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Mixed multiple oxidation states CoMoO4 nanowires (electrocatalysts) with tunable intrinsic oxygen vacancies were fabricated. CoMoO4 with proper oxygen vacancy can be employed to construct a Li-air battery with a high capacity and stable cyclability. This is possible because CoMoO4 contains surface oxygen vacancies, which result in the unit of CoMo bond, that is important for electrocatalysts used in Li-air batteries. Both the experimental and theoretical results demonstrate that the surface oxygen vacancies containing CoMoO4 nanowires have a higher electrocatalytic activity. This shows that the highly efficient electrocatalysts used for Li-air batteries were designed to modify the redox properties of the mixed metal oxide in the catalytic active sites. This successful material design led to an improved strategy for high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities based on the fast formation and extinction of ORR products.

Lithium oxygen (Li-O2) batteries have shown great potential as new energy-storage devices due to the high theoretical energy density. However, there are still substantial problems to be solved before practical application, including large overpotential, low energy efficiency, and poor cycle life. Herein, we have successfully synthesized a RuO2-Co3O4 nanohybrid with a rich oxygen vacancy and large specific surface area. The Li-O2 batteries based on the RuO2-Co3O4 nanohybrid shown obviously reduced overpotential and improved circulatory property, which can cycle stably for more than 100 cycles at a current density of 200 mA g-1. Experimental results and density function theory calculation prove that the introduction of RuO2 can increase oxygen vacancy concentration of Co3O4 and accelerate the charge transfer. Meanwhile, the hollow and porous structure leads to a large specific surface area about 104.5 m2 g-1, exposing more active sites. Due to the synergistic effect, the catalyst of the RuO2-Co3O4 nanohybrid can significantly reduce the adsorption energy of the LiO2 intermediate, thereby reducing the overpotential effectively.

Reasonably regulating electronic coupling to promote charge transfer and exciton separation has been regarded a promising approach in catalysis. The material engineering of van der Waals heterojunction (vdWsH) based on two-dimensional (2D) materials would be a potential way to optimize the as-prepared extrinsic physicochemical characteristics. However, it was still an almost uncultivated land waiting for exploration in catalysis. Herein, we introduced the inert h-boron nitride (h-BN) in non-metal reduced graphene oxide (GN) catalysts and constructed BN-GN vdWsH. The theoretical calculation demonstrated that the h-BN can effectively modify the electronic properties of graphene. With the introduction of h-BN, the BN-GN vdWsH can obviously enhance the catalytic activity of Li-CO2 battery. The existence of BN-GN vdWsH can reduce the overpotential more than 700 mV compared with reduced graphene oxide during the CO2 reduction reaction (CO2RR) and CO2 evolution reaction (CO2ER), and it extended cyclic stability more than three times, which was one of the most outstanding non-metallic catalysts. The reasonable structure design made it work as a high efficient electrocatalyst, which shed light on the development for functional treatment of catalytic materials.

Regulating the structure and morphology of discharge product is one of the key points for developing high performance Li-O

Due to the limited energy densities, which could be achieved by lithium-ion cells, Li-O2 batteries, which could provide a promising super energy storage medium, attract much attention nowadays. For its high activity, high storage and low cost, Mn-based oxides have shown versatile application in various batteries. To enhance the cyclability of Li-O2 batteries, here, we synthesized a kind of α-MnO2 nanowires as a bifunctional catalyst for Li-O2 batteries. The particular structure of α-MnO2 reduces the mass transfer resistance of the battery, and the MnO2 nanowires were ion exchanged by saturated lithium sulfate solution so as to further improve the performance of the catalyst. The exchanged α-MnO2 catalyst showed a high discharge specific capacity(6243 mA·h/g at a current density of 200 mA/g) and significantly improved the cyclability up to the 55th cycle(200 mA/g with capacity of 1000 mA·h/g). The results show that the Li ion exchange method is a promising strategy for improving the performance of MnO2 catalyst for Li-O2 batteries.

