Polymer engineering for electrodes of aqueous zinc ion batteries

With the increasing demand for scalable and cost-effective electrochemical energy storage,aqueous zinc ion batteries(AZIBs)have a broad application prospect as an inexpensive,efficient,and naturally secure energy storage device.However,the limitations suffered by AZIBs,including volume expansion and active materials dissolution of the cathode,electrochemical corrosion,irreversible side reactions,zinc dendrites of the anode,have seriously decelerated the civilianization process of AZIBs.Currently,polymers have tremendous superiority for application in AZIBs attributed to their exceptional chemical stability,tunable structure,high energy density and outstanding mechanical properties.Considering the expanding applications of AZIBs and the superiority of polymers,this comprehensive paper meticulously reviews the benefits of utilizing polymeric applied to cathodes and anodes,respectively.To begin with,with adjustable structure as an entry point,the correlation between polymer structure and the function of energy storage as well as optimization is deeply investigated in respect to the mechanism.Then,depending on the diversity of properties and structures,the development of polymers in AZIBs is summarized,including conductive polymers,redox polymers as well as carbon composite polymers for cathode and polyvinylidene fluoride-,carbonyl-,amino-,nitrile-based polymers for anode,and a comprehensive evaluation of the shortcomings of these strategies is provided.Finally,an outlook highlights some of the challenges posed by the application of polymers and offers insights into the potential future direction of polymers in AZIBs.It is designed to provide a thorough reference for researchers and developers working on polymer for AZIBs.

An Environment-Friendly High-Performance Aqueous Mg-Na Hybrid-Ion Battery Using an Organic Polymer Anode

Aqueous Mg ion batteries(AMIBs)show great potential in energy storage for their advantages of high capacity,abundant resource,and environmental friendliness.However,the development of AMIBs is limited due to the scarcity of suitable anode materials.In this study,a new polymer anode material(PNTAQ)with flower-like nanosheet structure is synthesized for aqueous Mg-Na hybrid-ion battery(AMNHIB).PNTAQ possess carbonyl functional groups which can be oxidized and reduced reversibly in aqueous solution containing alkaline metal ions.PNTAQ displays a discharge specific capacity of 245 mAh g^(−1)at 50 mA g^(−1)in 1 M MgCl_(2)+0.5 M NaCl electrolyte,which is much higher than that in single 1 M MgCl_(2)or 0.5 M NaCl electrolyte.Even cycling at 1000 mA g^(−1)for 1000 times,the capacity retention can still maintain at 87.2%.A full Mg-Na hybrid-ion cell is assembled by employingβ-MnO_(2)as cathode and PNTAQ as anode material,it exhibits a specific capacity of 91.6 mAh g^(−1)at 100 mA g^(−1).The polymer electrode material well maintains its framework structure during the discharge/charge cycling process of the hybrid-ion battery.

Dispersion polymerization of anionic polyacrylamide in an aqueous salt medium

Anionic polyacrylamide dispersions were prepared by dispersion polymerization in an aqueous salt medium, using acrylamide（AM） and acrylic acid（AA） as monomers and anionic polyelectrolytes as stabilizer. Effects of salt concentration, and molecular weight and concentration of stabilizers on the stability of the dispersions were investigated using a HAAKE rheometer and optical microscopy. The results showed that stable anionic polyacrylamide dispersions, consisting of smooth, spherical, polydisperse particles, could be obtained under the conditions of salt concentration ranging from 26 wt% to 30 wt%, concentration of stabilizers from 1.2 wt% to 1.8 wt%, and intrinsic viscosity of stabilizers from 2.98 dL·g^-1 to 3.74 dL·g^-1. The apparent viscosity of the stable dispersions changed very little with the shear rate, showing Newton fluid behavior.

AQUEOUS STABLE FREE RADICAL POLYMERIZATION PROCESSES

An overview of aqueous polymerizations, which include emulsion, miniemulsion and suspension polymerizations, under stable free radical polymerization (SFRP) conditions is presented. The success of miniemulsion and suspension SFRP polymerizations is contrasted with the difficulties associated with obtaining a stable emulsion polymerization. A recently developed unique microprecipitation technique is referenced as a means of making submicron sized particles that can be used to achieve a stable emulsion SFRP process.

