FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W3128082604> ?p ?o ?g. }

• W3128082604 endingPage "1304" @default.
• W3128082604 startingPage "1287" @default.
• W3128082604 abstract "•Single Zn2+-ion polymeric conductor was reported for the first time•Cost of PAN membrane is ∼$400 m−2, much lower than bipolar membrane (∼$3,200 m−2)•Atomically dispersed Co electrocatalysts stably catalyze ORR and OER in acid media•The assembled asymmetric MABs deliver higher performance than recently reported MABs Metal–air batteries (MABs) based on earth-abundant metals (e.g., Zn, Si, Fe, Sn) are promising candidates for energy storage due to their high theoretical energy densities and potentially low capital cost (<$150/kWh, DOE, 2023 target). However, MABs using aqueous electrolytes deliver low cell voltage resulting in inferior energy densities. Construction of asymmetric-electrolyte metal–air batteries (AMABs) can substantially improve the cell voltage. Nonetheless, the performance of state-of-the-art AMABs employing either NASICON-type ceramic membrane or bipolar polymer membrane is far from satisfactory due to the issues such as low ion conductivity and crossover of H+ and OH− ions. Here, we report a cost-effective polyacrylonitrile (PAN)-based membrane that can selectively transport Zn2+ ions while inhibiting crossover of H+ and OH− ions. The corresponding AMABs (metals Zn, Si, Sn) show significantly enhanced battery performance that surpasses most of recently reported MABs. Asymmetric-electrolyte metal–air batteries (AMABs) deliver high operating voltage and energy density. However, the demand for ion-selective transport separator and precious metal electrocatalysts hampers their applications. To address this issue, we develop a polyacrylonitrile (PAN) separator that can selectively transport Zn2+ ions and an atomically dispersed Co electrocatalyst that can catalyze oxygen evolution reactions (OERs) and oxygen reduction reactions (ORRs) in the challenging acidic medium. The selective ion transport behavior was associated with the Zn2+ ions’ bonded ladder structure of PAN, which raises the ion migration energy barrier for the crossover of H+ and OH−. In terms of electrocatalysts, extensive ex situ and in situ characterizations suggest that Co single-atom sites stably catalyze the OER and ORR. Several types of AMABs (metals Zn, Si, Sn) were tested. The assembled asymmetric metal–air Zn-, Si-, and Sn-air batteries delivered enhanced battery performance that surpassed those of recently reported Zn-, Si-, and Sn-air batteries, respectively. Asymmetric-electrolyte metal–air batteries (AMABs) deliver high operating voltage and energy density. However, the demand for ion-selective transport separator and precious metal electrocatalysts hampers their applications. To address this issue, we develop a polyacrylonitrile (PAN) separator that can selectively transport Zn2+ ions and an atomically dispersed Co electrocatalyst that can catalyze oxygen evolution reactions (OERs) and oxygen reduction reactions (ORRs) in the challenging acidic medium. The selective ion transport behavior was associated with the Zn2+ ions’ bonded ladder structure of PAN, which raises the ion migration energy barrier for the crossover of H+ and OH−. In terms of electrocatalysts, extensive ex situ and in situ characterizations suggest that Co single-atom sites stably catalyze the OER and ORR. Several types of AMABs (metals Zn, Si, Sn) were tested. The assembled asymmetric metal–air Zn-, Si-, and Sn-air batteries delivered enhanced battery performance that surpassed those of recently reported Zn-, Si-, and Sn-air batteries, respectively. Electricity storage will play a central role in future energy systems by providing service in the entire electricity value chain. The demand for developing advanced batteries with high safety, low cost, large energy density, and environmental friendliness is therefore immense. Metal–air batteries (MABs) with high theoretical specific energy densities are ideal candidates, and they have demonstrated great potential in various applications ranging from grid energy peak shifts to personal electronics.1Chen Y. Ji S. Zhao S. Chen W. Dong J. Cheong W.-C. Shen R. Wen X. Zheng L. Rykov A.I. et al.Enhanced oxygen reduction with single-atomic-site iron catalysts for a zinc-air battery and hydrogen-air fuel cell.Nat. Commun. 