Flexible and High-Voltage Coaxial-Fiber Aqueous Rechargeable Zinc

Subscriber access provided by UNIV OF WISCONSIN - MADISON

Communication

Flexible and High-Voltage Coaxial-Fiber Aqueous Rechargeable Zinc-Ion Battery Qichong Zhang, Chaowei Li, Qiulong Li, Zhenghui Pan, Juan Sun, Zhenyu Zhou, Bing He, Ping Man, Liyan Xie, Lixing Kang, Xiaona Wang, Jiao Yang, Ting Zhang, Perry Ping Shum, Qingwen Li, Yagang Yao, and Lei Wei Nano Lett., Just Accepted Manuscript • DOI: 10.1021/acs.nanolett.9b01403 • Publication Date (Web): 13 May 2019 Downloaded from http://pubs.acs.org on May 14, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

Flexible and High-Voltage Coaxial-Fiber Aqueous Rechargeable Zinc-Ion Battery Qichong Zhanga+, Chaowei Lic+, Qiulong Lib+, Zhenghui Pand, Juan Sunc, Zhenyu Zhouc, Bing Hec, Ping Manc, Liyan Xiec, Lixing Kanga, Xiaona Wangc, Jiao Yanga, Ting Zhanga, Perry Ping Shuma, Qingwen Lic, Yagang Yaob,c* and Lei Weia* a. School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore b. National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China c. Division of Advanced Nanomaterials, Key Laboratory of Nanodevices and Applications, Joint Key Laboratory of Functional Nanomaterials and Devices, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123, China d. Department of Materials Science and Engineering, National University of Singapore,117574 Singapore, Singapore [*] E-mail: [email protected]; [email protected] [+] These authors contribute equally to this work.

ACS Paragon Plus Environment

Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 23

ABSTRACT Extensive efforts have been devoted to construct fiber-shaped energy-storage device to fulfil the increasing demand for power consumption of textile-based wearable electronics. Despite the myriad of available material selections and device architectures, it is still fundamentally challenging to develop eco-friendly fiber-shaped aqueous rechargeable batteries (FARBs) on a single-fiber architecture with high energy density and long-term stability. Here, we demonstrate flexible and high-voltage coaxial-fiber aqueous rechargeable zinc-ion batteries (CARZIBs). By utilizing a novel spherical zinc hexacyanoferrate with prominent electrochemical performance as cathode material, the assembled CARZIB offers a large capacity of 100.2 mAh cm-3 and a high energy density of 195.39 mWh cm-3, outperforming the state-of-the-art FARBs. Moreover, the resulting CARZIB delivers outstanding flexibility with the capacity retention of 93.2% after bending 3000 times. Last, high operating voltage and output current are achieved by the serial and parallel connection of CARZIBs woven into the flexible textile to power high-energy-consuming devices. Thus, this work provides proof-of-concept design for next-generation wearable energy-storage devices. KEYWORDS: Zinc hexacyanoferrate, high voltage, coaxial-fiber, zinc-ion battery, portable and wearable electronics


Page 3 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

Given the increasing demand for textile-based wearable electronics, fiber-shaped energy-storage devices with mechaine weavability, high flexibility and approving wearability are the most effective solution to fulfil the power consumption of various wearable electronics1-12. To achieve high energy density, lithium-ion batteries are the first choice, but their inevitable shortcomings such as constrained lithium resources, high cost, and the toxicity of organic electrolytes, have impeded their further studies and applications13-15. As the most compelling alternative to the conventional lithium-ion batteries, aqueous rechargeable batteries (ARBs) have attracted wide attention owing to the utilization of low cost, nonflammable, nontoxic, and highly conductive aqueous electrolytes16-29. Currently, significant research efforts have been devoted to develop fiber-shaped ARBs (FARBs) with parallel and twisted architectures using two conductive fibers as electrodes30-35. Unfortunately, the former are too bulky for large-scale integration and being compatible with the weaving process, while the later comprise two twisted fiber electrodes that are easily separated during bending resulting poor stability. Different from these twin-fiber architecture, the single coaxial-fiber architecture offers a simple yet effective path for developing ultraflexible and small-size energy-storage devices. For example, fiber-shaped Zn-air batteries based a coaxial architecture have been demonstrated, although the issues of low voltage and the utilization of alkaline electrolyte still exist36-38. Thus, it still remains a fundamental challenge to develop eco-friendly FARBs on a single-fiber architecture with high energy density and long-term stability for the next-generation textile-based wearable electronics. Of the available ARBs, zinc-ion batteries (ZIBs) are particularly attractive due to their inherent safety and cost effectiveness39-52. In contrast to high theoretical capacity of Zn anodes (820 mAh/g) and low redox potential (−0.76 V vs. standard hydrogen electrode), the lack of high-capacity and


