A. H. Emwas, L. Cavallo, L. J. Li, J. Ming, ACS Energy Lett., 2018, 3 (12), 2899-2907. Figure 1

A new concept of steaming multiwalled carbon nanotubes (MWCNTs) via acid vapour was presented for controllable nanoengineering of the MWCNTs. This method is more simple, effective, precisely-controllable and environmentally-friendly compared to traditional ones. Moreover, novel porous carbon nanotubes, named carbon nanoflutes, were fabricated based on this strategy.

The salt effect of NaxA (A = SO42−, Cl−, NO3−, etc.) on the hydrothermal carbonization of biomass is reported. It is a new catalyst and recyclable template to more simply and effectively prepare carbon-based materials, such as porous carbon-coated anode materials (e.g., Fe3O4@porous-C) in lithium-ion battery applications with enhanced performance.

New dense hollow porous (DHP) metal oxide nanoparticles that are smaller than 100 nm and composed of Co3O4, FeOx, NiO and MnOx were prepared by densely assembling metal oxide nanocrystals based on the hard-template method using a carbon colloid as a sacrificial core. These nanoparticles are quite different from the traditional particles as their hollow interior originates from the stacking of nanocrystals rather than a spherical shell. The DHP nanoparticles preserve the intriguing properties of nanocrystals and possess desirable surface area and pore volume that enhance the active surface, which ultimately benefits applications such as lithium-ion batteries. The DHP Co3O4 nanoparticles demonstrated an enhanced capacity of 1168 mA h g(-1) at 100 mA g(-1)vs. 590 mA h g(-1) of powders and stable cycling performance greater than 250 cycles when used as an anode material. Most importantly, the electrochemical performance of DHP Co3O4 nanoparticles in a lithium-O2 battery was also investigated for the first time. A low charge potential of ∼4.0 V, a high discharge voltage near 2.74 V and a long cycle ability greater than 100 cycles at a delivered capacity of 2000 mA h g(-1) (current density, 200 mA g(-1)) were observed. The performances were considerably improved compared to recent results of mesoporous Co3O4, Co3O4 nanoparticles and a composite of Co3O4/RGO and Co3O4/Pd. Therefore, it would be promising to investigate such properties of DHP nanoparticles or other hollow metal (oxide) particles for the popular lithium-air battery.

In this study, an effective method of slow hydrolization of metal alkoxide (e.g., Ti(C4H9O)4) in an ethanol–water system was systematically investigated and used to finely control the deposition of titania on carbon colloids. A model of adsorption–hydrolization of precursors during the coating process was rationally built for the first time to interpret the usability of the method and facilitate its further extension. Using this strategy, titania in the form of supported nanocrystals or layers on carbon colloids (TiO2/C, C@TiO2) was successfully tailored. Meanwhile, finely dispersed hollow TiO2 nanoparticles with shells consisting of different crystalline structures were also prepared by varying the calcination conditions after removing the carbon cores. More importantly, the effects of the crystalline and nano/macrostructures of the as-prepared TiO2 samples in photocatalysis and lithium-ion battery applications were analyzed in detail. The preliminary results show that anatase–rutile TiO2 hollow particles demonstrate a higher catalytic activity in the photo-degradation of rhodamine B than anatase TiO2 hollow particles, powders, and P25. However, in the case of Li-ion battery applications, the anatase TiO2 hollow particles exhibited better performance as anode materials with high capacities of around 190 mA h g−1, 140 mA h g−1, and 120 mA h g−1 at current densities of 60 mA g−1, 120 mA g−1, and 300 mA g−1, respectively, accompanied by stable cyclability.

SnS2/graphene nanosheets (SnS2/GNS) composites were synthesized by a one-step hydrothermal method. The composites exhibit remarkably improved Li-storage ability with a good cycling life and high capability superior to that of the pure SnS2 counterpart due to a synergic effect between the graphene and SnS2 nanosheets.

In this contribution, we present an efficient, versatile and green strategy for finely controlling the metal (oxide) coating on core particles through in situ reaction of precursors in CO2 expanded ethanol without using any precipitants. It not only avoids the formation of free metal (oxide) and/or naked cores, but also permits individual dispersion of all the resultant particles without aggregation. With this method, the composition, thickness, uniformity, and structure of the metal (oxide) shell could be precisely controlled. A wide variety of unreported high-quality core-shell particles with a shell consisting of highly dispersed metal (oxide) nanocrystals or nanoalloys, such as C@Ni, CoO/C, C@Ni&Co and C@Ni&Pd particles have been fabricated, and the properties of the resultant particles were precisely tailored, such as the promising catalytic performance obtained over Ni/C and C@Ni particles in the hydrogenation of nitrobenzene. The present coating strategy is more simple and precisely controllable compared to the conventional deposition method and it is suitable for most precursors and even for multi-component materials, enabling the fabrication of nanostructured materials more easily and precisely.