Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 25
·10008-10013
·
IF 8.262
Jin-ling Ma,Xin-bo Zhang
Development of an efficient air cathode for metal–air batteries composed of an element that is abundant on earth is a scientific and technical challenge. Here, nitrogen (N)-doped carbon cathodes were prepared using two conventional doping methods, namely ammonia activation (ammoxidation) and introduction of an N-containing precursor. Interestingly, the introduction of N-containing precursors to prepare the N-doped carbon material not only gave a different pore distribution with increased surface area but also maintained considerable N content, unlike the use of the ammoxidation method – thus greatly enhancing the catalytic activity (low overpotential) and improving the discharge capacity (6905 mA h g−1) and cycle life (from 8 to 66 cycles) in sodium–oxygen batteries compared with the pure carbon material. This study also stresses the importance of adopting the optimized synthesis method to prepare the N-doped carbon cathode.
研究领域:
电化学
·
能源材料
·
纳米材料
·
电池技术
·
多孔材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Chao Liu,Xingang Liu,Jiang Tan,Qingfu Wang,Hao Wen,Chuhong Zhang
Nitrogen-doped graphene nanosheets (NGNS) are prepared by a novel mechanochemical method via all-solid-state ball-milling graphite with urea. The ball-milling process does not only successfully exfoliate the graphite into multi-layer (<10 layers) graphene nanosheets , but at the same time, enables the N element to be doped onto the graphene. Urea, acting as a new solid doping and assist-grinding agents, has the advantages of low cost and good water solubility that can simplify the fabrication process. The as-prepared NGNS are investigated in detail by XRD , SEM, HRTEM , TGA , XPS and Raman spectroscopy . The doping nitrogens are around 3.15% and dominated (>94%) by pyrindic-N and pyrrolic-N which facilitates the NGNS with enhanced electronic conductivity and Li-ion storage capability. For the first time, we demonstrate that the all-solid-state prepared NGNS exhibits, especially at high currents, enhanced cycling stability and rate capability as Lithium ion battery (LIB) anode active material when compared to pristine graphite and undoped graphene in half-cell configuration. The method presented in this article may provide a simple, clean, economical and scalable strategy for preparation of NGNS as a feasible and promising anode material for LIBs .
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机非金属材料
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2018
·Vol. 52
·期 2
·025502
·
IF 2.373
Yang Lu,Yange Wang,Weixiao Wang,Yan Guo,Yingge Zhang,Rongjie Luo,Xianming Liu,Tao Peng
Lithium-sulfur batteries are considered the most promising next-generation electrochemical energy storage devices due to their high theoretical energy density. However, their practical application is hindered by the severe shuttle effect of polysulfides and the low conductivity of sulfur cathode. Herein, we design a titanium nitride host with a three-dimensional honeycomb-like structure via a spray drying method, which has the advantages of metallic conductivity and ultrafast anchoring to realize efficient adsorption and conversion of polysulfide. The honeycomb-like architecture can shorten the diffusion path of lithium ions, and buffer the volume change of sulfur, which can improve reaction kinetics and maintain the stability of the material structure. As a result, the sulfur cathode based on titanium nitride host exhibits an excellent cycling performance with a stable capacity of 650.4 mAh g−1 within 500 cycles at 100 mA g−1. The excellent performance shows the importance of designing cathode materials with reasonable structures in lithium sulfur batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米结构材料
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Jun Wu,Ji Hu,Kaixin Song,Junming Xu,Huifang Gao
Spirulina was used for the first time as a raw nitrogen-doped porous carbon source to synthesize carbon/sulphur (carbon/S) composite cathodes for lithium-sulphur batteries. The composites consisting of sulphur and spirulina-derived carbon with micro- and meso-pores showed an obvious carbon encapsulating sulphur structure. The carbon/S cathodes exhibited much better electrochemical performance than pristine sulphur, delivering an initial discharge capacity of 662 mAh g −1 with nearly 60% capacity retention after 100 cycles at 1 C current density (1670 mA g −1 ). The improved electrochemical stability of the composites can be ascribed to the synergistic effects between the encapsulation of sulphur by spirulina-derived carbon and adsorption of polysulfides on N doped carbon lattice. These effects successfully prevented or retarded the shuttle effect of sulphur cathodes.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