2018; 9: 5422Crossref PubMed Scopus (404) Google Scholar, 2Wang H.-F. Xu Q. Materials design for rechargeable metal-air batteries.Matter. 2019; 1: 565-595Abstract Full Text Full Text PDF Scopus (188) Google Scholar, 3Huang Y. Wang Y. Tang C. Wang J. Zhang Q. Wang Y. Zhang J. Atomic modulation and structure design of carbons for bifunctional electrocatalysis in metal–air batteries.Adv. Mater. 2019; 31: 1803800Crossref PubMed Scopus (156) Google Scholar MABs that use earth-abundant metals such as Fe, Zn, Si, and Sn in environmentally benign aqueous alkaline electrolytes have recently received interest due to their high tolerance to moisture, non-flammable nature, good material recyclability, as well as ease of manufacturing.4Han X. Li X. White J. Zhong C. Deng Y. Hu W. Ma T. Metal–air batteries: from static to flow system.Adv. Energy Mater. 2018; 8: 1801396Crossref Scopus (99) Google Scholar,5Li Y. Lu J. Metal–air batteries: will they be the future electrochemical energy storage device of choice?.ACS Energy Lett. 2017; 2: 1370-1377Crossref Scopus (441) Google Scholar However, several challenges arising from the use of aqueous electrolyte must be urgently addressed as follows6Mainar A.R. Iruin E. Colmenares L.C. Kvasha A. De Meatza I. Bengoechea M. Leonet O. Boyano I. Zhang Z. Blazquez J.A. et al.An overview of progress in electrolytes for secondary zinc-air batteries and other storage systems based on zinc.J. Energy Storage. 2018; 15: 304-328Crossref Scopus (183) Google Scholar,7Fu J. Cano Z.P. Park M.G. Yu A. Fowler M. Chen Z. Electrically rechargeable zinc–air batteries: progress, challenges, and perspectives.Adv. Mater. 2017; 29: 1604685Crossref Scopus (804) Google Scholar:(1)Low nominal cell voltage. The discharging voltage of conventional aqueous MABs is usually below 1.5 V (e.g., 1.0–1.4 V for Zn–air batteries [ZnABs], 0.5–1.0 V for Fe–air batteries [FeABs], and 0.8–1.2 V for Si–air batteries [SiABs]),8Cao Z.-Q. Wu M.-Z. Hu H.-B. Liang G.-J. Zhi C.-Y. Monodisperse Co9S8 nanoparticles in situ embedded within N, S-codoped honeycomb-structured porous carbon for bifunctional oxygen electrocatalyst in a rechargeable Zn–air battery.NPG Asia Mater. 2018; 10: 670-684Crossref Scopus (63) Google Scholar,9Weinrich H. Durmus Y.E. Tempel H. Kungl H. Eichel R.-A. Silicon and iron as resource-efficient anode materials for ambient-temperature metal-air batteries: a review.Materials (Basel). 2019; 12: 2134Crossref Google Scholar due to the low redox potential of the oxygen reduction reaction (ORR) under an alkaline electrolyte (∼0.4 V versus the standard hydrogen electrode [SHE]).10Cheng F. Chen J. Metal-air batteries: from oxygen reduction electrochemistry to cathode catalysts.Chem. Soc. Rev. 2012; 41: 2172-2192Crossref PubMed Scopus (1932) Google Scholar Consequently, the practical energy density is far from theoretical values.(2)Persistent ingression of CO2 from air. CO2 causes degradation of the alkaline electrolyte, and the insoluble carbonate product can block the air electrode. Recently, pioneered by Yu and Manthiram,11Yu X. Manthiram A. Electrochemical energy storage with mediator-ion solid electrolytes.Joule. 2017; 1: 453-462Abstract Full Text Full Text PDF Scopus (17) Google Scholar an attractive concept of asymmetric-electrolyte MABs (AMABs) was proposed. In AMABs, acidic electrolyte at the cathode (catholyte; e.g., H2SO4) and alkaline electrolyte at the anode (anolyte; e.g., KOH) are separated by an ion-conductive solid-electrolyte separator.11Yu X. Manthiram A. Electrochemical energy storage with mediator-ion solid electrolytes.Joule. 2017; 1: 453-462Abstract Full Text Full Text PDF Scopus (17) Google Scholar The acidic electrolyte facing the air electrode is free from CO2 poisoning issues. More importantly, the ORR in acidic conditions can give a more positive potential of ∼1.23 V versus SHE, leading to increased battery output voltage.12Koper M.T.M. Theory of multiple proton–electron transfer reactions and its implications for electrocatalysis.Chem. Sci. 2013; 4: 2710-2723Crossref Scopus (376) Google Scholar Taking the asymmetric Zn–air battery (AZnAB) as an example, its theoretical discharging voltage can reach as high as 2.48 V. However, the cost and performance of reported AMABs is far from the commercialization prerequisite due to lack of a cost-effective separator and electrocatalyst. There are two types of separators reported for AMABs to date. One is bipolar polymer membrane, which is fabricated by laminating the cation-exchange and anion-exchange membranes in series (∼$3,200/m2).13Cai P. Li Y. Chen J. Jia J. Wang G. Wen Z. An asymmetric-electrolyte Zn−Air battery with ultrahigh power density and energy density.ChemElectroChem. 