Multi-channel-contained few-layered MoSe2 nanosheet/N-doped carbon hybrid nanofibers prepared using diethylenetriamine as anodes for high-performance sodium-ion batteries

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Abstract

A facile new strategy for the synthesis of multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 nanosheets (denoted as MC-NCNF/MoSe2) was introduced and the composite was demonstrated as an anode material for sodium-ion batteries. This was the first time that diethylenetriamine was introduced as a pore generator in the electrospinning process and played a key role in generating multi-channels in the structure by phase-separation from the molybdenum salt and subsequent volatilization without any additional process. Polyvinylpyrrolidone was used as a carbon precursor and played the role of a N-doping source for the carbon matrix. MC-NCNF/MoSe2 achieved a high reversible discharge capacity of 386 mA h g−1 at a current density of 0.5 A g−1 after the 300th cycle and superior rate capability of 285 mA h g-1 at 10.0 A g−1. The multi-channeled structure of MC-NCNF/MoSe2 facilitated effective Na+ and electron diffusion during repeated discharge/charge processes and accommodated the huge volume expansion of the MoSe2 nanosheets induced by electrochemical reaction of the Na+ ion.

Introduction

Recently, sodium-ion batteries (SIBs) have been considered as next-generation energy storage devices due to the abundance of Na resources and the electrochemical similarity of Na to Li [1], [2], [3], [4], [5]. Despite significant advances in SIBs, many challenges must be addressed for practical application. The major obstacle in the design of anode materials for SIBs is the slow Na+ diffusion rate and large volume expansion induced by the large ionic radius and molecular weight of Na+, which result in low capacity, short cycle life-time, and poor rate performance. Therefore, many approaches have been proposed toward engineering anode materials with suitable geometries and compositions to solve the above-mentioned problems [6], [7], [8], [9]. Hollow and porous 1-dimensional (1-D) nanomaterials have received widespread attention because they shorten the pathway for Na+ diffusion into the structure, lower the strain of the active material under volume variation, and allow penetration of the liquid electrolyte into the electrode during cycling [10], [11], [12], [13]. Wu et al. introduced porous TiO2-x nanofibers rich in oxygen vacancies and possessing high grain-boundary densities by employing electrospinning and subsequent vacuum treatment [10]. The oxygen vacancies in the composites improved the electronic conductivity and promoted fast Na+ diffusion. Therefore, the TiO2-x nanofibers showed excellent long cycling stability (134 mA h g−1 at 10 C after 4500 cycles) and superior rate performance (93 mA h g−1 after 4500 cycles at 20 C). Liu et al. also synthesized Sn nanodots (1–2 nm) encapsulated in porous N-doped carbon nanofibers by electrospinning and thermal treatment methods [11]. The small Sn nanodots could reduce the strain and improve the rate of utilization of the active materials during the sodiation/desodiation process. Therefore, capacities of 450 mA h g−1 at 10,000 mA g−1 and 483 mA h g−1 at 2000 mA g−1 were achieved over 1300 cycles. Li et al. also proposed porous carbon nanofibers prepared by pyrolysis of PAN-F127/DMF nanofibers via an electrospinning process [12]. The triblock copolymer Pluronic F127 was used as a pore generator during heat-treatment. The nanofibers delivered a reversible capacity of 266 mA h g−1 after 100 cycles at 0.2 C. A reversible capacity of 140 mA h g−1 was still delivered after 1000 cycles at a current density of 500 mA g−1.

Layered transition metal chalcogenides have recently attracted great attention for SIB anodes due to their superior energy storage properties compared to those of other oxides [14], [15], [16], [17]. In particular, MoSe2, consisting of covalently bonded Se-Mo-Se sandwiched layers with weak van der Waals interactions, possesses a relatively large interlayer spacing of 0.65 nm compared to graphite (0.335 nm) and MoS2 (0.615 nm), and higher electrical conductivity compared to MoS2. Therefore, such unique features of MoSe2 anodes facilitate faster and reversible sodiation/desodiation of Na+ ion between the layers [18], [19], [20], [21].