NiFe layered double hydroxides (LDHs) have been denoted as benchmark non-noble-metal electrocatalysts for the oxygen evolution reaction (OER). However, for laminates of NiFe LDHs, the edge sites are active, but the basal plane is inert, leading to underutilization as catalysts for the OER. Herein, for the first time, light and electron-deficient Li ions are intercalated into the basal plane of NiFe LDHs. The results of theoretical calculations and experiments both showed that electrons would be transferred from near Ni2+ to the surroundings of Li+ , resulting in electron-deficient properties of the Ni sites, which would function as "electron-hungry" sites, to enhance surface adsorption of electron-rich oxygen-containing groups, which would enhance the effective activity for the OER. As demonstrated by the catalytic performance, the Li-NiFe LDH electrodes showed an ultralow overpotential of only 298 mV at 50 mA cm-2 , which was lower than that of 347 mV for initial NiFe LDHs and lower than that of 373 mV for RuO2 . Reasonable intercalation adjustment effectively activates laminated Ni2+ sites and constructs the electron-deficient structure to enhance its electrocatalytic activity, which sheds light on the functional treatment of catalytic materials.

The topological structure of carbon materials for lithium storage performance is an active issue in energy resources. However, the low specific capacity of carbon materials limits their application in the rapidly developing market, although they have the highest marginal value. Herein, we develop a facile method for scaled-up production of materials with atomically dispersed metal sites anchored on nitrogen-enriched carbon nanosheets (M–N–C), including nickel, iron and manganese metal sites. This is the first time that low-cost atomically dispersed M–N–C has been used to enhance Li storage performance. The anchoring of the atomically dispersed metal sites effectively improves the extent of carbonization and optimizes the electronic structure, which enhances the conductivity and accelerates the adsorption kinetics for Li+; this results in high capacity and superior rate performance. In the case of Mn–N–C, it presents an ultrahigh specific capacity of 500 mA h g−1 at 1 A g−1 after 1000 cycles. The atomically dispersed materials also demonstrate satisfactory rate performance, with an extremely high specific capacity of 328 mA h g−1 at 10 A g−1; this is greatly superior to that of N-doped carbon nanosheets (

Two-dimensional MXene, a significant member of the two-dimensional family, has attracted much interest in physics, energy evolution, environmental science, and nanomedicine. However, the acute toxi...

We develop a facile method to prepare a hierarchical mesoporous nanocomposite of manganese carbodiimide nanoparticles modified with N-doping carbon materials (MnNCN/NC). The nanocomposite is endowe...

Li–oxygen batteries (LOBs) have drawn widespread attention in the past decades. Herein, bifunctional hybrid catalysts based on perovskite La0.5Sr0.5CoO3−δ with Ti3C2Tx MXene nanosheets have been pr...

The development of highly effective, universal, and economical electrocatalysts for hydrogen evolution reaction (HER) via structure modulations remains a great challenge. Herein, we propose a novel solidoid nitridation reduction method to synthesize α-MoC1–x quantum dots encapsulated in nitrogen-doped carbon (α-MoC1–x/NC) with a shape like “frog eggs”. Carbon nitride was first prepared by pyrolysis of urea and then mixed with ammonium molybdate tetrahydrate under a temperature-programmed reduction. With the assistance of nitrogen release during thermal treatment, N doping and an ultrathin porous structure were obtained. Benefiting from the strong interaction of α-MoC1–x quantum dots and nitrogen-doped carbon, the α-MoC1–x/NC delivered an outstanding performance toward HER at all pH values. Here, 118 mV, a lower overpotential, is needed to reach 10 mA cm–2 in alkaline solution, and the current density of α-MoC1–x grew much faster than the commercial Pt/C with increased potential. And, this can keep steadil...

