High Nitrogen Doping Level Research Articles

Low-grade lignite derived nitrogen doped hierarchical porous carbon for advanced lead-carbon batteries

The addition of carbon materials to the negative electrode would inhibit sulfation and prolong the cycle life of the lead-acid batteries. However, carbon materials contribute to the emergence of hydrogen evolution reaction (HER) and loss of water on the negative electrode. Accordingly, low-grade lignite raw material was one-step pyrolyzed to prepare nitrogen doped porous carbon (LNC) materials, which were further employed as negative additives to mitigate the above issues. The as-prepared LNC delivered large specific surface area (SSA) in the range of 1675.0–2503.3 m2 g−1, micro-mesoporous hierarchical structure, and high nitrogen doping level. Nitrogen doping considerably inhibited the HER and promoted the conversion kinetics between PbSO4/Pb in the negative electrode. Besides, the cycling life of lead-carbon battery containing LNC-1/3 at high-rate partial state of charge reached 9100 cycles, which reflected a 5.5-fold improvement over the blank. The improved performance could be attributed to the large SSA and plentiful functional groups, which offer active sites for the conversion of active substances, construct abundant ion channels, and refine the PbSO4 particles, thereby successfully minimizing irreversible sulfation. The short-route synthesis method provides a feasible approach to the reutilization of low-grade lignite, reflecting the circular economy.

Synthesis of N-doped graphene film with tunable graphitic and pyridinic doping content

Nitrogen-doped (N-doped) graphene films with up to a 17.39 at.% doping level were synthesized with the chemical vapor deposition growth method. An extensive range of tunable nitrogen doping levels was achieved by selecting organic molecules as precursors grown at a wide temperature range of 300 to 1000 °C. The benzene rings in the precursor significantly reduced the energy requirements of N-doped graphene. The incorporation of bridgehead nitrogen and amino groups ensured a high nitrogen doping level and offered the tunable modulation of nitrogen dopant concentrations. The influence of temperature on the nitrogen content was investigated, distinguishing the graphitic and pyridinic dopant types, each demonstrating unique trends considering the dopant stability and growth mechanism. Specifically, the proportion of graphitic doping could be modulated from 40 % to 100 %. Notably, the pyrrolic type was absent at lower temperatures and was nearly negligible at elevated temperatures. Therefore, we developed a synthesis method for N-doped graphene growth that allowed for the selective and prioritized tuning of nitrogen dopant types. This method is particularly favorable when specific nitrogen dopants at certain doping levels are required for electrical and chemical catalytic applications.

Supermolecule-regulated synthesis strategy of general biomass-derived highly nitrogen-doped carbons toward potassium-ion hybrid capacitors with enhanced performances

Biomass-derived carbons are promising anodes in potassium-ion hybrid capacitors owing to their tunable structure and competitive cost-effectiveness. The intercalation of K+ ions into carbonaceous anode is a sluggish reaction due to the turbostratic structure and large radius of K+ ions, resulting in the inability to exploit its high capacity and high-rate capability. Nitrogen-doping strategy could enhance the K-ion storage performance by surface capacitive adsorption mechanism. Nevertheless, conventional nitrogen-doping strategies could only endow biomass-derived carbons with low nitrogen-doping levels (<10 at.%), owing to the general agglomeration issue of biomass molecules and the easy release of nitrogen dopant during carbonization. Herein, we proposed a supermolecule-regulated strategy, which enables the breakage of the agglomeration of lignin molecule and disperses lignin in Lewis alkali-acid coupled supermolecule through inter-molecule interactions between lignin and the supermolecule. The co-decomposition of supermolecule/lignin composite precursor could form a covalent-bonded graphitic carbon nitride/carbon intermediate, ensuring the high nitrogen doping level (17.0 at.%) in lignin-derived carbon. The obtained carbon anode delivered high reversible capacities and high-rate capability. All-carbon potassium-ion hybrid capacitors constructed by this carbon as both anode and cathode exhibited a high energy density and power density. This work proposes a general method for constructing highly nitrogen-doped carbon anodes with superior performances.