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 23

high-voltage cathode materials remains a fundamental bottleneck to further improving ZIBs’energy density. Exhilaratingly, zinc hexacyanoferrate (ZnHCF) with an open-framework structure allowing for the coinsertion/extraction of Zn2+ is a promising cathode candidate for aqueous rechargeable ZIBs (ARZIBs)53. It should be noted that a rational nanoarchitecture design for ZnHCF is a feasible strategy for synthesizing high-performance cathode materials. Herein, we establish a facile and cost-effective method to fabricate spherical ZnHCF cathode materials with excellent electrochemical performance. We expect the newly designed spherical ZnHCF to be highly suitable for applications in high energy density wearable ARZIBs. Herein, as a proof-of-concept demonstration, we design and demonstarte the first prototype of high-voltage coaxial-fiber ARZIBs (CARZIBs) by adopting Zn nanosheet arrays (NSAs) on carbon nanotube fiber (CNTF) as the core electrode and ZnHCF composite on aligned CNT sheets (ACNTSs) as the outer electrode with ZnSO4-carboxymethyl cellulose sodium (CMC) as the gel electrolyte, which not only enable the aligned charge transport paths, large surface area and small contact resistance of the coaxial structure, but also provide superior mechanical flexibility and stability while maintainging high performance after long-term bending. The proof-of concept demonstration of the high-voltage CARZIBs opens up new opportunities for high-energy-density, safe and low-cost wearable energy-storage technologies. The ZnHCF sample was prepared via a facile high temperature co-precipitation method and the details are given in the experimental section. During the synthesis of ZnHCF, it is difficult to control particle size due to the rapid nucleation and growth processes10, 54-56. As shown in Figure S1, the fresh ZnHCF powder is yellow. The particle size and morphology of the ZnHCF sample were characterized using scanning electron microscope (SEM) (Figure 1a, b). It reveals that the


Page 5 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

as-prepared ZnHCF powder contained spherical particles with sizes of less than 300 nm. The crystal structure of the spherical ZnHCF was assessed by X-ray diffraction (XRD) (Figure 1c), in which all of diffraction peaks were perfectly indexed with the rhombohedral structure of Zn3[Fe(CN)6]2 (JCPDS # 38–0688). In the low-magnification transmission electron microscopy (TEM) image, spherical particles with sizes below 300 nm were observed (Figure S2), which agreed well with the SEM characterizations. The thermogravimetric analysis (TGA) curve in Figure S3 reveals that the as-prepared spherical ZnHCF possesses excellent thermal stability. The energy-dispersive spectroscopy (EDS) elemental mapping images distinctly show that these elements Zn, Fe, N, and O were homogeneously distributed across the whole spherical ZnHCF (Figure S4). Additionally, the EDS spectrum of the spherical ZnHCF presented in Figure 1c further illustrates that the atomic ratio of Zn:Fe:C:N was approximately 3:2:12:12, which was in good accordance with our XRD analysis. To further investigate elemental compositions and valence states of the spherical ZnHCF, X-ray photoelectron spectroscopy (XPS) measure was conducted. The XPS full spectrum of the as-prepared spherical ZnHCF (Figure S5) again reveals the coexistence of Zn, Fe, N, and O elements. The Fe 2p spectrum presented in Figure 2e is divided into two peaks centered at 709.2 and 722.1 eV, which can be assigned to the 2p3/2 and 2p1/2 of Fe (II), whereas the peaks in the Fe (III)2p band at 710.8 and 724.4 eV correspond to 2p3/2 and 2p1/2, respectively. The XPS spectra of the Zn 2p in Figure 1f display two distinct peaks at the binding energies of 1022.7 and 1045.8 eV, assigned to Zn 2p3/2 and Zn 2p1/2. Figure S6 and S7 illustrate the Raman and Fourier transforminfrared characterization of the as-prepared spherical ZnHCF. These results confirm the successful fabrication of spherical ZnHCF. The obtained spherical ZnHCF was then investigated for its potential applications in high-performance energy storage devices.


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 23

Figure 1 (a-b) SEM images of spherical ZnHCF at increasing magnifications; (c) XRD patterns of spherical ZnHCF; (d) EDS spectrum of spherical ZnHCF; (e-f) High-resolution XPS spectra of Fe 2p and Zn 2p. The electrochemical performances of the spherical ZnHCF were measured in a three-electrode system with 1M ZnSO4 as the aqueous electrolyte. CNT films are regarded as excellent current collectors due to their high conductivity and mechanical flexibility and their SEM characterization is displayed in Figure S821, 57-58. The ZnHCF electrode was prepared by scraping the mixed slurry consisting of the spherical ZnHCF, acetylene carbon black and polyvinylidene fluoride (PVDF) onto CNT film. The cyclic voltammeter (CV) curves of the spherical ZnHCF electrode at different scan rates ranging from from 1 to 10 mV/s displays a pair of well-defined sharp redox peaks (Figure 2a), implying presence redox reactions of the spherical ZnHCF during the electrochemical process. To reveal the electrochemical kinetics of the spherical ZnHCF electrode, the linear relationship between the square root of the scan rate and the cathodic peak current densities at scan rates is presented in Figure 2b, indicating a quasi-reversible and diffusion-controlled process during the