Hence, we introduce a facile new strategy for the synthesis of multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 nanosheets as promising anode materials for SIBs for the first time. Diethylenetriamine (DETA) is introduced as a pore generator for the first time in this study. DETA plays a key role in generating the mesoporous multi-channels in the structure by phase-separation from the molybdenum salt during the electrospinning process and subsequent volatilization during stabilization at low temperature. Additionally, polyvinylpyrrolidone (PVP) is used as a carbon precursor and plays the role of a N-doping source for the carbon matrix. The mechanism of formation of the multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 nanosheets and the Na+ ion storage properties of this material as an anode are investigated in detail.

Section snippets

Experimental

The multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 nanosheets (denoted as MC-NCNF/MoSe2) were synthesized via electrospinning and subsequent simple heat-treatment. The solution for electrospinning was prepared by dissolving 1.3 g ammonium molybdate ((NH4)6Mo7O24 4H2O, DAEJUNG, 98%), 1.0 g polyvinylpyrrolidone (PVP, (C6H9NO)n, Alfa Aesar, MW: 1300,000), and 1 mL diethylenetriamine (DETA, C4H13N3, JUNSEI, 98%) in 10 mL of distilled water. The solution for

Results and discussion

The multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 nanosheets (denoted as MC-NCNF/MoSe2) were synthesized by electrospinning and subsequent heat-treatment. For this purpose, precursor Mo salt/PVP/DETA composite nanofibers were firstly prepared by electrospinning the aqueous solution with ammonium molybdate, PVP as the carbon precursor, and DETA as a pore generator. The as-spun nanofibers, stabilized at 150 °C under air atmosphere, are shown in Fig. 1. As is

Conclusions

We introduced a facile new strategy for the synthesis of multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 by electrospinning and subsequent simple heat-treatment methods. A mechanism for the formation of MC-NCNF/MoSe2 was proposed and the potential of this composite as an anode for Na+ storage was demonstrated. Mesoporous multi-channels were formed along the fiber length direction by phase-separation between DETA and the molybdenum salt/PVP solution. During

Acknowledgements

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2018R1A4A1024691, NRF-2017M1A2A2087577, NRF-2018R1D1A3B07042514).

References (56)

  • L. Zhao et al.

    Adv. Energy Mater.

    (2012)
  • S.Y. Jeong et al.

    Chem. Eng. J.

    (2018)
  • Y. Lu et al.

    Adv. Funct. Mater.

    (2016)
  • Y. Xia et al.

    Electrochim. Acta

    (2016)
  • J.C. Groen et al.

    Microporous Mesoporous Mater.

    (2003)
  • H. Du et al.

    J. Power Sources

    (2011)
  • J.-S. Park et al.

    Chem. Eng. J.

    (2018)
  • B. Sun et al.

    Adv. Mater.

    (2018)
  • S.W. Kim et al.

    Adv. Energy Mater.

    (2012)
  • J. Sun et al.

    Nat. Nanotechnol.

    (2015)
  • M.D. Slater et al.

    Adv. Funct. Mater.

    (2013)
  • Z. Li et al.

    Acc. Chem. Res.

    (2015)
  • Y. Zhu et al.

    ACS Nano

    (2013)
  • S. Yuan et al.

    Adv. Mater.

    (2014)
  • J.S. Cho et al.

    ACS Appl. Mater. Interfaces

    (2016)
  • Y. Wu et al.

    Small

    (2017)
  • Y. Liu et al.

    J. Chen, Adv. Mater.

    (2015)
  • W. Li et al.

    Nanoscale

    (2014)
  • J.S. Cho et al.

    Nano Res.

    (2017)
  • J.S. Cho et al.

    Nanoscale

    (2017)
  • B. Qu et al.

    Adv. Mater.

    (2014)
  • L. David et al.

    ACS Nano

    (2014)
  • D. Chao et al.

    ACS Nano

    (2016)
  • G.D. Park et al.

    ACS Appl. Mater. Interfaces

    (2017)
  • Y. Tang et al.

    ACS Appl. Mater. Interfaces

    (2016)
  • D. Xie et al.

    Adv. Energy Mater.

    (2017)
  • F. Niu et al.

    Adv. Funct. Mater.

    (2017)
  • C. Zhu et al.

    Angew. Chem.

    (2014)
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