Porous graphitic carbon nitride nanosheets with three-dimensional interconnected network as electrode for supercapacitors

Graphitic carbon nitride material with hierarchical porous structure and high doping level has been reported to exhibit superior capacitive properties due to the facilitated electrolyte migration and redox process. In this work, porous graphitic carbon nitride layers (UMCN-A1.25) with typical three-dimensional (3D) network were prepared through a facile calcination process. For its preparation, NH4HCO3 was used as the pore generator and glucose was used as the carbon precursor. Urea and melamine, which worked as the binary precursors for sacrificial template, played important roles in the formation of the final 3D interconnected structure. The hierarchical pore structure and high nitrogen-doping level endow UMCN-A1.25 with high specific capacitances (520 F g−1 at 0.1 A g−1 and 219.4 F g−1 at 20 A g−1) and stable charge-discharge behavior with no capacitance declination after 10,000 cyclic tests. This work proposed an efficient route for the construction of inter-connected carbon nitride layers, and also revealed the importance of both lamellar morphology and interwoven structure for the acquisition of high capacitive properties.

Self-assembly of guanosine into carbon-based multilayer materials.

We report the utilization of guanosine as a supramolecular precursor that unprecedentedly renders the formation of carbon-based multilayer materials with naturally high-level nitrogen doping. As a proof-of-concept, the porous carbon multilayers after anchoring 0.5 wt% Rh electrocatalysts displayed an excellent hydrogen evolution reaction activity.

Soft‐template assisted preparation of hierarchically porous graphitic carbon nitride layers for high‐performance supercapacitors

AbstractStrong π–π interaction between two‐dimensional graphitic carbon nitride (CN) layers may cause the stacking phenomenon, which leads to the decrease of its surface area and thus the capacitive properties. Hard templates are usually used to avoid the stacking phenomena. However, the use of them needs redundant removing process and may cause environmental pollution. As a result, in this work, P123 was used as the soft template to expand the inter‐layer distance and create more mesopores in the CN sheets. Benefit from the synergistic effect between the unique porous structure and the high nitrogen doping level, the formed graphitic CN (P2‐g‐CN) could exhibit high specific capacitances (520.5 and 176.0 F g−1 at the current density of 0.5 and 50 A g−1), stable cyclic behavior and satisfied energy density. The superior energy storage performances and the facile synthetic approach of P2‐g‐CN indicate its promising application as high‐performance electrode for supercapacitors and other energy storage devices.

Facile Transformation of Waste Biomass into Nitrogen-Doped Graphene for Highly Efficient Metal-Free Electrocatalyst for the Oxygen Reduction Reaction

Key words: Metal-free catalyst, Oxygen reduction reactions, Pyridinic nitrogen, Stability It is of significant interest to produce metal-free electrocatalysts for oxygen reduction reactions (ORR) derived from low-cost and environmentally friendly biomass. This work presents a facile thermal annealing approach for large-scale synthesis of the nitrogen-doped graphene (N-GO) nanoflakes using melamine as the nitrogen source and chestnut shells-based biomass as the carbon source. This approach allows us to achieve a high nitrogen doping level in graphene. Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the N-GO. XPS analysis revealed the presence of pyridinic, graphitic, and pyrrolic nitrogen doping in graphene sheets, with pyridinic nitrogen being the most abundant. Electrochemical investigations showed that a higher concentration of pyridinic nitrogen configurations contribute significantly to the superior electrocatalytic activity toward oxygen reduction reactions (ORR) in alkaline electrolytes. The as-synthesized N-GO exhibits high ORR activity with the onset and half-wave potential of 0.90 V and 0.79 V in alkaline medium, respectively; which is among the best reported to the date for metal-free catalysts. Moreover, compared with the commercial Pt/C, optimized N-GO electrocatalyst exhibits more positive onset potential and better long-term stability, making it a promising metal-free catalyst for practical fuel cells. Acknowledgements: The authors are thankful to Campus France and the National Research Foundation of Korea for financing the PHC Star mobility project (45823YC). Figure 1

Symmetric supercapacitor devices based on pristine g-C3N4 mesoporous nanosheets with exceptional stability and wide operating voltage window

We report a facile low-cost thermal polymerization method of urea to produce 2D carbon nitride nanosheets (GCN) as confirmed via a plethora of morphological and structural characterization techniques. The GCN electrodes showed excellent electrochemical performance with a very wide operating voltage window upon their use as positive and negative poles in supercapacitor devices. The GCN exhibited high specific capacitance as positive and negative electrodes in 0.5 M H2SO4. The symmetric supercapacitor (GCN//GCN) device possesses a wide operating voltage window of 2 V, with an ultrahigh energy density of 19.33 Wh/kg and superior stability over 21,000 charge/discharge cycles. The device was assembled on graphite sheet and not on Ni foam to avoid the raised caveats on the contribution of the redox-active Ni foam to the measured capacities. These unique properties can be ascribed to the high nitrogen doping level (exceeding 12%), revealing the potential of pristine GCN as promising candidates for further investigation and development in energy conversion and storage applications.

Non-radical pathway dominated by singlet oxygen under high salinity condition towards efficient degradation of organic pollutants and inhibition of AOX formation

It is still a challenge to effectively treat organic pollutants and control the formation of adsorbable organic halogens (AOX) under high salinity owing to the inevitable side reactions among chloride ions and reactive radicals. Herein, 3D N-doped graphene aerogel supported on nickel foam (NGA@NF) was designed for non-radical pathway through peroxymonosulfate (PMS) activation. The NGA@NF exhibits excellent catalytic activity with 92% removal of acid orange 7 (AO7) within 10 min under high salinity environment ([Cl-]0 = 200 mM), owing to the synergistic effects of 3D hierarchy porous structure and high nitrogen doping level (6.8%). Due to the superb resistance of singlet oxygen (1O2) to radical scavengers (Cl-), 78% of the total organic carbon (TOC) was removed in NGA@NF/PMS system, which is much higher than the traditional Co2+/PMS system (3%). Importantly, AOX value in NGA@NF/PMS system was 6.5 times lower than that in Co2+/PMS system. Kinetic calculation indicates that the effective inhibition of AOX formation could be attributed to the non-radical pathway with 1O2 as primary reactive species. This work highlights leveraging the non-radical pathway dominated by 1O2 to environmental remediation under high salinity conditions by a promising material.

Porous Activity of Biomass-Activated Carbon Enhanced by Nitrogen-Dopant Towards High-Performance Lithium Ion Hybrid Battery-Supercapacitor

Biomass-activated carbon materials are promising electrode materials for lithium-ion hybrid capacitors (LiCs) because of their natural hierarchical pore structure. The efficient utilization of structural pores in activated carbon is very important for their electrochemical performance. Herein, porous biomass-activated carbon (PAC) with large specific surface area was prepared using a one-step activation method with biomass waste as the carbon source and ZnCl2 as the activator. To further improve its pore structure utilization efficiency, the PAC was doped with nitrogen using urea as the nitrogen source. The experimental results confirmed that PAC-1 with a high nitrogen doping level of 4.66% exhibited the most efficient pore utilization among all the samples investigated in this study. PAC-1 exhibited 92% capacity retention after 8000 cycles, showing good cycling stability. Then, to maximize the utilization of high-efficiency energy storage devices, LiNi0.8Co0.15Al0.05O2 (NCA), a promising cathode material for lithium-ion batteries with high specific capacity, was compounded with PAC-1 in different ratios to obtain NCA@PC composites. The NCA@PC-9 composite exhibited excellent capacitance in LiCs and an energy density of 105.45 Wh kg−1 at a high power density of 13.3 kW kg−1. These results provide guidelines for the design of high-performance and low-cost energy storage devices.

One-pot synthesis of ZnO quantum dots/N-doped Ti3C2 MXene: Tunable nitrogen-doping properties and efficient electrochemiluminescence sensing

Nitrogen doping has been proven to be a facile modification strategy to improve the electrochemical performance of 2D MXenes, and thus broaden the potential of MXene-based materials in electrochemistry. Herein, a unique 0D/2D heterostructure of ZnO quantum dots (QDs) decorated nitrogen-doped Ti3C2 MXene (ZnO/N-Ti3C2) with high nitrogen-doping level has been designed and prepared using glycine as N precursor via a facile thermal treatment. During the synthesis process, Ti3C2 MXene matrix acted as an important role to confine the nucleation and growth of ZnO QDs, and thus resulted in the well-dispersed ZnO QDs of 2 ∼ 5 nm on the surface of MXene. Meanwhile, the nitrogen-doping level of Ti3C2 MXene in the composites can be simply tuned from 1.52 wt% to 5.43 wt% by adjusting the amount of glycine. Electrochemical measurements demonstrated that the increasing doping contents in Ti3C2 MXene could boost the Electrochemiluminescence (ECL) performances, which might be attributed to that more nitrogen contents were beneficial for accelerating electron transfer and decreasing the barrier of ZnO QDs reduction. Remarkably, ECL testing of the ZnO/N-Ti3C2 with 5.43 wt% N revealed that the ECL intensity enhanced by 2.8-fold and the ECL onset potential increased for about 250 mV than those of ZnO QDs/undoped Ti3C2 MXene. By using the resultant ZnO/N-Ti3C2 nanocomposites as an efficient ECL platform, a novel ECL sensor was constructed for sensitive and selective detection of chloramphenicol, which displayed a wide linear range (0.1 ng/mL ∼ 100 ng/mL), a low detection limit (0.019 ng/mL) and high stability.

