Composite polyethylene-oxide/garnet electrolytes containing LiTFSI as the lithium salt have a Li+ conductivity σLi > 10−4Scm−1 at 55°C and a low plating/stripping impedance of a dendrite-free ...Li-metal anode; they have been developed for a safe solid-state Li-metal rechargeable battery. Composites consisting of “ceramic-in-polymer” to “polymer-in-ceramic” that are flexible and mechanically robust are fabricated by hot-pressing. Safe pouch cells with a remarkable flexibility have been fabricated. Solid-state LiFePO4|Li batteries with electrolytes of “ceramic-in-polymer” and “polymer-in-ceramic” deliver excellent cycling stability with high discharge capacities (139.1mAhg–1 with capacity retention of 93.6% after 100 cycles) and high capacity retention (103.6% with coulombic efficiency of 100% after 50 cycles) at 0.2C and 55°C. Both kinds of electrolytes can be applied to solid-state lithium batteries.
PEO/garnet composite electrolytes from “ceramic-in-polymer” to “polymer-in-ceramic” are prepared by hot-pressing technology without introducing any solvent. The resultant electrolytes exhibit excellent electrochemical properties and the assembled batteries deliver high cycling stability and stable interface with Li anode, demonstrating a promising strategy for a safe, high-performance and solid-state Lithium batteries. Display omitted
•PEO/garnet electrolyte has a Li+ conductivity σLi > 10−4Scm−1 at 55°C.•The electrolytes are flexible and mechanically robust.•The membrane has a low plating/stripping impedance.•All-solid-state LiFePO4/Li cell has a discharge capacities of 148.6mAhg−1.
We prepare in-situ TiC reinforced AlCoCrFeNi-based coatings by laser cladding. The in-situ TiC particles improve significantly the hardness and wear resistance of AlCoCrFeNi high entropy alloy ...coatings.
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•The in-situ reinforced TiC particles are synthesized in the AlCoCrFeNi-based high entropy alloy coatings by laser cladding.•The microstructure of composite coatings is mainly composed of the BCC and TiC phases.•The AlCoCrFeNi-20% TiC coating exhibits the best wear resistance with an average hardness of 684.4 HV0.3.•The hardness of TiC is analysed by the first-principles calculations.
High-entropy alloy (HEA) coatings of AlCoCrFeNi are being investigated as potential wear-resistance materials due to their excellent hardness and wear resistance. In this work, AlCoCrFeNi-based coatings were reinforced by in-situ TiC particles via laser cladding. The microstructure and wear resistance were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and wear resistance tests. In addition, the hardness of oxidation TiC particles was analyzed by first principles calculations. The results show that the dominant phase of AlCoCrFeNi-based coatings is BCC phase. In-situ TiC particles present a flower-shaped morphology with Al2O3 core. Based on the calculated hardness, the hardness of TiC decreases with the increase of oxygen atoms in TiC. The hardness and wear resistance are improved considerably with the generation of the in-situ TiC particles. The AlCoCrFeNi-20% TiC coating exhibits the best wear resistance with an average hardness of 684.4 HV0.3, and the main wear mechanism is abrasive wear.
Solid‐state electrolytes have emerged as a promising alternative to existing liquid electrolytes for next generation Li‐ion batteries for better safety and stability. Of various types of solid ...electrolytes, composite polymer electrolytes exhibit acceptable Li‐ion conductivity due to the interaction between nanofillers and polymer. Nevertheless, the agglomeration of nanofillers at high concentration has been a major obstacle for improving Li‐ion conductivity. In this study, we designed a three‐dimensional (3D) nanostructured hydrogel‐derived Li0.35La0.55TiO3 (LLTO) framework, which was used as a 3D nanofiller for high‐performance composite polymer Li‐ion electrolyte. The systematic percolation study revealed that the pre‐percolating structure of LLTO framework improved Li‐ion conductivity to 8.8×10−5 S cm−1 at room temperature.
Path finder: The percolation effect on the conductivity of composite polymer electrolytes has been investigated. Typical nanoparticle fillers agglomerate at high concentrations, resulting in discontinuous lithium‐ion conducting pathways. A nanostructured hydrogel‐framework electrolyte exhibits much higher conductivity through a continuous interphase formed by a pre‐percolated network.
Lithium metal, the ideal anode material for rechargeable batteries, suffers from the inherent limitations of sensitivity to the humid atmosphere and dendrite growth. Herein, low-cost fabrication of a ...metallic-lithium anode that is stable in air and plated dendrite-free from an organic-liquid electrolyte solves four key problems that have plagued the development of large-scale Li-ion batteries for storage of electric power. Replacing the low-capacity carbon anode with a safe, dendrite-free lithium anode provides a fast charge while reducing the cost of fabrication of a lithium battery, and increasing the cycle life of a rechargeable cell by eliminating the liquid-electrolyte ethylene-carbonate additive used to form a solid-electrolyte interphase passivation layer on the anode that is unstable during cycling. This solution is accomplished by formation of a hydrophobic solid-electrolyte interphase on a metallic-lithium anode that allows for handling of the treated lithium anode membrane in a standard dry room during cell fabrication.
