High-Cycle-Performance Aqueous Magnesium Ions Battery Capacitor

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High-Cycle-Performance Aqueous Magnesium Ions Battery Capacitor Based on a Mg-OMS-1/Graphene as Cathode and a Carbon Molecular Sieves as Anode Hongyu Zhang, Dianxue Cao, Xue Bai, Hongfei Xie, Xinzhong Liu, Xiaoyu Jiang, Hui Lin, and Huiyan He ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.8b06288 • Publication Date (Web): 21 Feb 2019 Downloaded from http://pubs.acs.org on February 23, 2019

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ACS Sustainable Chemistry & Engineering

High-Cycle-Performance Aqueous Magnesium Ions Battery Capacitor Based on a Mg-OMS-1/Graphene as Cathode and a Carbon Molecular Sieves as Anode Hongyu Zhang[a], Dianxue Cao[b], Xue Bai[a]*, Hongfei Xie[a], Xinzhong Liu[a], Xiaoyu Jiang[a], Hui Lin[a], Huiyan He[a]

a. College of Ecological Environment and Urban Construction, Fujian University of Technology, Xuefu South Road, NO.33, University New District, Fuzhou 350108, Fujian P.R. China *Corresponding author: Xue Bai, E-mail addresses: [email protected]

b. Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Nantong street, NO.145, Nangang District, Harbin, 150001, Heilongjiang P.R. China

Abstract The aqueous rechargeable magnesium ion batteries are dramatic safe, low-cost and green energy storage system but are trapped in the low-capacity cathode and enormously limited anode materials. Therefore, based on previous research foundations, the Mg-OMS-1/Graphene composite as cathode is obtained by combining the todorokite-type Mg-OMS-1 with nanowire morphology and flaky graphene, exhibiting the higher electrochemical properties. The discharged capacities of single and 1 ACS Paragon Plus Environment

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composite electrodes in Mg(NO3)2 electrolyte are 150.4 and 194.1 mAh g−1 at the current density of 20 mA g−1, respectively. Additionally, the self-made carbon molecular sieves (CMS) material is explored as anode material in this aqueous energy storage system, displaying a discharged capacity of 64.8 mAh g−1 at 100 mA g−1. Furthermore, the aqueous rechargeable magnesium ion battery capacitor device is assembled by the composite electrode material as cathode and the CMS material as anode. This system displays the excellent cycling lifespan with 98.6% capacity retained after 800 cycles at the current density of 100 mA g−1. Keywords: Green energy storage system; Mg-OMS-1/Graphene composite; Self-made CMS; Aqueous magnesium ion battery capacitor

Introduction In recent years, with the aggravation of energy crisis and environment problems, the promotion of large-scale application for renewable energy sources such as wind, solar and biomass energy, and the construction of smart grids are great important directions for the realization of low-carbon economy and sustainable development 1-3. Therefore, energy storage technology is a vital issue to ensure the stable operation of renewable energy sources and the rapid establishment of smart grid, which is distinguished as chemical energy storage and physical energy storage

4-6.

However,

physical energy storage is dependent on geographical conditions and requirements, restricting the popularization and application on a large scale. Electrochemical energy storage 7-8, as the main form of chemical energy storage, can achieve the energy storage 2 ACS Paragon Plus Environment

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based on the conversion between electrical energy and chemical energy, which has the characteristics of fast response, flexible application, high efficiency and freedom from geographical conditions. As the representative of electrochemical energy storage, battery is the main carrier for energy storage and conversion, regarding as to be an important part of the energy industry and also closely related to our life 9-10 . The traditional batteries

11-14,

such as lead-acid and nickel-cadmium battery,

exhibit the low energy density. Lithium ion battery owns the higher power density and energy density, however, the flammable and combustible organic electrolytes and the high-cost lithium resources are main problems that restrict its further development and wide application

15-18.

Therefore, exploring the safer and superior greener energy

storage system and low-cost battery materials become the research focus, which meets the demands of sustainable development for human in the future. Aqueous magnesium ion battery

19-20,

utilizing the aqueous solution of magnesium salt as electrolyte (such

as magnesium sulfate, magnesium nitrate and magnesium chloride) and suitable materials as cathode and anode electrodes, is a novel second-generation energy storage system. The advantages of this system are as followed: firstly, the water resource is very abundant. Compared with the expensive and limited lithium resources, magnesium resources have the low cost and large reserves. Secondly, the aqueous electrolyte is much safer and friendly for environment, which owns the higher ionic conductivity comparing with organic electrolytes

21.

Meanwhile, aqueous electrolyte can increase

the mobility of magnesium ions and avoid the problem that magnesium ions move slowly in organic electrolytes. Thirdly, magnesium ion and lithium ion have similar 3 ACS Paragon Plus Environment


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ionic radius and electrochemical properties. In addition, the magnesium ion carries two electrons which is twice bigger than that of lithium ion 22-23, theoretically indicating that aqueous magnesium ion battery can exhibit higher rate performance. Different types of manganese dioxides have been widely used as energy storage materials due to the characteristics of low cost, nontoxicity and availability 24-26, which is totally satisfied with the demands of second generation storage power. The todorokite-type magnesium manganese dioxide, one of the MnO2 families, is utilized in battery research areas as a result of its large tunnels that is constructed by MnO6 octahedra triple chains. However, the poor conductivity of manganese dioxide is always the fatal drawback that limited the extensive application of them. Graphene with the outstanding properties of large specific surface area, highly electrical conductivity and high mechanical has received widespread attention 27-28. Therefore, it is very reason to believe that the graphene composite is prospective to show more outstandingly electrochemical performance. In this work, the todorokite-type Mg-OMS-1 with large 3 × 3 tunnels structure providing enough for inserted magnesium ions that has been reported in our group before was further combined with the graphene as the cathode material

