Recent advances on flexible electrodes for Na-ion batteries and Li–S batteries

Flexible energy storage devices are essential for emerging flexible electronics. The existing state-of-the-art Li-ion batteries are slowly reaching their limitation in terms of cost and energy density. Hence, flexible Na-ion batteries (SIBs) with abundanee Na resources and Li-S batteries with high energy density become the alternative for the Li-ion batteries in future. This review summarizes the recent advances in the development of flexible electrode materials for SIBs with metallic matrix and carb on aceous matrix such as carb on nano-tubes, carbon nano-fiber, graphene, carbon cloth, carbon fiber cloth, and cotton textiles. Then, the potential prototype flexible full SIBs are discussed. Further, the recent progress in the development of flexible electrode materials for Li-S batteries based on carb on nano-fiber, carb on nano-tubes, graphene, and cotton textiles is reviewed. Moreover, the design strategies of suitable interlayer, separator, electrolyte, and electrodes to prevent the dissolution and shuttle effect of polysulfides in flexible Li-S batteries are provided. Finally some prospective investigation trends towards future research of flexible SIBs and Li-S batteries are also proposed and discussed. The scientific and engineering knowledge gained on flexible SIBs and Li-S batteries provides conceivable development for practical application in near future.

Tuning the electronic structure of the earth-abundant electrocatalysts for oxygen evolution reaction(OER)to achieve efficient alkaline water splitting-A review

Tuning the electronic structure of the electrocatalysts for oxygen evolution reaction(OER)is a promising way to achieve efficient alkaline water splitting for clean energy production(H2).At first,this paper introduces the significance of the tuning of electronic structure,where modifying the electronic structure of the electrocatalysts could generate active sites having optimal adsorption energy with OER intermediates,and that could diminish the energy barrier for OER,and that could improve the activity for OER.Later,this paper reviews the tuning of electronic structure along with catalytic performances,synthetic methodologies,chemical properties,and DFT calculations on various nanostructured earth-abundant electrocatalysts for OER in alkaline environment.Further,this review discusses the tuning of the electronic structure of the several nanostructured earth-abundant electrocatalysts including oxide,(oxy)hydroxide,layered double hydroxide,alloy,metal phosphide/phosphate,nitride,sulfide,selenide,carbon containing materials,MOF,core-shell/hetero/hollow structured materials,and materials with vacancies/defects for OER in alkaline environment(including activity:overpotential(η)of ≤200 mV at10 m A cm^(-2);stability:≥100 h;durability:≥5000 cycles).Then,this review discusses the robust stability of the electrocatalysts for OER towards practical application.Moreover,this review discusses the in situ formation of thin layer on the catalyst surface during OER.In addition,this review discusses the influence of the adsorption energy of the OER intermediates on OER performance of the catalysts.Finally,this review summarizes the various promising strategies for tuning the electronic structure of the electrocatalysts to achieve enhanced performance for OER in alkaline environment.

半金属氢氧化物材料用于电化学水氧化

寻找具有高本征活性的水氧化催化剂材料对许多清洁能源技术的发展至关重要.氢氧化物半导体对析氧反应具有一定的电催化活性.然而,该材料导电性较差,限制着其电催化本征活性的提升.本文提出一种兼具高导电性和高催化活性的半金属氢氧化物析氧电催化材料.通过阳离子掺杂和阴离子空位协同作用,镍铁水滑石半导体可转化为半金属材料,其电阻率降低了两个数量级.相应半金属氢氧化物阵列电极的电催化活性显著提升,在10 mA cm^(-2)电流密度下其析氧过电势仅为195 mV,Tafel斜率仅为40.9 mV dec^(-1),显著优于商用RuO_(2)催化剂(316 mV,99.6 mV dec^(-1)).原位拉曼光谱和理论计算结果表明,半金属氢氧化物可在较低过电位下转化为羟基氧化物中间体,有助于高价态金属活性位点的形成与稳定,从而提升材料的析氧本征活性.本研究表明,兼具优异导电性和催化活性的半金属氢氧化物可作为先进的电极材料.

A promising energy storage system:rechargeable Ni-Zn battery

The sharp depletion of fossil fuel resources and its associated increasingly deteriorated environmental pollution are vital challenging energy issues, which are one of the most crucial research hot spots in the twenty-first century.Rechargeable Ni–Zn batteries（RNZBs）, delivering high power density in aqueous electrolytes with stable cycle performance, are expected to be promising candidates to alleviate the current energy and environmental problems,and play an important role in green power sources. Many efforts have been focused on the investigations and improvements of RNZBs in recent decades, and it is necessary to summarize and review the achievements and challenges in this advancing field. In this paper, we review various batteries, compare and highlight the advantages of RNZBs, and introduce the recent advances in the development of electrode materials and electrolytes of RNZBs,especially the applications of novel nanostructured materials for the active electrodes. Some prospective investigation trends of RNZBs are also proposed and discussed.