Electrocatalysts for both the oxygen reduction and evolution reactions (ORR and OER) are vital for the performances of rechargeable metal–air batteries. Herein, we report an advanced bifunctional ...oxygen electrocatalyst consisting of porous metallic nickel‐iron nitride (Ni3FeN) supporting ordered Fe3Pt intermetallic nanoalloy. In this hybrid catalyst, the bimetallic nitride Ni3FeN mainly contributes to the high activity for the OER while the ordered Fe3Pt nanoalloy contributes to the excellent activity for the ORR. Robust Ni3FeN‐supported Fe3Pt catalysts show superior catalytic performance to the state‐of‐the‐art ORR catalyst (Pt/C) and OER catalyst (Ir/C). The Fe3Pt/Ni3FeN bifunctional catalyst enables Zn–air batteries to achieve a long‐term cycling performance of over 480 h at 10 mA cm−2 with high efficiency. The extraordinarily high performance of the Fe3Pt/Ni3FeN bifunctional catalyst makes it a very promising air cathode in alkaline electrolyte.
OER and ORR: A bifunctional Fe3Pt intermetallic nanoalloy supported by Ni3FeN has excellent electrocatalytic activity and stability for the oxygen evolution and oxygen reduction reactions (OER and ORR) under alkaline conditions. The Fe3Pt/Ni3FeN catalyst enabled a Zn–air battery to cycle steadily up to 480 h and significantly outperformed a Pt/C+Ir/C mixture of catalysts.
The molybdenum disulfide/reduced graphene oxide@polyaniline (MoS2/RGO@PANI) was facilely and effectively prepared through a two-stage synthetic method including hydrothermal and polymerized ...reactions. The rational combination of two components allowed polyaniline (PANI) to uniformly cover the outer face of molybdenum disulfide/reduced graphene oxide (MoS2/RGO). The interaction between the two initial electrode materials produced a synergistic effect and resulted in outstanding energy storage performance in terms of greatest capacitive property (1224 F g–1 at 1 A g–1), good rate (721 F g–1 at 20 A g–1), and cyclic performance (82.5% remaining content after 3000 loops). The symmetric cell with MoS2/RGO@PANI had a good capacitive property (160 F g–1 at 1 A g–1) and energy and power density (22.3 W h kg –1 and 5.08 kW kg–1).
Hollow carbon nanostructures have inspired numerous interests in areas such as energy conversion/storage, biomedicine, catalysis, and adsorption. Unfortunately, their synthesis mainly relies on ...template-based routes, which include tedious operating procedures and showed inadequate capability to build complex architectures. Here, by looking into the inner structure of single polymeric nanospheres, we identified the complicated compositional chemistry underneath their uniform shape, and confirmed that nanoparticles themselves stand for an effective and versatile synthetic platform for functional hollow carbon architectures. Using the formation of 3-aminophenol/formaldehyde resin as an example, we were able to tune its growth kinetics by controlling the molecular/environmental variables, forming resin nanospheres with designated styles of inner constitutional inhomogeneity. We confirmed that this intraparticle difference could be well exploited to create a large variety of hollow carbon architectures with desirable structural characters for their applications; for example, high-capacity anode for potassium-ion battery has been demonstrated with the multishelled hollow carbon nanospheres.
The unclear Li+ local environment and Li+ conduction mechanism in solid polymer electrolytes, especially in a ceramic/polymer composite electrolyte, hinder the design and development of a new ...composite electrolyte. Moreover, both the low room-temperature Li+ conductivity and large interfacial resistance with a metallic lithium anode of a polymer membrane limit its application below a relatively high temperature. Here we have identified the Li+ distribution and Li+ transport mechanism in a composite polymer electrolyte by investigating a new solid poly(ethylene oxide) (PEO)-based NASICON–LiZr2(PO4)3 composite with 7Li relaxation time and 6Li → 7Li trace-exchange NMR measurements. The Li+ population of the two local environments in the composite electrolytes depends on the Li-salt concentration and the amount of ceramic filler. A composite electrolyte with a EO/Li+ ratio n = 10 and 25 wt % LZP filler has a high Li+ conductivity of 1.2 × 10–4 S cm–1 at 30 °C and a low activation energy owing to the additional Li+ in the mobile A2 environment. Moreover, an in situ formed solid electrolyte interphase layer from the reaction between LiZr2(PO4)3 and a metallic lithium anode stabilized the Li/composite-electrolyte interface and reduced the interfacial resistance, which provided a symmetric Li/Li cell and all-solid-state Li/LiFePO4 and Li/LiNi0.8Co0.1Mn0.1O2 cells a good cycling performance at 40 °C.
Indium-oxide (In2O3) nanobelts coated by a 5-nm-thick carbon layer provide an enhanced photocatalytic reduction of CO2 to CO and CH4, yielding CO and CH4 evolution rates of 126.6 and 27.9 μmol h–1, ...respectively, with water as reductant and Pt as co-catalyst. The carbon coat promotes the absorption of visible light, improves the separation of photoinduced electron–hole pairs, increases the chemisorption of CO2, makes more protons from water splitting participate in CO2 reduction, and thereby facilitates the photocatalytic reduction of CO2 to CO and CH4.
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