29,

which

successfully obtained the composite of nanowire Mg-OMS-1/Graphene to solve the poor conductivity problem of MnO2 type material. Meanwhile, our self-made carbon molecular sieves (CMS) material as anode material was constructed by filling carbon source into sacrificial template of SBA-15, designing to use the mesoporous tunnel from SBA-15 as frame to adsorb more magnesium ions and improve the wettability 4 ACS Paragon Plus Environment

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between the electrode and electrolyte in order to enhance the cycle life. We utilized the nanowire composite electrode material as cathode and CMS as anode material to assemble the aqueous magnesium-ion battery capacitor, which is expected to exhibit excellent electrochemical performance. Experimental Fabrication of Mg-OMS-1/Graphene and carbon molecular sieves (CMS) The Mg-OMS-1/Graphene composite with nanowire structure was obtained on the basis of synthetic process of Mg-OMS-1 material 29, which was continued to add the 50 mg graphene at the conditions of 60 oC and 4 h during the ion exchange process and other synthetic steps remained the same, as shown in Scheme. 1.

Scheme 1. Schematic illustration of fabrication procedure of Mg-OMS-1/Graphene and CMS

The carbon molecular sieves (CMS) was prepared as followed 30: firstly, SBA-15 was obtained by hydrothermal method basing on the reported literature 31. Then, 1 g synthesized SAB-15 and 3.5 mmol sucrose were added into the beaker with 12.9 mmol H2SO4 and 10 mL deionized water, stirring 3 min until the sucrose was dissolved. This mixed solution was filtrated by its filtrate and repeated 6 times to get the filter cake. 5 ACS Paragon Plus Environment


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Subsequently, the filter cake and filtrate were together put in the oven at 160 oC for 6 h. The black powder after initial carbonization was grinded and repeated above process with the unchanged steps. The synthesized product was calcined at 800 oC and 1.5 h under argon atmosphere. After that, the obtained powder was soaked into the 15% HF solution and stirred for 24 h in order to remove the template of SBA-15. Finally, the resulting solids were washed with ethyl alcohol and deionized water (DDW) until the pH was neutral and subsequently dried at 60 oC overnight. The obtained black powder was carbon molecular sieves (CMS), simplified in three steps of Scheme. 1. Characterization The powder X-ray diffractometer (XRD, Brucke D8 Advance) was used to identify the crystal form of electrode material including the Cu Ka radiation (λ=0.1514178 nm). The field emission scanning electron microscope (FESEM) of Hitachi New Generation SU8000 was utilized to measure the morphologies of samples. The transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were employed to confirm the micro-morphologies of samples. The X-ray photoelectron spectroscopy (XPS, Thermo Scientific ESCALab 250 spectrometer) was utilized to check the valence states of manganese. Electrochemical measurement The electrodes were obtained by preparing the mixing muld of 10% polyvinylidene difluoride (PVDF) binder, 10% acetylene black and 80% Mg-OMS1/Graphene or CMS, which were together dispersed in organic solvent of NMP (1methyl-2-pyrrolidone) and coated the above slurry on the carbon cloths. And then they 6 ACS Paragon Plus Environment

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were dried in vacuum at 70 oC for 18 h. The electrochemical instruments include a LAND Battery Testing system (model CT2001A, Newware, China), which was used to measure the rate and cycle properties of electrodes, and the electrochemical workstation CHI660I (Chenhua, Shanghai, China) that uses a traditional three-electrode configuration to analyze the Cyclic voltammetry (CV) and Potentio electrochemical impedance spectroscope (EIS). Results and discussions The structure and morphology of Mg-OMS-1/Graphene cathode Fig. 1a exhibits the XRD lines for Mg-OMS-1/Graphene nanocomposite material. It can be indexed to the space group P2/m, which is conformable with the standard crystallographic tables (JCPDS no. 13-164), showing the todorokite-type with the monoclinic phase. The corresponding values of lattice parameters are similar and α, c, β close to 90° form the 3 × 3 tunnels structure, which means that the large tunnel can provide the enough space for Mg2+ ions to insert into the Mg-OMS-1/Graphene electrode. At the same time, the XRD peaks at 2θ = 9.2° and 2θ = 18.7° corresponded to the (100) (200) planes are the characteristic peaks of todorokite-type Mg-OMS-1. Moreover, another peak assigned to graphene can be also identified at 2θ = ~ 26°, indicating that the composite electrode successfully combined the characteristics of outstanding electrical property from graphene and large tunnel structure is expected to reveal the excellent electrochemical performance in aqueous magnesium ion battery.

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Figure 1. The XRD lines of Mg-OMS-1/Graphene powder curve (a), the SEM image (b) and TEM image (c) with different magnification and HRTEM image (d) of this material.

