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Metal fluoride (MF) conversion cathodes theoretically show higher gravimetric and volumetric capacities than Ni- or Co-based intercalation oxide cathodes, which makes metal fluoride-lithium batteries promising candidates for next-generation high-energy-density batteries. However, their high-energy characteristics are clouded by low-capacity utilization, large voltage hysteresis, and poor cycling stability of transition MF cathodes. A variety of reasons is responsible for this: poor reaction kinetics, low conductivities, unstable MF/electrolyte interfaces and dissolution of active species upon cycling. Herein, we combine the synthesis of the metal-organic-framework (MOF) with the low-temperature fluorination to prepare MOF-shaped CoF2@C nanocomposites that exhibit confinement of the CoF2 nanoparticles and efficient mixed-conducting wiring in the produced architecture. The ultrasmall CoF2 nanoparticles (5-20 nm on average) are uniformly covered by graphitic carbon walls and embedded in the porous carbon framework. Within the CoF2@C nanocomposite, the cross-linked carbon wall and interconnected nanopores serve as electron- and ion-conducting pathways, respectively, enabling a highly reversible conversion reaction of CoF2. As a result, the produced CoF2@C composite cathodes successfully restrain the above-mentioned challenges and demonstrate high-capacity utilization of ∼500 mAh g-1 at 0.2C, good rate capability (up to 2C), and long-term cycle stability over 400 cycles. Overall, the presented study not only reports on a simple composite design to achieve high-energy characteristics in CoF2-Li batteries but also may provide a general solution for many other metal fluoride-lithium batteries.

The interaction of oxygen vacancies and ferroelectric domain walls is of great scientific interest because it leads to different domain-structure behaviors. Here, we use high-resolution scanning transmission electron microscopy to study the ferroelectric domain structure and oxygen-vacancy ordering in a compressively strained Bi0.9Ca0.1FeO3−δ thin film. It was found that atomic plates, in which agglomerated oxygen vacancies are ordered, appear without any periodicity between the plates in out-of-plane and in-plane orientation. The oxygen non-stoichiometry with δ ≈ 1 in FeO2−δ planes is identical in both orientations and shows no preference. Within the plates, the oxygen vacancies form 1D channels in a pseudocubic [010] direction with a high number of vacancies that alternate with oxygen columns with few vacancies. These plates of oxygen vacancies always coincide with charged domain walls in a tail-to-tail configuration. Defects such as ordered oxygen vacancies are thereby known to lead to a pinning effect of the ferroelectric domain walls (causing application-critical aspects, such as fatigue mechanisms and countering of retention failure) and to have a critical influence on the domain-wall conductivity. Thus, intentional oxygen vacancy defect engineering could be useful for the design of multiferroic devices with advanced functionality.

The development of suitable anode materials is far from satisfactory and is a major scientific challenge for a competitive sodium-ion battery technology. Metal sulfides have demonstrated encouraging results, but still suffer from sluggish kinetics and severe capacity decay associated with the phase change. Herein we show that rational electrode design, that is, building efficient electron/ion mixed-conducting networks, can overcome the problems resulting from conversion reactions. A general strategy for the preparation of hierarchical carbon-coated metal sulfide (MS⊂C) spheres through thermal sulfurization of metal glycerate has been developed. We demonstrate the concept by synthesizing highly uniform hierarchical carbon coated vanadium sulfide (V2 S3 ⊂C) spheres, which exhibit a highly reversibly sodium storage capacity of 777 mAh g-1 at 100 mA g-1 , excellent rate capability (410 mAh g-1 at 4000 mA g-1 ), and impressive cycling ability.

Development of broadband absorption materials for solar energy harvesting is an important strategy to address global energy issues. Herein, it is demonstrated that an ultrablack silicon structure with abundant surface texturing can absorb about 98.7% solar light within the wavelength range of 300 to 2500 nm, i.e., a very large range and amount. Under 1 sun irradiation, the ultrablack silicon sample's surface temperature can increase from 21.2 to 51.2 °C in 15 min. During the photothermal water evaporation process, the ultrablack silicon sample's surface temperature can still reach a highest temperature of 43.2 °C. The average photothermal conversion efficiency (PTCE) can be as high as 72.96%. The excellent photothermal performance to the excellent light-trapping ability of the pyramidal surface nanostructures during solar illumination, which leads to extremely efficient absorption of light, is attributed. In addition, the large water contact area also enables fast vapor transport. The stability of the photothermal converter is also examined, presenting excellent structure and performance stabilities over 10 cycles. This indicates that the ultrablack Si absorber can be a promising photothermal conversion material for seawater desalination, water purification, photothermal therapy, and more.

