Functional Janus Membranes:Promising Platform for Advanced Lithium Batteries and Beyond

Separators or electrolyte membranes are recognized as the key components to guarantee ion transport in rechargeable batteries.However,the ever-growing applications of the battery systems for diverse working environments bring new challenges,which require advanced battery membranes with high thermal stability,excellent mechanical strength,high voltage tolerance,etc.Therefore,it is highly desirable to design novel methods/concepts to solve the current challenges for battery membranes through understanding the mechanism of novel phenomena and electrochemical reactions in battery systems working under unconventional conditions.Recently,the new emerging Janus separators or electrolyte membranes with two or more distinct chemical/physical properties arising from their asymmetric structure and composition,are promising to address the above challenges via rational design of their targeted functionalities.To this end,in this review,we first briefly cover the current challenges of the traditional battery membrane for battery devices working in unconventional conditions.Then,the state-of-art developments of the rational design of Janus membranes to overcome the above challenges for diverse battery applications are summarized.Finally,we outline these latest developments,challenges,and future potential directions of the Janus membrane.Our review is aimed to provide basic guidance for developing functional separators or electrolyte membranes for advanced batteries.

Nature-inspired materials and designs for flexible lithium-ion batteries

Flexible lithium-ion batteries(FLBs)are of critical importance to the seamless power supply of flexible and wearable electronic devices.However,the simultaneous acquirements of mechanical deformability and high energy density remain a major challenge for FLBs.Through billions of years of evolutions,many plants and animals have developed unique compositional and structural characteristics,which enable them to have both high mechanical deformability and robustness to cope with the complex and stressful environment.Inspired by nature,many new materials and designs emerge recently to achieve mechanically flexible and high storage capacity of lithiumion batteries at the same time.Here,we summarize these novel FLBs inspired by natural and biological materials and designs.We first give a brief introduction to the fundamentals and challenges of FLBs.Then,we highlight the latest achievements based on nature inspiration,including fiber-shaped FLBs,origami and kirigami-derived FLBs,and the nature-inspired structural designs in FLBs.Finally,we discuss the current status,remaining challenges,and future opportunities for the development of FLBs.This concise yet focused review highlights current inspirations in FLBs and wishes to broaden our view of FLB materials and designs,which can be directly“borrowed”from nature.

A Study of Phytoplankton Community Structure in Duobukuer Nature Reserve

In spring,summer,autumn 2015,we studied the seasonal variation of phytoplankton community structure in six rivers within Duobukuer Nature Reserve,and made preliminary evaluation of the water quality in Duobukuer Nature Reserve based on phytoplankton diversity.The results showed that a total of 7 phyla,41 genera,66 species and varieties of phytoplankton were identified in Duobukuer Nature Reserve;the annual species composition was dominated by diatom( 59%) which also preponderated in dominant species( 84. 3%),biomass( 68%)and abundance( 75%),with no significant seasonal variation. Shannon-Wiener diversity index( H') and Pielou evenness index( J) were used to evaluate the water quality in 13 sampling points,and the results showed that the water quality was good in Duobukuer Nature Reserve,the sampling points 5,6 and 12 presented β-pollution,and other sampling points were in an oligosaprobic-clean state.

Optimization Model and Pollution Treatment of Sintering Ore Distribution

Sintering process plays an important role in iron and steel smelting process.The subsequent production of blast furnace ironmaking is directly affected by the quality of sinter.Among them,the proportion of raw materials and the advanced degree of sintering process are the two main factors affecting the quality of sinter.Because the control parameters of sintering process are too many and the physical and chemical process is too complex,it is difficult to establish and control the model accurately.Therefore,workers have long relied on experience to set temperature and other factors to engage in production,resulting in the quality of sinter is unstable,the cost is not easy to be controlled.Moreover,the flue gas produced in the sintering process will have different effects on the environment.Through the data analysis of the ore distribution scheme and the results of the physicochemical analysis of sinter in a steel plant,two aspects of the work are completed:one is to establish the optimal model of the cost of the sintering process,and the most suitable temperature for the sintering process.The second is the analysis of harmful components produced in sintering process.

Policy Capital Research on Cultivating High-Quality Farmers in the Context of Rural Revitalization

The Law of the People’s Republic of China on the Promotion of Rural Revitalization has come into effect on June 1,2021,which stipulates in Article 24 that the State shall improve the institutional mechanism for working with rural talents and promote the cultivation of high-quality farmers.In 2022 and 2023,the No.1 document of the Central Government both proposed“implementing a plan to cultivate high-quality farmers”,and in the report of the 20th Party Congress,General Secretary Xi once again emphasized“solidly promoting the revitalization of rural talents”.High-quality farmers have become the core talent component of the rural talent team.In this context,there is an urgent need for in-depth research on the cultivation of high-quality farmers in China.This paper takes the cooperative leaders in Shanghai as an example,summarizes the current situation of high-quality farmer cultivation in Shanghai through quantitative and qualitative analysis,and proposes policy capital,explores the remaining problems of high-quality farmer cultivation from the micro,meso and macro aspects of policy capital,and puts forward some targeted development opinions,hoping to help the cultivation of high-quality farmers.

