Engineered Fabrication of Hierarchical Frameworks with Tuned Pore

Sep 1, 2017 - School of Materials Science and Engineering, Shaanxi Normal University, 620 West Chang'an Street, Xi'an, Shaanxi 710119, China...
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Engineered Fabrication of Hierarchical Frameworks with Tuned Pore Structure and N,O-co-doping for High Performance Supercapacitors Fangyuan Hu, Jinyan Wang, Shui Hu, Linfei Li, Wenlong Shao, Jieshan Qiu, Zhibin Lei, Wei-Qiao Deng, and Xigao Jian ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.7b09801 • Publication Date (Web): 01 Sep 2017 Downloaded from http://pubs.acs.org on September 3, 2017

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Engineered Fabrication of Hierarchical Frameworks

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with Tuned Pore Structure and N,O-co-doping for

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High Performance Supercapacitors

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Fangyuan Hu,†,‡ Jinyan Wang, ‡ Shui Hu,‡ Linfei Li,‡ Wenlong Shao,‡ Jieshan Qiu,§ Zhibin Lei, Weiqiao

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Deng,

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Email: [email protected]

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§

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Liaoning Key Lab for Energy Materials and Chemical Engineering, School of Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China



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State Key Laboratory of Fine Chemicals, Liaoning Province Engineering Research Centre of High Performance Resins. Dalian University of Technology, Dalian, 116024, China.

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Xigao Jian *,†,‡

School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024, China.

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School of Materials Science and Engineering, Shaanxi Normal University, 620 West Chang’an Street, Xi’an, Shaanxi 710119, China



State Key Lab of Molecular Reaction Dynamics, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China

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KEYWORDS: porous polymer, N,O-codoped, porous carbon electrode, high performance

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supercapacitor, energy density

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ABSTRACT: A series of multi-heteroatom porous carbon frameworks (MPCFs) is prepared

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successfully from the trimerization of cyano groups of our designed and synthesized 4,4′-(4-

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oxophthalazine-1,3(4H)-diyl)dibenzonitrile monomers and subsequent ionothermal synthesis.

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Benefiting from the molecular engineering strategy, the obtained MPCFs framework show the

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homogeneously distribution of nitrogen and oxygen heteroatoms at atomic level, confirmed by

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TEM mapping intuitively, thereby ensuring the stability of electrical properties. The

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supercapacitor with the obtained MPCFs@700 as electrode exhibits a high energy density of 65

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Wh kg-1 at 0.1 A g-1, with excellent long cycle life and cycle stability (98 % capacitance

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retention for 10000 cycles in [BMIM][BF4]). Another two electrolyte systems employed also

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demonstrate the delightful results, showing 112% capacitance retention for 30000 cycles in 1 M

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H2SO4 and 95% capacitance retention for 30000 cycles in TEABF4/AN. Moreover, the

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successful preparation of MPCFs provides new insights for the fabrication of electrode materials

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intrinsically containing nitrogen and oxygen in frameworks for readily available components

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through a facile routine.

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INTRODUCTION

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The rapid development of commercial electrical equipment market at present prompts an

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urgent requirement for a novel energy storage system that can afford high power capability and

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long cycle life.1-5 Supercapacitor is a novel environmental energy storage device and bridges the

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gap between high power conventional capacitors and high energy batteries, which has been

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considered a crucial candidate in high power supply of energy devices.6-11

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Carbonaceous materials are key candidates for supercapacitor applications due to low-cost,

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the abundance, good electronic conductivity, nontoxic nature, easy availability, chemical (both in

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acid and alkali) and electrochemical (high operational window of potential) stabilities.12,13 It has

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been reported that the presence of heteroatoms in the carbonaceous materials facilitate the

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enhancement of capacitive property of electrode.14 Usually, nitrogen doping is preferential in

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tuning the electronic properties of the carbon material,15-22 which can considerably enhance the

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capacitance of carbon electrodes as a result of the pseudocapacitance effect involved in charge or

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mass transfer between electrodes and electrolytes.23-26 In particularly, the multiple heteroatoms-

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doping is a versatile synthetic approach compared with singly heteroatom-doping, which can

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further improve the performance of monodoped electrode.27-29 Nevertheless, such introduction

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can result in several uncontrollable problems, such as uncontrollable position, categories and

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content of heteroatoms.30 To circumvent this problem, the porous polymer template strategy had

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been introduced by employing the heteroaromatic monomers as basic building unit. Therefore, in

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our recent work, we realize that the homogeneous distribution of multiple heteroatoms (N and O,

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etc.) can be solved by introducing heteroatoms via covalent bonds from precursor-defined before

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carbonization.31

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Based on this, a monomer containing nitrogen and oxygen heteroatoms, namely 4,4′-(4-

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oxophthalazine-1,3(4H)-diyl)dibenzonitrile (OPDN), is successfully prepared. OPDNs go

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through the trimerisation of cyano groups and subsequent ionothermal synthesis to build a

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porous structure with nitrogen and oxygen heteroatoms (Figure 1a and Figure 1b). The molecular

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models for the network fragments are generated using the Materials Studio Modelling 5.5

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package for atomistic simulations. Firstly, the molecular models are built based on the

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assumption that the cross-linking reactions are completed and all the reactive groups are linked

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in an ideal mode according to the geometrical structure of the monomer. The networks are

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successfully optimized by geometry, and then relaxed through dynamic calculation at 298 K for

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200 ps based on the COMPASS force field. Finally, the networks present the network topologies

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after these procedures are obtained and illustrated in Figure 1b. The designed multi-heteroatom

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porous carbon frameworks (MPCFs) present the following characteristics: 1) they are

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conductive; 2) their heteroatoms are fixed in a certain position via covalent bonds to ensure that

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the heteroatoms cannot be lost during the charge/discharge process; 3) they contain inherent

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micro- and meso- pores with optimized size, thereby allowing quick ion transmission during

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charge/discharge process, the HR-TEM are employed to intuitively observe the morphologies of

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MPCFs (Figure 1c-1h); 4) they exhibit high specific surface area, thereby providing substantial

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space to accommodate ion; 5) the uniform distribution of C, N and O species within the designed

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MPCFs is quantified using energy-dispersive X-ray spectroscopy and elemental mapping (Figure

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1i-1m). Given that these structural features work cooperatively, exceptional energy storage and

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power supply capacities are obtained. Accordingly, a novel electrode material for

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supercapacitors with high energy density (i.e., 65 Wh kg-1 at 0.1 A g-1) is obtained without

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sacrificing high cycling stability (ca. 98 % capacitance retention for 10000 cycles) in ionic liquid

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([BMIM][BF4]). Besides the electrolyte of the ionic liquid, the cycling stability is further tested

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in aqueous electrolyte (ca. 112% capacitance retention for 30000 cycles in 1 M H2SO4) and

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organic electrolyte (ca. 95% capacitance retention for 30000 cycles in TEABF4/AN).

