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Silicon is a promising candidate for negative electrodes due to its high theoretical specific capacity (~ 3579 mA h g −1 ) and low lithiation potential (~ 0.40 V vs. Li). However, its practical applications in battery have been inhibited by the large volume change (~ 400%) induced by Li + -insertion into Si lattices. Here, we attempt to resolve this issue at a fundamental level, and report for the first time a novel liquid metal (LM)-mediated spontaneous repairing conductive-additive-free Si anode for Li-ion battery. The fluidity of LM ensures the eternal contact between Si and the conducting-network during its repeated electrochemical reactions. The as-prepared nano-composite of LM/Si leads to superior performances as characterized by high capacity utilization (2300 mA h g −1 at 500 mA g −1 ), long-term stability (968 mA h g −1 after 1500 charge-discharge cycles at 8 A g −1 with 81.3% retention), high rate capability (360 mA h g −1 at 20 A g −1 , equivalence of 55 C, or full charge/discharge in 65 s), and, in particular, an extra-ordinarily high initial coulombic efficiency (95.92%), which is not only the highest reported for Si to the best of our knowledge, but also higher than the mature graphitic carbon anodes. The unique approach described in this work not only resolves the basic stress challenges faced by the promising but often problematic alloy-type materials; in broader context it also provides a universal inspiration to all electrode materials whose electric properties suffer from extreme mechanic upheavals induced by the electrochemical strains during the cell reactions. [ABSTRACT FROM AUTHOR]

Dual crosslinked system has been proved to be an efficient method to obtain tough and high strength hydrogels. Herein, we synthesized a novel graphene oxide/p(acrylamide- co -poly(ethylene glycol) methyl ether methacrylate)/α-cyclodextrin (GO/P(AM - co -PEGMA)/CD) physical dual crosslinked hydrogel via copolymerization of AM and PEGMA in the α-CD/GO solution. The polymer main chains adsorb onto the GO surface resulting in the first crosslinked system and multiple hydrogen bonds between α-CDs that thread on the PEGMA side chains establish the second crosslinked system. The GO/P(AM- co -PEGMA)/CD hydrogel exhibits favorable tensile properties with fracture strain of 1800% and high fracture stress of 660 kPa; in addition, the hydrogel can bear large compressive stress (2.7 MPa) at strain of 85% without rupture. Furthermore, physical dual crosslinked system endows the GO/P(AM- co -PEGMA)/CD hydrogel with thermoplastic ability and thermo-responsive shape memory behavior. This facial one-pot method will contribute to design and application of high performance hydrogel. [ABSTRACT FROM AUTHOR]

Facile and efficient encapsulation of epoxy and tetraethylenepentamine (TEPA) in polyurea (PU) microcapsules are accomplished with Pickering emulsion templates by one-step, interfacial polymerization. The formation of microcapsule is deftly achieved by lightly shaking Pickering emulsions. The whole process is time andenergy saving hardly with any waste and residual. Epoxy microcapsules keep the spherical shape with core content of more than 90 wt%. Amine microcapsules shrink a little for evaporation of water and the conserved TEPA after air-dried is 82.1 wt%. The shell walls of two microcapsules are about 1 μm. With the protection of PU shells, both microcapsules exhibit excellent thermal resistance. Furthermore, self-healing function of epoxy and amine microcapsules is measured by incorporating microcapsules into epoxy coating, and tested by brine-submersion corrosion-accelerating experiment. The dual core self-healing coatings demonstrate excellent self-repairing performance with the crack of embedded microcapsules and reaction between epoxy and amine. The core materials can outflow from microcapsules and form isolations for metal substrate from corrosion hazard, therefore, make for good self-repairing and preserving function of the self-healing coating. [ABSTRACT FROM AUTHOR]