The lithium metal anode is regarded as ideal for high-energy rechargeable batteries. Unfortunately, the uncontrolled lithium dendritic growth and the infinite volume expansion upon cycling result in low Coulombic efficiency, fast capacity decay and safety issues. Herein, a mismatch electrical-conductivity framework has been designed as a stable host to regulate lithium deposition behaviour. Due to the ionic conductivity of the lithiophilic layer and the electron conductivity of hollow carbon nanofibres (HCF), lithium metal is preferentially deposited into and encapsulated by the HCF, resulting in greatly improved electrochemical performance. The heat generation upon lithium storage and release in the Al2O3 coated HCF (A–HCF) during cycling is lower compared to the plating/stripping on copper foil. The A-HCF electrodes show high Coulombic efficiency (97%) upon 500 cycles employing a conventional, alkyl carbonate-based electrolyte, demonstrating improved reversibility of Li plating/stripping. Complete cells assembled employing LiNi0.8Co0.1Mn0.1O2 (NMC811)-based positive electrodes exhibit high capacity retention (94%) after 120 cycles at 1 C, delivering a high energy density (363 Wh per kg of NMC811). Even upon cycling at 5 C rate, the cells, employing less than three times excess lithium, deliver a very high capacity (133 mAh per g of NMC811) for 50 cycles.

A key step in engineering resistive switching is the ability to control the device switching behavior. Here, we investigate the possibility to tune the resistive switching of tantalum oxide (TaOx)-based memristors from a non-switchable state to a switchable state by applying postfabrication annealing of the devices. The switching of the devices was found to be related to: (1) the oxidation state changes in the TaOx thin film after annealing and (2) the local variations in oxygen stoichiometry in the vicinity of the interface between the TiN electrode and the TaOx active resistive layer. We further discuss the possible mechanism behind the resistive switching after annealing. This experimental approach provides a simple but powerful pathway to trigger the resistive switching in devices that do not show any resistive switching initially.

Sodium-ion batteries (SIB) are regarded as the most promising competitors to lithium-ion batteries in spite of expected electrochemical disadvantages. Here a “cross-linking” strategy is proposed to mitigate the typical SIB problems. We present a SIB full battery that exhibits a working potential of 3.3 V and an energy density of 180 Wh kg–1 with good cycle life. The anode is composed of cross-linking hollow carbon sheet encapsulated CuP2 nanoparticles (CHCS-CuP2) and a cathode of carbon coated Na3V2(PO4)2F3 (C-NVPF). For the preparation of the CHCS-CuP2 nanocomposites, we develop an in situ phosphorization approach, which is superior to mechanical mixing. Such CHCS-CuP2 nanocomposites deliver a high reversible capacity of 451 mAh g–1 at 80 mA g–1, showing an excellent capacity retention ratio of 91% in 200 cycles together with good rate capability and stable cycling performance. Post mortem analysis reveals that the cross-linking hollow carbon sheet structure as well as the initially formed SEI layers are...

In conventional light-emitting diodes the epitaxial strain and related piezoelectric polarization arising along the polar [0001] growth direction of the InGaN/GaN quantum wells (QWs) induce internal fields which adversely affect the radiative recombination of electron-hole pairs therein. Growing the quantum wells along a nonpolar orientation can, in principle, avoid this problem but seems to face with another problem associated with indium clustering. In this study, we present experimental evidence that supports the inhomogeneous distribution of indium in non-polar a-plane InGaN QWs by using dark-field inline electron holography as well as atom probe tomography measurements and discuss the possible origin by density functional theory calculation. A model non-polar a-plane QW structure with 10 nm-thick In0.1Ga0.9N double QWs was investigated and compared with the polar c-plane QWs with the same QW structure. Unlike the random distribution in the polar QWs, the indium atoms in the non-polar QW exhibit inhomogeneous distribution and show a tendency of periodic clustering. We suggest the dipole interaction energy and the strain energy associated with indium substitution could have a substantial influence on the local composition of strained InGaN QWs and, particularly, triggers In clustering in the non-polar a-plane QW structure. Accompanying phase field modeling rationalizes that In clustering can also modify the in-plane polarization through piezoelectric effects, preventing the electrostatic potential from diverging along the in-plane polar direction.