2018; 5: 589-592Crossref Scopus (32) Google Scholar,14Cai P. Peng X. Huang J. Jia J. Hu X. Wen Z. Covalent organic frameworks derived hollow structured N-doped noble carbon for asymmetric-electrolyte Zn-air battery.Sci. China Chem. 2019; 62: 385-392Crossref Scopus (20) Google Scholar The crossover of H+ and OH− ions and the following neutralization cannot be avoided, resulting in frequent replenishment of fresh electrolytes. Another type is the NASICON (Na super ionic conductor)-type ceramic solid-state membrane, which allows selective transportation of Li+ or Na+ as mediator ions for charge balance between the anolyte and catholyte.15Yu X. Gross M.M. Wang S. Manthiram A. Aqueous electrochemical energy storage with a mediator-ion solid electrolyte.Adv. Energy Mater. 2017; 7: 1602454Crossref Scopus (18) Google Scholar Nonetheless, the limited ionic conductivity and high thickness (∼1 mm) of NASICON-type solid-state electrolyte (∼$6,000/kg) places restrictions on the power density and maximum discharging current density. Recently reported AZnABs and asymmetric Fe–air batteries based on NASICON-type solid-state electrolyte showed small power densities of 5 and 2 mW cm−2, respectively.15Yu X. Gross M.M. Wang S. Manthiram A. Aqueous electrochemical energy storage with a mediator-ion solid electrolyte.Adv. Energy Mater. 2017; 7: 1602454Crossref Scopus (18) Google Scholar,16Li L. Manthiram A. Long-life, high-voltage acidic Zn–air batteries.Adv. Energy Mater. 2016; 6: 1502054Crossref Scopus (77) Google Scholar Therefore, a breakthrough in separator for AMABs is urgently required. Electrocatalyst is another major challenge for AMABs. Electrocatalyst loaded at the air electrodes should possess bifunctional activities toward ORR and oxygen evolution reaction (OER) in acidic electrolyte during consecutive cycles of discharge and charge. Previous reports used precious metal catalyst and employed a decoupled air electrode design in which Pt and IrO2 loaded at different electrodes and separately catalyzed ORR and OER.15Yu X. Gross M.M. Wang S. Manthiram A. Aqueous electrochemical energy storage with a mediator-ion solid electrolyte.Adv. Energy Mater. 2017; 7: 1602454Crossref Scopus (18) Google Scholar,16Li L. Manthiram A. Long-life, high-voltage acidic Zn–air batteries.Adv. Energy Mater. 2016; 6: 1502054Crossref Scopus (77) Google Scholar The high cost of air electrode inevitably hampers the application. Bifunctional electrocatalysts based on earth-abundant metals are highly desirable but have been very rarely reported because metal leaching can hardly be avoided in acid, especially under anodizing OER condition. Here, we report breakthroughs in both the separator and electrocatalyst. In contrast to previously reported solid-electrolyte separator that transports Li+ or Na+, here we construct a solid polymer electrolyte separator based on polyacrylonitrile (PAN) that can electively and quickly transport divalent Zn2+ ions while inhibiting crossover of H+ and OH− ions. Extensive characterizations together with density functional theory (DFT) calculations suggest that the unique selective Zn ion transportation behavior originate from the ladder structure of PAN-bonded Zn2+ ions, which increases ion migration energy barrier for the crossover of H+ and OH−. In terms of electrocatalyst, we fabricate an atomically dispersed Co electrocatalyst supported by nitrogen-doped carbon nanosheet (Co/NS). We find that Co single-atom sites can survive in strong acid and catalyze ORR and OER, as shown by ex situ electron microscopy and in situ extended X-ray absorption fine structure (EXAFS) studies. Bifunctional Co electrocatalyst not only reduces the cost but also can simplify the battery design. An AZnAB was assembled using Zn2+ ion-selective transport membrane (ZnSTM) as the separator and carbon-supported atomic Co-based