Fig. 1b demonstrates the typical SEM image of Mg-OMS-1/Graphene composite, presenting a nanowire morphology. Meanwhile, it can be also recognized that the MgOMS-1 with nanowire morphology grows along the both sides of graphene and is uniformly distributed. The composite still holds graphene sheets and nanowire structures together as shown in Fig. 1c. The width of nanowire is 60 nm in inset of Fig. 1c. And this TEM image also exhibits a preferably close contact between graphene sheets and Mg-OMS-1 nanowire, indicating the successfully synthesized of this composite material. The crystallinity can be observed from the distinct lattice fringes in HRTEM image (Fig. 1d). The interlayer distance of 0.94 nm corresponds to the (100) plane with the angle of 9.2°, confirming the existence of 3 × 3 tunnels 32. Based on the 8 ACS Paragon Plus Environment

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results of N2 adsorption-desorption isotherms and pore size distribution curve of this composite material in Fig. S1, the BET surface area of Mg-OMS-1/Graphene is 69.2 m2 g-1. This larger tunnel structure formed by three edge-sharing MnO6 octahedra along the c-axis and the built octahedra panels arranged vertically is supported by magnesium ions and bouncy water molecules, which maintains the stable frame structure without collapse during the charged/discharged process. Therefore, the composite material not only holds the large tunnel structure but also inherits the outstanding feature of highly electrical conductivity from graphene, which is reasonable to believe that the composite as the cathode material is very prospective to achieve large-scale energy storage. The electrochemical evaluation of Mg-OMS-1/Graphene electrode The potentiodynamic behaviors of composite electrode material are compared in these types of magnesium salt electrolytes. Fig. 2 shows the cyclic voltammetry curves of these electrodes in the voltage window at -0.65 ~ 0.8 V at sweep rates of 1, 2, 5, 10 mV s−1 in 0.5 mol dm−3 Mg(NO3)2, MgSO4 and MgCl2 electrolytes. Based on these changes of scan rates and anodic or cathodic peaks, the process is considered as the reversible electrochemical reaction. And the electrodes all exhibit two redox couples located at ~0.2 V/-0.16 V and ~0.5 V/-0.16 V in these three electrolytes, which resulted from the acceptor and donor of electrons in company with these magnesium ions to insert into the lattice of Mg-OMS-1/Graphene electrode. Meanwhile, in MgCl2 and Mg(NO3)2 electrolytes, the composite cathode reveals preferable electrochemical properties than that in MgSO4 electrolyte according to the peak currents.



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Figure 2. The CV curves of cathode material with various sweep rates in three electrolytes including MgCl2 (a), Mg(NO3)2(b), and MgSO4 (c).

For inspecting the effects on different electrolytes furtherly, potentio electrochemical impedance spectroscope (EIS) is used to identify the chemical diffusion coefficient. The Nyquist plots of this composite material are demonstrated in three magnesium salt electrolytes and the equivalent circuit for EIS is obtained by fitting electrochemical impedance parameters from the ZView software (Fig. 3a). All these lines reveal a semicircle part connected with the charge transfer (Rct) process in the high frequency range and a straight line part related to the Warburg diffusion process in low frequency range, which is utilized to determine the magnesium ions diffusion coefficient in the composite electrode. All the related fitting parameters obtained from the ZView software are shown in Table S1.


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Figure 3. The EIS measurement of Mg-OMS-1/Graphene composite (a) and slope of the scatter diagram of ZRe against ω−1/2 (b).

Herein, the diffusion coefficient of magnesium ion (DMg2+) could be theoretically calculated by the following equations (1-2) based on the above related parameters. Where F and R are the Faraday constant and gas constant, C is the concentration of magnesium ion, T is the room temperature, n is the numbers of electrons transferred, A is the surface area of electrode, σ is the slope of scatter diagram of ZRe against ω-1/2 (Fig. 3b). And ZRe is obtained by equations (2). It is clear that the DMg2+ results in the Mg(NO3)2 and MgCl2 two type electrolytes are larger, which indicates that magnesium ions can move rapider to the surface of material. Thus, this composite displays the superior electrochemical properties in these two electrolytes, attributing to the lager magnesium-ion diffusion coefficient and the smaller charge transfer impedance.

DMg

2

R 2T 2 = 2 4 4 2 2 2A n F C 

Z Re =Rs +Rct +

-1

(1)

2

(2)

Depending on the comparation of CV lines for electrodes in three different electrolyte, the Mg(NO3)2 electrolyte is selected to further examine both rate and cycle



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properties of single and composite electrodes. The rate performance of these two electrodes are shown at the current densities of 20, 50, 100, 200, 500, after 20 mA g−1 in the voltage window of −0.65 V~ 0.8 V (Fig. 4 a-b). It is clearly found that the discharged curves of them in Mg(NO3)2 electrolyte display obvious plateau located at ~ 0.1 V well consistent with the CV results, which represents the insertion sites for magnesium ions. The discharged capacities of single and composite electrodes at the current density of 20 mA g−1 in Mg(NO3)2 electrolyte are 150.4 and 194.1 mAh g−1 and the coulombic efficiencies are nearly 100%. Moreover, the composite electrode shows the more excellent rate properties than that of single electrode at any current densities. And when the current density reduces to 20 mA g−1, the discharged capacity of composite electrode can still remain 170.3 mAh g−1 and that of single electrode can only reach up to 118.2 mAh g−1. The measured consequence are consistent with the CV measurements, which also further demonstrates that the composite electrode, inheriting the higher electrical conductivity from graphene than that of single electrode, exhibits the preferable electrochemical properties in aqueous magnesium ion battery system. Except for the excellent high rate capability, the Mg-OMS-1/Graphene composite electrode also displays a superior cycle ability. As showed in Fig. 4c, the single and composite electrodes in Mg(NO3)2 electrolyte demonstrate the reversible discharged capacity of 93.5 mAh g−1 and 100.1 mAh g−1 at 100 mA g−1, respectively, corresponding to 90.3% and 92.5% capacity retention after 200 cycles with totally 100 % coulombic efficiency. More than that, the capacity of composite electrode decreases from 100.1 mA g−1 to 88.5 mA g−1 over 400 cycles at the same current density. The 12 ACS Paragon Plus Environment

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excellent cycle ability of Mg-OMS-1/Graphene is obviously due to the large tunnel feature of todorokite-type magnesium manganese dioxide and high electrical conductivity from graphene that facilitates reversible magnesium ions insertion without structural change.