Nanoparticle-based electrode materials have sparked enormous excitement in the sodium-ion battery community because of potentially fast transport kinetics. However, they may suffer from many challenging static and dynamic problems, such as agglomeration of nanoparticles, high contact resistance, volume change, and instability of solid electrolyte interphase. Herein, we develop inter-connected 2D carbon nanosheets in which ultrasmall 0D Sb nanodots are embedded homogenously through a previously unexplored “top-down” strategy. Starting from the laminar structure K3Sb3P2O14, H3Sb3P2O14 nanosheets are exfoliated by ion exchange and then serve as templates for the synthesis of carbon sheets and Sb nanodots. Such combination of multi-dimensional and multi-scale nanostructures in the electrode materials lead to excellent electron/ion transport kinetics and pronounced integrity of the electrode structure on cycling, providing a promising pathway for developing advanced electrode materials in terms of reversibility, rate capability and cycle life.

Sodium ion batteries are realistic and promising alternatives to lithium due to the abundance of Na and the similar intercalation chemistry of Na when compared to the lithium counterpart. Developing high-power and high-energy sodium batteries is still a significant challenge. Na3V2(PO4)2F3 (NVPF) has been shown to combine excellent charge–discharge kinetics with a competitively high voltage. However, the major issue is, as for the vast majority of electrode materials, the lack of distinct knowledge of fundamental transport parameters, on which an optimized strategy for developing a high-power and high-energy sodium cathode can be based. This work aims at filling this gap. We experimentally investigate the intrinsic ionic and electronic conductivities, as well as the chemical diffusion coefficient of sodium of Na3V2(PO4)2F3 by impedance and dc polarization. On the basis of these results, we develop an optimized design. As the electronic conductivity is found to be much smaller than the ionic one, electroni...

Calcium bodies are specialized organs of terrestrial isopod crustaceans (woodlice) in the family Trichoniscidae. These organs are epithelial sacs that contain an extracellular matrix, mineralized with calcium salts. Recent studies have demonstrated that the mineral content of these organs changes periodically in relation to molt, the process in which crustaceans shed their old exoskeleton and form a new one. During the preparation for molt, minerals are deposited in the calcium bodies and are resorbed during and shortly after molt [1, 2]. As the crustacean exoskeleton contains large amounts of calcium carbonate and calcium phosphate [3], calcium bodies may function as reservoirs that allow woodlice to temporarily deposit minerals from their exoskeleton before molt and mobilize it after molt, when great amounts of calcium are needed for the mineralization of the new exoskeleton.

Pseudo-capacitive mechanisms can provide higher energy densities than electrical double-layer capacitors while being faster than bulk storage mechanisms. Usually, they suffer from low intrinsic electronic and ion conductivities of the active materials. Here, taking advantage of the combination of TiS2 decoration, sulfur doping, and a nanometer-sized structure, as-spun TiO2/C nanofiber composites are developed that enable rapid transport of sodium ions and electrons, and exhibit enhanced pseudo-capacitively dominated capacities. At a scan rate of 0.5 mV s−1, a high pseudo-capacitive contribution (76% of the total storage) is obtained for the S-doped TiS2/TiO2/C electrode (termed as TiS2/S-TiO2/C). Such enhanced pseudo-capacitive activity allows rapid chemical kinetics and significantly improves the high-rate sodium storage performance of TiO2. The TiS2/S-TiO2/C composite electrode delivers a high capacity of 114 mAh g−1 at a current density of 5000 mA g−1. The capacity maintains at high level (161 mAh g−1) even after 1500 cycles and is still characterized by 58 mAh g−1 at the extreme condition of 10,000 mA g−1 after 10,000 cycles. Highlights: 1 One-dimensional elongated TiS2-modified and S-doped TiO2/C nanofibers electrode was synthesized through electrospinning, which exhibited a high specific capacity, excellent cyclic stability, and rate capability in sodium-ion battery.2 An enhanced pseudo-capacitive capacity because of S doping and TiS2 decoration contributes to noticeable sodium storage performance. High capacity of 161 mAh g−1 (at 3000 mA g−1) after 1500 cycles and 58 mAh g−1 (at 10,000 mA g−1) after 10,000 cycles is delivered outstandingly.

The availability of aberration correctors for the probe-forming lenses makes simultaneous modification and characterization of materials down to atomic scale inside a transmission electron microscopy (TEM) realizable. In this work, we report on the electron-beam-induced reconstructions of three types of antiphase boundaries (APBs) in a probe-aberration-corrected TEM. With the utilization of high-angle annular dark-field scanning transmission electron microscopy (STEM), annular bright-field STEM, and electron energy-loss spectroscopy, the motion of both heavy element Mn and light element O atomic columns under moderate electron beam irradiation are revealed at atomic resolution. Besides, Mn segregated in the APBs was observed to have reduced valence states which can be directly correlated with oxygen loss. Charge states of the APBs are finally discussed on the basis of these experimental results. This study provides support for the design of radiation-engineering solid-oxide fuel cell materials.