Ultrathin two-dimensional metal–organic frameworks (2D MOFs) have the potential to improve the performance of Li–O2 batteries with high O2 accessibility, open catalytic active sites, and large surface areas. To obtain highly efficient cathode catalysts for aprotic Li–O2 batteries, a facile ultrasonicated method has been developed to synthesize three kinds of 2D MOFs (2D Co-MOF, Ni-MOF, and Mn-MOF). Contributing from the inherent open active sites of the Mn–O framework, the discharge specific capacity of 9464 mAh g–1 is achieved with the 2D Mn-MOF cathode, higher than those of the 2D Co-MOF and Ni-MOF cathodes. During the cycling test, the 2D Mn-MOF cathode stably operates more than 200 cycles at 100 mA g–1 with a curtailed discharge capacity of 1000 mAh g–1, quite longer than those of others. According to further electrochemical analysis, we observe that the 2D Mn-MOF outperforms 2D Ni-MOF and Co-MOF due to a superior oxygen reduction reactions and oxygen evolution reactions activity, in particular, the e...

Defect engineering is an important approach to enhancing the catalytic activity of a material, but there have been few reported controllable experiments due to the lack of systematic and comprehensive understanding of the effects of defects. For nanocarbon catalysts, it is still a challenge to prepare both atom-doped and defect-engineered catalysts with the desired more effective active centers, which requires an in-depth understanding of both experiment and theory. Herein, a topological rich-vacancy-defect nitrogen-doped nanocarbon (TRNC) material is constructed in situ via a simple magnesiothermic technology. It exhibits remarkable oxygen catalytic performance, which can be compared to the best metal-free bifunctional carbon electrocatalysts reported, even better than that of commercial noble-metal RuO2. Combined with density functional theory (DFT) calculations, the carbon vacancy defects with edge nitrogen doping as intrinsic active sites were found to exhibit excellent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity. When used practically as a catalyst in Li–O2 batteries, with a capacity restriction of 500 mA h g−1, it displays a long cycling and high rate durability of over 300 cycles at 200 mA g−1. This excellent performance arises from the three-dimensional topological rich-vacancy-defect nitrogen-doped nanocarbon. The effects of vacancy sites and nitrogen doping were probed via first-principles simulations to clarify the catalytic mechanisms which contribute to this superior performance.

NiFe layered double hydroxides (NiFe-LDHs) have been regarded as significant electrocatalysts for the oxygen evolution reaction (OER). However, their overpotential must still be further reduced to enable commercial applications. Herein, a promising and highly effective "hydroxyl ions hungry" electrode structure was prepared for the first time via a two-step hydrothermal reaction procedure to enhance the surface adsorption kinetics to obtain an ultralow overpotential. The electrode exhibits OER activity with ultralow overpotentials of 203 mV and 293 mV at the current densities of 10 mA cm-2 and 100 mA cm-2, respectively, in 1.0 M KOH. These results reveal an important way to improve the catalytic performance in an alkaline medium.

Hollow PdO-Co3O4 nano-dodecahedrons with moderate catalytic activity were designed as electrocatalysts for Li-O2 batteries, and not only reduce the overpotentials effectively but also improve the reversibility of the ORR and OER, and cycle for more than 90 cycles stably with extremely low overpotentials.

The development of high-performance, low-cost, and long-lasting electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is urgently needed for effective electrochemical water splitting. In the present study, an engineering process was employed to prepare "Lewis base-hungry" amorphous-crystalline nickel borate-nickel sulfide (Ni3(BO3)2-Ni3S2) heterostructures, which exhibited unprecedentedly high electrocatalytic activity toward both OER and HER in alkaline media. The optimal Ni3(BO3)2-Ni3S2/nickel foam (Ni3(BO3)2-Ni3S2/NF) electrode displayed an ultralow overpotential of only -92 and +217 mV to reach the current density of 10 mA cm-2 for HER and OER, respectively. When the Ni3(BO3)2-Ni3S2/NF electrode was used as both the anode and cathode for overall water splitting, a low cell voltage of 1.49 V was needed to achieve the current density of 10 mA cm-2, which was superior to the performance of most noble metal-free electrocatalysts. Results from density functional theory calculations showed that the Lewis base-hungry sites in the heterostructures effectively enhanced the chemisorption of hydrogen and oxygen intermediates, a critical step in HER and OER electrocatalysis. Results from this study highlight the significance of rational design and engineering of heterostructured materials for the development of high-efficiency electrocatalysts.