Page 7 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

electrode material redox reaction59-60. The slopes of the corresponding log(v)–log(i) plots for cathodic and anodic peaks are 0.83 and 0.76, respectively, indicating that the kinetics were dominated by Faradaic intercalation processes (Figure S9)61-62. The nearly symmetric charge-discharge curves of the spherical ZnHCF electrode at different current densities, as shown in Figure 2c, clearly demonstrate remarkable reversibility and well-defined discharge plateau with voltage of 0.85 V, which is higher than most reported values (Table S1). Notably, a high capacity of 94.9 mAh g-1 was achieved at 0.1 A g-1 and it still maintained at 68.7 mAh g-1 when the current density increased to 1 A g-1 (Figure S10), which is also superior to the values of most reported metal hexacyanoferrate (Table S1). The electrochemical impedance spectroscopy (EIS) Nyquist plot of the ZnHCF/CNT film is shown in Figure S11. Additionally, the capacity retention remains 88.2% after 300 cycles cycling (Figure S12). These attractive properties make the spherical ZnHCF a promising cathode material for high-performance ZIBs. An ARZIB with ZnHCF as the cathode, Zn NSAs as the anode and 1M ZnSO4 as the aqueous electrolyte is schematically illustrated in Figure 2d. Figure 2e demonstrates that a couple of redox peaks can be clearly observed in both Zn anode and ZnHCF cathode at 5 mV s−1. Specifically, the Zn NWAs anode shows a pair of redox peaks at −0.80/−1.20 V versus Ag/AgCl, corresponding to the stripping/plating process of Zn/Zn2+. In addition, the spherical ZnHCF displays well-defined redox peaks at 0.95/0.70 V versus Ag/AgCl, corresponding to Zn2+ intercalation and deintercalation. Thus, it is believed that such a Zn/ZnSO4/ZnHCF full battery possesses a high working voltage. As depicted in Figure 2f, when the full battery device was discharged to 1.85 V, a potential of 0.80 and −1.05 V was applied to the cathode and anode, respectively, consistent with the operating voltage of the single electrode, clearly confirming the high working voltage of 1.85 V. On the basis of the Zn2+ intercalation of


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 23

ZnHCF, the electrochemical reaction mechanism of such a full battery device can be described as follows: Cathode: Zn2+ +2e-+ Zn3[Fe(CN)6]2 Anode:

Zn

Zn4[Fe(CN)6]2

（1）

Zn2++2e-

(2)

As demonstrated here, the cathode electrode reaction was related to the insertion/extraction of Zn2+ into/from ZnHCF, which is well supported by ex-situ XRD patterns of ZnHCF electrode at different charge/discharge states (Figure S13), and the anode electrode reaction involved the deposition and dissolution of Zn in the anode53. During the charging-discharging process, Zn2+ ions were transferred as shuttles in aqueous ZnSO4 electrolytes between the anode and cathode.

Figure 2 (a) CV curves of the spherical ZnHCF electrode at different scan rates. (b) Plot of the cathodic and anodic peak currents versus the square root of the scan rate. (c) Charge-discharge curves of the spherical ZnHCF under different current densities. (d) Schematic illustration of the Zn-ZnHCF ARZIB. (e) CV curves of the Zn anode and the spherical ZnHCF cathode in the 1M ZnSO4 aqueous electrolyte at a scan rate of 5 mV/s. (f) Charge-discharge curves for anode (green),


Page 9 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

cathode (red) and full battery (blue) in 1M ZnSO4 aqueous electrolyte at a current density of 0.5 A cm-3. To further demonstrate the feasibility of using the spherical ZnHCF electrode for wearable energy storage applications, a prototype CARZIB device was assembled using Zn NSAs/CNTF as the core electrode, ZnHCF/CNT composite sheets as the outer electrode, and ZnSO4-CMC as the gel electrolyte. The fabrication process of the CARZIB is schematically illustrated in Figure 3a and the details can be seen in the experimental section. To obtain the longer CARZIB, continuous production consisting of roll-electrodeposition, roll-dip-coating and rotating coating processes is schematically illustrated in Figure S14, which is beneficial for the weaving process later. Figure 3b shows a schematic of the cross-sectional structure of the CARZIB, and it can be clearly seen that the aligned structure favored rapid charge transport and the coaxial structure could fully utilize the effective surface area between the two electrodes. The ACNTSs were easily wrapped around the modified CNTF using the unique setup shown schematically in Figure 3c.