Effects of physical properties of supercritical water on heat transfer characteristics of single particle within a particle cluster Author links open overlay panel

The complex physical properties of supercritical water(SCW)make the heat transfer characteristics of particles within a particle cluster complicated.The heat transfer characteristics of single particle within a particle cluster in SCW,influenced by surrounding particles,have not been effectively explored.The numerical simulations were conducted to investigate the heat transfer characteristics of particle clusters in SCW under different conditions.The results were compared and analyzed with those from constant property flow.It was found that Reynolds number(Re)and the void fraction of particle cluster have no special effects on the variation trends of Nusselt number(Nu)for the focused particle.However,the particle temperature had a significant effect on the variation trends of Nu.The effect of Re on the heat transfer rate exponent(η)of the focused particle can be divided into two zones:a significant effect zone and a non-significant effect zone.The effect of void fraction onηin the non-significant effect zone was minimal.Within the non-significant effect zone,ηdecreased with the increasing particle temperature.In the significant effect zone,the variation trends ofηbecame more complex.The fundamental reason for this series of phenomena is the changes in distribution of physical properties.A model forηwas developed for the non-significant effect zone.This model can filter out the effects of Re and certain particle cluster spatial configurations,and it demonstrates good predictive performance.

A numerical investigation on heat transfer characteristics of a particle cluster in fluid with variable properties

This work investigates the heat transfer characteristics of particle clusters under the effects of the complex properties of supercritical water(SCW).It analyzes the heat transfer characteristics of sub-particles and the average heat transfer characteristics of particle clusters.The results reveal a phenomenon of shifting positions of high specific heat regions.It led to variations in the dimensionless heat transfer coefficient distribution.Furthermore,the results indicate that as the heat transfer process strengthens,the effects of variations in property distribution on heat transfer tends to stabilize.Based on this conclusion,the effects of variations in property distribution on heat transfer are categorized into Stable Effects Region and Non-Stable Effects Region.By utilizing the principles of fluid flow-heat transfer coupling and similarity,a heat transfer prediction model for particle clusters in SCW is established.

Revitalizing sodium-ion batteries via controllable microstructures and advanced electrolytes for hard carbon

Sodium-ion batteries(SIBs)with low cost and high safety are considered as an electrochemical energy storage technology suitable for large-scale energy storage.Hard carbon,which is inexpensive and has both high capacity and low sodium storage potential,is regarded as the most promising anode for commercial SIBs.However,the commercialization of hard carbon still faces technical issues of low initial Coulombic efficiency,poor rate performance,and insufficient cycling stability,due to the intrinsically irregular microstructure of hard carbon.To address these challenges,the rational design of the hard carbon microstructure is crucial for achieving high-performance SIBs,via gaining an in-depth understanding of its structure-performance correlations.In this context,our review firstly describes the sodium storage mechanism from the perspective of the hard carbon microstructure's formation.We then summarize the state-of-art development of hard carbon,providing a critical overview of emergence of hard carbon in terms of precursor selection,microstructure design,and electrolyte regulation to optimize strategies for addressing practical problems.Finally,we highlight directions for the future development of hard carbon to achieve the commercialization of high-performance SIBs.We believe this review will serve as basic guidance for the rational design of hard carbon and stimulate more exciting research into other types of energy storage devices.

Biocompatible carbon dots with low-saturation-intensity and highphotobleaching-resistance for STED nanoscopy imaging of the nucleolus and tunneling nanotubes in living cells

Many kinds of nano particles and organic dyes as fluorescent probes have been used in the stimulated emission depletion(STED)nanoscopy.Due to high toxicity,photobleaching and non-water solubility,these fluorescent probes are hard to apply in living cell imaging.Here,we reporta new fluorescence carbon dots(FNCDs)with high photoluminescence quantum yield(56%),low toxicity,anti-photobleaching and goodwater-solubility that suitable for live-cell imaging can be obtained by doping fluorine element.Moreover,the FNCDs can stain the nucleolusand tunneling nanotubes(TNTs)in the living cell.More importantly,for STED nanoscopy imaging,the FNCDs effectively depleted backgroundsignals and improved imaging resolution.Furthermore,the lateral resolution of single FNCDs size under the STED nanoscopy is up to 22.1 nm for FNCDs deposited on a glass slide was obtained.And because of their good water dispersibility,the higher resolution of single FNCDs sizein the nucleolus of a living cell can be up to 19.7 nm.After the image optimizati on steps,the fine fluoresce nee images of TNTs diameter with ca.75 nm resolution is obtained living cell,yielding a threefold enhancement compared with that in confocal imaging.Additionally,the FNCDs show excellent photobleaching resistance after 1,000 scan cycles in the STED model.All results show that FNCDs have significant potentialfor application in STED nanoscopy.