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Figure 1. Design and synthesis of materials: (a) the polymerization of OPDN; (b) Node-strut

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topology of simulated fragments for MPCFs. A triazine node connects three other nodes via rigid

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struts; (c-e) TEM images of MPCFs@600, MPCFs@650 and MPCFs@700 at 100nm; (f-h) and

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HR-TEM images of MPCFs@600, MPCFs@650 and MPCFs@700 at 20nm; (i) high resolution

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STEM image of MPCFs@700; (j) an enlarged view of the STEM image; (k) carbon atom

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mapping image; (l) nitrogen atom mapping image; (m) oxygen atom mapping image.

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RESULTS AND DISCUSSION The pore structures

of all

these MPCFs

are characterized

by the nitrogen

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adsorption/desorption measurement at 77 K. The isotherms of MPCFs@600 and MPCFs@650

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exhibit typical type I reversible sorption profiles, which indicate that MPCFs@600 and 5 Environment ACS Paragon Plus

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MPCFs@650 mainly contain micropores (Figure 2a). As the polymerization temperature

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increases, the isotherm gradually changes from type I to type IV, which indicates mesoporous

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structures (Figure 2a). The pore size distributions of MPCFs are further determined based on

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DFT (density functional theory). The results demonstrate that the amount of additional

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mesopores apart from the micropores with the polymerization temperature increases (Figure 2b).

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Additionally, the maximum Brunauer–Emmett–Teller (BET) surface area of MPCFs is 1638 m2

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g-1 when the polymerization temperature is 700 oC. The average pore size is about 2 nm. The

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results of measurements of the porosity of MPCFs are shown in Table S1.

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The structures of the MPCFs are studied using FT-IR, Raman and XRD techniques. The

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formation of MPCFs is confirmed by FT-IR, as shown in Figure S4. The strong intense

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characteristic C≡N stretching band of the building block (OPDN) at approximately 2223 cm-1

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disappears, while the formation of characteristic C=N stretching band at 1571 cm-1 and C=O

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stretching band at 1620 cm-1 appears, which indicates that the nitrogen and oxygen heteroatoms

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exist in the material (Figure S4). Raman spectroscopy is an effective tool for characterizing the

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disordered structure of carbonaceous materials.32-34 The typical D-band located at 1330 cm-1 and

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the G-band at 1594 cm-1 of MPCFs and the intensity ratio of ID/IG are usually used to

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characterize the defects and disorder in samples.35,36 According to the data in Figure S5, ID/IG

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increases from 0.96 (MPCFs@600) to 1.45 (MPCFs@700). This increase indicates a decrease in

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microstructure ordering. The XRD patterns of MPCFs display no distinguishable peaks (Figure

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S6), thereby indicating that MPCFs exhibit amorphous structures. FE-SEM are also employed to

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intuitively observe the morphologies of MPCFs. Figure S7 shows that MPCFs@600,

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MPCFs@650 and MPCFs@700 exhibit disordered modalities, which are consistent with other

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amorphous microporous organic polymers.37

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Figure 2. (a) Nitrogen adsorption-desorption curves; (b) pore size of MPCFs. XPS spectra of

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MPCFs; (c) survey spectra of MPCFs; (d) high-resolution N1s XPS spectra of MPCFs; (e)

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possible locations for N incorporation into carbon frameworks; (f) the ratios of different nitrogen

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configurations determined from the XPS N1s deconvolution results.

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X-ray photoelectron spectra (XPS) and elemental analysis (EA) are performed to obtain

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additional information regarding the elemental chemical states of MPCFs, showing C 1s, N 1s

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and O 1s (Figure 2c). The XPS analysis reveals that the atomic percentages of nitrogen in

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MPCFs@600, MPCFs@650, and MPCFs@700 are 7.18, 5.72 and 4.36 at%, respectively. At the

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same time, the atomic percentages of oxygen in MPCFs@600, MPCFs@650, and MPCFs@700

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are 6.57, 6.05 and 5.29 at%, respectively. These results are consistent with the EA results,

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showing that nitrogen contents are 7.26, 5.83 and 4.56 wt% and oxygen contents are 7.34, 6.89,

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and 5.77 wt% (Table S2, Supporting Information). The complex N1s spectra of the MPCFs are

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further deconvoluted into three different peaks centred at the binding energies of 398.3, 399.6

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and 400.7 eV,38,39 these peaks correspond to the pyridinic N (N-6), pyrrolic N (N-5), graphitic N

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(N-Q) (Figure 2d). Among them, graphitic N can enhance the electrical conductivity of

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carbonous materials.40,41 The map of various N configurations in the skeleton of MPCFs is

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shown in Figure 2e. The ratios of various N configurations of different MPCFs are plotted in

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Figure 2f and Table S3. The figure shows that the contents of N-Q increases with the elevated

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polymerization temperature.

