Nanomaterials
·
2020
·Vol. 10
·期 9
·1629
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IF 4.324
Ranran Jiao,Li Zhao,Shuli Zhou,Yanjun Zhai,Denghu Wei,Suyuan Zeng,Xianxi Zhang
In this study, a simple method was adopted for the synthesis of MnO@C nanocomposites by combining in-situ reduction and carbonization of the Mn3O4precursor. The carbon content, which was controlled by altering the annealing time in the C2H2/Ar atmosphere, was proved to have great influences on the electrochemical performances of the samples. The relationships between the carbon contents and electrochemical performances of the samples were systematically investigated using the cyclic voltammetry (CV) as well as the electrochemical impedance spectroscopy (EIS) method. The results clearly indicated that the carbon content could influence the electrochemical performances of the samples by altering the Li+diffusion rate, electrical conductivity, polarization, and the electrochemical mechanism. When being used as the anode materials in lithium-ion batteries, the capacity retention rate of the resulting MnO@C after 300 cycles could reach 94% (593 mAh g−1, the specific energy of 182 mWh g−1) under a current density of 1.0 A g−1(1.32 C charge/discharge rate). Meanwhile, this method could be easily scaled up, making the rational design and large-scale application of MnO@C possible.Keywords:MnO@C nanocomposites;carbon content;current density;lithium-ion battery;transition metal oxide anode
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高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 41
·21699-21708
·
IF 8.867
Zhe Cui,Qian Liu,Chaoting Xu,Rujia Zou,Jianhua Zhang,Wenlong Zhang,Guoqiang Guan,Junqing Hu,Yangang Sun
Herein, a simple and an environmentally friendly approach is developed to fabricate the novel MnO@C hierarchical structure, derived from Mn-based metal organic frameworks, which is explored as an anode material for lithium ion batteries. Remarkably, the MnO@C microsphere electrode delivers an outstanding, long cycling capacity of 596.3 mA h g−1 at 5C (1C = 765 mA g−1) after 1000 cycles, and an excellent rate performance of 380.1 mA h g−1 at 10C. The overall outstanding properties of the hierarchical MnO@C composite can be attributed to the success of a new strategy for dual structure design, which provides two pathways for effectively alleviating volume changes and enhancing conductivity based on in situ TEM electrochemical experiments and electrochemical impedance spectra. Both the poor conductivity and great volume changes of the MnO electrode material can be effectively improved in two ways: the porous carbon matrix confining the MnO nanoparticles, and the hierarchical nanorod-assembled architecture. The structures herein suggest new design concepts for metal oxide nanoarchitectures for high performance electrode materials in lithium ion batteries.
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COMPOSITES PART B-ENGINEERING
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2021
·
IF 9.078
Qihao Li,Xin Wang,Cheng Li,Xinwei Yang,Lichao Jia,Jian Li
NiMn 2 O 4 (NMO) coated Gd-doped CeO 2 (GDC) and NiO powders are prepared by a hydrothermal method for the anode of a metal (Ni-10 at.% Fe)-supported solid oxide fuel cell fueled by wet CH 4 (3 vol.% H 2 O). NMO remains on NiO but dissolves into GDC at 1400 °C. Upon reduction in H 2 at 700 °C for 2 h, Ni nanoparticles exsolve on the doped-CeO 2 (DCO) substrate (DCO@Ni), while MnO nanoparticles form on Ni (Ni@MnO). DCO@Ni demonstrates high catalytic activity for reforming wet CH 4 and high resistance to carbon deposition with a yield of H 2 increasing from 11 (500 °C) to 33 (700 °C) ml min −1 and remaining around 25 ml min −1 at 600 °C for 30 h. The metal-supported single-cell with a Ni@MnO-DCO@Ni anode shows high initial and durable electrochemical performance with a maximum power density increasing from 160 (500 °C) to 720 (700 °C) mW cm −2 and a cell voltage remaining above 0.55 V at 600 °C for 200 h under 400 mA cm −2 and 20 ml min −1 . Such high performance is ascribed to the metal support with low ohmic resistance and the engineered anode with high catalytic activity and enhanced resistance to carbon deposition.
研究领域:
能源材料
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电化学
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燃料电池技术
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纳米材料
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催化
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Huiting Xu,Huibin Liu,Wenyue Yang,Meng Li,Fan Zhao,Chunli Li,Junjie Qi,Honghai Wang,Wenchao Peng,Xiaobin Fan,Jiapeng Liu
Rechargeable aqueous zinc batteries (AZBs) are increasingly recognized as an alternative to conventional energy storage systems due to their environmentally safe nature, abundant zinc resources, and high theoretical capacity. However, the intercalation or surface redox mechanisms limit the development of AZBs cathode materials due to low specific capacity and energy density. The tellurium-based (Te) materials with conversion mechanisms are promising cathode materials for AZBs. Nevertheless, the slow kinetics are detrimental to the increase in specific capacity and energy density for Zn-Te battery. Therefore, a hierarchical structure of manganese oxide (MnO) hollow nanospheres loaded on nitrogen-doped carbon nanosheets (MnO@NC) was rationally designed and used as Te hosts (Te/MnO@NC) for Zn-Te battery. This hierarchical structure facilitates the loading of more Te species. Meanwhile, the MnO hollow nanospheres can expose more active sites, which can promote the kinetics of Te redox reactions thereby lowering the reaction energy barrier. The Te/MnO@NC cathode exhibits high specific capacity and high energy density (429 mAh g −1 and 407 Wh Kg −1 at 0.1 A g −1 ). Additionally, the conversion mechanism was investigated by systematic characterization and density functional theory (DFT) calculations. This study presents a new design platform for developing AZBs with high specific capacity and energy density.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2020
·
IF 3.807
Lili Xiao,Lin Jia,Shengzhi Zhao,Xiaoying Tang,Chengjie Zhu,Huan Huang,Jin Jiang,Mingtian Li
A kind of one-step, solvent-free, environment-friendly method is always highly appreciated in synthesis of electrocatalyst . In this work, MnO nanoparticles were coated by sheet-like carbon (MnO/C) for building a three-dimensional electrocatalyst with interconnected mesopores . Moreover, the unique porous structure of MnO/C can be facilely achieved through a one-step solvent-free calcination . In the calcination, 2-methylimidazole (2-MeIm) decomposed into carbon framework at the catalysis of MnO. The interconnected pores consisted of sheet-like carbon can significantly reduce mass transfer resistances and prevent the aggregation of MnO. Therefore MnO/C modified glassy carbon electrode (GCE) exhibited high activities in simultaneous detection of dopamine (DA) and uric acid (UA), with the sensitivities of 9.92 μA μM − 1 for DA, 8.42 μA μM − 1 for UA. The limits of detection were calculated as 0.009 μM and 0.03 μM for DA and UA, respectively. Moreover, MnO/C has promising application in detection of human urine and serum due to the satisfactory recoveries.
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Energy & Environmental Science
·
2019
·Vol. 12
·期 3
·1046-1054
·
IF 33.25
Siwu Li,Yuan Liu,Junwen Zhou,Shanshan Hong,Yu Dong,Jiaming Wang,Xing Gao,Pengfei Qi,Yuzhen Han,Bo Wang
Li–CO2 batteries have been developed in recent years, aiming to utilize CO2, a major cause of the greenhouse effect, as an effective energy storage medium. However, current Li–CO2 batteries still suffer from low energy efficiency, poor rate capability and short cycle life, demanding the design of more efficient CO2 cathodes. Herein, we synthesized ultrafine MnO nanoparticles dispersed in a graphene-interconnected N-doped 3D carbon framework, MnO@NC-G, by pyrolyzing a composite of a GO-wrapped metal–organic framework (MOF) containing Mn(II) active sites as the cathode material for Li–CO2 batteries. This material can enable low voltage hysteresis (0.88 V at 50 mA g−1), high rate capability (up to 1 A g−1) and long cycle life (more than 200 cycles) in cells. By comparing MnO@NC-G with four other Mn(II)-based cathodes, MnO@NC, parent Mn-MOF, MnO@KB and bulk MnO, we propose three key aspects for designing CO2 cathodes: (1) dispersed catalytic species, (2) fast electron transport, and (3) a robust interconnected network. We also found that the performance of a cycled MnO@NC-G cathode can be replenished simply by replacing the anode, indicating that the cell cycle life can be further extended with effective anode protection. Our findings here provide useful guidelines for improving the performance of Li–CO2 batteries, thus shedding light on the development of practical Li battery systems based on gaseous cathodes.
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APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Ran Zhang,Xinyu Gao,Kaiyuan Zhang,Donghong Duan,Xianxian Zhou,Junwen Wang,Shibin Liu
In order to realize efficient hydrogen production with low energy consumption, the urea oxidation reaction (UOR) is the most practical alternative counter-reactions to the hydrogen evolution reaction (HER) in the overall electrochemical water splitting process. It’s highly desirable through the development of suitable cost-effective and non-precious catalysts, to design brilliant bifunctional electrocatalysts for the UOR and HER with both fast electron. Herein, the electrodeposition technique was used for synthesizing the hierarchical MnP/MnO@NiP on nickel foam (NF) and its electrocatalytic behavior was explored for HER and UOR. For delivering the 10 mA·cm −2 current density, the Co-MnP/MnO@NiP/NF electrode needed only 36.2 mV overpotential in HER and 1.24 V in UOR. During overall urea electrolysis, the cell voltage in 10 mA·cm −2 was only 1.52 V, which is 300 mV lower than the HER-OER process. The remarkable catalytic performance for HER and UOR can be attributed to the protective role of MnO x and the interfacial electron interactions within the material, which significantly boosted its overall activity, and the introduction of Co could enhance the electrochemical interface to obtain highly dispersed samples. The introduction of Ni could form a NiOOH with good catalytic activity intermediates with good catalytic activity to facilitate the UOR process.
研究领域:
材料科学
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电化学
·
催化科学
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ADVANCED FUNCTIONAL MATERIALS
·
2026
·
IF 19.9
Hongbo Liang,Mengfan Pei,Shuo Zhuo,Rui Xie,Hui Lin,Wenkai Song,Zirui Guo,Xigao Jian,Fangyuan Hu
The high activation barriers for sodium polysulfide conversion during the charge–discharge processes of room-temperature sodium–sulfur batteries lead to sluggish reaction kinetics, thereby resulting in limited practical specific capacities. This simultaneously triggers the shuttle effect, leading to a rapid decay in specific capacity. In this study, we propose a hierarchical (crystalline-atomic) catalytic strategy, where the hierarchical catalyst features both manganese oxide crystalline sites and Mn single-atom sites. The two catalytic sites selectively anchor the sulfur and metal moieties of sodium polysulfides, respectively, exerting a “tearing” effect that weakens the chemical bonds and lowers the activation energy, thereby accelerating the polysulfide conversion. The cathode material synthesized using this method retains a specific capacity of 309 mAh g −1 after 2000 cycles at a current density of 2C, indicating that hierarchical parallel catalysis can effectively mitigate the shuttle effect and accelerate the reaction kinetics. Therefore, this work demonstrates the practical potential of hierarchical parallel catalysis in metal-sulfur batteries and provides a new approach for catalyst design in this domain.
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APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Cheng He,Jing Li,Xiaoyang Zhao,Xi Peng,Xiaochun Lin,Yanfei Ke,Xin Xiao,Xiaoxi Zuo,Junmin Nan
Although transition metal oxides have the advantages of large theoretical capacity, low cost and eco-friendliness, their application as anodes for lithium-ion batteries (LIBs) is still limited due to their undesirable electrical conductivity and large volume expansion. Herein, a novel two-step rapid freeze-drying-calcination strategy was applied to prepare highly dispersed nano-MnO-anchored three-dimensional nitrogen-doped porous carbon framework composites (MnO@3D N-PCF). Compared with MnO and undoped MnO@3D PCF, the MnO@3D N-PCF anode exhibits superb cycle stability, remarkable specific capacity and impressive high-rate performance (1037.0 mAh g −1 over 100 cycles at 0.1 A g −1 and 760.9 mAh g −1 over 500 cycles at 5 A g −1 ), mainly due to its well-designed 3D nanoarchitecture. It is found that 3D nitrogen-doped carbon networks can act as stable conductive bridges to facilitate electron transport and sufficient diffusion channels for Li ions. The MnO nanoparticles obtained by rapid lyophilization and calcination technology are highly dispersed in the porous 3D carbon skeleton, which can buffer volume expansion and preserve the stability of the electrode. It is expected that this simple and green synthesis strategy will open the door for the development of transition metal oxide/carbon three-dimensional nanocomposites with high stability and excellent electrochemical properties.
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LANGMUIR
·
2020
·
IF 3.557
Lun Zhang,Kuo Wei,Juanjuan Yin,Jingxin Zhou,Lexin Zhang,Jinghong Li,Tifeng Jiao
Constructing the nanostructure of transition metal oxides for high energy density lithium-ion batteries has been widely studied recently. Prompted by the idea that the transition metal can serve as a catalyzer influence on the reversibility of solid–electrolyte interphase films, Co/MnO@C composite nanofibers were designed by electrospinning and chemical vapor deposition methods. The Co/MnO@C electrode showed superior electrochemical performance with a large capacity increase for the first 400 cycles and a high rate performance of 1345 mA h g–1 at 1000 mA g–1. There was no obvious decay of capacity over the whole 1000 cycles, demonstrating the excellent cycling stability of the samples. The new design and synthesis of the anodic materials may offer a prototype for high-performance and strong-stability batteries.
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高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Fengmei Wang,Huimin Zhao,Yiru Ma,Yu Yang,Bin Li,Yuanyuan Cui,Ziyang Guo,Lei Wang
Designing the highly catalytic activity and durable bifunctional catalysts toward oxygen reduction/evolution reaction (ORR/OER) is paramount for metal–air batteries . Metal–organic frameworks (MOFs)-based materials have attracted a great deal of attention as the potential candidate for effectively catalyzing ORR/OER due to their adjustable composition and porous structure . Herein, we first introduce the Mn species into zeolitic-imidazole frameworks (ZIFs) and then further pyrolyze the Mn-containing bimetallic ZIFs to synthesize core-shell-structured Co@Co 4 N nanoparticles embedded into MnO-modified porous N-doped carbon nanocubes (Co@Co 4 N/MnO NC). Co@Co 4 N/MnO NC exhibits the outstanding catalytic activity toward ORR and OER which is attributed to its abundant pyridinic/graphitic N and Co 4 N, the optimized content of MnO species, highly dispersed catalytic sites and porous carbon matrix. As a result, the Co@Co 4 N/MnO NC-based Zn–air battery exhibits enhanced performances, including the high discharge capacity (762 mAh g Zn −1 ), large power density (200.5 mW cm −2 ), stable potential profile over 72 h, low overpotential (<1.0 V) and superior cycling life (2800 cycles). Moreover, the belt-shaped Co@Co 4 N/MnO NC cathode-based Zn–air batteries are also designed which exhibit the superb electrochemical properties at different bending/twisting conditions.
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ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Shouji Huang,Liwen Yang,Ming Gao,Qi Zhang,Guobao Xu,Xiong Liu,Juexian Cao,Xiaolin Wei
MnO is one of the most attractive anode materials for Li ion batteries (LIBs) due to its high theoretical capacity and low voltage hysteresis. However, its inherent low conductivity and large volume expansion hinder real application. Herein, we construct a flexible freestanding film of MnO quantum dots , N-doped carbon layer and carbon nanotubes by an effective method and demonstrate its direct application as an anode for LIBs. The microstructure observations reveal that well-dispersed MnO quantum dots with the average of 2–5 nm attach tightly on highly conductive carbon nanotube substrates and covered by N-doped carbon layers. Such unique nanocomposite structure provides effective carbon protective layers to accommodate volume change, ensure almost the whole surface of each MnO quantum dots to attend electrochemical reaction , and increases electron conductivity and reduces Li + diffusion distance. Furthermore, kinetic analysis and characterization tests indicate that capacitive contribution for Li storage in the freestanding film is calculated to be high and further oxidation of Mn 2+ to higher valence state upon cycling generates lots of specific capacity, thus endowing it with excellent rate, ultrahigh capacity and outstanding cycling stability. The flexible freestanding anode delivers ultrahigh capacity of 1741mAh g −1 after 120 cycles at 0.1 A g −1 , a high-rate capability of 858 mAh g −1 at 3.2 A g −1 after 120 cycles at 0.1 A g −1 , and long-term cycling stability with a capacity of 136.5% at 1.0 A g −1 after 1000 cycles. The unique nanostructure design is believed to have great potential in general synthesis of the composite consisted of CNT and oxide quantum dots for energy storage.
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