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 23

Figure 3 (a) Schematic illustrations showing the fabrication process of the CARZIB. (b) Schematic illustration of the cross-section view of the CARZIB. (c) Wrapping ACNTSs around the modified CNTF. As shown in Figure S15a, the pristine CNTF with a uniform diameter of around 125 μm had a compact structure, which was fabricated by twisting a CNT strip (Figure S15b)63. The corresponding photograph and SEM images of the CNTF are presented in Figures S15c and S15d. As shown in Figure 4a, Zn NSAs were homogeneously and densely electrodeposited on the entire CNTF surface at a constant current. The high-magnification SEM image in Figure 4b clearly demonstrates that the Zn NSAs were uniformly distributed and highly aligned in the hybrid fiber. The Zn NSAs were further investigated with TEM, as shown in Figure S16. The TEM results show that the lattice fringe spacing was 0.21 nm, corresponding to the (101) plane of hexagonal zinc. The crystal structure of the Zn NSAs was characterized by XRD (Figure S17), in which all of the peaks were well in accordance with hexagonal Zn (JCPDS No. 87-0713). Furthmore, the XPS spectrum of Zn NSAs is illustrated in Figure S18. After soaking ZnSO4-CMC gel electrolyte, the surface of the as-obtained hybrid fiber became smooth (Figure 4c). When the ACNTSs were wrapped around the ZnSO4-CMC gel electrolyte at a certain helical angle, the CNTs were loosely attached on the surface and remained highly aligned (Figure 4d, 4e) and such structure is expected to improve the mass loading of the active materials. It is worth noting that the aligned structure of the CNTs in the sheet originated from the vertical array (Figure S19 and S20). Furthermore, the high-resolution TEM image of the CNTs (Figure S21) shows a multi-walled structure with an average diameter of 10 nm. As expected, the ZnHCF slurry was uniformly coated on the ACNTSs as a cathode material for the ZIBs (Figure 4f and inset). The second layer of ACNTSs was wrapped around the surface of


Page 11 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

the ZnHCF, as shown in Figure 4g, effectively avoiding the separation from the active materials during bending. Finally, a second layer of CMC gel electrolyte was coated to achieve the desired CARZIB (Figure 4h). SEM images for a cross section of the as-assembled CARZIB at increasing magnification are shown in Figure S22. As illustrated in Figure 4i, the as-prepared CARZIB device possessed great flexibility, and it was easily tied into a knot.

Figure 4 (a-b) SEM images of Zn NSAs on CNTF with increasing magnifications. (c) SEM images of the ZnSO4-CMC gel electrolyte coating the surface of Zn NSAs/CNTF. (d-e) SEM images of ACNTSs covering (c) at increasing magnifications. (f) SEM images of ZnHCF slurry coating the surface of (e). (g) High-magnification SEM image of ACNTSs coating (f). (h) SEM images of ACNTSs/ZnSO4-CMC composite sheets. (i) SEM image of the CARZIB tied into a knot.


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 23

The typical CV curves of the as-assembled CARZIBs in Figure 5a display a pair of redox peaks at each different scan rates, which can be well assigned to the following reaction: Zn+Zn3[Fe(CN)6]2

Zn4[Fe(CN)6]2

The electrochemical performance of our CARZIB was further investigated at different current densities from 0.1 to 1 A cm-3, and the corresponding charge-discharge curves presented remarkable symmetry and high discharge plateaus, indicating its desirable battery behavior. As demonstrated in Figure 5c, the discharge capacities maintain 100.2 mAh cm-3 at a current density of 0.1 A cm-3 and 66.5 mAh cm-3 at a high current density of 1 A cm-3, indicating superior rate capability. It is well known that energy and power density are two key parameters for estimating the electrochemical performance of energy-storage device. Figure 5d compares the Ragone plots of the volumetric energy and power density of our CARZIB with some representative high-performance FARBs. Clearly, the device can deliver an ultrahigh energy density of 195.4 mWh cm-3 at a power density of 0.2 W cm-3, and still deliver 126.9 mWh cm-3 even at a high power density of 1.9 Wcm-3. These values considerably exceed the previously reported FARBs (Table S3) such as the NiCo//Zn battery29, Co//Zn battery32, Ni//Fe battery33, Ni//Zn battery30 and sodium-ion battery28. Figure S23 and S24 present the areal capability and Ragone plots of our CARZIB device. Electrochemical EIS results in Figure 5e exhibits an equivalent series resistance as low as 20.6 Ω, and the nearly 90° angle in the low-frequency region indicates efficient ions diffusion. Furthermore, our as-assembled CARZIB presents outstanding capacity retention of 91.8% after 200 cycles and satisfactory coulombic efficiency of 96.8% (Figure 5f).


Page 13 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

Figure 5 (a) CV curves of the as-assembled CARZIB measured at different scan rates. (b) Charge-discharge curves collected at different current densities. (c) Rate capability of the as-assembled CARZIB at varied current densities. (d) Volumetric energy and power densities of our CARZIB device compared with previously reported FARBs. (e) EIS Nyquist plot of the as-assembled CARZIB. (f) Cycling performance and coulombic efficiency of our CARZIB device. (The inset is charge-discharge curves at different cycles.) To further demonstrate the potential application of our CARZIBs in wearable electronics, a series of flexibility tests were performed. As illustrated in Figure 6a, a negligible degradation of electrochemical performance could be observed at various angles from 0° to 180°, manifesting the exceptional flexibility of our CARZIBs. In addition, Figure 6b shows that the capacity still remains at 93.2% after bending at 90° for more than 3,000 cycles, further confirming the CARZIB’s high mechanical stability. To meet the expected energy and power density demands for practical applications, higher operating voltages and output currents can be achieved by the serial and parallel connection of devices. As presented in Figure 6c and 6d, the operating voltage and discharge time were doubled when two devices were connected in series and in parallel, respectively. To power an ACS Paragon Plus Environment

Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 23

energy consuming device, a fully charged CARZIB device with a bending angle of 90o can illuminate a red light-emitting diode (LED) (Figure 6g). Interestingly, the neglectable brightness change brightness of the red LED is evidently observed regardless of the angles of our CARZIB (Figure S25). To further demonstrate the favorable weavability of the newly developed CARZIBs, two long CARZIB devices were woven into the flexible textile in series (Figure 6f and Figure S26), and the resulting energy textile could illuminate a 3.3 V blue LED.

Figure 6 (a) Charge-discharge curves of the CARZIBs at a current density of 0.1 A cm−3 under different bent angles. (b) Normalized capacities of our CARZIBs bent for 3,000 cycles with the angle of 90°. Charge-discharge curves of single CARZIB device and two CARZIBs connected in series (c) and in parallel(d). (e) Photograph of a red LED illuminated by a fully charged CARZIB device under 90o bending. (f) Photograph of a blue LED illuminated by the charged energy textile consisting of our CARZIBs. In summary, we successfully developed a facile and cost-effective method to fabricate spherical ZnHCF with excellent electrochemical performance. Furthermore, a prototype high


Page 15 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

voltage CARZIB with impressive energy density was demonstrated for the first time. To be specific, this CARZIB device consists of Zn NWAs on CNTF as the core electrode, ZnSO4-CMC as the gel electrolyte, and ZnHCF composite on ACNTs as the outer electrode. Taking advantages of the CARZIB device’s novel coaxial structure and electrode nanomaterials, a high capacity of 100.2 mAh cm-3 and energy density of 195.4 mWh cm-3 were achieved, representing highest values so far achieved for a FARB. Additionally, the as-assembled CARZIB retained 93.2% of its initial capacity after bending 3,000 times, which further indicates remarkable wearability. Thus, our encouraging results may facilitate the rapid development of high-energy-density wearable ZIBs for powering future portable and wearable electronics. Synthesis of the spherical ZnHCF. The spherical ZnHCF was prepared via a high-temperature co-precipitation method. Typically, 80 mL of 0.1 M ZnSO4•7H2O and 80 mL of 0.05 M K3Fe(CN)6 were simultaneously injected dropwise into 50 mL H2O under vigorous stirring at 60 oC. The dropping speeds of ZnSO4•7H2O and K3Fe(CN)6 solutions were precisely controlled via peristaltic pump (1.5 ml min-1). After the reaction, the suspension was left to stand for 3 hours and a yellow ZnHCF slurry was formed. The resulting yellow precipitates were filtered, washed with deionizer water several times, and then dried at 60°C in a vacuum overnight. The cathode slurry was prepared by dispersing the synthesized spherical ZnHCF material (70 wt. %), acetylene carbon black (20 wt. %) and PVDF (10 wt. %) in N-Methyl pyrrolidone. Assembling CARZIB. The ZnSO4-CMC gel electrolytes were prepared by dissolving 10 g ZnSO4•7H2O and 3 g CMC in 80 ml distilled water and heated at 85 °C for 90 min under vigorous stirring. First, Zn NSAs were directly deposited on highly conductive CNTFs via a facile electrodeposition method in a 50 ml mixed aqueous solution consisting of 6.25 g ZnSO4•7H2O, 6.25


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 23

g Na2SO4, and 1 g H3BO3 with a current density of -40 mA cm-2. The Zn NSAs/CNTF electrode was coated with a thin layer of ZnSO4-CMC gel electrolyte and maintained at 60 °C for 2 h to evaporate excess water. After drying, the ACNTSs were wrapped around the surface of ZnSO4-CMC/Zn NSAs/CNTF. Thereafter, the ZnHCF slurry was uniformly coated on the resulting fiber and maintained at 60 °C overnight, which was followed by wrapping the second layer of ACNTSs. Finally, a second coating of CMC gel electrolyte was applied to obtain the desired CARZIB. ■AUTHOR INFORMATION Corresponding Author: *E-mail: [email protected]; [email protected] Notes The authors declare no competing financial interest. Acknowledgements This work was supported in part by the Singapore Ministry of Education Academic Research Fund Tier 2 (MOE2015-T2-1-066 and MOE2015-T2-2-010), Singapore Ministry of Education Academic Research Fund Tier 1 (RG85/16), and Nanyang Technological University (Start-up grant M4081515: Lei Wei). This work was supported by National Natural Science Foundation of China (Nos. 51522211, 51602339, 51703241 and U1710122). Supporting Information Available: The Supporting Information is available free of charge on the ACS Publications website at DOI: Photograph of the fresh spherical ZnHCF powder; Low-magnification TEM image of the as-prepared spherical ZnHCF; TGA curves of the as-prepared spherical ZnHCF; EDS mapping images of Zn, Fe, N and O for the as-prepared