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Considering all the features, the electrochemical performances CV, GC and electrochemical

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impedance spectroscopy (EIS) of the MPCFs are examined in 1 M H2SO4 aqueous electrolyte in

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a conventional three-electrode system (Experimental Section). In brief, the CV curves (Figure

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3a) of MPCFs@600, MPCFs@650 and MPCFs@700 do not exhibit similar quasi-rectangular

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shapes at a scan rate of 5 mV s-1. This result is attributed to the occurrence of a few redox events

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over a high voltage range of 0.1-0.6 V. These redox reactions occur because of the presence of

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certain heteroatoms (nitrogen and oxygen) in the materials as implied in the elemental and XPS

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analyzes.42,43 Therefore, introducing nitrogen and oxygen in MPCFs cannot only enhance the

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surface wettability between electrolyte and electrode materials but also participate in the pseudo-

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capacitance reaction.44,45 Notably, the CV curve of MPCFs@700 exhibits a large integrated area

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within the potential window.This finding implies that the specific capacity of MPCFs@700 is

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higher than that of the others under the same measurement conditions.

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The GC experiments are performed at 3 A g-1 in a three-electrode system with the similar

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voltage windows as that for the CV analysis to further investigate the performance of the

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samples. As shown in GC curves (Figure 3b), the discharging time of MPCFs@700 is longer

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compared with that of other materials. This long discharging time indicates that MPCFs@700

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offers a large capacitance, and this result is in good agreement with those obtained from the CV

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tests. Moreover, the GC curve of MPCFs@700 is nearly symmetrical with a gradual slope

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change (Figure 3b and Figure S8e-8f, Supporting Information). In addition, the Ohmic drop of

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MPCFs@700 is limited compared with that of the other samples for the GC at a high current

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load of 5.0 A g−1. This finding is attributed to the existence of the appropriate quantity of

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mesopores in the sample thereby accelerating the rate of ion transfer and possibly reducing the

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inner resistance of the electrodes; another reason is its good conductivity as reflected by the

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decrease in voltage drop, as IR drops (Figure S8), which can be further confirmed by the

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electrochemical impedance spectroscopy testing results (Figure 3d).46,47 The values of the

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specific capacitance of MPCFs are summarised in Figure 3c. The specific capacitances are

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extracted from the discharge slopes (Experimental Section). The figure reveals that MPCFs

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synthesized at high temperatures show better rate capability and high capacitive property. This

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finding is consistent with the CV results. The specific capacitance at a current rate of 0.1 A g-1

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increases from 277 F g-1 (MPCFs@600) to 292 F g-1 (MPCFs@650) and to 302 F g-1

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(MPCFs@700) in 1 M H2SO4.

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Long cycle life is also a crucial parameter for supercapacitors and can determine their

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practical applications.48 Hence, the durability of the MPCFs@700 electrode is tested by cycling

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at 10 A g-1 for 30000 cycles (Figure 3e). The specific capacitance of the MPCFs@700 electrode

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still remains Specifically, its specific capacitance performs a tendency to rise instead of decline

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after 30000 cycles in 1 M H2SO4, thereby indicating the long-term durability of the electrode.

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This result is possibly attributed to the improved wettability and active processes of the

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MPCFs@700 electrode.31 Moreover, the GC curves remain triangular even after 30000 cycles

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(the inset of Figure 3e). The above results illustrate that the electrode displays good long-term

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durability behavior as the supercapacitive electrode material.

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Considering that the energy density of a supercapacitor is limited by the nominal voltage and

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based on recent reports, the electrolyte used in the present study can also be applied over 2.5

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V.49-51 Figure 4 shows the CV curves and GC curves of the representative MPCFs@700

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electrode. MPCFs@700 exhibits typical rectangular CV curves without distinct peaks in the 0-

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2.5 V window of the TEABF4/AN electrolyte and 0-2.6 V window of the TEMABF4/PC

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electrolyte. The current response is thus primarily a result of electrical double layer (EDL)

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formation without contribution from the pseudocapacitive behaviour at the interface between the

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electrode materials and the electrolyte ions. The nearly rectangular CV curves at a high scan rate

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of 500 mV s-1 and the nearly triangular GC curves at a current density of 10 A g-1 show an

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approximate ideal EDL capacitive behaviour and an efficient electrolyte ion transport throughout

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the interconnected carbon nanostructured electrode. The electrode also shows a typical EDL

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capacitive behaviour (Figure 4b-4c, Figure S9) by the linear GC profiles at current densities

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between 0.1-10 A g-1. At the same time, 30000 cycles of charge/discharge are recorded for

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MPCFs@700 in TEABF4/AN at a current density of 5 A g-1 to investigate the life cycle. As

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shown in Figure 4d, MPCFs@700 exhibits a stable capacitance (ca. 95% of the original

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capacitance) after 30000 cycles.

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Figure 3. (a) CV curves of MPCF electrodes measured at 5 mV s-1 in a three-electrode system;

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(b) GC curves of MPCF electrodes at 3 A g-1; (c) Specific capacitances at various current

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densities; (d) Nyquist plots of MPCF electrodes partially enlarged detail inserted; (e) Cycle life

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tests of MPCFs@700 at a current density of 10 A g-1 (three-electrode system) with the first and

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last fifteen cycles of GC curves inserted.

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Figure 4. (a) CV curves of MPCFs@700 electrodes measured in the electrolyte of TEABF4/AN

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in a two-electrode system at different scan rates; (b,c) GC curves of MPCFs@700 electrodes in

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the electrolyte of TEABF4/AN at different current densities; (d) Cycle life tests of MPCFs@700

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at current density of 5 A g-1 (voltage range from 0 V to 2.5 V) with the first and last fifteen

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cycles of GC curves inserted.