Lithium-oxygen batteries have attracted considerable interest in the past a few years, because they have higher theoretical specific energy than Li-ion batteries. However, the available energy densities of the Li-O2 batteries are much less than expected. It is particularly urgent to find catalyst with high activity. Herein, a series of Co3O4 with different morphologies (ordered two-dimensional porous nanosheets, flowerlike and cuboidlike) were successfully prepared through facile hydrothermal and calcination methods. Ordered two-dimensional Co3O4 nanosheets show the best cycling stability. Detailed experimental results reveal that the superiority of the unique two-dimensional uniform porous structures is vital for Li-O2 batteries cathode catalysts. Due to the ordered structures with high surface areas and active sites, the catalysts indicate a high specific discharge capacity of about 10,417 mAh/g at a current density of 200 mA/g, and steadily cycle for more than 50 times with a limited capacity of 1,000 mAh/g.

An amorphous boron oxide layer has been deposited in situ on the NiCo-LDH (layered double hydroxide) nanosheet arrays via the simple chemical vapor deposition. The overpotential of the NiCo-LDHs@B2O3/carbon paper (NiCo-LDHs@B2O3/CP) electrode is only 213 mV at the current density of 10 mA cm–2 in 1 M KOH, which is 123 mV less than that of NiCo-LDHs/CP and slightly better than noble metal catalyst RuO2/CP (230 mV). What’s more, at 50 mA cm–2 in 1.0 M KOH, the overpotential of NiCo-LDHs@B2O3/CP is still kept at a low value of 320 mV much better than that of NiCo-LDHs/CP (441 mV) and RuO2/CP (373 mV). Importantly, it showed long-term electrochemical stability. The introduction of amorphous boron oxide layers can be promoted to form a borate interface, and it can effectively enhance reactivity of active species. The boron oxide shell on the surface of LDHs can protect active species stability to enhance cycling stability. This work may inspire the development of low-cost and efficient OER electrocatalysts for...

NiFe layered double hydroxides (LDHs) have been denoted as benchmark non-noble-metal electrocatalysts for the oxygen evolution reaction (OER). However, for laminates of NiFe LDHs, the edge sites are active, but the basal plane is inert, leading to underutilization as catalysts for the OER. Herein, for the first time, light and electron-deficient Li ions are intercalated into the basal plane of NiFe LDHs. The results of theoretical calculations and experiments both showed that electrons would be transferred from near Ni

Metal-oxygen batteries, especially Li-oxygen batteries (LOBs), have attracted tremendous research attentions in the past decades. It is necessary to design novel cost-effective catalysts in the development of high performance rechargeable LOBs. Herein, we prepare the atom-layered two-dimensional (2D) β -Co(OH) 2 nanosheets (AL- β -Co(OH) 2 ) via phase transition of layered α- Co(OH) 2 nanosheets ( α- Co(OH) 2 ) in a mild wet chemical process. The thickness of AL- β- Co(OH) 2 is less than 1.5 nm. It is the first time of using atom-layered β -Co(OH) 2 in the system of LOBs and this material shows outstanding catalytic performance. The AL- β -Co(OH) 2 nanosheets as electrocatalysts in LOBs can better reduce the over-potential, enhance the specific capacity and improve cycling capability. It demonstrates a high initial capacity 11841 mAh g −1 at a current density of 100 mA g −1 . It displays long cycle stability more than 70 cycles with a capacity restriction of 1000 mAh g −1 . These results suggest that this strategy for designing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts via exfoliation of materials to atom-layered level could be a promising way to improve the performance of LOBs.

The large over-potential during the battery operation is a great obstacle for the application of Li-O2 batteries. The porous structure and electrical conductivity of the electrocatalysts are significant for the electrocatalytic performance of Li-O2 batteries. In this work, a porous Co3O4/GN nanocomposite (Co3O4 nanorods anchored on graphene nanosheets) is prepared via a facile hydrothermal method assisted with heat treatment. The unique structure of Co3O4/GN endows efficient electrocatalystic activity for Li-O2 batteries. In comparison to the Co3O4, the Co3O4/GN demonstrates a better cycle performance showing more than 40 cycles with a 1500 mAh g−1 capacity limit strategy at a current density of 300 mA g−1, and a reduced over-potential of 110 mV at high current density (1200 mA g−1). The Co3O4/GN also displays a high initial specific capacity (7600 mAh g−1) and a good reversibility in full cycle with a coulombic efficiency of 99.8% in the first cycle. The impressed cyclability, specific capacity, rate performance, and low over-potentials indicate that the as-prepared Co3O4/GN nanocomposite is a promising catalyst candidate for reversible Li-O2 batteries.