A dual redox-active and robust polymer enables ultrafast and durable proton-storage capability

Aqueous proton batteries(APBs) offer a viable and attractive option in the field of affordable and sustainable energy solutions.Organic polymers are highly favored due to their environmentally friendly manufacturability and malleable molecular configurations,making them suitable materials for constructing APB electrodes.Nonetheless,their currently limited capacity for proton-associated redox reactions poses a challenge to the widespread usage.Herein,we have developed a highly redox-active organic polymer(PTA) tailored for APB applications.The inclusion of dual redox-active moieties in the extended nconjugated frameworks not only enhances the redox activity and refines the electronic properties,but also ensures the high structural integrity of the PTA polymer.When used as an electrode,the PTA polymer has a notable ability to store protons,with a large capacity of 213.99 mA h g^(-1) at 1 A g^(-1) and exceptional long-term stability,as evidenced by retaining 94.6% of its initial capacity after 20,000 cycles.In situ techniques alongside theoretical calculations have unveiled efficient redox processes occurring at C=N and C=O redox-active sites within the PTA electrode upon proton uptake/removal.Furthermore,a softpackage APB device has been assembled with impressive electrochemical behaviors and excellent operational lifespan,accentuating its significant promise for real-world deployment.

OXIDATIVE POLYMERIZATION BEHAVIOR OF 2,6-DIMETHYLPHENOL IN AQUEOUS MEDIA WITH POTASSIUM FERRICYANIDE

The effects of potassium ferricyanide,sodium n-dodecyl sulfate,sodium hydroxide and temperature on the molecular weight and the yield of poly(2,6-dimethyl-1,4-phenylene oxide)(PPO) synthesized in an aqueous medium were studied.It was found that oxygen in air had little influence on the oxidative polymerization of 2,6-dimethylphenol(DMP) in the aqueous medium,and potassium ferricyanide was only an oxidant during the oxidative polymerization of DMP.Sodium n-dodecyl sulfate could stabilize polymer particles an...

Aqueous Self-Assembly of Block Copolymers to Form Manganese Oxide-Based Polymeric Vesicles for Tumor Microenvironment-Activated Drug Delivery

Molecular self-assembly is crucially fundamental to nature.However,the aqueous self-assembly of polymers is still a challenge.To achieve self-assembly of block copolymers [(polyacrylic acid-block-polyethylene glycol-block-polyacrylic acid(PAA68-b-PEG86-b-PAA68)] in an aqueous phase,manganese oxide(MnO2) is first generated to drive phase separation of the PAA block to form the PAA68-b-PEG68-b-PAA68/MnO2 polymeric assembly that exhibits a stable structure in a physiological medium.The polymeric assembly exhibits vesicular morphology with a diameter of approximately 30 nm and high doxorubicin(DOX) loading capacity of approximately 94%.The transformation from MnO2 to Mn2+caused by endogenous glutathione(GSH)facilitates the disassembly of PAA68-b-PEG68-b-PAA68/MnO2 to enable its drug delivery at the tumor sites.The toxicity of DOXloaded PAA68-b-PEG68-b-PAA69/MnO2 to tumor cells has been verified in vitro and in vivo.Notably,drug-loaded polymeric vesicles have been demonstrated,especially in in vivo studies,to overcome the cardiotoxicity of DOX.We expect this work to encourage the potential application of polymer self-assembly.

Long-lifespan aqueous alkaline and acidic batteries enabled by redox conjugated covalent organic polymer anodes

Herein,we introduce a redox conjugated covalent organic polymer(p-HATN,HATN=hexaazatrinaphthylene)anode bearing HATN species for long-lifespan aqueous alkaline and acidic batteries.The p-HATN features intriguing superhydrophilicity and unique wide pH adaptability,while the conjugated network and amorphous cross-linked structure further endow p-HATN with improved electron transport,facile ion diffusion and superior acid-alkali tolerability.As a result,p-HATN exhibits fast surface-controlled redox activity and superior stability for K^(+)and H^(+)ions storage with remarkable capacity retentions in three-electrode cells(88%capacity retention in 13 M KOH over 30000 cycles;nearly 100%capacity retention in 0.5 M H_(2)SO_(4)over 54000 cycles).Moreover,the assembled p-HATN//Ni(OH)_(2)cell with 13 M KOH and p-HATN//PbO_(2)cell with 0.5 M H_(2)SO_(4)also achieve ca-pacity retentions of 83%retention over 55000 cycles and 92%over 15000 cycles,respectively,outperforming most similar systems.This work sheds light on the rational design of advanced polymer anodes for long-lifespan alkaline and acidic batteries.