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An ionic liquid such as 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) is

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employed to broaden the voltage window. Figure 5 shows the electrochemical performance

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analysed through GC curves (Figure 5a). Consequently, a supercapacitor based on MPCFs@700

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is further tested with a voltage of 3.5 V; the CV curves and GC curves are shown in Figure S10

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and S11, respectively. All the GC curves at different current densities show a nearly isosceles-

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triangular shape (Figure 5a and S11), which indicates their excellent double layer capacitor

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performance. Ragone plots (Figure 5b) show the overall supercapacitor performance of the

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device made with a combination of MPCF electrodes and [BMIM][BF4] electrolyte. The device

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obtains highest energy density and power density of 65 Wh kg-1 and 8810 W kg-1, respectively;

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these values are comparable to those obtained by most advanced systems reported in literature

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(Figure 5c), and higher than those of other various carbonaceous materials as the

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electrodes.14,18,52-58 In addition, the preparation method of these MPCF-based materials is much

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easier than that of the reported materials. Notably, their properties can be further tuned by using

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different kinds of monomers or changing the reaction procedures. Such approach provides a

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versatile reservoir for developing mass producible electrode materials for practical applications

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in ionic liquid-based supercapacitors. More importantly, the MPCF-based supercapacitor also

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exhibits a remarkable cycling stability (Figure 5e). The capacitance of the device shows a

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relatively stable performance with 98% capacitance retention achieved at 5 A g-1. The nearly

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identical capacitive behaviour as shown by the GC curves (the inset of Figure 5e) further

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demonstrates the cycling stability of the device. The reason is that such structure can effectively

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prevent the loss of heteroatoms from the electrode and ensure an efficient charge transfer

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between the pseudocapacitive part and the EDL part. The MPCFs@700-based supercapacitor is

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also tested to drive commercial LEDs (Figure 5e and 5f) to intuitively manifest the performance

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of the designed high voltage supercapacitor. The MPCFs@700-based supercapacitor can

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successfully drive a commercial green LED when charged to 2.6 V (Figure 5e) and a commercial

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blue LED when its voltage increased to 3.0 V (Figure 5f).

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Figure 5. (a) GC curves of MPCF electrodes at 1 A g-1 in a two-electrode system; (b) Ragone

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plots of MPCFs@700 with specific capacitances inserted; (c) Summary of the highest energy

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density of MPCFs (this work) and other carbon materials reported in literature; (d) Cycle life

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tests of MPCFs@700 at current density of 10 A g-1 (voltage range from 0 V to 3.5 V) with the

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first and last fifteen cycles of GC curves inserted; (e) the supercapacitor can drive a commercial

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green LED at 2.6 V; (f) the supercapacitor can drive a commercial blue LED at 3.0 V.

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CONCLUSIONS

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In summary, a series of multi-heteroatom porous carbon frameworks (MPCFs) is designed

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and synthezed using the molecular engineering strategy. High-performance MPCF electrodes

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with nitrogen and oxygen contained through the ionothermal reaction are successfully

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constructed. The electrochemical performances of MPCF electrodes are tested in aqueous

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electrolyte (1 M H2SO4), organic electrolyte (TEABM4/AN and TEMABF4/PC) and ionic

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electrolyte ([BMIM][BF4]). The as-made MPCFs@700 electrode exhibits excellent cycling

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stability, such as capacity retention maintains ca. 112% after 30000 cycles in 1 M H2SO4, ca.

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95% after 30000 cycles in TEABM4/AN, ca. 98% after 10000 cycles in [BMIM][BF4]. Given the

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high specific surface area, nanoporous structure and well-distributed heteroatoms, the as-made

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MPCFs@700 electrode exhibits excellent electrochemical performance with energy density of

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up to 65 Wh kg-1 and with excellent long cycle life. Thus, it is a promising electrode for

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supercapacitors. More importantly, the electrical properties of the electrodes can be adjusted by

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altering the porous structures, whilst the types and contents of the heteroatoms can be adjusted

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by changing the structure of the monomer.

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EXPERIMENTAL SECTION

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Materials. All starting materials, except for OPDN, were purchased commercially and used

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without further purification.

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Synthesis of OPDN. The precursor, OPDN, was prepared as fine white power, with a yield of

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61%.59 mp: 313-315 oC; 1H-NMR (500 MHz, CDCl3/TMS int, ppm) d: 8.64 (d, 1H), 7.98 (d, 15 Environment ACS Paragon Plus

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2H), 7.88 (d, 4H), 7.78 (d, 4H), 7.71 (d, 1H); MS calculated for C22H12N4O, 348.1011; found,

2

348.1020; anal. calculated for C22H14N4O2: C, 75.85; H, 3.47; N, 16.08; found: C, 75.52; H,

3

3.36; N, 15.95.

4

Synthesis of MPCFs. MPCFs@600 was synthesized at 600 oC with ZnCl2 as the catalyst.

5

Typically, OPDN (400 mg, 1.15 mmol) and anhydrous ZnCl2 (782 mg, 5.75 mmol) were mixed

6

in a glove box (argon with 0.1 ppm oxygen and 0.1 ppm water) and transferred into a quartz

7

ampoule (Ф20 mm×150 mm). The ampoule was evacuated by vacuum, sealed and heated at the

8

rate of 5 oC/min to 600 oC and maintained at this temperature for 40 h. Thereafter, the inside

9

compound was washed thoroughly with 5% HCl solution and deionized water. Then, the

10

resultant was dried under vacuum at 120 °C for 24h to obtain the black powder. MPCFs@650

11

and MPCFs@700 were synthesized under the similar procedure of MPCFs@600 but at high

12

temperatures of 650 oC and 700 oC in quartz ampoules. Finally, the black powders were

13

obtained.

14

Methods. The Fourier transform infrared (FT-IR) spectra were recorded with a Bruker

15

Equinox 55 spectrometer. Samples were measured using pallets prepared by compressing

16

the dispersed mixture of sample and KBr powder. The powder X-ray diffraction (XRD)

17

patterns of the samples were recorded with a SmartLab diffractometer using CuKa

18

radiation operated at 45 kV and 200 mA and performing from 2o to 80o at a speed of 8

19

min-1. Raman spectra were obtained using a RENISHAW in Via Raman Microscope.

20

Atomistic Simulations. The molecular models for the MPCF networks were generated

21

using the Materials Studio Modelling 5.5 package. Differential scanning calorimetry

22

(DSC) measurements were performed on a TA Q20 DSC instrument at a heating rate of

23

10 oC/min from room temperature to 350 oC with a constant flow of N2 at 80 mL/min.