bifunctional electrocatalysts as the air electrodes. The operating voltage of the AZnAB increased by ∼50% as compared with conversional (ZnABs). The AZnAB also displays an ultrahigh specific energy density of 1,354 Wh kgZn−1 and a long cycle stability with a round-trip efficiency of 76.6%, which is superior to those of state-of-the-art rechargeable AZnABs. We also employed ZnSTM in asymmetric Si–air battery (ASiAB), and asymmetric Sn–air battery (ASnAB), in which Zn2+ ions serve as mediator ions to sustain charge transfer between the anolyte and catholyte. Significant enhancements in the battery performance were achieved due to the fast and selective Zn2+ ion transport properties. The corresponding ASiAB and ASnAB displayed enhanced operating voltage and power densities, and excellent rate performance, which surpasses that of recently reported Si–air batteries (SiABs) and Sn–air batteries (SnABs). The ZnSTM was synthesized by a facile casting method as shown in Figure 1A. First, Zn(OAc)2 and PAN (molecular weight [Mw]: 150,000) were dissolved in 1-methyl-2-pyrrolidone with intensive stirring at 80°C. The oxidative stabilization process occurred when the mixture was heated to 140°C in air. Cyclization is the key reaction in this step, which converts the triple-bond structure (C≡N) to a double-bond structure (C=N) with the formation of a Zn2+ anchored ladder structure.17Park O.-K. Lee S. Joh H.-I. Kim J.K. Kang P.-H. Lee J.H. Ku B.-C. Effect of functional groups of carbon nanotubes on the cyclization mechanism of polyacrylonitrile (PAN).Polymer. 2012; 53: 2168-2174Crossref Scopus (64) Google Scholar, 18Chen R. Hu Y. Shen Z. Pan P. He X. Wu K. Zhang X. Cheng Z. Facile fabrication of foldable electrospun polyacrylonitrile-based carbon nanofibers for flexible lithium-ion batteries.J. Mater. Chem. A. 2017; 5: 12914-12921Crossref Google Scholar, 19Abd Rahaman M.S. Ismail A.F. Mustafa A. A review of heat treatment on polyacrylonitrile fiber.Polym. Degrad. Stab. 2007; 92: 1421-1432Crossref Scopus (1028) Google Scholar The color of the solution changed from white to dark red after polymerization, which has been regarded as evidence of the formation of a typical ladder structure.19Abd Rahaman M.S. Ismail A.F. Mustafa A. A review of heat treatment on polyacrylonitrile fiber.Polym. Degrad. Stab. 2007; 92: 1421-1432Crossref Scopus (1028) Google Scholar Finally, the crosslinking reactions between the adjacent ladder polymeric molecular chains develop the interconnections between molecules of PAN,19Abd Rahaman M.S. Ismail A.F. Mustafa A. A review of heat treatment on polyacrylonitrile fiber.Polym. Degrad. Stab. 2007; 92: 1421-1432Crossref Scopus (1028) Google Scholar resulting in the formation of a mechanically stable and flexible polymer membrane (Figure 1B). The physical properties of ZnSTM were measured. ZnSTM demonstrated decent mechanical stability with its tensile strength of ZnSTM determined to be ∼0.8 MPa (Figure S1). Figure 1C shows the cross-sectional SEM image of ZnSTM that is free of pinholes, and the corresponding energy dispersive spectroscopy (EDS) mapping images demonstrate the homogeneous distribution of C, N, and Zn through the membrane (Figure S2). The X-ray diffraction (XRD) pattern of ZnSTM was recorded (Figure 2A). A broad Bragg peak centered at 21.6° corresponds to the intermolecular spacing of 0.41 nm, which well matches with the dimension of Zn ions’ bonded ladder-like molecule structure (∼0.4 nm) of ZnSTM. Fourier transform infrared spectroscopy (FTIR) measurements were carried out to probe the functional groups (Figure 2B). The spectrum of PAN shows a pronounced peak at around 2,244 cm−1, which can be assigned to the C≡N stretching.20Eren O. Ucar N. Onen A. Kizildag N. Karacan I. Synergistic effect of polyaniline, nanosilver, and carbon nanotube mixtures on the structure and properties of polyacrylonitrile composite nanofiber.J. Compos. Mater. 