A lamellar hybrid assembled from metal disulfide (MoS2 , WS2 ) nanowall arrays anchored on nitrogen-doped carbon layers is developed via an in situ hybridization strategy through a synergistic pyrolysis reaction of thiourea and oxometalates. Such a hybrid provides adequate electrical and chemical coupling between the active materials and the carbon substrate, thus realizing a high-efficiency electron-conduction/ion-transportation system and exhibiting excellent sodium-storage properties.

Peapod-like carbon-encapsulated cobalt chalcogenide nanowires are designed and synthesized by a facile method. The nanowires show excellent electrochemical performance for sodium storage, suggesting that chalcogenides, especially selenides, have potential as advanced anodes for sodium-ion batteries.

Protein-based bottom-up synthesis of functional nanomaterials and devices is one of the most promising areas in bio-nanotechnology. Here, we demonstrate that organic assemblies can serve as biologically controllable scaffolds for the deposition of inorganic nanoparticles. In this work, wild-type M13 phages were employed for controlled mineralization of zinc oxide particles. Our aim was to construct layered structures of organic and inorganic materials which contain alternating layers on a smooth substrate. The structure, elemental composition, and also the integrity of the organic and the biologically-templated inorganic layers were studied. A uniform nano-hybrid structure without significant thickness fluctuations was fabricated by using a high concentration of M13 phages and a carbon-coated substrate. The current study gives insight into the combination of organic–inorganic materials to form a multilayered structure, which in turn sets the stage for the fabrication of electronic devices, e. g. actuators or capacitors.

Novel electrode materials consisting of hollow cobalt sulfide nanoparticles embedded in graphitic carbon nanocages (HCSP⊂GCC) are facilely synthesized by a top-down route applying room-temperature synthesized Co-based zeolitic imidazolate framework (ZIF-67) as the template. Owing to the good mechanical flexibility and pronounced structure stability of carbon nanocages-encapsulated Co9 S8 , the as-obtained HCSP⊂GCC exhibit superior Li-ion storage. Working in the voltage of 1.0-3.0 V, they display a very high energy density (707 Wh kg(-1) ), superior rate capability (reversible capabilities of 536, 489, 438, 393, 345, and 278 mA h g(-1) at 0.2, 0.5, 1, 2, 5, and 10C, respectively), and stable cycling performance (≈26% capacity loss after long 150 cycles at 1C with a capacity retention of 365 mA h g(-1) ). When the work voltage is extended into 0.01-3.0 V, a higher stable capacity of 1600 mA h g(-1) at a current density of 100 mA g(-1) is still achieved.

Metal fluoride-lithium batteries with potentially high energy densities, even higher than lithium-sulfur batteries, are viewed as very promising candidates for next-generation lightweight and low-cost rechargeable batteries. However, so far, metal fluoride cathodes have suffered from poor electronic conductivity, sluggish reaction kinetics and side reactions causing high voltage hysteresis, poor rate capability, and rapid capacity degradation upon cycling. Herein, it is reported that an FeF3 @C composite having a 3D honeycomb architecture synthesized by a simple method may overcome these issues. The FeF3 nanoparticles (10-50 nm) are uniformly embedded in the 3D honeycomb carbon framework where the honeycomb walls and hexagonal-like channels provide sufficient pathways for the fast electron and Li-ion diffusion, respectively. As a result, the as-produced 3D honeycomb FeF3 @C composite cathodes even with high areal FeF3 loadings of 2.2 and 5.3 mg cm-2 offer unprecedented rate capability up to 100 C and remarkable cycle stability within 1000 cycles, displaying capacity retentions of 95%-100% within 200 cycles at various C rates, and ≈85% at 2C within 1000 cycles. The reported results demonstrate that the 3D honeycomb architecture is a powerful composite design for conversion-type metal fluorides to achieve excellent electrochemical performance in metal fluoride-lithium batteries.

