Optimizing the electrolyte salt of aqueous zinc-ion batteries based on a high-performance calcium vanadate hydrate cathode material

It is urgent to develop high-performance cathode materials for the emerging aqueous zinc-ion batteries with a facile strategy and optimize the related components.Herein,a Ca0.23V2O5·0.95 H2O nanobelt cathode material with a rather large interlayer spacing of 13.0 A is prepared via a one-step hydrothermal approach.The battery with this cathode material and 3 M Zn(CF3SO3)2 electrolyte displays high specific capacity(355.2 mAh g^(-1) at 0.2 A g^(-1)),great rate capability(240.8 mAh g^(-1) at 5 A g^(-1)),and excellent cyclability(97.7% capacity retention over 2000 cycles).Such superior performances are ascribed to fast electrochemical kinetics,outstanding electrode/electrolyte interface stability,and nearly dendrite-free characteristic.Instead,when ZnSO4 or Zn(ClO4)2 is used to replace Zn(CF3SO3)2,the electrochemical performances become much inferior,due to the slow electrochemical kinetics,inhomogeneous Zn stripping/plating process,and the formation of large dendrites and byproducts.This work not only discloses a high-performance cathode material for aqueous zinc-ion batteries but also offers a reference for the choice of electrolyte salt.

一种多功能隔膜实现对多硫离子和锂离子的双重调控

多硫离子穿梭和锂枝晶生长严重阻碍了锂硫电池的实际应用进程,而合理的隔膜结构可以达到一石二鸟的作用.本工作设计了一种携带有分散性TiN/CoO颗粒的氮掺杂碳纳米管结构(TCCNT),并将其用于锂硫电池隔膜修饰层.TCCNT的多孔结构和表面/内部携带的TiN/CoO颗粒不但实现了对多硫化物的物理、化学吸附和快速催化转化作用,其高导电性的空腔结构和亲锂作用还能够均化锂离子流,在5 mA cm^(-2)的电流密度下实现长达2000 h的均匀锂沉积/剥离过程.TCCNT合理的结构设计有利于各材料组分之间最大限度地发挥协同效应.采用改性隔膜所组装的锂硫电池在常规和高硫载量两种情况下均表现出较好的电化学性能,表明其具有一定的实际应用潜力.

Environment-tolerant ionic hydrogel-elastomer hybrids with robust interfaces,high transparence,and biocompatibility for a mechanical-thermal multimode sensor

The human skin,an important sensory organ,responds sensitively to external stimuli under various harsh conditions.However,the simultaneous achievement of mechanical/thermal sensitivity and extreme environmental tolerance remains an enormous challenge for skin-like hydrogel-based sensors.In this study,a novel skin-inspired hydrogel–elastomer hybrid with a sandwich structure and strong interfacial bonding for mechanical–thermal multimode sensing applications is developed.An inner-layered ionic hydrogel with a semiinterpenetrating network is prepared using sodium carboxymethyl cellulose(CMC)as a nanofiller,lithium chloride(LiCl)as an ionic transport conductor,and polyacrylamide(PAM)as a polymer matrix.The outer-layered polydimethylsiloxane(PDMS)elastomers fully encapsulating the hydrogel endow the hybrids with improved mechanical properties,intrinsic waterproofness,and long-term water retention(>98%).The silane modification of the hydrogels and elastomers imparts the hybrids with enhanced interfacial bonding strength and integrity.The hybrids exhibit a high transmittance(~91.2%),fatigue resistance,and biocompatibility.The multifunctional sensors assembled from the hybrids realize real-time temperature(temperature coefficient of resistance,approximately1.1%℃^(-1))responsiveness,wide-range strain sensing capability(gauge factor,~3.8)over a wide temperature range(from-20℃ to 60℃),and underwater information transmission.Notably,the dualparameter sensor can recognize the superimposed signals of temperature and strain.The designed prototype sensor arrays can detect the magnitude and spatial distribution of forces and temperatures.The comprehensive performance of the sensor prepared via a facile method is superior to that of most similar sensors previously reported.Finally,this study develops a new material platform for monitoring human health in extreme environments.