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ACS Applied Materials & Interfaces

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Thermogravimetric analysis (TGA) was conducted by TGA on a Shimadzu DT-30B at a

2

heating rate of 10 oC/min from room temperature to 800 oC with a continuous purge of

3

N2. The nitrogen sorption/desorption isotherms of the samples were measured at 77.15 K

4

with an ASAP 2020 (Micromeritics). Prior to adsorption, the samples were outgassed at

5

100 oC for 6 h under a vacuum of 10-6 Torr. The Brunauer-Emmett-Teller (BET) method

6

and the pore model of density functional theory (DFT) were utilized to calculate the

7

specific surface area and pore size distribution, respectively. The morphologies of the as-

8

obtained products were observed using high-resolution transmission electron microscopy

9

(HR-TEM) and scanning electron microscopy (SEM). Elemental mapping images were

10

obtained from a Tecnai G2 F20 U-TWIN microscope with an STEM-HAADF

11

attachment. Elemental analyzes were performed with a FLASH EA1112 analyzer. X-ray

12

photoelectron spectroscopy (XPS) measurement was conducted on an ESCALAB250

13

apparatus at base pressure of 1×10-9 mbar and an X-ray source of Al Kα.

14

Preparation of MPCF-based electrodes. MPCF-based electrodes were assembled in a

15

three-electrode system and a two-electrode system: (1) in the three-electrode system,

16

electrode films were prepared by grinding MPCFs (80 wt %), carbon black (10 wt%, Alfa

17

Aesar), and polytetrafluoroethylene (10 wt%, 60% in water, Aldrich Co., diluted to 6 %

18

before use) in a mortar. The thin film was dried under vacuum at 120 °C for 24 h, and

19

then cut to a circular shape with a diameter of 12 mm and a mass of 2.5-3 mg. The

20

circular film was pressed to a titanium mesh (400 mesh) as the working electrode; (2) in

21

the two-electrode system, MPCFs (80 wt %), acetylene black (10 wt%) as the conducting

22

filler, and polyvinylideneuoride (10 wt%) in N-methyl-2-pyrrolidone were well mixed in

23

a mortar. The resultant was coated onto a commercial carbon-coated aluminium foil as a

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current collector. The thin film was dried under vacuum at 120 °C for 24 h, and the sheet

2

was then punched into 12 mm diameter electrodes with a loading mass of 1.7 mg.

3

Electrochemical measurements. Electrochemical measurements were performed in a three-

4

electrode system and a two-electrode system: (1) in the three-electrode system, a MPCF film

5

pressed on a titanium mesh was used as the working electrode, a platinum sheet (10 mm × 20

6

mm) was used as the counter electrode, and an aqueous Ag/AgCl was used as the reference

7

electrode. The three electrodes were immersed into a beaker containing 1 M H2SO4 solution to

8

form the three-electrode testing system; cyclic voltammograms (CVs), galvanostatic

9

charge/discharge (GC) curves, and Nyquist plots were collected on a CHI760E electrochemical

10

workstation; (2) in the two-electrode system, two MPCF sheets with exactly the same weight

11

were selected as two symmetrical working electrodes. Thereafter, the two electrodes were

12

assembled in a coin-type cell of 2032 size with tetraethylammonium tetrafluoroborate in an

13

acetonitrile solution (TEABF4/AN), triethylmethylammonium tetrafluoroborate in a propylene

14

carbonate (TEMABF4/PC), and room temperature ionic liquid, 1-butyl-3- methylimidazolium

15

tetrafluoroborate (BMIMBF4), to form the two-electrode testing system. The specific capacitance

16

(C, F g-1) was calculated from the slope of discharge curve using: (1) C=It/mV (three-electrode

17

system); (2) C=2It/mV (two-electrode system), where I (unit: A) is the discharge current, t (unit:

18

s) is the discharge time, m (unit: g) is the mass of MPCFs in the working electrodes, and V (unit:

19

V) is the discharge voltage. The energy densities (E, Wh/kg) were calculated by E=

20

1/8(CV2)(1000/3600). The power densities (P, W/kg) were calculated by P=E/(t/3600).

21 22

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ACS Applied Materials & Interfaces

1

ASSOCIATED CONTENT

2

The Supporting Information is available free of charge on the ACS Publications website at DOI:

3

10.1021/acsami. xxx.

4

Complementary experimental results and computational details and additional computational

5

results (PDF).

6

AUTHOR INFORMATION

7

Corresponding Author

8

*E-mail (Xigao Jian): [email protected].

9

Notes

10

The authors declare no competing financial interest.

11

ACKNOWLEDGMENT

12

The authors acknowledge the support from the National Natural Science Foundation of China

13

(No. 51503024), State Key Laboratory of Organic-Inorganic Composites (No. oic-201601007),

14

National High Technology Research and Development Program (863 Program) of China (No.

15

2015AA033802) and the Fundamental Research Funds for the Central Universities (No.

16

DUT17RC(3)003, DUT16LK14).

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1 2 3

REFERENCES

4

(1) Armand, M.; Tarascon, J. M. Building Better Batteries. Nature 2008, 451, 652-657.

5

(2) Miller, J. R.; Simon, P. Electrochemical Capacitors for Energy Management. Science 2008,

6

321, 651-652.

7

(3) Yang, J.; Yu, C.; Fan, X.; Qiu, J. 3D Architecture Materials Made of NiCoAl-LDH

8

Nanoplates Coupled with NiCo-Carbonate Hydroxide Nanowires Grown on Flexible Graphite

9

Paper for Asymmetric Supercapacitors. Adv. Energy Mater. 2014, 4, 1400761(1-8).

10

(4) Yang, J.; Yu, C.; Liang, S.; Li, S.; Huang, H.; Han, X.; Zhao, C.; Song, X.; Hao, C.; Ajayan,

11

P.; Qiu, J. Bridging of Ultrathin NiCo2O4 Nanosheets and Graphene with Polyaniline: A

12

Theoretical and Experimental Study. Chem. Mater. 2016, 28, 5855-5863.

13

(5) Yang, J.; Yu, C.; Fan, X.; Liang, S.; Li, S.; Huang, H.; Ling, Z.; Hao, C.; Qiu, J. Electroactive

14

Edge Site-enriched Nickel-Cobalt Sulfide into Graphene Frameworks for High-performance

15

Asymmetric Supercapacitors. Energy Environ. Sci. 2016, 9, 1299-1307.

16

(6) Li, Z.; Liu, Z.; Sun, H.; Gao, C. Superstructured Assembly of Nanocarbons: Fullerenes,

17

Nanotubes, and Graphene. Chem. Rev. 2015, 115, 7046-7117.

18

(7) Simon, P.; Gogotsi, Y. Materials for Electrochemical Capacitors. Nat. Mater. 2008, 7, 845-

19

854.

20

(8) Liu, S.; Sankar, K. V.; Kundu, A.; Ma, M.; Kwon, J.; Jun S. Honeycomb-Like Interconnected

21

Network of Nickel Phosphide Heteronanoparticles with Superior Electrochemical Performance

22

for Supercapacitors. ACS Appl. Mater. Interfaces 2017, 9, 21829-21838.

20 Environment ACS Paragon Plus

Page 21 of 28

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

ACS Applied Materials & Interfaces

1

(9) Wang, K.; Wu H.; Meng Y.; Zhang Y.; Wei Z. Integrated Energy Storage and

2

Electrochromic Function in One Flexible Device: An Energy Storage Smart Window. Energy

3

Environ. Sci. 2012,5, 8384-8389.

4

(10) Wang, K.; Zhao, P.; Zhou, X.; Wu H.; Wei Z. Flexible Supercapacitors Based on Cloth-

5

Supported Electrodes of Conducting Polymer Nanowire Array/SWCNT Composites. J. Mater.

6

Chem. 2011, 21, 16373-16378.

7

(11) Xu, J.; Wang, K.; Zu, S.; Han, B.; Wei, Z. Hierarchical Nanocomposites of Polyaniline

8

Nanowire Arrays on Graphene Oxide Sheets with Synergistic Effect for Energy Storage. ACS

9

Nano 2010, 4, 5019-5026.

10

(12) Zhu, Y.; Murali, S.; Stoller, M. D.; Ganesh, K. J.; Cai, W.; Ferreira, P. J.; Pirkle, A.; Wallace,

11

R. M.; Cychosz, K. A.; Thommes, M.; Su, D.; Stach, E. A.; Ruoff, R. S. Carbon-Based

12

Supercapacitors Produced by Activation of Graphene. Science 2011, 332, 1537-1541.

13

(13) Yang, X.; Zhu, J.; Qiu, L.; Li, D. Bioinspired Effective Prevention of Restacking in

14

Multilayered Graphene Films: Towards The Next Generation of High-performance

15

Supercapacitors. Adv. Mater. 2011, 23, 2833-2838.

16

(14) Zhao, Y.; Liu, M.; Deng, X. Nitrogen-Functionalized Microporous Carbon Nanoparticles

17

for High Performance Supercapacitor Electrode. Electrochim. Acta 2015, 153, 448-455.

18

(15) Zhang, J.;Dai. L. Nitrogen, Phosphorus, and Fluorine Tri-Doped Graphene as An

19

Multifunctional Catalyst for Self-powered Electrochemical Water Splitting. Angew. Chem. Int.

20

Ed. 2016, 55, 13296-13300.

21

(16) Kajdos, A.; Kvit, A.; Jones, F.; Jagiello, J.; Yushin, G. Tailoring the Pore Alignment for

22

Rapid Ion Transport in Microporous Carbons. J. Am. Chem. Soc. 2010, 132, 3252-3253.

23

(17) Lin, T.; Chen, W.; Liu, F.; Yang, C.; Bi, H.; Xu, F.; Huang, F. Nitrogen-Doped Mesoporous

21 Environment ACS Paragon Plus

ACS Applied Materials & Interfaces

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 28

1

Carbon of Extraordinary Capacitance For Electrochemical Energy Storage. Science 2015, 350,

2

1508-1531.

3

(18) Chmiola, J.; Yushin, G.; Gogosti, Y.; Portet, C.; Simon, P.; Taberna, P. L. Anomalous

4

Increase in Carbon Capacitance at Pore Sizes Less Than 1 Nanometer. Science 2006, 313, 1760-

5

1763.

6

(19) Dash, R.; Chmiola, J.; Yushin, G.; Gogosti, Y.; Laudisio, G.; Singer, J.; Fischer, J.;

7

Kucheyev, S. Titanium Carbide Derived Nanoporous Carbon for Energy-Related Applications.

8

Carbon 2006, 44, 2489-2497.

9

(20) Burke, A. R&D Considerations for The Performance and Application of Electrochemical

10

Capacitors. Electrochim. Acta 2007, 53, 1083-1091.

11

(21) Du, X.; Guo, P.; Song, H.; Chen, X. Graphene Nanosheets as Electrode Material for Electric

12

Double-Layer Capacitors. Electrochim. Acta 2010, 55, 4812-4819.

13

(22) Wu, Q.; Xu, Y.; Yao, Z.; Liu, A.; Shi, G. Supercapacitors Based on Flexible

14

Graphene/Polyaniline Nanofiber Composite Films. ACS Nano 2010, 4, 1963-1970.

15

(23) Frackowiak, E.; Beguin, F. Electrochemical Storage of Energy in Carbon Nanotubes and

16

Nanostructured Carbons. Carbon 2002, 40, 1775-1787.

17

(24) Han, J.; Zhang L.; Lee, S.; Oh, J.; Lee, K.; Potts, J.; Ji, J.; Zhao, X.; Ruoff, R. S.; Park, S.

18

Generation

19

Their Supercapacitor Applications. ACS Nano 2013, 7, 19-26.

20

(25) Xu, Z.; Zhuang, X.; Yang, C.; Cao, J.; Yao, Z.; Tang, Y.; Jiang, J.; Wu, D.; Feng, X.

21

Nitrogen-Doped Porous Carbon Superstructures Derived from Hierarchical Assembly of

22

Polyimide Nanosheets. Adv. Mater. 2016, 28, 1981-1987.

23

(26) Su, F.; Poh, C. K.; Chen, J. S.; Xu, G.; Wang, D.; Li, Q.; Lin, J.; Lou, X. W. Nitrogen-

Of

B-Doped

Graphene

Nanoplatelets

Using

22 Environment ACS Paragon Plus

A Solution

Process

and

Page 23 of 28

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

ACS Applied Materials & Interfaces

1

Containing Microporous Carbon Nanospheres with Improved Capacitive Properties, Energy

2

Environ. Sci. 2011, 4, 717-724.

3

(27) Paraknowitsch, J. P.; Zhang, J.; Su, D.; Thomas, A.; Antonietti, M.; Ionic Liquids as

4

Precursors for Nitrogen-Doped Graphitic Carbon. Adv. Mater. 2010, 22, 87-92.

5

(28) Hulicova-Jurcakova, D.; Puziy, A. M.; Poddubnaya, O. I.; Suarez-Garcia, F.; Tascon, J. M.

6

D.; Lu, G. Q. Highly Stable Performance of Supercapacitors from Phosphorus-Enriched

7

Carbons. J. Am. Chem. Soc. 2009, 131, 5026-5027.

8

(29) Li, T.; Zhang, W.; Zhi, L.; Yu, H.; Dang, L.; Shi, F.; Xu, H.; Hu, F.; Liu, Z.; Lei, Z.; Qiu, J.

9

High-energy Asymmetric Electrochemical Capacitors Based on Oxides Functionalized Hollow

10

Carbon Fibers Electrodes. Nano Energy 2016, 30, 9-17.

11

(30) Xu, Y.; Lin, Z.; Huang, X.; Wang, Y.; Huang, Y.; Duan, X. Functionalized Graphene

12

Hydrogel-Based High-Performance Supercapacitors. Adv. Mater. 2013, 25, 5779-5784.

13

(31) Hu, F.; Wang, J.; Hu, S.; Li, L.; Wang, G.; Qiu, J.; Jian, X. Inherent N,O-Containing Carbon

14

Frameworks as Electrode Materials for High-performance Supercapacitors. Nanoscale 2016, 8,

15

16323-16331.

16

(32) Sun, H.; Xie, S.; Li, Y.; Jiang, Y.; Sun, X.; Wang, B.; Peng H. Large-Area Supercapacitor

17

Textiles with Novel Hierarchical Conducting Structures. Adv. Mater. 2016, 28, 8431-8438.

18

(33) Zhao, Y.; Liu, M.; Deng, X.; Miao, L.; Tripathi, P. K.; Ma, X.; Zhu, D.; Xu, Z.; Hao, Z.;

19

Gan, L. Nitrogen-Functionalized Microporous Carbon Nanoparticles for High Performance

20

Supercapacitor Electrode. Electrochim. Acta 2015, 153, 448-455.

21

(34) Liu, M.; Gan, L.; Xiong, W.; Xu, Z.; Zhu, D.; Chen, L. Development of MnO2/Porous

22

Carbon Microspheres with A Partially Graphitic Structure for High Performance Supercapacitor

23

Electrodes. J. Mater. Chem. A 2014, 2, 2555-2562.

23 Environment ACS Paragon Plus

ACS Applied Materials & Interfaces

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 24 of 28

1

(35) Fan, H.; Wang, H.; Zhao, N.; Zhang, X.; Xu, J. Hierarchical Nanocomposite

2

of Polyaniline Nanorods Grown on The Surface of Carbon Nanotubes for High-Performance

3

Supercapacitor Electrode. J. Mater. Chem. 2012, 22, 2774-2780.

4

(36) Stoller, M. D.; Park, S. J.; Zhu, Y. W.; An, J. H.; Ruoff, R. S. Graphene-Based

5

Ultracapacitors. Nano Lett. 2008, 8, 3498-3502.

6

(37) Zhao, Y.; Zhang, L.; Wang, T.; Han, B. Microporous Organic Polymers with Acetal

7

Linkages: Synthesis, Characterization, and Gas Sorption Properties. Polym. Chem. 2014, 5, 614-

8

621.

9

(38) Wei, W.; Liang, H.; Parvez, K.; Zhuang, X.; Feng, X.; Müllen, K. Near-IR Phosphorescent

10

Ruthenium(II) and Iridium(III) Perylene Bisimide Metal Complexes. Angew. Chem. Int. Ed.

11

2014, 53, 1570-1574.

12

(39) Chen, C.; Wang, Z.; Saito, M.; Tohei, T.; Takano, Y.; Ikuhara, Y. Fluorine in Shark Teeth: Its

13

Direct Atomic-Resolution Imaging and Strengthening Function. Angew. Chem. Int. Ed. 2014, 53,

14

1543-1547.

15

(40) Sakaushi, K.; Antonietti M. Carbon- and Nitrogen-Based Organic Frameworks. Acc. Chem.

16

Res. 2015, 48, 1591-1600.

17

(41) Hao, L.; Li, X.; Zhi, L. Carbonaceous Electrode Materials for Supercapacitors. Adv. Mater.

18

2013, 25, 3899-3904.

19

(42) Simon, P.; Gogotsi, Y.; Dunn, B. Where Do Batteries End and Supercapacitors Begin.

20

Science 2014, 343, 1210-1211.

21

(43) Tao, L.; Wang, Q.; Dou, S.; Ma, Z.; Huo, J.; Wang, S.; Dai, L.; Edge-Rich and Dopant-Free

22

Graphene as Highly Efficient Metal-free Electrocatalyst for Oxygen Reduction Reaction. Chem.

23

Commun. 2016, 52, 2764-2767.

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Page 25 of 28

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

ACS Applied Materials & Interfaces

1

(44) Chen, C.; Xu, G.; Wei X.; Yang, L. A Macroscopic Three-Dimensional Tetrapodseparated

2

Graphene-Like

3

Supercapacitors. J. Mater. Chem. A 2016, 4, 9900-9909.