Constructing 3D carbon structures built from carbon nanotubes (CNTs) and graphene has been considered as an effective approach to achieve superior properties in energy conversion and storage because of the synergistic combination of the advantages of each building block. Herein, a facile solid-state growth strategy is reported for the first time to fabricate highly nitrogen doped CNT–graphene 3D nanostructures without the necessity to use chemical vapor deposition. As cathode hosts for lithium–sulfur batteries, the hybrid architectures exhibit reversible capacities of 1314 and 922 mAh g−1 at 0.2 and 1 C, respectively, and a capacity retention of 97% after 200 cycles at a high rate of 2 C, revealing their great potential for energy storage application.

Silicon is an attractive anode material in energy storage devices, as it has a ten times higher theoretical capacity than its state-of-art carbonaceous counterpart. However, the common process to synthesize silicon nanostructured electrodes is complex, costly, and energy-intensive. Three-dimensional (3D) porous silicon-based anode materials have been fabricated from natural reed leaves by calcination and magnesiothermic reduction. This sustainable and highly abundant silica source allows for facile production of 3D porous silicon with very good electrochemical performance. The obtained silicon anode retains the 3D hierarchical architecture of the reed leaf. Impurity leaching and gas release during the fabrication process leads to an interconnected porosity and the reductive treatment to an inside carbon coating. Such anodes show a remarkable Li-ion storage performance: even after 4000 cycles and at a rate of 10 C, a specific capacity of 420 mA h g(-1) is achieved.

Sodium ion batteries attract increasing attention for large-scale energy storage as a promising alternative to the lithium counterparts in view of low cost and abundant sodium source. However, the large ion radius of Na brings about a series of challenging thermodynamic and kinetic difficulties to the electrodes for sodium-storage, including low reversible capacity and low ion transport, as well as large volume change. To mitigate or even overcome the kinetic problems, we develop a self-assembly route to a novel architecture consisting of nanosized porous NASICON-type NaTi2(PO4)3 particles embedded in microsized 3D graphene network. Such architecture synergistically combines the advantages of a 3D graphene network and of 0D porous nanoparticles. It greatly increases the electron/ion transport kinetics and assures the electrode structure integrity, leading to attractive electrochemical performance as reflected by a high rate-capability (112 mAh g(-1) at 1C, 105 mAh g(-1) at 5C, 96 mAh g(-1) at 10C, 67 mAh g(-1) at 50C), a long cycle-life (capacity retention of 80% after 1000 cycles at 10C), and a high initial Coulombic efficiency (79%). This nanostructure design provides a promising pathway for developing high performance NASICON-type materials for sodium storage.

Two-dimensional (2D) nanostructures of earth-abundant jarosite and their analogues were fabricated for the first time by a facile template-assisted redox co-precipitation method at room temperature. When evaluated as cathode materials for lithium ion batteries (LIBs), the as-prepared 2D materials deliver high capacities and good rate capability and cycling performance. As for jarosite KFe3(SO4)2(OH)6 nanosheets (KNSs), the reversible capacities of 117, 114, and 75 mAh g–1 were achieved at 0.2, 1, and 10 C, respectively, 4–13 times higher than those of bulk sample. Capacity retentions of above 90% are both obtained after 50 cycles at 2 and 10 C. Such findings show that 2D jarosite nanostructures would be promising cathode materials for next-generation LIBs.

Much attention has been paid to increase the energy density of Li-ion batteries, in order to fulfill the requirements of electric vehicles and grid-scale energy storage. While for anodes various options are available, this is not at all the case for cathodes. In this context, the inexpensive and environmentally benign iron sulfides have been investigated as cathode materials due to the remarkably high capacity based on the conversion reaction. Here, the preparation of FeS nanodots accommodated in porous graphitic carbon nanowires is reported via a combination of electrospinning technique and biomolecular-assisted hydrothermal method. These materials exhibit excellent electrochemical performances also as cathode materials, with energy densities even higher than the current LiCoO2 intercalation cathode. Moreover, key problems of conversion reaction, such as the low degree of reversibility, large polarization are far-reachingly mitigated.

Three-dimensional (3D) hierarchical nanostructures have been demonstrated as one of the most ideal electrode materials in energy storage systems owing to the synergistic combination of the advantages of both nanostructures and microstructures. In this work, 3D V6O13 nanotextiles built from interconnected 1D nanogrooves with diameter of 20–50 nm were fabricated via a facile solution-redox-based self-assembly route at room temperature, and the mesh size in the textile structure can be controllably tuned by adjusting the precursor concentration. It is suggested that the formation of 3D fabric structure built from nanogrooves is attributed to the rolling and self-assembly processes of produced V6O13 nanosheet intermediates. When evaluated as cathodes for lithium ion batteries (LIBs), the products delivered reversible capacities of 326 mAh g–1 at 20 mA g–1 and 134 mAh g–1 at 500 mA g–1, and a capacity retention of above 80% after 100 cycles at 500 mA g–1. Importantly, the resulting textiles exhibit a specific ...