Figure 4. The rate properties of Mg-OMS-1 (a) and Mg-OMS-1/Graphene (b); the cycle performance of them in Mg(NO3)2.

Characterization of the CMS anode The self-made carbon molecular sieves (CMS) as anode material is firstly characterized by the powder X-ray diffractometer. Fig. S2a shows the XRD line of SBA-15 (the precursor of CMS ) in good accordance with the article reported. It can be seen that the peaks at 2θ = 0.82° and 2θ = 1.42° corresponded to the (100) (110) planes are the characteristic peaks of SBA-15, demonstrating the existence of mesoporous 13 ACS Paragon Plus Environment


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structure. After the carbonization process, the prepared CMS still maintains mesoporous structure, proving by the XRD peaks of CMS at 2θ = 0.78° corresponded to the (100) plane in Fig. 5a. Meanwhile, the peak of CMS shifts to the left towards that of SBA-15, which is due to an increase d-spacing and the unit cell parameter after the processes of filling inside the mesoporous tunnels by carbon source and subsequently removing the template 33-34.

Figure 5. The XRD pattern (a) of CMS, the SEM image (b), TEM images (c) and (d) with different magnification of CMS.

The typical SEM image of CMS is revealed in Fig. 5b and that of SBA-15 is shown in Fig. S2b. It is obvious that they all display the regular nanobelt structure. The length and width of SBA-15 are ~800 nm and ~12 nm, respectively. Although the agglomeration phenomenon happens for CMS, it also maintains nanobelt morphology. Associating with the TEM images of them, it can be effortless found that the CMS 14 ACS Paragon Plus Environment

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shows the uniformly parallel and regular mesoporous structure with the size of ~8 nm (Fig. 5c). Meanwhile, the textural properties of CMS are checked by nitrogen physisorption analysis in Fig. S3, which can be observed that the isotherms are attributed to the typical type IV. From the pore size distribution curve, only one peak located at around 5 nm is observed, which powerfully indicates the existence of mesoporous structure. With the addition of magnifying TEM image (Fig. 5d), the CMS exhibits two-dimensional hexagonal structure from section drawing, which persuasively demonstrate that the CMS maintains the mesoporous structure from SBA15, which is more beneficial for magnesium ions transportation between electrode and electrolyte 35, and then enhance the electrochemical properties. The electrochemical evaluation of the CMS anode in aqueous magnesium ion solution To further reveal the electrochemical performance of CMS, the rate and cycle properties are evaluated in 0.5 mol dm−3 Mg(NO3)2 electrolyte at −0.6 V ~ 0.8 V. Fig. 6a shows the rate properties of CMS. It is clearly observed that the discharged capacities of CMS electrodes at the various current densities of 50, 100, 200, 300 and 500 mA g−1 are 70.6, 64.8, 59.1, 56.8 and 54.3 mAh g−1. The self-made CMS with the mesoporous structure as anode material can effectively adsorb magnesium ions as much as possible, displaying the excellent capacitor performance. In addition, the CMS also exhibits outstanding cycling stability with 98.1% capacity retained after 300 cycles at the current density of 100 mA g−1 in Fig. 6b, which is due to the mesoporous structure and stability of carbon material. 15 ACS Paragon Plus Environment


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Figure 6. The rate and cycle properties of CMS (a) and (b) in Mg(NO3)2.

The discussion about the reaction mechanism of Mg-OMS-1/Graphene and CMS electrodes The reaction mechanism for cathode material is explored by XPS measurement whether the Mg2+ ions can insert into the lattice of composite material during the discharged stage. More details about the oxidization states of original and reduced composite electrodes are analyzed in Fig. 7. The survey spectra of these two samples are clearly compared and the Mg 1s, Mg 2s, Mg 2p can be detected in Fig. 7a, which distinctly verifies the lots of Mg2+ ions in the reduced electrode after discharged at −0.6 V. Moreover, the peak intensity of Mg 1s for reduced electrode can also prove it from Fig. 7b.


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Figure 7. The survey XPS spectra of original and reduced composite materials (a) and the core level spectra of Mg 1s (b), the core level spectra of Mn 2p for original (c) and reduced (d) electrodes.