Nickel nanoparticles encapsulated by nitrogen-doped bamboo-shaped carbon nanotubes with a high-level doping: A boosting electrocatalyst for alkaline hydrogen evolution

The development of highly active and stable alkaline hydrogen evolution electrocatalysts is highly desired in the field of clean energy. Herein, we chose urea and nickel chloride as precursors, and synthesized metallic Ni nanoparticles encapsulated by nitrogen-doped bamboo-shaped carbon nanotubes through one-pot calcination at low temperature (550 °C). Along with the increase in the amount of Ni salt, the electrocatalyst support has undergone a transformation from polymeric carbon nitride to nitrogen-doped carbon, and the charge transport ability and electrochemical active surface area of the electrocatalysts have been significantly improved. For the optimized Ni/NC-0.35 electrocatalyst with 13.42 wt% nitrogen-doping level, the overpotential at cathodic current density of 10 mA cm−2 is 133 mV (vs. RHE) in alkaline electrolyte, the corresponding Tafel slope is 109 mV dec-1, and there is no significant decrease in hydrogen evolution activity after 16 h. The boosting activity can be attributed to the synergistic effect of the mixed phase Ni nanoparticles, the high nitrogen-doping level and the bamboo-shaped carbon nanotube structure towards the alkaline hydrogen evolution reaction. This work provides a new way for the design of high-activity alkaline hydrogen evolution electrocatalysts and the facile synthesis of high nitrogen-doping carbon-coated metal nanoparticle catalysts.

Biowaste derived porous carbon sponge for high performance supercapacitors

Here, an agricultural waste (the stem pith of helianthus annuus, SPHA) is firstly used as the precursor for preparing three-dimensional (3D) porous carbon sponge (PCS). The as-prepared 3D PCS (SPHA-700) possesses unique sponge-like structure, large specific surface area (SSA) and high nitrogen doping level (4.52 at.%), which benefit the enhancement of conductivity (5.8 S cm−1) and wettability. As a binder-free electrode for solid-state symmetric supercapacitor, SPHA-700 delivers a relatively high specific capacitance of 137.1 F g−1 at 0.5 A g−1. Moreover, activated SPHA-700 (SPHA-ac-700–2) displays an even higher specific capacitance (403.6 F g−1 at 0.5 A g−1) in 6.0 M KOH electrolyte. The SPHA-ac-700–2-based symmetrical supercapacitor can offer high specific capacitance (271 F g−1 at 1 A g−1) and good rate capability (82.1% of capacitance retention at 1–80 A g−1) in 6.0 M KOH electrolyte, together with high energy density (23.3 Wh kg−1 at 450 W kg−1) in 1.0 M Na2SO4 electrolyte. Such excellent performance of SPHA-ac-700–2 is believed to have originated from the crushed sponge-like structure, O/N-co-doping (10.6 at.% O and 3.3 at.% N), high SSA, large total pore volume, and hierarchical pore structure.

Hetero-Dimensional 2D Ti3C2Tx MXene and 1D Graphene Nanoribbon Hybrids for Machine Learning-Assisted Pressure Sensors.

Hybridization of low-dimensional components with diverse geometrical dimensions should offer an opportunity for the discovery of synergistic nanocomposite structures. In this regard, how to establish a reliable interfacial interaction is the key requirement for the successful integration of geometrically different components. Here, we present 1D/2D heterodimensional hybrids via dopant induced hybridization of 2D Ti3C2Tx MXene with 1D nitrogen-doped graphene nanoribbon. Edge abundant nanoribbon structures allow a high level nitrogen doping (∼6.8 at%), desirable for the strong coordination interaction with Ti3C2Tx MXene surface. For piezoresistive pressure sensor application, strong adhesion between the conductive layers and at the conductive layer/elastomer interface significantly diminishes the sensing hysteresis down to 1.33% and enhances the sensing stability up to 10 000 cycles at high pressure (100 kPa). Moreover, large-area pressure sensor array reveals a high potential for smart seat cushion-based posture monitoring application with high accuracy (>95%) by exploiting machine learning algorithm.