Much attention is being paid to sodium ion batteries (SIBs) in view of the abundance of sodium sources and the cost issues. Layered transition metal dichalcogenides (such as MoS2 and WS2) have great potential to be used as anode materials for sodium storage owing to their high capacity. However, they still suffer from low rate capability and poor cycling stability. Compared to MoS2, WS2 has been scarcely studied in view of sodium storage. Here, we report, for the first time, a 3D porous interconnected WS2/C nanocomposite prepared by an electrostatic spray deposition (ESD) technique, which is composed of nano-0D WS2, nano-1D CNTs and nano-2D reduced graphene oxide. Such a nanocomposite shows excellent rate performance and long cycling stability, demonstrating great potential for its use as a sodium anode. Moreover, this strategy can be applied to other electrode materials for both lithium and sodium batteries.

Uniform yolk–shell Sn4P3@C nanospheres were facilely synthesized via a top-down phosphorized route with yolk–shell Sn@C nanospheres as the precursor. As anode materials for Na-ion batteries, they exhibit very high reversible capacity (790 mA h g−1), superior rate capability (reversible capabilities of 720, 651, 581, 505, and 421 mA h g−1 at 0.2C, 0.4C, 0.8C, 1.5C, and 3C, respectively) and stable cycling performance (a high capacity of 360 mA h g−1 at 1.5C after long 400 cycles).

The lithium-sulfur battery is considered as one of the most promising energy storage systems and has received enormous attentions due to its high energy density and low cost. However, polysulfide dissolution and the resulting shuttle effects hinder its practical application unless very costly solutions are considered. Herein, a sulfur-rich polymer termed sulfur-limonene polysulfide is proposed as powerful electroactive material that uniquely combines decisive advantages and leads out of this dilemma. It is amenable to a large-scale synthesis by the abundant, inexpensive, and environmentally benign raw materials sulfur and limonene (from orange and lemon peels). Moreover, owing to self-protection and confinement of lithium sulfide and sulfur, detrimental dissolution and shuttle effects are successfully avoided. The sulfur-limonene-based electrodes (without elaborate synthesis or surface modification) exhibit excellent electrochemical performances characterized by high discharge capacities (≈1000 mA h g-1 at C/2) and remarkable cycle stability (average fading rate as low as 0.008% per cycle during 300 cycles).

A 3D yolk-shell-like electrode material composed of a porous interconnected graphene network and embedded Ni2 P nanoparticles is designed and fabricated by an assembly and self-template strategy. This novel nanoarchitecture integrates the advantages of nanostructure and microstructure, and provides highly efficient and stable electrochemical circuits involving the active nanoparticles, leading to excellent electrochemical performance in terms of reversibility, rate capability, and cycle stability.

Terrestrial isopods from the group Trichoniscidae accumulate calcium in specialized organs, known as the calcium bodies. These consist of two pairs of epithelial sacs located alongside the digestive system. These organs contain various forms of calcium and constantly present bacteria. To elucidate their origin and role, we analyzed the bacteria of the calcium bodies in the cave-dwelling isopod Titanethes albus and the epigean species Hyloniscus riparius, by microscopy, histochemistry, energy dispersive X-ray spectrometry, 16S rRNA analysis and in situ hybridization. The calcium bodies of both species comprise numerous and diverse bacterial communities consisting of known soil bacteria. Despite their diversity, these bacteria share the polyphosphate-accumulation ability. We present the model of phosphorous dynamics in the calcium bodies during the molting cycle and potentially beneficial utilization of the symbiotic phosphate by the host in cyclic regeneration of the cuticle. Although not fully understood, this unique symbiosis represents the first evidence of polyphosphate-accumulating bacterial symbionts in the tissue of a terrestrial animal.

Highly porous Ni3Sn2 microcages composed of tiny nanoparticles were synthesized by a facile template-free solvothermal method (based on Ostwald ripening and etching mechanism) for use as anode materials for high-capacity and high-rate-capability Li-ion and Na-ion batteries. The Ni3Sn2 porous microcages exhibit highly stable and substantial discharge capacities of the amount to 700 mA h g(-1) after 400 cycles at 0.2C and 530 mA h g(-1) after 1000 cycles at 1C for Li-ion battery anode. For Na-ions storage performance, a reversible capacity of approximate 270 mA h g(-1) is stably maintained at 1C during the first 300 cycles.