功能碳材料
·
电池技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Xiao Huang,Mingqi Li
To improve the cycling stability and rate capability of SiO electrodes, multi-channel and porous SiO@N-doped C (mp-SiO@N-doped C) rods are fabricated by the combination of electrospinning and heat treatment with the assistance of poly(methyl methacrylate) (PMMA). During annealing, in-situ PMMA degradation and gasification lead to the formation of multi-channel structure and more pores. As anodes for lithium ion batteries, the mp-SiO@N-doped C rods exhibit excellent cycling stability. At a current density of 400 mA g −1 , a discharge capacity of 806 mAh g −1 can be kept after 250 cycles, the retention of which is over than 100% versus the initial reversible capacity. Compared with the SiO@N-doped C rods synthesized without the help of PMMA, the mp-SiO@N-doped C rods exhibit more excellent rate capability. The excellent electrochemical performance is attributed to the special structure of the mp-SiO@N-doped C rods. In addition to the conductivity improved by carbon fibers, the multi-channel and porous structures not only make ions/electrons transfer and electrolyte diffusion easier, but also contribute to the structural stability of the electrodes.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Dacheng Zhang,Linlin Wang,Qian Wu,Yujie Yang,Jingli Xu
In this work, a novel N/O Co-doped hollow carbon nanocapsule-supported Ge nanoparticles nanocomposite (Ge-N/O-CNCs) was successfully prepared by a facile heating reflux method. N/O codoped hollow carbon nanocapsule-supported Ge nanoparticles not only relieve the agglomeration of Ge nanoparticles and control the volume expansion, but also facilitate the rapid transmission of electrons. In LIBs, the unique Ge-N/O-CNCs nanoarchitecture was used as the anode material. At a high current density of 1 A g -1 , it remains a stable specific capacity of 448 mAh g -1 remained after 100 cycles. Additionally, even at 3.2 A g -1 , this material exhibited a high-rate specific capacity of 350 mAh g -1 .
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
电池技术
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 11
·3819-3830
·
IF 4.099
Karim Khan,Ayesha Khan Tareen,Sayed Elshahat,Ashish Yadav,Usman Khan,Minghui Yang,Luigi Bibbò,Zhengbiao Ouyang
One of the greatest challenges in the enhancement of the electrical properties of conductive mayenite [Ca24Al28O64]4+(4e−) (hereinafter C12A7:e−) is the design of a more suitable/simple synthesis strategy that can be employed to obtain the required properties such as excellent stable electrical conductivity, a high electron concentration, outstanding mobility, and an exceptionally large surface area. Therefore, to synthesize C12A7:e− in the metallic state, we proposed a facile, direct synthesis strategy based on an optimized sol–gel combustion method under a nitrogen gas environment using the low-cost precursors Ca(NO3)2·4H2O and Al(NO3)3·9H2O. Using this developed strategy, we successfully synthesized moderately conductive nanoscale C12A7:e− powder, but with unexpected carbon components (reduced graphene oxide (rGO) and/or graphene oxide (GO)). The synthesized C12A7:e− composite at room temperature has an electrical conductivity of about 21 S cm−1, a high electron concentration of approximately 1.5 × 1021 cm−3, and a maximum specific surface area of 265 m2 g−1. Probably, the synthesized rGO was coated on nanocage C12A7:e− particles. In general, the C12A7:e− electride is sensitive to the environment (especially to oxygen and moisture) and protected by an rGO coating on C12A7:e− particles, which also enhances the mobility and keeps the conductivity of C12A7:e− electride stable over a long period. Doped mayenite electride exhibits a conductivity that is strongly dependent on the substitution level. The conductivity of gallium-doped mayenite electride increases with the doping level and has a maximum value of 270 S cm−1, which for the first time has been reported for the stable C12A7:e− electride. In the case of Si-substituted calcium aluminate, the conductivity has a maximum value of 222 S cm−1 at room temperature.