The Mn 2p region of XPS spectra for original and reduced electrodes are exhibited in Fig. 7c and d. For original sample (Fig. 7c), two typical peaks are centered at 654 eV and 642 eV that can be assigned to the Mn 2p1/2 and Mn 2p3/2 binding energies, respectively. These features distinctly imply both 37.6% Mn2+ and 62.4% Mn4+ are dominant in the electrode after analyzing the XPS data 36-37. For reduced sample (Fig. 7d), the Mn 2p detailed spectrum exhibit two characteristic peaks at binding energies of 654.1 eV and 642.6 eV, assigned to the Mn 2p1/2 and Mn 2p3/2, manifesting the coexistence of Mn2+, Mn3+ and Mn4+ 38-39. According to the fitted XPS data, the reduced electrode is composed of 45.8% Mn2+, 23.3% Mn3+ and 30.9% Mn4+. During the discharged progress, a portion of Mn4+ are reduced to Mn3+ and Mn3+ is reduced to 17 ACS Paragon Plus Environment


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Mn2+, which is well explained the two pairs of redox peaks in CV curves (Fig. 2). Therefore, the insertion or deinsertion of Mg2+ ions into or from the Mg-OMS1/Graphene composite material is accompanied by the changes in the valence of manganese element. For the anode electrode, the CMS as mesoporous carbon material can adsorb/desorb Mg2+ ions in the electrochemical reaction progress 40. The mesoporous tunnel structure from CMS is beneficial to enhance the permeability between the electrode and electrolyte and offer the fast transport route for the electrons, which can improve its own electrochemical performance 35. The electrochemical evaluation of Mg-OMS-1/Graphene // CMS battery capacitor

Figure 8. The CV curve (a) and cycle performance (b) of Mg-OMS-1/Graphene // CMS battery capacitor.

In according to the study and measurements on above materials, the aqueous magnesium ion battery capacitor is constructed by the composite material as cathode, carbon molecular sieves as anode and 0.5 mol dm−3 Mg(NO3)2 as electrolyte. In consideration of two different reaction mechanism for them, the anode material is tried to adjust the much mass loadings so that it can efficiently compensate charge resulted 18 ACS Paragon Plus Environment

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from the deficiency of capacitor material. Fig. 8a shows the CV results of this device in the voltage window at 0 ~ 1.8 V at sweep rate of 1 mV s−1 in 0.5 mol dm−3 Mg(NO3)2 electrolyte. It is obviously recognized that the anodic peak located at 1.1 V represents the battery performance and the half rectangle of CV curve represents the capacitor performance, demonstrating that the Mg-OMS-1/Graphene // CMS device successfully builds and exhibits the certain electrochemical performance. Fig. 8b reveals the cycle ability of this device. It can be seen that this battery capacitor at the current density of 100 mA g−1 displays the excellent cycling lifespan with 98.6% capacity retained after 800 cycles, which is more superior than other different energy storage systems as shown in Table 1. Table 1 The comparison of cycle performance in different energy storage systems energy storage systems

electrodes

electrolyte

cycle ability

lifespan

SnO2/Cu/CNT//AC

LiPF6

200

81%

LiFePO4/C//VO2

LiNO3

50

94%

λ-MnO2//AC

Na2SO4

500

85%

Na-ion battery 44

NaMnO2//NaTi2(PO4)3

Na2SO4

500

75%

Mg-ion battery 45

Mg-PAQS

Mg(HMDS)2 -4MgCl2/THF

100

70%

Mg-OMS1/Graphene//CMS

Mg(NO3)2

800

98.6%

Li-ion battery 41 capacitor Li-ion battery 42 Na-ion battery 43 capacitor

This work

Meanwhile, these two electrodes after 100 cycles also maintain the original phase and structure respectively by XRD measurements in Fig. S4. And the outstanding cycle performance is derived from the stable graphene of cathode composite and the selfmade CMS carbon material with the mesoporous structure. 19 ACS Paragon Plus Environment


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Conclusions In summary, we propose an aqueous rechargeable magnesium-ion battery capacitor system integrating two electrode processes associated with Mg2+ ions insertion/extraction in the Mg-OMS-1/Graphene composite as cathode and Mg2+ ions adsorption/desorption in the CMS as anode, respectively. The cathode composite material combining the large aperture of ordered tunnel structure from Mg-OMS-1 and excellent electrochemical characteristics from graphene can achieve the improvement of specific capacity. The self-made anode material depending on the particular mesoporous structure from CMS can obtain the outstanding cycle performance. The constructed battery capacitor system would enhance the existing aqueous rechargeable magnesium ion battery chemistry and be a prospective battery technology for largescale energy storage. Supporting Information Supporting Information consists of one table and four figures over six pages, which are Table S1 about the EIS values, Figure S1 about the N2 adsorption/desorption measurements of Mg-OMS-1/Graphene, Figure S2 about the XRD pattern and SEM image of SBA-15, Figure S3 about the N2 adsorption/desorption measurements of CMS and Figure S4 about the XRD surves of two electrodes after 100 cycles. Acknowledgements This work was supported by the Scientific Research Starting Foundation Project of Fujian University of Technology (GY-Z18141), (GY-Z18144), Scientific Research 20 ACS Paragon Plus Environment

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Development Foundation Project of Fujian University of Technology (GY-Z18177), ( GY-Z18176).

References 1.

Amin, M., Energy: The smart-grid solution. Nature 2013, 499 (7457), 145-147,

DOI: 10.1038/499145a. 2.

Yang, Z.; Zhang, J.; Kintner-Meyer, M. C.; Lu, X.; Choi, D.; Lemmon, J. P.; Liu,

J., Electrochemical energy storage for green grid. Chem. Rev. 2011, 111 (5), 3577-3613, DOI: 10.1021/cr100290v. 3.

Gogotsi, Y.; Simon, P., True performance metrics in electrochemical energy

storage. Science 2011, 334 (6058), 917-918, DOI: 10.1126/science.1213003. 4.

Yang, Z.; Liu, J.; Baskaran, S.; Imhoff, C. H.; Holladay, J. D., Enabling renewable

energy-and the future grid-with advanced electricity storage. Jom 2010, 62 (9), 14-23, DOI：10.1007/s11837-010-0129-0. 5.