Dr. K. Tang, Prof. J. MaierMax Planck Institute for Solid State Research Heisenbergstr. 1,70569, Stuttgart, Germany E-mail: k.tang@fkf.mpg.de; s. weiglein@fkf.mpg.de Prof. Y. YuDepartment of Materials Science and Engineering University of Science and Technology of China Anhui, Hefei, 230026, China X. Mu, Prof. P. A. van AkenMax Planck Institute for Intelligent Systems Heisenbergstr. 3, 70569, Stuttgart, Germany

Up to now, chemical synthesis routes only provide restricted opportunities for the formation of structured nano particles. In contrast, living microorganisms generate nano materials of well defined shapes by the precise control of biomineralization. Here we reveal new principles for the generation of functional nano materials through the process of biomineralization. We used the detoxification mechanism of the unicellular alga Scenedesmus obliquus to generate a techno logically interesting zinc-phosphate-based nano material. The algae were incubated in media with a sublethal zinc concentration (6.53 mg Zn dm-3) for 4 weeks. Using BF-and ADF-STEM imaging combined with analytical XEDS we could show that nano needles containing phosphorus and zinc were formed inside the living cells. Further more, the cells incubated with zinc show a strong fluorescence. Our findings indicate that the algae used polyphosphate bodies for detoxification of the zinc ions, leading to the generation of intracellular zinc-phosphate-based nano needles. Beside the technological application of this material, the fluorescent cells can be used for labeling of e.g. biological probes. This new experimental protocol for the production of an inorganic functional material can be applied also for other substances.

Sodium-ion batteries are emerging as promising candidates for grid energy storage because of the abundant sodium resources and low cost. However, the identification and development of suitable anode materials is far from being satisfactory. Here, it is demonstrated that the Ti2 Nb2 O9 nanosheets with tunnel structure can be used as suitable anode materials for sodium-ion batteries. Ti2 Nb2 O9 nanosheets are synthesized by liquid exfoliation combined with topotactic dehydration, delivering a high reversible capacity of 250 mAh g-1 at 50 mA g-1 at a suitable average voltage of ≈0.7 V. It is found that a low energy diffusion barrier, enlarged interlayer spacing, and exceptional nanoporosity together give rise to high rate performance characterized by pseudocapacitive behavior. The observed high reversible capacity, excellent rate capability, and good cyclability of Ti2 Nb2 O9 nanosheets make this material competitive when compared to other sodium insertion anode materials.

capacity fade. Among a variety of options, carbonaceous materials are prom-ising candidates. Graphite is widely used nowadays as anodes in commercial cells, nevertheless its capacity is re-stricted to 372 mAhg[1]1(maximum stage by forming LiC6). Therefore, extensive research is currently focusing on the elec-trochemical performance of carbon-based composites which promise advantages for lithium-storage applications owing to their intrinsic characteristics possessing a vast number of active sites and offering presuppositions for a fast electronic and ionic transporting network. On the other hand, low cost, high molar density and superior chemical resistance of the transition metal nitrides render them desirable candidates for the next-generation of lithium batteries and supercapacitors. Among them, TiN was reported to possess a good electronic conductivity but with minor capacity and hence usually used as current collector, whereas VN was reported to exhibit a larger capacity for thin film lithium battery and supercapacitor applications despite poor electronic conductivity.

A new nanocomposite of Ge/carbon nanotubes (n-Ge/CNTs) was reported by a facile precursor method through a pyrolysis technique. Among it, germanium nanoparticles are encapsulated with a thin layer of amorphous carbon, which benefits to keep a good electronic contact with carbon nanotubes. Germanium nanoparticles are mainly supported inside the carbon nanotubes, which can effectively buffer the volume changes of Germanium. The composite was an effectively mixed (Li + and e − ) conducting network, which is vital to a quick Li insertion. The composite was shown to exhibit a reversible capacity of about 750 mAh g −1 (74.4 mA g −1 ) and an improved rate performance, compared with that of CNTs processed as the same condition. Our results demonstrated the composite to be a good active Li-storage material for Li batteries.