Synthesis and electrochemical performance of an electroactive nitrogen-doping SnO2nanoarray supported on carbon fiber

An electroactive nitrogen-doping tin dioxide nanorod array (N-SnO2NRA) is designed as an effective energy-storage electrode material for supercapacitor applications. N-SnO2supported on a carbon fiber substrate is prepared using SnCl4as a precursor through hydrolysis, hydrothermal growth, and an NH3-nitriding process. Electroactive N-SnO2is formed by an N-doping reaction between Sn(OH)4and NH3, revealing a high nitrogen-doping level of 12.5% in N-SnO2. N-SnO2/carbon fiber reveals a lower ohmic resistance and charge transfer resistance than SnO2/carbon fiber, which is consistent with its higher current response and lower voltage drop in electrochemical measurements. N-SnO2NRA has an independent nanoarray structure and a small side length of a quadrangular nanorod, contributing to a more accessible interspace, reactive sites, and feasible electrolyte ion diffusion. The N-SnO2/carbon fiber NRA electrode shows higher specific capacitance (105.4 F g−1at 0.5 A g−1) and rate capacitance retention (45.0% from 0.5 to 5 A g−1) than a SnO2/carbon fiber NRA electrode (58.6 F g−1, 38.4%). Significantly, the cycling capacitance retention after 2000 cycles increases from 78.1% of SnO2/carbon fiber to 98.8% of N-SnO2/carbon fiber, presenting a superior electrochemical cycling stability. The N-SnO2supercapacitor maintains stable power working at an output voltage of 1.6 V. The specific capacitance decreases from 75.2 to 55.1 F g−1when the current density increases from 1 to 10 A g−1. The corresponding energy density decreases from 24.23 to 9.81 Wh kg−1, presenting a reasonable rate capability. So, the prepared N-SnO2nanorod array demonstrates superior capacitance performance for energy-storage applications.

Dual‐Active Sites Engineering of N‐Doped Hollow Carbon Nanocubes Confining Bimetal Alloys as Bifunctional Oxygen Electrocatalysts for Flexible Metal–Air Batteries

Since the sluggish kinetic process of oxygen reduction (ORR)/evolution (OER) reactions, the design of highly-efficient, robust, and cost-effective catalysts for flexible metal-air batteries is desired but challenging. Herein, bimetallic nanoparticles encapsulated in the N-doped hollow carbon nanocubes (e.g., FeCo-NPs/NC, FeNi-NPs/NC, and CoNi-NPs/NC) are rationally designed via a general heat-treatment strategy of introducing NH3 pyrolysis of dopamine-coated metal-organic frameworks. Impressively, the resultant FeCo-NPs/NC hybrid exhibits superior bifunctional electrocatalytic performance for ORR/OER, manifesting exceptional discharging performance, outstanding lifespan, and prime flexibility for both Zn/Al-air batteries, superior to those of state-of-the-art Pt/C and RuO2 catalysts. X-ray absorption near edge structure and density functional theory indicate that the strong synergy between FeCo alloy and N-doped carbon frameworks has a distinctive activation effect on bimetallic Fe/Co atoms to synchronously modify the electronic structure and afford abundant dual-active Fe/Co-Nx sites, large surface area, high nitrogen doping level, and conductive carbon frameworks to boost the reversible oxygen electrocatalysis. Such N-doped carbon with bimetallic alloy bonds provides new pathways for the rational creation of high-efficiency energy conversion and storage equipment.

Nitrogen-rich microporous carbon framework as an efficient polysulfide host for lithium-sulfur batteries

Lithium-sulfur batteries are recognized as a promising high-energy-density and low-cost energy storage devices. However, the sulfur cathode suffers from poor cycling stability resulting from the serious polysulfide shuttle. Herein, we develop a nitrogen-rich and highly porous carbon polyhedron for effectively hosting sulfur. The carbon host manifests an ultrahigh specific surface area of 3400 m2 g−1, a dominated micropore volume of 0.96 cm3 g−1, and a high-level nitrogen doping of 8.3 at.%. Such an intriguing structure could suppress the polysulfide shuttle via physical confinement by micropores and strong chemical adsorption by polar nitrogen species. Moreover, the electrically conductive carbon enables a substantially enhanced electrochemical kinetics. Consequently, the carbon/sulfur composite electrode delivers an ultralow fading rate of 0.033% per cycle at 2 C over 500 cycles and superior rate capability (483 mAh g−1 at a high 5 C rate). The present study demonstrates the potential use of nitrogen-rich porous carbon framework as an efficient polysulfide host for lithium-sulfur batteries.