2016; 50: 2073-2086Crossref Scopus (34) Google Scholar The decreased intensity of this band in the recorded spectrum of ZnSTM together with a new characteristic band of C=N at 1,560 cm−1 confirmed the successful cyclization.21Zhao J. Zhang J. Zhou T. Liu X. Yuan Q. Zhang A. New understanding on the reaction pathways of the polyacrylonitrile copolymer fiber pre-oxidation: online tracking by two-dimensional correlation FTIR spectroscopy.RSC Adv. 2016; 6: 4397-4409Crossref Google Scholar,22Badii K. Church J.S. Golkarnarenji G. Naebe M. Khayyam H. Chemical structure based prediction of PAN and oxidized PAN fiber density through a non-linear mathematical model.Polym. Degrad. Stab. 2016; 131: 53-61Crossref Scopus (34) Google Scholar In addition, the absorption bands at 1,666 cm−1 and 1,400 cm−1 were clearly observed, corresponding to C=O stretching and overlapped bands of C–H, N–H, O–H in the rings, respectively.21Zhao J. Zhang J. Zhou T. Liu X. Yuan Q. Zhang A. New understanding on the reaction pathways of the polyacrylonitrile copolymer fiber pre-oxidation: online tracking by two-dimensional correlation FTIR spectroscopy.RSC Adv. 2016; 6: 4397-4409Crossref Google Scholar A new peak at 448 cm−1 was only observed in the spectrum of ZnSTM, which can be assigned to the typical Zn–N stretching, verifying the formation of bonds between Zn2+ and N species at the edge of ladder structure.23Mao J. Ge M. Huang J. Lai Y. Lin C. Zhang K. Meng K. Tang Y. Constructing multifunctional [email protected] hydro-/aerogels by the self-assembly process for customized water remediation.J. Mater. Chem. A. 2017; 5: 11873-11881Crossref Google Scholar X-ray photoelectron spectroscopy (XPS) was performed to analyze the compositional elements of ZnSTM as well as their corresponding chemical states. The survey scan result shows the presence of C, O, N, and Zn species in the ZnSTM with quantitative atomic percentages of 49.51 at.%, 31.40 at.%, 8.41 at.%, and 10.68 at.%, respectively (Figure 2C, Table S1). The high-resolution C 1s XPS spectra of ZnSTM (Figure S3) can be decoupled into three main peaks of C–C (284.8 eV), C=N/C–O (286.3 eV), and C=O (288.6 eV), revealing the bridging of N with carbon rings.24Cao X. Deng J. Pan K. Electrospinning Janus type CoOx/C nanofibers as electrocatalysts for oxygen reduction reaction.Adv. Fiber Mater. 2020; 2: 85-92Crossref Scopus (20) Google Scholar,25Li Z. Shao M. Yang Q. Tang Y. Wei M. Evans D.G. Duan X. Directed synthesis of carbon nanotube arrays based on layered double hydroxides toward highly-efficient bifunctional oxygen electrocatalysis.Nano Energy. 2017; 37: 98-107Crossref Scopus (111) Google Scholar The N 1s spectrum of PAN (Figure 2D) displayed a typical N peak corresponding to C≡N (398.1 eV).26Yue Z. Benak K.R. Wang J. Mangun C.L. Economy J. Elucidating the porous and chemical structures of ZnCl2-activated polyacrylonitrile on a fiberglass substrate.J. Mater. Chem. 2005; 15: 3142-3148Crossref Scopus (40) Google Scholar The main N peak for the ZnSTM shifted to 399.5 eV (metal-coordinated N), indicating that most of nitrogen species in ZnSTM were bound with Zn2+ and well matched the FTIR results.27Li J. Chen S. Yang N. Deng M. Ibraheem S. Deng J. Li J. Li L. Wei Z. Ultrahigh-loading zinc single-atom catalyst for highly efficient oxygen reduction in both acidic and alkaline media.Angew. Chem. Int. Ed. 2019; 58: 7035-7039Crossref PubMed Scopus (277) Google Scholar,28Song P. Luo M. Liu X. Xing W. Xu W. Jiang Z. Gu L. Zn single atom catalyst for highly efficient oxygen reduction reaction.Adv. Funct. Mater. 2017; 27: 1700802Crossref Scopus (198) Google Scholar The Zn 2p spectrum of ZnSTM (Figure 2E) consists of two characteristic peaks of Zn2+ centered at 1,045.2 and 1,022.0 eV, corresponding to Zn2+ 2p1/2 and Zn2+ 2p3/2, respectively.28Song P. Luo M. Liu X. Xing W. Xu W. Jiang Z. Gu L. Zn single atom catalyst for highly efficient oxygen reduction reaction.Adv. Funct. Mater. 2017; 27: 1700802Crossref Scopus (198) Google Scholar Transmission electron microscopy (TEM) was employed to investigate the nanostructure of ZnSTM (Figure 3A). The ZnSTM displays microphase separation structure with the hydrophobic domains (bright regions) composed of polymer backbones and the hydrophilic domains (dark regions) formed by Zn2+ ions aggregated around the N-related groups at the edge of carbon backbones. The selected area electron diffraction (SAED) pattern confirms the amorphous nature of ZnSTM, which is generally accepted as fast ion transport regions.29Berthier C. Gorecki W. Minier M. Armand M.B. Chabagno J.M. Rigaud P. Microscopic investigation of ionic conductivity in alkali metal salts-poly(ethylene oxide) adducts.Solid State Ion. 