“Co-coordination force”assisted rigid-flexible coupling crystalline polymer for high-performance aqueous zinc-organic batteries

Organic electrode materials(OEMs)have attracted substantial attention for aqueous zinc-ion batteries(AZIBs)due to their advantages in relieving resource and environmental anxiety.However,the potential of OEMs is plagued by their low achievable capacity and high solubility.Here,we have proposed a new concept of“co-coordination force”and designed a rigid-flexible coupling crystalline polymer that can overcome the abovementioned limitations.The obtained crystalline polymer(BQSPNs)with multiredox centres makes the BQSPNs exist intermolecular hydrogen bonds(HB)among-C=O,-C=N,and-NH and consequently exhibits transverse two-dimensional arrays and longitudinalπ-πstacking structure.Additionally,in-situ FTIR,Raman,variable temperature FTIR spectra,and 2D nuclear overhauser effect spectroscopy(NOESY)well capture the existence and evolution process of HB during the electrochemistry reaction process of BQSPNs,uncovering the effect of HB in stabilizing the structure and promoting the reaction kinetics.As a result,the BQSPNs with rationally designed“co-coordination force”deliver a high capacity of 459.6 m Ah/g and a stable cycling lifetime for more than 100,000 cycles at 10 A/g in AZIBs.Our results disclose the HB effect and provide a brand-new strategy for high-performance OEMs design.

Aqueous Two-Phase Interfacial Assembly of COF Membranes for Water Desalination

Aqueous two-phase system features with ultralow interfacial tension and thick interfacial region,affording unique confined space for membrane assembly.Here,for the first time,an aqueous two-phase interfacial assembly method is proposed to fabricate covalent organic framework(COF)membranes.The aqueous solution containing polyethylene glycol and dextran undergoes segregated phase separation into two water-rich phases.By respectively distributing aldehyde and amine monomers into two aqueous phases,a series of COF membranes are fabricated at water-water interface.The resultant membranes exhibit high NaCl rejection of 93.0-93.6% and water permeance reaching 1.7-3.7 L m^(−2) h^(−1) bar^(−1),superior to most water desalination membranes.Interestingly,the interfacial tension is found to have pronounced effect on membrane structures.The appropriate interfacial tension range(0.1-1.0 mN m^(−1))leads to the tight and intact COF membranes.Furthermore,the method is extended to the fabrication of other COF and metal-organic polymer membranes.This work is the first exploitation of fabricating membranes in all-aqueous system,confering a green and generic method for advanced membrane manufacturing.

Experimental investigation on the spread of aqueous foam over ethanol surface

The presence of ethanol has an adverse effect on foam spreading,and ethanol fire is difficult to extinguish with aqueous fire-fighting foams.Thus,it is necessary to explore the foam formulation suitable for ethanol fuels and study the spreading behavior of foam over ethanol surface.In the current work,stable foams based on hydrocarbon surfactant(SDS),fluorocarbon surfactant(FC1157),and polymers(XG)were prepared by using the compressed-air foam system.The spreading behaviors of foam on polar ethanol and non-polar heptane surface were observed and compared.Furthermore,the effects of stabilizer concentrations,foam flow rates and expansion ratios on foam spreading performance were investigated,respectively.The results indicate that aqueous SDS foam can spread on the heptane layer continuously,but it is difficult to cover the ethanol surface.The addition of XG and FC1157 can synergistically improve the spreading performance of aqueous foam over ethanol.Depending on stabilizer concentrations,there are remarkable differences in foam spreading behaviors.Besides,different foam application parameters including expansion ratios and foam flow rates significantly affect the foam spreading rate,despite the same foam formulation.The research methods and results guide the optimal design of foam formulations as well as the practical application of aqueous foam for ethanol fire extinguishment.

Synthesis and Characterization of a Novel Aqueous Dispersion Poly[urethane-(disperse blue 14)-urethane] Dye

A novel polymeric dye of aqueous dispersion poly[urethane-(disperse blue 14)-urethane] was synthesized based on poly(propylene glycol) (PPG), 2, 4-tolylene diisocyanate (TDI), klimethylol propionic acid (DMPA), disperse blue 14 and triethylamine (TEA) depending on a modified acetone process. Fourier transform infrared spectroscopy (FTIR) was used to identify Lhe structure of the polymeric dye, indicating an obvious carbonyl stretching absorption in disperse blue 14. The polymer was also characterized by the analysis of DSC, TGA, WAXD and UV-Vis spectroscopy.