Palacin, M. R., Recent advances in rechargeable battery materials: a chemist’s

perspective.

Chemical

Society

Reviews

2009,

38

(9),

2565-2575,

DOI:10.1039/B820555H. 6.

Bai, X.; Liu, Q.; Liu, J.; Zhang, H.; Li, Z.; Jing, X.; Liu, P.; Wang, J.; Li, R.,

Hierarchical Co3O4@Ni(OH)2 core-shell nanosheet arrays for isolated all-solid state supercapacitor electrodes with superior electrochemical performance. Chemical Engineering Journal 2017, 315, 35-45, DOI: 10.1016/j.cej.2017.01.010. 21 ACS Paragon Plus Environment


7.

Page 22 of 35

Morioka, Y.; Narukawa, S.; Itou, T., State-of-the-art of alkaline rechargeable

batteries. Journal of Power Sources 2001, 100 (1-2), 107-116, DOI: 10.1016/S03787753(01)00888-6. 8.

Neubauer, J.; Pesaran, A.; Bae, C.; Elder, R.; Cunningham, B., Updating United

States Advanced Battery Consortium and Department of Energy battery technology targets for battery electric vehicles. Journal of Power Sources 2014, 271, 614-621, DOI: 10.1016/j.jpowsour.2014.06.043. 9.

Adany, R.; Aurbach, D.; Kraus, S., Switching algorithms for extending battery life

in Electric Vehicles. Journal of Power Sources 2013, 231, 50-59, DOI: 10.1016/j.jpowsour.2012.12.075. 10. Zalba, B.; Marın, J. M.; Cabeza, L. F.; Mehling, H., Review on thermal energy storage with phase change: materials, heat transfer analysis and applications. Applied thermal engineering 2003, 23 (3), 251-283, DOI: 10.1016/S1359-4311(02)00192-8. 11. Wang, G.; Zhang, H.; Fu, L.; Wang, B.; Wu, Y., Aqueous rechargeable lithium battery (ARLB) based on LiV3O8 and LiMn2O4 with good cycling performance. Electrochemistry

Communications

2007,

9

(8),

1873-1876,

DOI:

10.1016/j.elecom.2007.04.017. 12. Stojković, I. B.; Cvjetićanin, N. D.; Mentus, S. V., The improvement of the Li-ion insertion behaviour of Li1.05Cr0.1Mn1.85O4 in an aqueous medium upon addition of vinylene carbonate. Electrochemistry Communications 2010, 12 (3), 371-373, DOI: 10.1016/j.elecom.2009.12.037. 13. Gummow, R.; De Kock, A.; Thackeray, M., Improved capacity retention in 22 ACS Paragon Plus Environment

Page 23 of 35 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


rechargeable 4 V lithium/lithium-manganese oxide (spinel) cells. Solid State Ionics 1994, 69 (1), 59-67, DOI: 10.1016/0167-2738(94)90450-2. 14. Zu, C.-X.; Li, H., Thermodynamic analysis on energy densities of batteries. Energy & Environmental Science 2011, 4 (8), 2614-2624, DOI: 10.1039/C0EE00777C. 15. Suo, L.; Hu, Y.-S.; Li, H.; Armand, M.; Chen, L., A new class of solvent-in-salt electrolyte for high-energy rechargeable metallic lithium batteries. Nature communications 2013, 4, 1481, DOI: 10.1038/ncomms2513. 16. Thackeray, M.; De Kock, A.; David, W., Synthesis and structural characterization of defect spinels in the lithium-manganese-oxide system. Materials Research Bulletin 1993, 28 (10), 1041-1049, DOI: 10.1016/0025-5408(93)90142-Z. 17. Chen, L.; Bao, J.; Dong, X.; Truhlar, D.; Wang, Y.; Wang, C.; Xia, Y., Aqueous Mg-Ion battery based on polyimide anode and Prussian blue cathode. ACS Energy Letters 2017, 2 (5), 1115-1121, DOI: 10.1021/acsenergylett.7b00040. 18. Cabello, M.; Alcantara, R.; Nacimiento, F.; Ortiz, G.; Lavela, P.; Tirado, J., Electrochemical and chemical insertion/deinsertion of magnesium in spinel-type MgMn2O4 and lambda-MnO2 for both aqueous and non-aqueous magnesium-ion batteries. CrystEngComm 2015, 17 (45), 8728-8735, DOI: 10.1039/C5CE01436K. 19. Duncan, M.; Leroux, F.; Corbett, J.; Nazar, L., Todorokite as a Li Insertion Cathode Comparison of a Large Tunnel Framework “MnO2” Structure with Its Related Layered Structures. Journal of the Electrochemical Society 1998, 145 (11), 3746-3757, DOI: 10.1149/1.1838869. 20. Zhang, Y.; Cheng, K.; Ye, K.; Gao, Y.; Zhao, W.; Wang, G.; Cao, D., Preparation 23 ACS Paragon Plus Environment