Page 17 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

spherical ZnHCF; Full spectrum of the as-prepared spherical ZnHCF; Raman spectra of the as-prepared spherical ZnHCF; Fourier transforminfrared spectroscopy of the as-prepared spherical ZnHCF; Photograph of the 2-m carbon nanotube film and high-magnification SEM image of carbon nanotube film; Corresponding log(i) versus log(v) plots for cathodic and anodic peaks; Comparison of electrochemical performance of MeHCF; Rate capability of the ZnHCF/CNT film at varied current densities; EIS Nyquist plot for the ZnHCF/CNT film; Cycling stability of the ZnHCF/CNT film at a current density of 0.25 A g-1; Ex situ XRD patterns at different discharge/charge states of Zn/ZnSO4/ZnHCF full battery; Low-magnification SEM image and photograph of the CNTF; TEM images of the Zn nanosheet; XRD pattern of the as-deposited Zn nanosheets on CNTF; XPS spectrum of Zn NWAs; Cross-section SEM image of a spinnable CNT array; A transparent aligned CNT sheet and SEM images of aligned CNT sheets with cross-stacking angles 90o; High-magnification TEM image of a CNT; Comparison of our CFARZIB with previously reported FARBs; Areal capability of the as-assembled CFARZIB at varied current densities; Areal energy and power densities of our CFARZIB device; Photograph of CFARZIBs used to power a light-emitting diode under normal and bending conditions; Photograph of our CFARZIBs woven into flexible textiles.These materials are available free of charge via the internet at http://pubs.acs.org.

References (1) Zhang , Q.; Wang, X.; Pan, Z.; Sun, J.; Zhao, J.; Zhang, J.; Zhang, C.; Tang, L.; Luo, J.; Song, B.; Zhang, Z.; Lu, W.; Li, Q.; Zhang, Y.; Yao, Y. Nano Lett. 2017, 17, 2719. (2) Zhang, Q.; Xu,W.; Sun, J.; Pan, Z.; Zhao, J.; Wang, X.; Zhang, J.; Man, P.; Guo, J.; Zhou, Z.; He, B; Zhang, Z.; Li, Q.; Zhang, Y.; Xu, L.; Yao,Y. Nano Lett. 2017, 17, 7552.


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 23

(3) Zhou, Z.; Zhang, Q.; Sun, J.; He, B.; Guo, J.; Li, Q.; Li, C.; Xie, L.; Yao, Y. ACS Nano 2018, 12, 9333. (4) Zhang, Q.; Sun, J.; Pan, Z.; Zhang, J.; Zhao, J.; Wang, X.; Zhang, C.; Yao, Y.; Lu, W.; Li, Q.; Zhang,Y.; Zhang, Z. Nano Energy 2017, 39, 219. (5) Wan, F.; Zhang, L.; Wang, X.; Bi, S.; Niu, Z.; Chen, J. Adv. Funct. Mater. 2018, 28, 1804975. (6) Yu, N.; Yin, H.; Zhang, W.; Liu, Y.; Tang, Z.; Zhu, M.-Q. Adv. Energy Mater. 2016, 6, 1501458. (7) Zhang,Y.; Zhao,Y.; Ren,J.; Weng, W.; Peng, H. Adv Mater. 2016. 28, 4524. (8) Weng, W.; Sun, Q.; Zhang,Y.; Lin, H.; Ren, J.; Lu, X.; Wang, M.; Peng, H. Nano Lett. 2014, 14, 3432. (9) Zhang, Y.; Bai, W.; Cheng, X.; Ren, J.; Weng, W.; Chen, P.; Fang, X.; Zhang, Z.; Peng, H. Angew. Chem. Int. Ed. 2014, 53, 14564. (10) Zhang, Y.; Wang, L.; Guo, Z.; Xu, Y.; Wang, Y.; Peng, H. Angew. Chem. Int. Ed. 2016, 55, 4487. (11)Lin, H.; Weng, W.; Ren, J.; Qiu, L.; Zhang, Z.; Chen, P.; Chen, X.; Deng, J.; Wang, Y.; Peng, H. Adv Mater. 2014, 26, 1217. (12) Ren, J.; Li, L.; Chen, C.; Chen, X.; Cai, Z.; Qiu, L.; Wang, Y.; Zhu, X.; Peng, H. Adv Mater. 2013, 25, 1155. (13) Sun,Y. K.; Chen, Z.; Chen, H. J.; Lee, D. J.; Jung, H. G.; Ren, Y.; Wang, S.; Yoon, C. S.; Myung, S. T.; Amine, K. Nat Mater. 2012, 11, 942. (14) Sathiya, M.; Rousse, G.; Ramesha, K.; Laisa, C. P.; Vezin, H.; Sougrati, M. T.; Doublet, M. L.; Foix, D.; Gonbeau, D.; Walker, W.; Prakash, A. S.; Hassine, M. Ben; Dupont, L.; Tarascon, J. M.