An Ion-imprinted Silica Gel Polymer Prepared by Surface Imprinting Technique Combined with Aqueous Solution Polymerization for Selective Adsorption of Ni(Ⅱ) from Aqueous Solution

A novel Ni（Ⅱ） ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPS） as a functional monomer for the selective separation of Ni（Ⅱ） from aqueous solution. The sorbent showed good chemical and thermal stability. Kinetics studies indicated that the equilibrium adsorption was achieved within 10 min and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The maximum adsorption capacity of the ion-imprinted polymer towards Ni（Ⅱ） at the optimal p H of 7.0 was 66.22 mg·g^（-1）. The relative selectivity coefficients of the sorbent were 9.23, 15.71, 14.72 and 20.15 for Ni（Ⅱ）/Co（Ⅱ）, Ni（Ⅱ）/Cu（Ⅱ）, Ni（Ⅱ）/Zn（Ⅱ） and Ni（Ⅱ）/Pb（Ⅱ）, respectively. The adsorption isotherm fitted well with Langmuir isotherm model. The thermodynamic results indicated that the adsorption of Ni（Ⅱ） was a spontaneous and endothermic process. The sorbent showed good reusability evidenced by six cycles of adsorption/desorption experiments. The precision of this method is satisfactory. Thus, the prepared sorbent can be considered as a promising sorbent for selective separation of Ni（Ⅱ） in real water samples.

Aqueous RAFT Polymerization of Acrylamide： A Convenient Method for Polyacrylamide with Narrow Molecular Weight Distribution

Controlled and homogeneous flee-radical polymerization of acrylamide （AM） in aqueous phase was realized by using S,S＇-bis（α, α＇-dimethyl-α＂-acetic acid）-trithiocarbonate as a reversible addition-fragmentation transfer （RAFT） agent. Linear increases in molecular weight with conversion and narrow molecular weight distribution were observed for polyacrylamide （PAM） throughout the polymerization. By this method, PAMs with controlled molecular weight （up to 1.0 ~ 106） and narrow molecular weight distribution （Mw/Mn 〈 1.2） were prepared. This study provides an effective method for synthesis of PAMs with narrow molecular weight distribution under environmentally friendly conditions.

Chromatographic Characterization of Molecularly Imprinted Microspheres Synthesized by Aqueous Microsuspension Polymerization: Influences of pH, Kinds and Concentration of Buffer on Capacity Factors

Molecularly imprinted microspheres (MIMs) were prepared using 4-aminopyridine (4-AP) as template molecule by aqueous microsuspension polymerization. The MIMs were packed into stainless steel column (250×4.6 mm I.D.) for selective separation of 4-aminopyridine (4-AP) and 2-aminopyridine (2-AP). The influences of pH, kinds and concentration (c) of buffer on capacity factors were investigated in detail. The relationships of capacity factor (k′) with pH and concentration of buffer are quantitatively described firstly. The effects of pH of phosphate and acetate buffer on capacity factors are very different. The relationship between k′ and pH can be described by the following equation: k′=-8.23 + 9.23 pH-0.99 pH 2 (in phosphate buffer) with R 2=0.9775 and k′=6.79-3.76 pH + 0.68 pH 2 (in acetate buffer) with R 2=0.9866. Furthermore, the capacity factors were also greatly affected by the concentration of acetate buffer in mobile phase while non-imprinted molecule is poorly changed. It increases with decreasing the concentration of buffer-especially in low concentration buffer (c acetate<0.02 mol/L, final concentration in mobile phase). The fit curve of log k′ to log c is described by equation: log k′=-0.571-1.256×log c-0.186×(log c) 2 with R 2=0.9979. The ratio of acetate buffer to methanol was investigated and the optimal ratio for separation of 4-AP and 2-AP is below 1∶7.5 (V/V).

A widely used nonionic surfactant with desired functional groups as aqueous electrolyte additives for stabilizing Zn anode

Aqueous Zn-ion batteries(AZIBs) have emerged as potential candidates for Li-ion batteries due to their intrinsic safety and high capacity.However,metallic Zn anodes encounter dendrite growth and water-induced corrosion,rendering poor stability and severe irreversibility at the electrode/electrolyte interface during cycling.To stabilize the Zn anode,we report a low-cost and effective nonionic surfactant,Tween-20 polymer,as an electrolyte additive for AZIBs.For Tween-20,sequential oxyethylene groups tended to be preferentially adsorbed on the Zn electrode to form a shielding layer for regulating uniform Zn nucleation.Moreover,the hydrophobic hendecyl chains prevented H_(2)O-induced corrosion on the Zn anode surface.Benefiting from the desired functional groups,when only trace amounts of Tween-20(0.050 g·L^(-1)) were used,the Zn anode displayed good cycling stability over 2170 h at10 mA·cm^(-2) and a high average Coulombic efficiency of98.94% over 1000 cycles.The Tween-20 polymer can also be effectively employed in MnO_(2)/Zn full batteries.Considering their toxicity,price and amount of usage,these surfactant additives provide a promising strategy for realizing the stability and reversibility of high-performance Zn anodes.