Lignin-based azo polymer (AL-azo-H) was prepared from alkali lignin (AL) and then used to prepare uniform colloids via self-assembly. Due to the unique UV-blocking performance, AL-azo-H colloids were applied to encapsulate photosensitive pesticide avermectin (AVM). The self-assembled structure of AL-azo-H colloids and their controlled release and anti-photolysis performances for AVM were investigated by dynamic light scattering (DLS), static light scattering (SLS), transmission electron microscopy (TEM) and high performance liquid chromatography (HPLC). Results show that AL-azo-H colloids are hollow spheres. Hollow AL-azo-H colloidal spheres have remarkable AVM encapsulation efficiency as high as 61.49% (w/w). The cumulative release amount of AVM encapsulated by AL-azo-H (AL-azo-H@AVM) after 120 h was 84% and the release was still going on. The decomposition rate of AL-azo-H@AVM was less than 41% even after 72 h of UV irradiation. Hollow AL-azo-H colloidal spheres showed excellent UV-blocking and controlled release performance for AVM. [ABSTRACT FROM AUTHOR]

The employment of localized high concentration electrolytes (LHCEs) has been demonstrated as an effective strategy for the fabrication of next-generation high-energy-density lithium metal batteries. However, the low ionic conductivity of LHCEs and their parasitic side reactions with lithium metal anodes severely hinder the cycling stability of lithium metal batteries. Herein, a partially fluorinated ether of bis (2,2-difluoroethyl) ether (BDE) is proposed as a bifunctional co-solvent to form novel LHCEs for realizing dendrite-free and long-term lithium metal batteries. The BDE co-solvent serves as a diluent to improve the ionic conductivity up to 6.4 mS/cm by dissociating lithium salt via weak interaction and decreasing the electrolyte viscosity. In addition, the BDE co-solvent could promote the formation of uniform lithium fluoride (LiF)-rich solid electrolyte interphase (SEI) to suppress the dendrite deposition by regulating the solvation shell structure, resulting in high Coulombic efficiency of 99.6%. As a result, the assembled full cell exhibits outstanding cycling stability (97% capacity retention after 200 cycles @0.5 C) with high areal capacity (2 mAh/cm2) and high rate capability (2 C) under practical conditions (50 µm Li, lean electrolyte: 3 g/Ah). We also demonstrate the real application of electrolyte with a commercial cathode in 320-mAh-level pouch cells. [Display omitted] • A partially fluorinated ether was prepared as a bifunctional electrolyte co-solvent. • Dendrite-free and long-term lithium metal batteries were developed. • Li plating/stripping Coulombic efficiency was high up to 99.6%. • Outstanding cycling stability of a 320-mAh-level pouch cell was achieved. [ABSTRACT FROM AUTHOR]

Solid-state lithium metal batteries (LMBs) receive increasing attentions worldwide due to their safety and high energy density. Herein, the practical application of conversion reaction-type transition metal oxides (TMOs, Fe 2 O 3 , Mn 2 O 3 or CuO) as Li-free cathodes for solid-state LMBs is demonstrated for the first time, employing poly(ethylene oxide) (PEO), lithium garnet Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 or Li 1.5 Al 0.5 Ge 1.5 (PO 3) 4 solid-state electrolytes (SSEs). The cathodes embody good interfacial compatibility with the SSEs, ensuring the excellent electrochemical performance of the TMOs/SSEs/Li solid-state cells. The as-prepared Fe 2 O 3 /PEO/Li cell measured at 60 °C delivers a high discharge capacity of 990 mAh g−1 at 10 mA g−1, which is comparable to the Fe 2 O 3 liquid cell. When cycling at 200 mA g−1, a stable capacity of 733 mAh g−1 is achieved at the 1,100th cycle for the Fe 2 O 3 /PEO/Li cell, while the Fe 2 O 3 liquid cell only sustains 860 cycles until failure. In order to further demonstrate the application feasibility, stable cycling of the Fe 2 O 3 /PEO/Li cells with high mass loading of 2.83 mg cm−2 and thus high areal capacity of 1.67 mAh cm−2 or with limited Li usage (150% in excess) is preliminarily achieved. In addition, the Fe 2 O 3 /PEO/Li pouch cells are assembled, which exhibit satisfied electrochemical performance. Moreover, poly(vinylidene difluoride) (PVDF)-based solid polymer electrolye is employed to make the Fe 2 O 3 solid-state cell work at 30 °C successfully. These results convince the great promise of TMOs in future high-energy-density solid-state LMBs. Image 1 • Li-free cathodes are developed for solid-state lithium metal batteries. • Fe 2 O 3 in solid cell delivers a high capacity of 990 mAh g−1 at 10 mA g−1. • Fe 2 O 3 /PEO/Li solid cell exhibits ultra-stable long-term cycling performance. • Stable cycling on high areal capacity of 1.67 mAh cm−2 is preliminarily achieved. [ABSTRACT FROM AUTHOR]