Page 19 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

Nat Mater. 2013, 12, 827. (15) Kennedy, T.; Brandon, M.; Ryan, K. M. Adv Mater. 2016, 28, 5696. (16) Parker, J. F.; Chervin C. N.; Pala I. R.; Machler, M.; Burz, M. F.; Long, J. W Rolison, D. R. Science 2017, 356, 415. (17) Kundu, D.; Adams, B. D.; Duffort, V.; Vajargah, S. H.; Nazar, L. F. Nat. Energy 2016, 1, 16119. (18) Guan, C.; Zhao, W.; Hu, Y.; Ke, Q.; Li, X.; Zhang, H.; Wang, J. Adv. Energy Mater. 2016, 6, 1601034. (19) Wang, F.; Borodin, O.; Gao, T.; Fan, X.; Sun, W.; Han, F.; Faraone, A.; Dura, J. A.; Xu, K.; Wang, C.; Nat Mater. 2018, 17, 543. (20) Luo, J. Y.; Cui, W. J.; He, P.; Xia, Y. Y. Nat Chem. 2010, 2, 760. (21) Zhao Q.; Huang, W.; Luo, Z.; Liu, L.; Lu, Y.; Li,Y.; Li, L.; Hu, J.; Ma, H.; Chen, J., Sci. Adv. 2018, 4, eaao1761. (22) Pasta, M.; Wessells, C. D.; Liu, N.; Nelson, J.; McDowell, M. T.; Huggins, R. A.; Toney, M. F.; Cui, Y. Nat. Commun. 2014, 5, 3007. (23)Liu, J.; Guan, C.; Zhou, C.; Fan, Z.; Ke, Q. ; Zhang, G.; Liu, C.; Wang, J. Adv Mater. 2016, 28, 8732. (24) Liu, C.; Wang, X.; Deng, W.; Li, C.; Chen, J.; Xue, M.; Li, R.; Pan, F. Angew. Chem. Int. Ed. 2018, 57, 7046. (25) Pan, H.; Shao, Y.; Yan, P.; Cheng, Y.; Han, K. S.; Nie, Z.; Wang, C.; Yang, J.; Li, X.; Bhattacharya, P. ; Mueller, K. T.; Liu, J.; Nat. Energy 2016, 1, 16039. (26) Chen, L.; Shao, H.; Zhou, X.; Liu, G.; Jiang, J.; Liu, Z. Nat Commun. 2016, 7, 11982.


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 23

(27) Liu, J.; Chen, M.; Zhang, L.; Jiang, J.; Yan, J.; Huang, Y.; Lin, J.; Fan, H. J.; Shen, Z. X. Nano Lett. 2014, 14, 7180. (28) Yang, C.; Ji, X.; Fan, X.; Gao, T.; Suo, L.; Wang, F.; Sun, W.; Chen, J.; Chen, L.; Han , F.; Miao, L., Xu, K.; Gerasopoulos, K.; Wang, C. Adv Mater. 2017, 29,1701972. (29) Zeng, Y.; Lin, Z.; Meng, Y.; Wang, Y.; Yu, M.; Lu, X.; Tong, Y. Adv Mater. 2016, 28, 9188. (30) Guo, Z.; Zhao, Y.; Ding, Y.; Dong, X.; Chen, L.; Cao, J.; Wang, C.; Xia, Y.; Peng, H.; Wang, Y. Chem 2017, 3, 348. (31) Huang, Y.; Ip, W. S.; Lau, Y. Y.; Sun, J.; Zeng, J.; Yeung, N. S. S.; Ng, W. S.; Li, H.; Pei, Z.; Xue, Q.; Wang, Y.; Yu, J.; Hu, H.; Zhi, C.ACS Nano 2017, 11, 8953. (32) Zeng, Y.; Meng, Y.; Lai, Z.; Zhang, X.; Yu, M.; Fang, P.; Wu, M.; Tong, Y.; Lu, X. Adv Mater. 2017, 29, 1702698. (33)Zamarayeva, A. M.; Ostfeld, A. E.; Wang, M.; Duey, J. K.; Deckman, I.; Lechêne, B. P.; Davies, G.; Steingart, D. A.; Arias, A. C. Sci. Adv. 2017, 3, e1602051. (34)Li, M.; Meng, J.; Li, Q.; Huang, M.; Liu, X.; Owusu, K. A.; Liu, Z.; Mai, L. Adv. Funct. Mater. 2018, 28, 1802016. (35)Zhang, Q.; Zhou, Z.; Pan, Z.; Sun, J.; He, B.; Li, Q.; Zhang, T.; Zhao, J.; Tang, L.; Zhang, Z.; Wei, L.; Yao, Y. Adv. Sci. 2018, 5, 1801462. (36) Yin, J.; Li, Y.; Lv, F.; Fan, Q.; Zhao, Y. Q.; Zhang, Q.; Wang, W.; Cheng, F.; Xi, P.; Guo, S. ACS Nano 2017, 11, 2275. (37)Xu, Y.; Zhang, Y.; Guo, Z.; Ren, J.; Wang, Y.; Peng, H. Angew. Chem. Int. Ed. 2015, 54, 15390. (38)Meng, F.; Zhong, H.; Bao, D.; Yan, J.; Zhang, X. J. Am. Chem. Soc. 2016, 138, 10226.