1983; 11: 91-95Crossref Scopus (981) Google Scholar,30Druger S.D. Ratner M.A. Nitzan A. Polymeric solid electrolytes: Dynamic bond percolation and free volume models for diffusion.Solid State Ion. 1983; 9-10: 1115-1120Crossref Scopus (102) Google Scholar In order to investigate the Zn2+ transport properties in ZnSTM, the Zn2+ ionic conductivity (σ) of ZnSTM was examined via electrochemical impedance spectroscopy (EIS) by sandwiching the fresh membrane between two silver plate electrodes at temperatures ranging from 263 to 313 K. The conductivities were determined to be 0.8 × 10−5, 1.1 × 10−5, 2.1 × 10−5, 3.7 × 10−5, 1.5 × 10−4, and 1.9 × 10−4 S cm−1 at 263, 273, 283, 293, 303, and 313 K, respectively. The corresponding Arrhenius plot is displayed in Figure 3B and shows high linearity. The activation energy of ZnSTM was calculated to be 0.2 eV (<0.4 eV). This suggests that Zn2+ migrating in ZnSTM follows the Grotthuss hopping mechanism,31Yuan S. Bao J.L. Wei J. Xia Y. Truhlar D.G. Wang Y. A versatile single-ion electrolyte with a Grotthuss-like Li conduction mechanism for dendrite-free Li metal batteries.Energy Environ. Sci. 2019; 12: 2741-2750Crossref Google Scholar where Zn2+ hops between two adjacent functional groups throughout the polymeric backbone. The electric transference number is defined as the ratio of the charge carried by the cations across the reference plane in solid-state electrolyte to the total charge passed across the plane.32Evans J. Vincent C.A. Bruce P.G. Electrochemical measurement of transference numbers in polymer electrolytes.Polymer. 1987; 28: 2324-2328Crossref Scopus (1227) Google Scholar The Zn2+ ion transference number was determined to be 0.8 based on the Bruce-Vincent-Evans equation, suggesting that the ionic conduction was mainly from the mobility of cation (Zn2+) in ZnSTM (Figure S4).32Evans J. Vincent C.A. Bruce P.G. Electrochemical measurement of transference numbers in polymer electrolytes.Polymer. 1987; 28: 2324-2328Crossref Scopus (1227) Google Scholar,33Hwang J.-Y. Park S.-J. Yoon C.S. Sun Y.-K. Customizing a Li–metal battery that survives practical operating conditions for electric vehicle applications.Energy Environ. Sci. 2019; 12: 2174-2184Crossref Google Scholar A home-made diffusion cell with two chambers separated by ZnSTM was filled with 6 M KOH (or 3 M H2SO4) and pure deionized water, respectively (Figure S5). Phenolphthalein papers were immersed in the chambers to visualize the pH value change on both sides of the ZnSTM. No significant color change of phenolphthalein papers was observed in deionized water, suggesting that ZnSTM effectively suppressed the crossover of H+ and OH−. The electrochemical stability window is another important parameter for battery applications.34Hou Z. Zhang X. Li X. Zhu Y. Liang J. Qian Y. Surfactant widens the electrochemical window of an aqueous electrolyte for better rechargeable aqueous sodium/zinc battery.J. Mater. Chem. A. 2017; 5: 730-738Crossref Google Scholar,35Kundu D. Hosseini Vajargah S. Wan L. Adams B. Prendergast D. Nazar L.F. Aqueous vs. nonaqueous Zn-ion batteries: consequences of the desolvation penalty at the interface.Energy Environ. Sci. 2018; 11: 881-892Crossref Google Scholar As shown in Figure 3C, the ZnSTM remained stable when the applied voltage was less than 4.6 V. Since the charging and discharging voltage of reported AMABs are usually below 3 V,15Yu X. Gross M.M. Wang S. Manthiram A. Aqueous electrochemical energy storage with a mediator-ion solid electrolyte.Adv. Energy Mater. 2017; 7: 1602454Crossref Scopus (18) Google Scholar,16Li L. Manthiram A. Long-life, high-voltage acidic Zn–air batteries.Adv. Energy Mater. 