研究领域:
无机化学
·
材料科学
·
纳米材料
·
固态化学
·
电化学
·
功能材料
✓ 已验证
DOI
高影响因子
Nano Research
·
2024
·Vol. 17
·期 6
·5578-5586
·
IF 9.5
Ni Qingchao,Lou Qing,Shen Chenglong,Zheng Guangsong,Song Runwei,Hao Jingnan,Liu Jialu,Zhu Jinyang,Zang Jinhao,Dong Lin,Shan Chong-Xin
The emergence of novel self-powered humidity sensors has attracted considerable attention in the fields of smart electronic devices and personal healthcare. Herein, self-powered humidity sensors have been fabricated using a moisture-driven energy generation (MEG) device based on asymmetric tubular graphitic carbon nitride (g-CN) films prepared on anodized aluminum (AAO) template. At a relative humidity (RH) of 96%, the MEG device can provide an open-circuit voltage of 0.47 V and a short-circuit current of 3.51 µA, with a maximum output power of 0.08 µW. With inherent self-powered ability and humidity response via current variation, an extraordinary response of 1.78 × 10 6 % (41%–96% RH) can be gained from the MEG device. The possible power generation mechanism is that g-CN/AAO heterostructure can form ion gradient and diffusion under the action of moisture to convert chemical potential into electrical potential, evoking a connaturally sensitive response to humidity. Self-powered respiration monitoring device based on the sensor is designed to monitor human movement (sitting, warming up, and running) and sleep status (normal, snoring, and apnea), maintaining excellent stability during cumulative 12-h respiration monitoring. This self-powered humidity sensing technology has promising potential for extensive integration into smart electronic and round-the-clock health monitoring devices.
研究领域:
智能电子设备
·
个人健康护理
·
传感器
·
能量收集
·
纳米技术
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2024
·
IF 4.8
Kai Zhang,Ruili Song,Ning Wu,Yunhu Wang,Mingming Zhang,Xilei Chen,Lei Wang,Jun Xing
Graphitic carbon nitride (g-CN) materials exhibit attractive optoelectronic physical properties; however, their low photoluminescence quantum yields (PLQYs) limit their applications in luminescent devices. Here, boron-doped aromatic carbon nitride (B-PhCNx) was synthesized for the first time via direct thermal polymerization of 2,4-diamino-6-phenyl-1,3,5-triazine and boric acid. The impact of B doping and phenyl modifying on the structural and optical characteristics of the samples was investigated in detail. The highest PLQY of 40.7% was achieved in B-PhCN20, which is 6.8 times that of pristine carbon nitride (p-CN). The B-PhCN20-based light-emitting diode demonstrates a maximum luminance of 1494 cd m–2 and a maximum external quantum efficiency of 1.03%, which are 3.5 and 4.9 times that of the p-CN-based device, respectively. Our findings will provide a reference for rationally designing low-cost and high-performance carbon-nitride-based optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Guoqiang Zhao,Changwei Luo,Qingsong Hua
This paper elucidates the mechanism of BN as sintering additive and the enhancement for LLZO performance. The introduction of the sintering additive boron nitride (BN) to Li 6.25 Ga 0.25 La 3 Zr 2 O 12 (LGLZO) can effectively eliminate the insulating phase Li 2 CO 3 and form the liquid phase Li 3 BO 3 along the grain boundaries, which significantly enhances the relative density (from 72.4% to 92.9%), ionic conductivity (from 1.3 × 10 − 5 to 6.7 × 10 − 4 S cm − 1 ), mechanical strength (from 1.36 to 5.36 GPa) and air stability (anti-Li 2 CO 3 ) of the electrolyte. Density functional theory (DFT) results reveal that the formation of Li 3 BO 3 contributes to the improvement of the interfacial lithiophilicity, and the interface resistance is reduced from 1219 to 32 Ω cm −2 . The critical current density (CCD) is enhanced from 0.1 to 0.7 mA cm −2 , and the cells can be stably cycled for more than 1000 h at a current density of 0.2 mA cm −2 with a low overpotential at room temperature.
研究领域:
材料科学
·
电化学
·
能源存储
·
固体离子学
·
无机非金属材料
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2018
·Vol. 5
·期 9
·2092-2099
·
IF 5.106
Jinxue Guo,Ke Zhang,Yanfang Sun,Yingxia Zong,Ziyang Guo,Qingyun Liu,Xiao Zhang,Yongyao Xia
Layered MoS2 has been recognized as a promising low-cost alternative to Pt-based electrocatalysts towards the hydrogen evolution reaction (HER). Intensive interest has been mainly focused on designing MoS2 nanostructures with large amounts of active edge sites and fast charge transfer. Here we report the synthesis of vanadium and nitrogen co-doped MoS2 on reduced graphene oxide with new defect sites on the basal/edge planes and expanded interlayer spacing, which shows remarkable catalytic merits with an extremely low overpotential of 68 mV at 10 mA cm−2 and a Tafel slope of 41 mV dec−1. