Facile preparation of MnO/nitrogen-doped porous carbon nanotubes composites and their application in energy storage
Graphical abstract
Introduction
Rechargeable lithium-ion batteries (LIBs) have been widely used for portable electronics, tools and electric vehicles [[1], [2], [3]]. The key point in LIBs is the nature of electrode material, which affects significantly the performance of LIBs. However, the commercial graphite anode cannot meet the ever-increasing demand for LIBs with high electrochemical performance due to its low capacity [4]. To this end, considerable attention has been paid to developing alternative electrode materials for high electrochemical performance LIBs [5,6]. To date, significant achievements have been made on transition metal oxides (e.g. NiO [7], SnO2 [8], Fe3O4 [9], RuO2 [10], MnO2 [11], MnOOH [12,13], and MnO [14]) for LIBs. In particular, MnO has received tremendous recent interest because of its high capacity (theoretically 756 mAh g−1) [15], low potential plateau, and the plentiful Mn source [16,17]. Nevertheless, the MnO-based electrode commonly suffers from low electrical conductivity, large volume expansion, poor rate performance and cycling stability [18,19]. Therefore, a range of strategies have been developed to enhance the electrochemical performance of MnO-based LIBs. These mainly include nano-sized MnO and carbon-based nano-composites, such as the combination of activated carbon and MnO [20], MnO@C composites [21], core-shell MnO/C [22], MnO/C nanotubes [23], and MnO/carbon nanopeapods [24]. Among them, one dimensional (1D) porous carbon nanotubes show some advantages to obtain MnO/C nanotubes composite electrode for high performance LIBs. The 1D tubular nature can endow the composite electrode high electrical conductivity, and the high surface area of porous carbon nanotubes can provide the composite electrode with plentiful active sites for Li storage and promote the charge transfer and Li ions transportation [25]. In addition, the N-doped carbonaceous electrode materials can provide some defects and enhance the electrochemical activity [26,27]. Therefore, high-performance LIBs could be expected by using MnO/N-doped porous carbon nanotubes composite electrode materials.
We recently demonstrated that porous carbon nanotubes with high surface area could be easily obtained by pyrolysis of a 1D tubular hypercrosslinked polymer [28], which could be facilely prepared via Friedel-Crafts alkylation of aromatic hydrocarbon and formaldehyde dimethyl acetal (FDA) promoted by FeCl3 at mild reaction conditions. Herein, we synthesized a novel N-containing porous hypercrosslinked tubular polymer using triphenylamine (TPA) as the building block. MnO/N-doped porous carbon nanotubes (MnO/N-PCNTs) composite was further obtained by pyrolysis of the N-containing hypercrosslinked tubular polymer precursor loaded with Mn(CH3COO)2·4H2O. The obtained composite material as anode for LIBs exhibits excellent electrochemical performances.
Section snippets
Synthesis of the N-HCPTs precursor
A flask was charged with triphenylamine (1.0 mmol, 245 mg), FeCl3 (3.0 mmol, 486 mg), formaldehyde dimethyl acetal (3.0 mmol, 228 mg) and 1,2-dichloroethane (50 mL). The reaction mixture was ultrasonicated for 3 h at room temperature. The obtained solid from filtration was washed by water, methanol, dichloromethane and acetone, respectively. After Soxhlet extraction with tetrahydrofuran for 24 h, the N-HCPTs product was dried in vacuum and obtained as a tawny powder (yield: 80.9%). Elemental
Results and discussion
Fig. 1 displays the preparation strategy of the MnO/N-PCNTs composite. Initially, the nitrogen-containing tubular hypercrosslinked polymer (N-HCPTs) precursor was prepared by a Friedel-Crafts reaction of TPA and FDA without any template and surfactant under ultrasonic condition according to our previous report [28]. Then, the obtained N-HCPTs precursor was immersed in the ethanol solution containing Mn(CH3COO)2·4H2O to get the mixture of N-HCPTs and Mn(CH3COO)2·4H2O. The MnO/N-PCNTs composite
Conclusion
In conclusion, we report a facile approach to prepare MnO and N-doped porous carbon nanotubes composite by pyrolysis of a nitrogen-containing hypercrosslinked tubular polymer loaded with manganese acetate. The N-HCPTs precursor could be facilely prepared via Friedel-Crafts reaction of triphenylamine and formaldehyde dimethyl acetal promoted by FeCl3. The resultant MnO/N-PCNTs shows outstanding electrochemical performances as anode for LIBs because of the high redox activity of the MnO, the
Acknowledgment
This work was supported by the National Natural Science Foundation of China (21574077, 21574087 & 21304055), the Fundamental Research Funds for the Central Universities (GK201801001 & GK201701007).
References (44)
J. Power Sources
(2006)- et al.
Electrochem. Commun.
(2007) - et al.
Mater. Char.
(2016) - et al.
J. Alloy. Comp.
(2013) - et al.
J. Power Sources
(2010) - et al.
Electr. Commun.
(2009) - et al.
J. Power Sources
(2011) - et al.
Electrochim. Acta
(2011) - et al.
Nano. Energy
(2013) - et al.
Carbon
(2017)
Appl. Catal., B
Electrochim. Acta
Electrochim. Acta
Nature
Adv. Mater.
Nanoscale
Adv. Funct. Mater.
Chem. Commun.
Adv. Mater.
Nano. Lett.
Adv. Mater.
Nano. Lett.
Cited by (27)
Synthesis, thermoelectric and energy storage performance of transition metal oxides composites
2024, Coordination Chemistry ReviewsDefect-rich conversion-based manganese oxide nanofibers: An ultra-high rate capable anode for next-generation binder-free rechargeable batteries
2023, Journal of Alloys and CompoundsCoordination polymer-derived hierarchically structured MnO/NC composites as anode materials for high-performance lithium-ion batteries
2023, Journal of Alloys and CompoundsOne-pot synthesis of nanosized MnO incorporated into N-doped carbon nanosheets for high performance lithium storage
2022, Journal of Alloys and CompoundsCitation Excerpt :And the capacity can be recovered to as high as 810 mA h g−1 when the current is suddenly reduced to 0.1 A g−1 (Fig. 3c). It suggests that the MnO/NCN electrode has a desired Li-ion storage characteristic, which is superior to the MnO/C and MnO/CN electrodes, as well as comparable to other reported MnO-based LIBs anode materials (Fig. 3d, Table S1) [56–65]. Excitingly, the MnO/NCN electrode also shows excellent stability during cycling, as represented by Fig. 3e.
- 1
The authors contributed equally to this work.