We have investigated the structural, magnetic and electrical transport properties of the Ni doped FeRh films prepared by magnetron co-sputtering. A large magetoresistance of 35%, induced by a reversible antiferromagnetic to ferromagnetic phase transition, is obtained at room temperature with only 1 mol.% Ni addition. Magnetic field is revealed to have an equivalent effect as temperature to drive the magnetic phase transition. Moreover, the way to realize a nonvolatile room temperature magetoresistance effect is also discussed. These results give FeRh the possibility of technological application in the spintronic field at room temperature, which are referential to other material systems with a first-order magnetic phase transition.

Due to the increasing demand for energy, improving the current density of fuel cells is an urgent issue. Here we report a bifunctional electrocatalyst for fuel cells involving methanol or formic acid oxidation. A nanocomposite consisting of 7.2 nm NiPt nanocrystals, which are grown in situ on graphene nanosheets (NiPt/GN), has been prepared via a solution thermal decomposition method. The NiPt/GN nanocatalyst presents specific activities as high as 41.1 mA cm-2 and 42.9 mA cm-2 for methanol oxidation and formic acid oxidation, respectively, outperforming most reported catalysts. Moreover, it retains 76.3% of this activity after 900 cycles of methanol oxidation. Additionally, in comparison with general NiPt nanoparticles, the NiPt/GN nanocatalyst shows higher electrocatalytic activity in methanol and formic acid oxidation. All these results indicate that ultrathin NiPt nanocrystals grown in situ on graphene nanosheet substrates can significantly improve performance as a bifunctional electrocatalyst.

Herein, hierarchical dendrite-like Pt crystals with a distinct morphology were synthesized via a facile one-pot method without any templates. Formation of this hierarchical structure is dependent on the reaction duration. Interestingly, different hierarchical structures show different catalytic activities. After a 12 hour reaction, tertiary structures of Pt are formed, which can act as outstanding catalysts in the hydrogen evolution reaction (HER). The onset potential of this dendrite-like Pt catalyst for the HER in a 0.5 M H2SO4 solution is 15 mV, which outperforms that of commercial Pt/C (30 mV). Moreover, it shows significantly improved stability for HER as the polarization curve after 10 000 cycles retains a similar performance as in the initial test; this results in a loss of only 2.6% of its initial current density at an overpotential of 0.05 V. The distinct hierarchical dendrite-like structures are maintained after cycling and current–time tests, which can be responsible for the excellent performance of this catalyst.

MOFs present potential application in electrocatalysis. The structure-activity of the Ni-MOFs with different morphologies, nanowires, neurons, and urchins is systemically investigated. The Ni-MOFs were controllably synthesized via the facile solvothermal method. Among them, the Ni-MOF nanowires are endowed with the highest electrocatalytic activity due to the unique structure, more exposed active sites, lower charge transfer resistance, and the fast and direct electron transfer in 1D structures. The typical morphology of the Ni-MOF nanowires is ca. 10 nm in diameter and several micrometers in length. When employed as an electrocatalyst in urea oxidation reaction, it exhibits a lower overpotential than and superior stability to the Ni-MOFs with other morphologies. Ni-MOF nanowires require a potential of ∼0.80 V (vs Ag/AgCl) to obtain 160 mA cm-2. In addition, after continuous electrocatalyzing for 3600 s at 0.40 V (vs Ag/AgCl), the current density retention of Ni-MOF nanowires could still reach more than 60% (>12 mA cm-2), which demonstrates Ni-MOF nanowires as promising electrocatalysts for urea oxidation.