Effects of nitrogen incorporation on N-doped DLC thin film electrodes fabricated by dielectric barrier discharge plasma: Structural evolution and electrochemical performances

Hydrogenated amorphous carbon-nitride (a-C:H:N) thin films (or N-DLC) were deposited on glass and FTO substrates by a dielectric barrier discharge plasma technique using CH4/N2 gas mixture. The XPS results reveal that as the nitrogen ratio in the CH4:N2 gas mixture increases from 50% to 80%, the nitrogen doping level increased from 5.5 at.% to a maximum value of 11.5 at.% with especially high amounts of pyridinic (6.4 at %), and graphitic (4.7 at %) nitrogen. FEG-SEM results indicate a worm-like porous morphology for the 20%:80% CH4:N2 sample, relying on high amounts of pyridinic and graphitic N, which is a favorable structure to boost the ions diffusion process. This optimized N-DLC electrode with high nitrogen incorporation not only exhibits a nearly electrochemical reversibility with ΔEp (125 mV) and Jpa/Jpc (1.03) in K3Fe(CN)6 electrolyte, but also a fast charge transfer constant (6.59 × 10−4 cms−1). The excellent performance of this electrode is ascribed to the high nitrogen doping level, large surface area, the abundant holes, and the high nano-pore volume possessing excellent electron transfer ability for redox reaction. N-DLC thin film exhibits a promising prospect for biosensors and electrochemical electrode applications.

High‐Level Pyridinic‐N‐Doped Carbon Nanosheets with Promising Performances Severed as Li‐Ion Battery Anodes

Defects engineering is recognized as one promising strategy to enhance the electrochemical performance of carbon materials applied in energy storage field. Different from the commonly used methods, high‐level N‐doped carbon nanosheets are synthesized in this work via controllable removal of nitrogen atoms from nitrogen‐rich graphite carbon nitride (g‐C3N4). The nitrogen doping levels and the relative amount of variable nitrogen types, including pyridinic‐, pyrrolic‐, and graphitic‐N, are easily engineered for the obtained carbon nanosheets. Ultrahigh pyridinic‐N content as high as 19.1 at% is achieved, closing to the highest values among the reported nitrogen‐doped carbon materials. Extraordinary initial discharging capacity of 5190 mAh g−1 at a current density of 50 mA g−1 and excellent cycling stability (1639 mAh g−1 after 200 cycles) as well as promising rate performance (517 mAh g−1 at 2 A g−1) are demonstrated when serving as Li‐ion battery anodes. The high nitrogen doping level, especially for the high pyridinic‐N doping content in materials, is responsible for these outstanding electrochemical Li‐ion storage performances. This work opens a new gateway to develop promising nitrogen‐doped carbon materials for the practical application in energy storage devices.

Ultra-small MnCo2O4 nanocrystals decorated on nitrogen-enriched carbon nanofibers as oxygen cathode for Li-O2 batteries

Ultra-small MnCo2O4 nanocrystals/nitrogen enriched carbon nanofiber composites, with particle size as small as 2–4[Formula: see text]nm and nitrogen content as high as [Formula: see text][Formula: see text]at.%, were designed and used as oxygen cathode materials for Li-O2 batteries, with an aprotic electrolyte. Via an in-situ nucleation and growth, the morphology, size and distribution of MnCo2O4 nanocrystals were well controlled on surface of nanofibers, with strong interfacial interactions between the two components. Benefitting from the unique microstructure and high-level nitrogen doping, the MnCo2O4/NCF composite can deliver discharge and charge capacities of 4147.8 and 3842.8[Formula: see text]mAh/g as oxygen cathode materials, and columbic efficiencies are about 92.6%. More importantly, the discharge products can completely decompose in charging process as evidenced by an ex-situ FESEM investigation, while for pure NCF cathode, particle and plate-like Li2O2 were still observed on its surface, which confirmed that the MnCo2O4/NCF composite has a superior electrocatalytic activity that that of NCF.