Iterative design of polymer fabric cathode for metal-ion batteries

Organic electrode materials(OEMs)have attracted significant attention for use in aqueous zinc-ion batteries(AZIBs)because of their abundant resources and flexible designability.However,the development of high-performance OEMs is strongly hindered by their high solubility,poor conductivity,sluggish ion diffusion kinetics,and difficult coordination toward Zn^(2+).Herein,inspired by fabric crafts,we have designed a robust polymer fabric through the iterative evolution of the building blocks from point to line and plane.The evolution from point to line could not only improve the structural stability and electrical conductivity but also adjust the active site arrangement to enable the storage of Zn^(2+).In addition to further boosting the aforementioned properties,the evolution from line to plane could also facilitate the construction of noninterference channels for ion migration.Accordingly,the poly(1,4,5,8-naphthalenete tracarboxylic dianhydride/2,3,5,6-tetraaminocyclohexa-2,5-diene-1,4-dione)(PNT)polymer fabric has the most enhanced structural stability,optimized active site arrangement,improved electrical conductivity,and suitable ion channels,resulting in a record-high capacity retention of 96%at a high mass loading of 56.9 mg cm-2and a stable cycle life of more than 20,000 cycles at 150 C(1 C=200 mA g^(-1))in AZIBs.In addition,PNT exhibits universality for a wide range of ions in organic electrolyte systems,such as Li/Na/K-ion batteries.Our iterative design of polymer fabric cathode has laid the foundation for the development of advanced OEMs to promote the performance of metal-ion batteries.

Manipulating crystallographic growth orientation bycation-enhanced gel-polymer electrolytes toward reversiblelow-temperature zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) have garnered significant research interestas promising next-generation energy storage technologies owing to theiraffordability and high level of safety. However, their restricted ionic conductivityat subzero temperatures, along with dendrite formation and subsequentside reactions, unavoidably hinder the implementation of grid-scale applications.In this study, a novel bimetallic cation-enhanced gel polymer electrolyte(Ni/Zn-GPE) was engineered to address these issues. The Ni/Zn-GPE effectivelydisrupted the hydrogen-bonding network of water, resulting in a significantreduction in the freezing point of the electrolyte. Consequently, thedesigned electrolyte demonstrates an impressive ionic conductivity of 28.70 m^(-)cm^(-1) at 20℃. In addition, Ni^(2+) creates an electrostatic shielding interphaseon the Zn surface, which confines the sequential Zn^(2+) nucleation and depositionto the Zn (002) crystal plane. Moreover, the intrinsically high activationenergy of the Zn (002) crystal plane generated a dense and dendrite-free plating/stripping morphology and resisted side reactions. Consequently, symmetricalbatteries can achieve over 2700 hours of reversible cycling at 5 mA cm^(-2),while the Zn jj V_(2)O_(5) battery retains 85.3% capacity after 1000 cycles at -20℃.This study provides novel insights for the development and design of reversiblelow-temperature zinc-ion batteries.

A personal journey on using polymerization in aqueous dispersed media to synthesize polymers with branched structures

This short review is dedicated to celebrate Prof.Shoukuan Fu’s 80 th birthday by discussing several of my accomplished projects over the past twenty years,which all applied radical polymerization in aqueous dispersed media for producing polymers with branched structures.These projects include the use of microemulsion polymerization for syntheses of fluorescent nanoparticles,hairy nanoparticles and hyperbranched polymers;the use of miniemulsion polymerization for synthesis of star polymers and light-emitting nanoparticles;the use of seeded emulsion polymerization for synthesis of hairy nanoparticles and hyperstar polymers;and the use of precipitation polymerization for synthesis of hollow polymer nanocapsules.Discussion of these projects demonstrates intriguing features of polymerization in biphasic dispersed media via either conventional radical polymerization or controlled radical polymerization to effectively regulate the branched structure of functional polymers.

Linear polymer aqueous solutions in soft lubrication:From boundary to mixed lubrication

In order to better understand linear polymer aqueous solutions in soft lubrication from boundary to mixed lubrication,poly(ethylene glycol) and sodium hyaluronateare used as model polymers were investigated by using UMT-2 tribometer with the ball-on-disk mode. The relationship between the master Stribeck curves of the polymer aqueous solutions and the influence factors were investigated. Experimental results indicated that soft lubrication is determined by lubricant rheological properties and surface-lubricant interactions, e.g., wetting behavior of polymer aqueous solution on tribological surfaces.