2016; 6: 1502054Crossref Scopus (77) Google Scholar the electrochemical stability window of ZnSTM is wide enough for high-voltage aqueous AMABs when using Zn2+ as mediator ion for charge transfer. In order to gain insights into the ion transportation mechanism in the ZnSTM, plane-wave DFT calculations were performed. The characterization results suggest the presence of abundant Zn-N coordination in the ZnSTM. Therefore, we placed Zn atoms on several potential nearby position of N-related functional groups to optimize the host structure of ZnSTM. Figure 3D depicts the most stable structure, where Zn atoms periodically and intermittently coordinated to N atoms at the edge of ladder structure. The calculated energetically most favorable guest ions’ (including H+, OH−, Zn2+) migration pathways and key intermediate structures are also illustrated (Figure 3D). All of the guest ions prefer to hop between the Zn2+ sites that are anchored on the skeleton of the host structure. In terms of H+ and OH− ions, there are attractive force between guest ions and skeleton coordinated Zn2+ sites, which inhibit the migration of H+ and OH− ions. On the contrary, a repulsive force exists between the guest Zn2+ ions and skeleton-bonded Zn2+ sites, which benefits the transport of Zn2+ ions. The corresponding energy paths are calculated by using the climbing image nudged elastic band (CI-NEB) method (Figure 3E). The migration energy barriers of H+ and Zn2+ are determined to be 0.26 and 0.24 eV, respectively, which are much lower than that of OH− (0.76 eV). The underlying reason is that the diffusion of OH− ions from strong bonded Zn2+ to nearby sites requires high energy, resulting from the strong coulombic interaction between OH− ions and skeleton-bonded Zn2+ ions. Ion transport through a dense nonporous polymer membrane can be divided into two consecutive steps, including ion adsorption onto the polymer surface and ion diffusion through the polymer matrix.36Epsztein R. Shaulsky E. Qin M. Elimelech M. Activation behavior for ion permeation in ion-exchange membranes: role of ion dehydration in selective transport.J. Membr. Sci. 2019; 580: 316-326Crossref Scopus (80) Google Scholar The ion-selective permeability of ZnSTM is further investigated by employing EIS in the home-made symmetric cell (insets of Figure 4A).37Chen L. Guo Z. Xia Y. Wang Y. High-voltage aqueous battery approaching 3 V using an acidic–alkaline double electrolyte.Chem. Commun. (Camb.). 2013; 49: 2204-2206Crossref PubMed Scopus (51) Google Scholar Typically, a ZnSTM solid-state separator is sandwiched between two vessels containing 1 M CH3COOH (HOAc) or Zn(OAc)2. The interfacial resistance value of ZnSTM in the HOAc || ZnSTM || HOAc system is measured to be around 153 Ω, which is much larger than that of the Zn(OAc)2 || ZnSTM || Zn(OAc)2 system (22.8 Ω) (Figure 4A). The proton conductivity on the surface of the membrane is closely related to the proton density and functional group network at the surface. The strong adsorption of Zn2+ ions blocks functional sites on the surface of ZnSTM and facilitates the deprotonation of functional groups, which ultimately decreases the proton density at the interface and damages the continuity of the proton conduction tracks.38Wu L. Jiang X. Proton transfer at the interaction interface of graphene oxide.Anal. Chem. 2018; 90: 10223-10230Crossref PubMed Scopus (8) Google Scholar, 39Hatakeyama K. Razaul Karim M. Ogata C. Tateishi H. Taniguchi T. Koinuma M. Hayami S. Matsumoto Y. Optimization of proton conductivity in graphene oxide by filling sulfate ions.Chem. Commun. (Camb.). 2014; 50: 14527-14530Crossref PubMed Google Scholar, 40Tang C.Y. Allen H.C. Ionic binding of Na+ versus K+ to the carboxylic acid headgroup of palmitic acid monolayers studied by vibrational sum frequency generation spectroscopy.J. Phys. Chem. A. 2009; 113: 7383-7393Crossref PubMed Scopus (101) Google Scholar Therefore, we propose that the anchored Zn2+ ions on the ZnSTM surface increase the proton transfer energy barrier at the interface between aqueous electrolyte and ZnSTM (Figure 4B). Bifunctional electrocatalyst that stably operates in acid media is the key component of AMABs.41Kreider M.E. Stevens M.B. Liu Y. Patel A.M. Statt M.J. Gibbons B.M. Gallo A. Ben-Naim M. Mehta A. Davis R.C. et al.Nitride or oxynitride? Elucidating the composition–activity relationships in molybdenum nitride electrocatalysts for the oxygen reduction reaction.Chem. Mater. 2020; 32: 2946-2960Crossref Scopus (26) Google Scholar, 42Strickler A.L. Flores R.A. King L.A. Nørskov J.K. Bajdich M. Jaramillo T.F. Systematic investigation of iridium-based bimetallic thin film catalysts for the oxygen evolution reaction in acidic media.ACS Appl. Mater. Interfaces. 2019; 11: 34059-34066Crossref PubMed Scopus (32) Google Scholar, 43Chen G. Stevens M.B. Li" @default.
• W3128082604 created "2021-02-15" @default.
• W3128082604 creator A5027968768 @default.