Page 24 of 35

of M1/3Ni1/3Mn2/3O2 (M= Mg or Zn) and its performance as the cathode material of aqueous divalent cations battery. Electrochim. Acta 2015, 182, 971-978, DOI: 10.1016/j.electacta.2015.10.008. 21. Yuan, C.; Zhang, Y.; Pan, Y.; Liu, X.; Wang, G.; Cao, D., Investigation of the intercalation of polyvalent cations (Mg2+, Zn2+) into λ-MnO2 for rechargeable aqueous battery. Electrochim. Acta 2014, 116, 404-412, DOI: 10.1016/j.electacta.2013.11.090. 22. Zhou, H.; Shen, Y.; Wang, J.; Chen, X.; O'Young, C.-L.; Suib, S. L., Studies of decomposition of H2O2 over manganese oxide octahedral molecular sieve materials. Journal of Catalysis 1998, 176 (2), 321-328, DOI: 10.1006/jcat.1998.2061. 23. Vileno, E.; Ma, Y.; Zhou, H.; Suib, S. L., Facile synthesis of synthetic todorokite (OMS-1), co-precipitation reactions in the presence of a microwave field. Microporous and mesoporous materials 1998, 20 (1-3), 3-15, DOI: 10.1016/S1387-1811(97)000164. 24. Zhang, K.; Han, X.; Hu, Z.; Zhang, X.; Tao, Z.; Chen, J., Nanostructured Mn-based oxides for electrochemical energy storage and conversion. Chemical Society Reviews 2015, 44 (3), 699-728, DOI:10.1039/C4CS00218K. 25. Novoselov, K. S.; Geim, A. K.; Morozov, S.; Jiang, D.; Katsnelson, M.; Grigorieva, I.; Dubonos, S.; Firsov; AA, Two-dimensional gas of massless Dirac fermions in graphene. nature 2005, 438 (7065), 197-200, DOI: 10.1038/nature04233. 26. Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A., Electric field effect in atomically thin carbon films. science 2004, 306 (5696), 666-669, DOI: 10.1126/science.1102896. 24 ACS Paragon Plus Environment

Page 25 of 35 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


27. Geim, A. K., Graphene: status and prospects. science 2009, 324 (5934), 1530-1534, DOI: 10.1126/science.1158877. 28. Soavi, G.; Wang, G.; Rostami, H.; Purdie, D. G.; De Fazio, D.; Ma, T.; Luo, B.; Wang, J.; Ott, A. K.; Yoon, D., Broadband, electrically tunable third-harmonic generation in graphene. Nature nanotechnology 2018, 1, 583-588, DOI: 10.1038/s41565-018-0145-8. 29. Zhang, H.; Ye, K.; Huang, X.; Wang, X.; Cheng, K.; Xiao, X.; Wang, G.; Cao, D., Preparation of Mg1. 1Mn6O12 ·4.5H2O with nanobelt structure and its application in aqueous magnesium-ion battery. Journal of Power Sources 2017, 338, 136-144, DOI: 10.1016/j.jpowsour.2016.10.078. 30. Wenz, G. B.; Koros, W. J., Tuning carbon molecular sieves for natural gas separations: A diamine molecular approach. AIChE Journal 2017, 63 (2), 751-760, DOI: 10.1002/aic.15405. 31. Carrero, A.; Vizcaíno, A. J.; Calles, J. A.; García-Moreno, L., Hydrogen production through glycerol steam reforming using Co catalysts supported on SBA-15 doped with Zr, Ce and La. Journal of Energy Chemistry 2017, 26 (1), 42-48, DOI: 10.1016/j.jechem.2016.09.001. 32. Cui, H.; Feng, X.; Tan, W.; Zhao, W.; Wang, M. K.; Tsao, T. M.; Liu, F., Synthesis of a Nanofibrous Manganese Oxide Octahedral Molecular Sieve with Co (NH3) 63+ Complex Ions as a Template via a Reflux Method. Crystal Growth & Design 2010, 10 (8), 3355-3362, DOI: 10.1021/cg900927j. 33. Kim, M.-J.; Chae, H.-J.; Ha, K.-S.; Jeong, K.-E.; Kim, C.-U.; Jeong, S.-Y.; Kim, 25 ACS Paragon Plus Environment


Page 26 of 35

T.-W., Hydrogenation of carbon monoxide to higher alcohols over ordered mesoporous carbon nanoparticle-supported Rh-based catalysts. Journal of Porous Materials 2014, 21 (4), 365-377, DOI: 10.1007/s10934-014-9782-y. 34. Kim, N.-I.; Cheon, J. Y.; Kim, J. H.; Seong, J.; Park, J.-Y.; Joo, S. H.; Kwon, K., Impact of framework structure of ordered mesoporous carbons on the performance of supported Pt catalysts for oxygen reduction reaction. Carbon 2014, 72, 354-364, DOI: 10.1016/j.carbon.2014.02.023. 35. Du, X.; Zhao, H.; Zhang, Z.; Lu, Y.; Gao, C.; Li, Z.; Teng, Y.; Zhao, L.; Świerczek, K., Core-shell structured ZnS-C nanoparticles with enhanced electrochemical properties for high-performance lithium-ion battery anodes. Electrochim. Acta 2017, 225, 129-136, DOI: 10.1016/j.electacta.2016.12.118. 36. Raj, A. M. E.; Victoria, S. G.; Jothy, V. B.; Ravidhas, C.; Wollschläger, J.; Suendorf, M.; Neumann, M.; Jayachandran, M.; Sanjeeviraja, C., XRD and XPS characterization of mixed valence Mn3O4 hausmannite thin films prepared by chemical spray pyrolysis technique. Applied Surface Science 2010, 256 (9), 2920-2926, DOI: 10.1016/j.apsusc.2009.11.051. 37. Shen, Y.-F.; Zerger, R. P.; Suib, S. L.; McCurdy, L.; Potter, D. I.; O'Young, C.-L., Octahedral molecular sieves: preparation, characterization and applications. Journal of the Chemical Society, Chemical Communications 1992, (17), 1213-1214, DOI: 10.1039/C39920001213. 38. Ilton, E. S.; Post, J. E.; Heaney, P. J.; Ling, F. T.; Kerisit, S. N., XPS determination of Mn oxidation states in Mn (hydr) oxides. Applied Surface Science 2016, 366, 47526 ACS Paragon Plus Environment