Ultrathin two-dimensional metal-organic frameworks (2D MOFs) have the potential to improve the performance of Li-O

Large over-potentials during battery operation remain a big obstacle for aprotic Li-O

A novel two-phase approach towards the corrosion of PtNi10 nanoctahedra has been developed. In this strategy, the active component of Ni in oil-soluble PtNi10 nanoctahedra which resided in the upper toluene phase, suffered from etching and was then transferred into a lower aqueous phase with coordination by ethylenediaminetetraacetate (EDTA). Due to the existence of the phase-transfer interface promoted by EDTA, the corrosion reaction proceeded at an accelerated rate under the mild conditions. Specifically, the resultant products of octahedral Pt4Ni nanoframes were successfully fabricated for the first time, and PtNi4 porous octahedra could be obtained when the dosage of EDTA-2Na was reduced. After a systematic study of this two-phase system, a “synergetic corrosion” mechanism is proposed to account for the formation of octahedral Pt4Ni nanoframes, involving contributions from many species (i.e., O2, H2O, H+, OAm, and EDTA4−). As a result of the fascinating three-dimensional geometry of Pt4Ni nanoframes and PtNi4 porous octahedra, both of the corroded nanocrystals showed superior activity over the pristine PtNi10 nanoctahedra for ethanol electrooxidation in alkaline media and hydrogenation of nitrobenzene.

Lithium/sulfur (Li/S) cells have a theoretical specific energy five times higher than that of lithium-ion (Li-ion) cells (2600 vs. ~500 Wh kg−1). The conventional Li/S cells that use an organic liquid electrolyte are short-lived with low coulombic efficiency due to the polysulfide shuttle. We herein design carbon-coated NanoLi2S (NanoLi2S@carbon) composites, which consist of Li2S nanoparticles as the core and a carbon coating as the shell. The carbon shell prevents the NanoLi2S core from directly contacting the liquid electrolyte, which improves the performance of Li/S cells to provide longer cycle life and high sulfur utilization. The cyclability of Li/S cells is further enhanced by mixing the core–shell NanoLi2S@carbon composites with graphene oxide, which chemically immobilizes polysulfides in the cathode through their functional groups. The resulting Li/S cell shows an initial specific discharge capacity of 1263 mAh g−1 (normalized to sulfur) at the C/10 rate and a capacity retention of 65.4% after 200 cycles. The capacity decay mechanism during cycling is also characterized in detail using near edge X-ray absorption fine structure (NEXAFS) spectra.

Nickel sulfide (NiS) materials with a different 1D structure are successfully synthesized by strictly controlling the reaction time and temperature, using dodecanethiol as both solvent and sulfur source. The formation of the NiS nanomaterials results from a “dispersion–decomposition” mechanism. Remarkably, 1D NiS electrode materials show super specific capacitance and stability.

Multiferroic Co/BaTiO3 layered composite thin films were grown on Nb-doped SrTiO3 single crystal by pulse laser deposition, in which the polycrystalline Co film was annealed under magnetic field to induce in-plane uniaxial magnetic easy axis. Voltage-induced magnetization changes along and perpendicular to the easy axis were measured by Magneto-Optical Kerr effect (MOKE) magnetometer without applied magnetic field. These changes in magnetization could be due to magnetoelectric coupling between Co and BaTiO3, and to possibly electro-optical effect of BTO if the MOKE laser could penetrate the top Co film. After excluding the electro-optical interference by analyzing the experimental results within an optical model, a hysteric loop of magnetization versus voltage is identified with a relative change in magnetization of about 8%.

To improve the dielectric performance of polyvinylidene fluoride (PVDF), blend films based on PVDF and aromatic polythiourea (ArPTU) were prepared by the solution casting method. The blend films have higher dielectric constant (9.2) and lower loss at low fields (0.02 at 1 kHz) than a pure PVDF film (8.4, 0.05 at 1 kHz). More importantly, the blend films can also inhibit the early polarization saturation at low fields and result in the significant enhancement of the dielectric strength and increase in the energy density and reduction of loss at high fields. For the PVDF/ArPTU(90/10) film, the maximum operating electric field is about 700 MV m−1 and the released energy density can be up to 10.8 J cm−3 with an efficiency of above 83%. The X-ray diffraction data and atomic force microscopy images show that these blend films exhibit clear structural changes with an increasing percentage of ArPTU. It is proven that the increase of the β phase content and decrease of the crystalline grains in blend films are helpful to reduce the dielectric loss and enhance the dielectric strength.