锌离子传导聚合物缓冲层:抑制锌离子水电池锌负极寄生反应

由于锌金属在电解液中热力学不稳定而自发地发生寄生反应(析氢、枝晶生长等),水系锌离子电池的商业化应用受到了阻碍.因此,我们构建了一种高粘附性的锌离子传导聚合物聚乙烯醇缩甲醛(PVF)缓冲层,来抑制这些寄生反应的发生,从而提高锌沉积的可逆性.这种致密的人工缓冲层不仅能有效隔绝电解质与锌负极之间的直接接触,还能适应锌沉积/剥离过程中的体积膨胀,并引导锌成核过程.具体来说,PVF层可提高成核过电位,并促进Zn2+的三维扩散过程,使PVF层下的Zn2+沉积通量均匀化.我们设计的PVF@Zn具有高循环稳定性和不易生成枝晶的特点,基于该电极的对称电池的长循环寿命超过5200 h,比Zn负极电池提高了近35倍,甚至可以在40.0 mA cm^(−2)的超高电流密度下稳定运行.此外,PVF@Zn||NVO全电池在1.0 A g^(−1)的条件下进行2400个循环后,仍能保持172.4 mA h g^(−1)的比容量.这种通过消除自发寄生反应并调节锌均匀沉积及成核的策略,为设计实用化高性能锌负极提供了重要借鉴.

Realizing the highly reversible Zn^(2+)and Na^(+) dual ions storage in high-crystallinity nickel hexacyanoferrate microcubes for aqueous zinc-ion batteries

Prussian blue analogues(PBAs)with the 3D open framework are regarded as promising cathode candidates for aqueous Zinc ion batteries(ZIBs).Among various PBAs,nickel hexacyanoferrate(NiHCF)has attracted considerable attention because of its high operating voltage and economic merit.However,the cyclability of NiHCF is unsatisfactory due to poor structural stability during Zn^(2+) ions insertion/deinsertion.Moreover,the ion storage mechanism of NiHCF in aqueous electrolytes has not been fully revealed yet.Herein,high-crystallinity NiHCF(HC-NiHCF)microcubes with improved structural stability and larger crystal plane spacing are synthesized.For the first time,highly reversible Zn2+ions and Na+ions co-insertion/extraction are achieved for the HC-NiHCF microcubes in mixed aqueous electrolyte,as evidenced by various observations including two separated discharge plateaus and sequential changes of Na 1s and Zn 2p signals in ex-situ X-ray photoelectron spectroscopy(XPS).As a result,a high specific capacity of 73.9 mAh g^(−1) is obtained for the HC-NiHCF microcubes at 0.1 A g−1,combined with enhanced cycle stability(75%vs.16.4%)over 1000 cycles at 2 A g^(−1).The reversible Zn^(2+) ions and Na+ions co-insertion in HC-NiHCF microcubes reveals a new ion storage mechanism of Ni-based PBAs in aqueous electrolytes.

Effects of physical properties of supercritical water on coarse graining of particle cluster

The coarse graining of particle cluster is of great significance to the study of a fluidized bed. The effects of variations in the physical properties of supercritical water on the coarse graining of particle cluster are investigated in this work. The drag coefficient distributions of the particle cluster are not influenced by the physical properties. However, the physical properties have effects on the values of drag coefficient. The effects of physical properties are weaker in the case of large particle concentrations. Furthermore, the physical properties lead to that the effect of particle cluster wake on the drag of downstream particles being significantly different from that of constant property flow. The variation trend of drag of coarse graining particle is consistent with that of isolated particle. The physical properties lead to significant differences in the values of drag. In this paper, the dominance of the effects of physical properties in a variety of cases is confirmed. Finally, a physical properties effect model is developed accordingly.

Tuning the Oxygen Anionic Redox Reversibility in Na_(0.67)Mn_(0.8)Fe_(0.1)Co_(0.1)O_(2)Through Sn Doping

Oxygen anion redox chemistry in layered oxide cathodes for sodium-ion batteries has attracted great interest.However,the release of lattice oxygen caused by the irreversible anionic redox and Jahn–Teller effect accelerates the structural distortion and electrochemical degradation.Herein,we rationally construct a stable crystal lattice to enhance the reactivity and reversibility of oxygen redox and inhibit the Jahn–Teller effect by Sn doping.The stronger binding energy of Sn–O enhances the structural stability of the cathode,which is favorable to suppress the oxygen release and Jahn–Teller effect.Thus,the reversibility of oxygen redox and the stability of the layered structure are enhanced.The expansion of the interlayer spacing decreases the energy barriers for Na+ion intercalation,improving the rate performance of the electrode.Benefitting from the rational design,the electrode delivers an enhanced rate performance and cycling stability.This work offers some insights into tuning the oxygen anion redox chemistry as well as suppressing the Jahn–Teller effect by lattice modulation.