Abstract: The solution behavior of purified sodium lignosulfonate (PSL) at different pH values were investigated by means of acid–base titration, surface tension, viscosity, fluorescence spectrometry, dynamic light scattering (DLS) and environmental scanning electron microscopy (ESEM) experiments. Fluorescence experiments showed that the critical aggregate concentration (CAC) of PSL was 0.05g/L. DLS results indicated that the average dimension of PSL molecule and PSL aggregate was about 8nm and 80nm, respectively. The surface charge of PSL molecules and the aggregation degree of PSL in solution increased with the increasing of pH due to the ionization of sulfonic and phenolic hydroxyl groups. The size of PSL aggregates and reduced viscosity of PSL solution increased as pH values increased because expansion of the PSL cores. A model for the assembly behavior of PSL was first proposed to explain the influence of pH on the molecular configuration and aggregation behaviors of lignosulfonate in aqueous solutions. [ABSTRACT FROM AUTHOR]

Using conductive binders, instead of the traditional binders and conductive additives, is an effective way to increase the specific capacity and long cycle life of the silicon (Si) anode. However, the rigid conductive binders of Si anodes tend to form cracks during the repetitive huge volume changes of Si. Here, a novel n-type conductive binder, multi-block polymer of poly(1-pyrenemethyl methacrylate) and polybutadiene (PPy- b -PB) was designed. The polybutadiene (PB) rubber was incorporated into the conductive binder by combining condensation and reversible addition-fragmentation chain transfer polymerization. With high initial coulombic efficiency of 77.9%, the PPy- b -PB/Si anode possesses high reversible capacity (2274 mAh g−1) and capacity retention (87.1%) at the rate of 0.2 C (0.84 A g−1) after 200 cycles. The superior cyclic performance of the PPy- b -PB can be ascribed to the PB rubber, which enhanced the reversible deformation ability, flexibility, and adhesion length scale of the binder, without with a negligible change of the charge-transfer resistance for the anode. The original structure and the preparation method of the multi-block conductive binder provide a new way to manufacture multifunctional binders. A n-type multi-block polymer PPy- b -PB of poly(1-pyrenemethyl methacrylate) (PPy) and polybutadiene (PB) was designed to enhance the reversible deformation ability, flexibility, and adhesion length scale of the conductive binder PPy. With high initial coulombic efficiency of 77.9%, the PPy- b -PB/Si anode possesses high reversible capacity (2274 mAh g−1) and capacity retention (87.1%) at the rate of 0.2 C (0.84 A g−1) after 200 cycles. Image 1 • A novel multi-block binder was prepared by Condensation and RAFT polymerization. • The binder was used as conductive binder for Si anodes in Li-ion batteries. • Reversible deformation ability of the binder was improved with polybutadiene. • High capacity and cycling stability of Si anode was achieved by using the binder. [ABSTRACT FROM AUTHOR]

Here a highly porous melamine sponge based matels absorbent (MF-PEI/CS 2 ) possessing abundent imine and dithiocarbamate groups was prepared via a simple two-step process including crosslinking reaction with polyethylenimine (PEI) under the assistance of epichlorohydrin and esterification with CS 2 under a basic condition. The combination of melamine sponge with large surface area and polyethylenimine and dithiocarbamate groups with strong metals chelating ability into one composite ensures MF-PEI/CS 2 sponge an excellent multi-metals removal performance. This monolithic product, which is easily separated from treated water, can quickly chelate amounts of metals in a short time as its absorption capacity reaches about 96% of the saturation absorption capacity (93 mg/g) in 25 min and reach the saturation point (97 mg/g) after 35 min without stirring toward Cu (II) ions. [ABSTRACT FROM AUTHOR]