Advances and perspectives on separators of aqueous zinc ion batteries

With the advantages of intrinsic safety,good affordability,environmental friendliness,moderate energy density,and large power density,aqueous zinc ion batteries(AZIBs)have gained considerable research interest.However,zinc dendrites,hydrogen evolution,inert byproducts,and zinc metal corrosion severely hinder practical applications of AZIBs.In order to address these issues,many research works have been carried out to modify the interface between zinc metal anode and aqueous electrolyte.In fact,the interface engineering takes effect at the surface and near the surface of separator.However,a specialized review on the separators of AZIBs is still lacking.Herein,basic requirements of separators and recent advances on the modification strategies including employment of functional groups,establishment of surface coatings,construction of hybrid architectures,regulations of porosity,and utilization of bipolar membrane are reviewed.Besides,the perspectives for further investigations on the separators of AZIBs are outlined.This review could offer useful guidance for the future explorations of separators for AZIBs.

Dynamical mechanical behaviors of rubber-filled wood fiber composites with urea formaldehyde resin

Wood composites glued with thermosetting synthetic resins tend to show inadequate damping performance caused by the cured resinous matrix.Waste rubber maintains prominent elasticity and is feasible to be an optional modifier.To that end,composite panels of granulated tire rub-ber(GTR)powders and thermal-mechanically pulped wood fibers were fabricated in this study.Urea formaldehyde(UF)resin was applied as the bonding agent(10%based on wood/rubber total weight).Dynamical mechanical analysis(DMA)was conducted to disclose the thermo-mechanical behaviors of the rubber-filled wood fiber composites.Influence of two technical pa-rameters,i.e.,GTR powder size(0.55-1.09 mm)and addition content(10%,20%and 30%based on wood/rubber total weight),was specifically discussed.The results showed that storage modu-lus(E’)of the rubber-filled composite decreased while loss factor(tan𝛿)increased monotonously along with elevated temperature.A steady“plateau”region among 110-170°C was found where both E’and tan𝛿keep constant.Accordingly,tan𝛿showed two peak values at 103-108 and 231-233°C due to glass transition of lignin and thermal degradation of hemicellulose,respectively.Addition of rubber fillers resulted in lower bending and internal bonding strengths as well as stor-age modulus values.When the temperature was above 183°C,all the rubber-filled composites showed higher tan𝛿values than the control.The findings above fully demonstrate the improved damping performance of the UF-bonded wood fiber composites on account of rubber component.Further work is still needed to optimize the rubber/fiber interfacial bonding strength.

Dynamical mechanical properties of wood-high density polyethylene composites filled with recycled rubber

Application of out-of-service rubber from a variety of sources is of both environment-protecting and resource-saving importance.To that end,recycled tire rubber was utilized as a filler to fabricate wood-high density polyethylene(HDPE)composite with enhanced toughening performance using the injection procedure in this work.Dosages of rubber powders were 0,5,10,and 15wt%based on the overall weight of poplar wood flour and HDPE(HDPE:wood flour=70꞉30).The injection-fabricated composites were subjected to a four-cycle repetitive compressing loadings(0-3 kN)and dynamical mechanical analysis(DMA,room temperature to 150℃,in the dual cantilever mode).It was found that the rubber-filled materials exhibit advantageous energy absorption performance compared to wood-HDPE composites under repetitive compressions.The rubber-filled wood-HDPE composites are thermomechanically labile in an environment with raised temperature.The HDPE matrix substance occupies the predominant role in thermally yielding of the overall composite,typically in the temperature range of 50-75℃ resulting in a loss modulus peak.Up to 130-150℃,all the composites fully loses their moduli with loss factor(Tan δ)reaching its peak values of 0.30-0.38.To conclude,rubber-filled wood-HDPE is a qualified material applicable in proper temperature range.