4

(45) Zhou, J.; Lian, J.; Hou, L.; Zhang, J.; Gou, H.; Xia, M.; Zhao, Y.; Strobel, T. A.; Tao, L.;

5

Gao. F. Ultrahigh Volumetric Capacitance and Cyclic Stability of Fluorine and Nitrogen Co-

6

Doped Carbon Microspheres. Nature Commun. 2015, 6, 8503(1-8).

7

(46) Kim, W.; Kang, M. Y.; Joo, J. B.; Kim, N. D.; Song, I. K.; Kim, P.; Yoon, J. R.; Yi, J.

8

Preparation of Ordered Mesoporous Carbon Nanopipes with Controlled Nitrogen Species for

9

Application in Electrical Double-Layer Capacitors. Power Sources 2010, 195, 2125-2129.

Oxygenated

N-Doped

Carbon

Nanosheet

Architecture

for

Use

in

10

(47) Usachov, D.; Vilkov, O.; Grueneis, A.; Haberer, D.; Fedorov, A.; Adamchuk, V. K.;

11

Preobrajenski, A. B.; Dudin, P.; Barinov, A.; Oehzelt, M.; Laubschat, C.; Vyalikh, D. V.

12

Nitrogen-Doped Graphene: Efficient Growth, Structure, and Electronic Properties. Nano Lett.

13

2011, 11, 5401-5407.

14

(48) He, S.; Chen, W. High Performance Supercapacitors Based on Three-Dimensional Ultralight

15

Flexible Manganese Oxide Nanosheets/Carbon Foam Composites. J. Power Sources 2014, 262,

16

391-400.

17

(49) Chen, J.; Xu, J.; Zhou, S.; Zhao, N.; Wong, C. P. Nitrogen-Doped Hierarchically Porous

18

Carbon Foam: A Free-Standing Electrode and Mechanical Support for High-Performance

19

Supercapacitors. Nano Energy 2016, 25, 193-202.

20

(50) Raymundo-Piñero, E.; Kierzek, K.; Machnikowski, J.; Béguin, F. Relationship between The

21

Nanoporous Texture of Activated Carbons and Their Capacitance Properties in Different

22

Electrolytes. Carbon 2006, 44, 2498-2507.

23

(51) Chmiola, J.; Largeot, C.; Taberna, P. L.; Simon, P.; Gogotsi, Y. Desolvation of Ions in

25 Environment ACS Paragon Plus

ACS Applied Materials & Interfaces

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 26 of 28

1

Subnanometer Pores and Its Effect on Capacitance and Double-Layer Theory. Angew. Chem. Int.

2

Ed. 2008, 47, 3392-3395.

3

(52) Zheng, C.; Qian, W.; Cui, C.; Zhang, Q.; Jin, Y.; Zhao, M.; Tan, P.; Wei, F. Hierarchical

4

Carbon Nanotube Membrane with High Packing Density and Tunable Porous Structure for High

5

Voltage Supercapacitors. Carbon 2012, 50, 5167-5175.

6

(53) Hao, G.; Lu, A.; Dong, W.; Jin, Z.; Zhang, X.; Zhang, J.; Li, W. Sandwich-Type

7

Microporous Carbon Nanosheets for Enhanced Supercapacitor Performance. Adv. Energy Mater.

8

2013, 3, 1421-1427.

9

(54) Jung, N.; Kwon, S.; Lee, D.; Yoon, D.; Park, Y.; Benayad, A.; Choi, J.; Park, J. Synthesis of

10

Chemically Bonded Graphene/Carbon Nanotube Composites and Their Application in Large

11

Volumetric Capacitance Supercapacitors. Adv. Mater. 2013, 25, 6854-6858.

12

(55) Zhang, L.; Zhao, X.; Stoller, M. D.; Zhu, Y.; Ji, H.; Murali, S.; Wu, Y.; Perales, S.;

13

Clevenger, B.; Ruoff, R. S. Highly Conductive and Porous Activated Reduced Graphene Oxide

14

Films for High-Power Supercapacitors. Nano Lett. 2012, 12, 1806-1812.

15

(56) Wang, H.; Xu, Z.; Kohandehghan, A.; Li, Z.; Cui, K.; Tan, X.; Stephenson, T. J.; King’ondu,

16

C. K.; Holt, C. M. B.; Olsen, B. C.; Tak, J. K.; Harfield, D.; Anyia, A. O.; Mitlin, D.

17

Interconnected Carbon Nanosheets Derived from Hemp for Ultrafast Supercapacitors with High

18

Energy. ACS Nano, 2013, 7, 5131-5141.

19

(57) Kim, T.; Kang, H. C.; Tung, T. T.; Lee, J. D.; Kim, H.; Yang, W. S.; Yoon, H. G.; Suh, K. S.

20

Ionic Liquid-Assisted Microwave Reduction of Graphite Oxide For Supercapacitors. RSC Adv.

21

2012, 2, 8808-8812.

22

(58) Lei, Z.; Liu, Z.; Wang, H.; Sun, X.; Lu, L.; Zhao, X. S. A high-Energy-Density

23

Supercapacitor With Graphene-CMK-5 as The Electrode and Ionic Liquid as The Electrolyte. J.

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ACS Applied Materials & Interfaces

1

Mater. Chem. A 2013, 1, 2313-2321.

2

(59) Yuan, K.; Liu, C.; Han, J.; Yu, G.; Wang, J.; Duan, H.; Wang, Z.; Jian, X. Phthalazinone

3

Structure-Based Covalent Triazine Frameworks and Their Gas Adsorption and Separation

4

Properties. RSC Adv. 2016, 6, 12009-12020.

5

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Table of contents

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Multi-heteroatom porous carbon frameworks (MPCFs) for supercapacitors with high energy

7

density (65 Wh kg-1), power density (8810 W kg-1) and cycle stability (98 % capacitance

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retention for 10000 cycles at 3.5V).

28 Environment ACS Paragon Plus

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