Page 21 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

(39) Chao, D.; Zhu, C. R.; Song, M.; Liang, P.; Zhang, X.; Tiep, N. H.; Zhao, H.; Wang, J.; Wang, R.; Zhang, H.; Fan, H. J. Adv Mater. 2018, 30, e1803181. (40) Hu, P.; Zhu, T.; Wang, X.; Wei, X.; Yan, M.; Li, J.; Luo, W.; Yang, W.; Zhang, W.; Zhou, L.; Zhou, Z.; Mai, L. Nano Lett. 2018, 18, 1758. (41) Fang, G.; Zhou, J.; Pan, A.; Liang, S. ACS Energy Lett. 2018, 3, 2480. (42) Song, M.; Tan, H.; Chao, D.; Fan, H. J. Adv. Funct. Mater. 2018, 28, 1802564. (43) Li, H.; Liu, Z.; Liang, G.; Huang, Y.; Huang, Y.; Zhu, M.; Pei, Z.; Xue, Q.; Tang, Z.; Wang, Y.; Li, B.; Zhi, C. ACS Nano 2018, 12, 3140. (44) Zeng, Y.; Zhang, X.; Meng, Y.; Yu, M.; Yi, J.; Wu, Y.; Lu, X.; Tong, Y. Adv Mater. 2017, 29,1700274. (45) Li, H.; Han, C.; Huang, Y.; Huang, Y.; Zhu, M.; Pei, Z.; Xue, Q.; Wang, Z.; Liu, Z.; Tang, Z.; Wang, Y.; Kang, F.; Li, B.; Zhi, C. Energy Environ. Sci. 2018, 11, 941. (46) Guo, Z.; Ma, Y.; Dong, X.; Huang, J.; Wang, Y.; Xia, Y. Angew. Chem. Int. Ed. 2018, 57, 11737. (47) He, P.; Yan, M.; Zhang, G.; Sun, R.; Chen, L.; An, Q.; Mai, L. Adv. Energy Mater. 2017, 7, 1601920. (48) Zhang, N.; Cheng, F.; Liu, J.; Wang, L.; Long, X.; Liu, X.; Li, F.; Chen, J. Nat Commun. 2017, 8, 405. (49) Wan, F.; Zhang, L.; Dai, X.; Wang, X.; Niu, Z.; Chen, J. Nat Commun. 2018, 9, 1656. (50) Huang, J.; Wang, Z.; Hou, M.; Dong, X.; Liu, Y.; Wang, Y.; Xia, Y. Nat Commun. 2018, 9, 2906. (51) Xia, C.; Guo, J.; Lei, Y.; Liang, H.; Zhao, C.; Alshareef, H. N. Adv Mater. 2018, 30, 1705580.


Nano Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 23

(52) Yan, M.; He, P.; Chen, Y.; Wang, S.; Wei, Q.; Zhao, K.; Xu, X.; An, Q.; Shuang, Y.; Shao, Y.; Mueller, K. T.; Mai, L.; Liu, J.; Yang, J. Adv Mater. 2018, 30,1703725. (53) Zhang, L.; Chen, L.; Zhou, X.; Liu, Z. Adv. Energy Mater. 2015, 5, 1400930. (54) Wessells, C. D.; Huggins, R. A.; Cui, Y. Nat Commun. 2011, 2, 550. (55) Wessells, C. D.; Peddada, S. V.; Huggins, R. A.; Cui, Y. Nano Lett. 2011, 11, 5421. (56) Wang, R. Y.; Wessells, C. D.; Huggins, R. A.; Cui, Y. Nano Lett. 2013, 13, 5748. (57) He, B.; Zhang, Q.; Li, L.; Sun, J.; Man, P.; Zhou, Z.; Li, Q.; Guo, J.; Xie, L.; Li, C.; Wang, X.; Zhao, J.; Zhang, T.; Yao, Y. J. Mater. Chem. A 2018, 6, 14594. (58) Zhang, Q.; Zhang, J.; Zhou, Z.; Wei, L.; Yao, Y. J. Mater. Chem. A 2018, 6, 20145. (59) Kim, H. S.; Cook, J. B.; Lin, H.; Ko, J. S.; Tolbert, S. H.; Ozolins, V.; Dunn, B. Nat Mater. 2017, 16, 454. (60) Chao, D.; Zhu, C.; Yang, P.; Xia, X.; Liu, J.; Wang, J.; Fan, X.; Savilov, S. V.; Lin, J.; Fan, H. J.; Shen, Z. X. Nat Commun. 2016, 7, 12122. (61) Ren, W.; Chen, X.; Zhao, C. Adv. Energy Mater. 2018, 8, 1801413. (62) Su, D.; McDonagh, A.; Qiao, S. Z.; Wang, G. Adv Mater. 2017, 29,1604007. (63) Di, J.; Zhang, X.; Yong, Z.; Zhang, Y.; Li, D.; Li, R.; Li, Q. Adv Mater. 2016, 28, 10529.


Page 23 of 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Nano Letters

Table of Contents Graphic


Flexible and High-Voltage Coaxial-Fiber Aqueous Rechargeable Zinc

Recommend Documents