Lithium iron phosphate (LiFePO4) is a potential high efficiency cathode material for lithium ion batteries, but the low electronic conductivity and single diffusion channel for lithium ions require good particle size and shape control during the synthesis of this material. In this paper, six LiFePO4 nanocrystals with different size and shape have been successfully synthesized in ethylene glycol. The addition sequence Fe-PO4-Li helps to form LiFePO4 nanocrystals with mostly {010} faces exposed, and increasing the amount of LiOH leads to a decrease in particle size. The electrochemical performance of the six distinct LiFePO4 particles show that the most promising LiFePO4 nanocrystals either have predominant {010} face exposure or high specific area, with little iron(II) oxidation.

Li 0.35 La 0.55 TiO 3 (LLTO) powder was mixed with Li 7 La 3 Zr 2 O 12 (LLZO) sol and finally sintered into ceramic pellets. In the low-temperature calcined precursor powder, Zr exists in the amorphous phase around LLTO aggregated particles. After high-temperature sintering, the LLZO phase does not exist, whereas Zr is doped into the LLTO grain interior but is richer in the grain boundary. The introduction of LLZO could modify the grain boundary region of the ceramics and thus change its electrical properties. The LLTO-based ceramics sintered at 1350 °C with 5 wt.% LLZO sol introduced in the precursor powder exhibit a high total conductivity of about 1.2 × 10 − 4 S/cm at room temperature.

By using a novel coating approach based on the reaction between MC(2)O(4)·xH(2)O and Ti(OC(4)H(9))(4), a series of nanoscale Li(2)TiO(3)-coated LiMO(2) nanobelts with varied Ni, Co, and Mn contents was prepared for the first time. The complete, thin Li(2)TiO(3) coating layer strongly adheres to the host material and has a 3D diffusion path for Li(+) ions. It is doped with Ni(2+) and Co(3+) ions in addition to Ti(4+) in LiMO(2), both of which were found to favor Li(+)-ion transfer at the interface. As a result, the coated nanobelts show improved rate, cycling, and thermal capabilities when used as the cathode for Li-ion battery.

[020]-oriented tin sulfide nanobelts with a length/thickness ratio of 100 have been synthesized by a facile hydrothermal method without any surfactants, and the nanobelts have shown good strain-accommodating properties as well as good electrochemical performance as the anode for Li-ion batteries. The formation of the nanobelts results from a precipitation-dissolution-transformation mechanism, and the [020] oriented growth can be ascribed to the {010} facet family having the lowest atomic density. In particular, SnS shows clear Li-Sn alloying/de-alloying reversible reactions in the potential range 0.1–1.0 V. Based on galvanostatic measurements and electrochemical impedance spectroscopy, SnS nanobelts have shown impressive rate performance. The post-cycled SnS nanobelts were completely transformed into metallic tin, and preserved the one-dimensional structure due to their flexibility which accommodates the large volumetric expansion. Open image in new window

Scientific Reports 4: Article number: 7507; published online: 16 December 2014; updated: 25 February 2016. This Article contains a typographical error in a grant number in the Acknowledgements section. “This work was supported by the NSF of China (Grant Nos. 51332001, 11234005, 51472140 and 51221291), and the NSF (Grant No: DMR-1410714, DMR-0820404, and DMR-1210588).

Scientific Reports 5: Article number:10459; published online: 21 May 2015; updated: 23 February 2016 This Article contains a typographical error in a grant number in the Acknowledgements section. “This work was supported by the NSF of China (Grant Nos 11234005, 51332001, 51221291, and 51472140), andthe NSF (Grant No: DMR-1410714, DMR-0820404, and DMR-1210588).