Aiming at tailoring optical properties, the precipitation of LaF3 nano-crystals in LaF3–Na2O–Al2O3–SiO2 glass-ceramics is studied thoroughly on the nano-scale using advanced transmission electron microscopic techniques. Nano-sized phase-separation droplets enriched in lanthanum and silicon are formed already in the base glass. Within these less than 20 nm large droplets, LaF3 crystallizes upon heat treatment. The nano-crystallization mechanism revealed is self-limited since growth is restricted by the size of the droplets. An average crystallite size of around 12 nm is achieved with a narrow size distribution since the phase-separation droplets also contain silicon not incorporated into the growing crystal. Instead, excess silicon relocated to the periphery of the pre-existing phase-separation droplets forms a diffusion barrier around the LaF3 nano-crystals preventing further crystal growth and/or ripening.

Doped yttrium aluminum garnet, Y3Al5O12 (YAG), has drawn considerable attention for solid-state industrial, medical and scientific laser applications. The crystal optical activity is closely related to the type and amount of doping element. Studies on highly yttrium doped, creep resistant alumina ceramics with Ca and Si contamination have indicated that YAG precipitates in the ceramic had a propensity to allow simultaneous incorporation of Ca and Si impurities on the order of 1 % in their structure. Co-solubility potential for Ca and Si in YAG crystals was investigated through systematic doping and co-doping YAG polycrystals with Ca2+ and/or Si4+. It was shown via X-ray diffraction and electron probe microanalysis techniques, that the ceramic can accommodate more than order of magnitude larger amounts of Ca2+ and Si4+ when incorporated in equal amounts simultaneously than when the dopants are introduced alone. The co-solubility limit for Ca and Si was determined to be between 3 and 4 % of the cation amount in pure YAG. Enhanced co-solubility was discussed in terms of size and charge compensations in the lattice. Co-doping with a suitable element is introduced as a possible way to increase the solubility of useful cations in this ceramic that is the host material for lasers

Indium tin oxide (ITO) has attracted intense interest as the most important transparent conducting oxide (TCO) that sees wide use in many opto-electronic and photo-chemical devices. The goal of this study is to explore the possibility of depositing ITO thin films using a bioinspired aqueous deposition route as an alternative. On the surface of sulfonated-self assembled monolayers, Sn-doped indium hydroxide films are obtained via a hydrogen peroxide-assisted method. As a result, the as-deposited indium tin hydroxide films possess a single hexagonal phase of In(OH) 3 ·xH 2 O (0 ≤ x < 1) with Sn doping percentage of (1.7 ± 0.2) at % and a column-like hierachical microstructure. Structural, compositional and property studies, including electron microscopy, X-ray diffraction, photoelectron spectroscopy, optical transmittance, photoluminescence and four-probe conductivity measurements, are conducted. The possible mechanism based on oriented attachment is discussed for the film growth. Strong room temperature photoluminescence within the near UV range is observed in the case of Sn-doped, but not in the one of the pure In(OH) 3 ·xH 2 O films. Annealing of the indium tin hydroxide films above 200 °C gives nanocrystalline Sn:In 2 O 3 films with higher UV and visible transparency and electrical conductivity compared with those of pure In 2 O 3 films. The influence of annealing atmosphere is investigated.

(Figure Presented) Extreme chemistry: The carbon nitride imide C 2 N 2 (NH) is synthesized from the single-source precursor 1-cyanoguanidine under high-pressure and high-temperature conditions in a laser-heated diamond-anvil cell. Characterization of single crystals recovered at ambient conditions reveals that the new compound adopts a defect wurtzite structure (see picture). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.

A novel generalizable strategy is proposed by Y. Yu and co‐workers in article 1500200 for fabrication of a 3D porous interconnected metal sulfide/carbon nanocomposite by the electrostatic spray deposition technique. Such a technique is simple but versatile and can be easily applied to other compounds. The obtained SnS/C composite exhibits a high reversible capacity, high rate capability and long cycling stability for both lithium and sodium storage.

Transition metal sulfides have a great potential for energy storage due to the pronouncedly higher capacity (owing to conversion to metal or even alloy) than traditional insertion electrode materials. However, the poor cycling stability still limits the development and application in lithium and sodium ion batteries. Here, taking SnS as a model material, a novel general strategy is proposed to fabricate a 3D porous interconnected metal sulfide/carbon nanocomposite by the electrostatic spray deposition technique without adding any expensive carbonaceous materials such as graphene or carbon nanotube. In this way, small nanorods of SnS are generated with sizes of ≈10-20 nm embedded in amorphous carbon and self-assembled into a 3D porous interconnected nanocomposite. The SnS:C is directly deposited on the Ti foil as a current collector and neither conductive additives nor binder are needed for battery assembly. Such electrodes exhibit a high reversible capacity, high rate capability, and long cycling stability for both lithium and sodium storage.