Page 27 of 35 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


485, DOI: 10.1016/j.apsusc.2015.12.159. 39. Huang, Z.; Zhou, W.; Ouyang, C.; Wu, J.; Zhang, F.; Huang, J.; Gao, Y.; Chu, J., High performance of Mn-Co-Ni-O spinel nanofilms sputtered from acetate precursors. Scientific reports 2015, 5, 10899, DOI: 10.1038/srep10899. 40. Chandrasekaran, R.; Palma, J.; Anderson, M., Carbide derived carbon electrode with natural graphite addition in magnesium electrolyte based cell for supercapacitor enhancements. Journal of Energy Chemistry 2015, 24 (3), 264-270, DOI: 10.1016/S2095-4956(15)60310-2. 41. Hsieh, C.-L.; Tsai, D.-S.; Chiang, W.-W.; Liu, Y.-H., A composite electrode of tin dioxide and carbon nanotubes and its role as negative electrode in lithium ion hybrid capacitor.

Electrochim.

Acta

2016,

209,

332-340,

DOI:

10.1016/j.electacta.2016.05.090. 42. Vujković, M.; Stojković, I.; Cvjetićanin, N.; Mentus, S., Gel-combustion synthesis of LiFePO4/C composite with improved capacity retention in aerated aqueous electrolyte

solution.

Electrochim.

Acta

2013,

92,

248-256,

DOI:

10.1016/j.electacta.2013.01.030. 43. Zhang, Y.; Yuan, C.; Ye, K.; Jiang, X.; Yin, J.; Wang, G.; Cao, D., An aqueous capacitor battery hybrid device based on Na-ion insertion-deinsertion in λ-MnO2 positive

electrode.

Electrochim.

Acta

2014,

148,

237-243,

DOI:

10.1016/j.electacta.2014.10.052. 44. Hou, Z.; Li, X.; Liang, J.; Zhu, Y.; Qian, Y., An aqueous rechargeable sodium ion battery based on a NaMnO2-NaTi2(PO4)3 hybrid system for stationary energy storage. 27 ACS Paragon Plus Environment


Page 28 of 35

Journal of Materials Chemistry A 2015, 3 (4), 1400-1404, DOI: 10.1039/C4TA06018K. 45. Pan, B.; Huang, J.; Feng, Z.; Zeng, L.; He, M.; Zhang, L.; Vaughey, J. T.; Bedzyk, M. J.; Fenter, P.; Zhang, Z., Polyanthraquinone‐Based Organic Cathode for HighPerformance Rechargeable Magnesium-Ion Batteries. Adv. Energy Mater. 2016, 6 (14), 1600140, DOI: 10.1002/aenm.201600140.


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Table of Contents (TOC image)

Brief Description : The aqueous rechargeable magnesium ions battery capacitor is assembled by Mg-OMS1/Graphene composite as cathode and CMS as anode in 0.5 mol dm−3 Mg(NO3)2 electrolyte, displaying the excellent cycling lifespan with 98.6% capacity retained after 800 cycles at the current density of 100 mA g−1.



Scheme 1. Schematic illustration of fabrication procedure of Mg-OMS-1/Graphene and CMS

Figure 1. The XRD lines of Mg-OMS-1/Graphene powder curve (a), the SEM image (b) and TEM image (c) with different magnification and HRTEM image (d) of this material.

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Figure 2. The CV curves of cathode material with various sweep rates in three electrolytes including MgCl2 (a), Mg(NO3)2(b), and MgSO4 (c).

Figure 3. The EIS measurement of Mg-OMS-1/Graphene composite (a) and slope of the scatter diagram of ZRe against ω−1/2 (b).



Figure 4. The rate properties of Mg-OMS-1 (a) and Mg-OMS-1/Graphene (b); the cycle performance of them in Mg(NO3)2.


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Figure 5. The XRD pattern (a) of CMS, the SEM image (b), TEM images (c) and (d) with different magnification of CMS.

Figure 6. The rate and cycle properties of CMS (a)and (b) in Mg(NO3)2.

Figure 7. The survey XPS spectra of original and reduced composite materials (a) and the core level spectra of Mg 1s (b), the core level spectra of Mn 2p for original (c) and reduced (d) electrodes.



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Figure 8. The CV curve (a) and cycle performanc (b) of Mg-OMS-1/Graphene // CMS battery capacitor.

Table 1 The comparison of cycle performance in different energy storage systems energy storage systems

electrodes

electrolyte

cycle ability

lifespan

SnO2/Cu/CNT//AC

LiPF6

200

81%

LiFePO4/C//VO2

LiNO3

50

94%

λ-MnO2//AC

Na2SO4

500

85%

Na-ion battery 44

NaMnO2//NaTi2(PO4)3

Na2SO4

500

75%

Mg-ion battery 45

Mg-PAQS

Mg(HMDS)2 -4MgCl2/THF

100

70%

Mg-OMS-1/Graphene//CMS

Mg(NO3)2

800

98.6%

Li-ion battery 41 capacitor Li-ion battery 42 Na-ion battery 43 capacitor

This work


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High-Cycle-Performance Aqueous Magnesium Ions Battery Capacitor

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