• W3128082604 creator A5029372812 @default.
• W3128082604 creator A5035664461 @default.
• W3128082604 creator A5038741162 @default.
• W3128082604 creator A5047591931 @default.
• W3128082604 creator A5052849069 @default.
• W3128082604 creator A5062642315 @default.
• W3128082604 creator A5067715323 @default.
• W3128082604 creator A5069765087 @default.
• W3128082604 creator A5071304630 @default.
• W3128082604 creator A5090717104 @default.
• W3128082604 date "2021-04-01" @default.
• W3128082604 modified "2023-10-16" @default.
• W3128082604 title "High-voltage asymmetric metal–air batteries based on polymeric single-Zn2+-ion conductor" @default.
• W3128082604 cites W1430358328 @default.
• W3128082604 cites W1759492038 @default.
• W3128082604 cites W1970127494 @default.
• W3128082604 cites W1971889037 @default.
• W3128082604 cites W1977498610 @default.
• W3128082604 cites W1979544533 @default.
• W3128082604 cites W1980282438 @default.
• W3128082604 cites W1981368803 @default.
• W3128082604 cites W1984625256 @default.
• W3128082604 cites W1986186070 @default.
• W3128082604 cites W2000932596 @default.
• W3128082604 cites W2023505220 @default.
• W3128082604 cites W2040163905 @default.
• W3128082604 cites W2060599594 @default.
• W3128082604 cites W2063252389 @default.
• W3128082604 cites W2080028758 @default.
• W3128082604 cites W2087557408 @default.
• W3128082604 cites W2088342359 @default.
• W3128082604 cites W2089403233 @default.
• W3128082604 cites W2090692532 @default.
• W3128082604 cites W2091532336 @default.
• W3128082604 cites W2092157292 @default.
• W3128082604 cites W2098846053 @default.
• W3128082604 cites W2113060945 @default.
• W3128082604 cites W2122427541 @default.
• W3128082604 cites W2135572322 @default.
• W3128082604 cites W2156357247 @default.
• W3128082604 cites W2207912619 @default.
• W3128082604 cites W2279536848 @default.
• W3128082604 cites W2300119918 @default.
• W3128082604 cites W2474990914 @default.
• W3128082604 cites W2518428332 @default.
• W3128082604 cites W2550458272 @default.
• W3128082604 cites W2558095361 @default.
• W3128082604 cites W2560893993 @default.
• W3128082604 cites W2562919331 @default.
• W3128082604 cites W2571401235 @default.
• W3128082604 cites W2588986811 @default.
• W3128082604 cites W2610218531 @default.
• W3128082604 cites W2610292905 @default.
• W3128082604 cites W2612476198 @default.
• W3128082604 cites W2617907721 @default.
• W3128082604 cites W2624890256 @default.
• W3128082604 cites W2626285542 @default.
• W3128082604 cites W2742531612 @default.
• W3128082604 cites W2748096516 @default.
• W3128082604 cites W2767630263 @default.
• W3128082604 cites W2768063271 @default.
• W3128082604 cites W2770478678 @default.
• W3128082604 cites W2773821117 @default.
• W3128082604 cites W2775056688 @default.
• W3128082604 cites W2784065565 @default.
• W3128082604 cites W2784943348 @default.
• W3128082604 cites W2788749521 @default.
• W3128082604 cites W2791500365 @default.
• W3128082604 cites W2792775201 @default.
• W3128082604 cites W2883284504 @default.
• W3128082604 cites W2885419396 @default.
• W3128082604 cites W2887948098 @default.
• W3128082604 cites W2887954547 @default.
• W3128082604 cites W2893589305 @default.
• W3128082604 cites W2894033777 @default.
• W3128082604 cites W2895013710 @default.
• W3128082604 cites W2903807505 @default.
• W3128082604 cites W2905511962 @default.
• W3128082604 cites W2912494865 @default.
• W3128082604 cites W2912922527 @default.
• W3128082604 cites W2914887577 @default.
• W3128082604 cites W2924691801 @default.
• W3128082604 cites W2940904991 @default.
• W3128082604 cites W2948655687 @default.
• W3128082604 cites W2954702825 @default.
• W3128082604 cites W2956737081 @default.
• W3128082604 cites W2969822955 @default.
• W3128082604 cites W2971678601 @default.
• W3128082604 cites W2979548319 @default.
• W3128082604 cites W3003088310 @default.
• W3128082604 cites W3012614023 @default.
• W3128082604 cites W3013819849 @default.
• W3128082604 cites W3048673068 @default.
• W3128082604 cites W3081174091 @default.
• W3128082604 cites W3096723849 @default.

• next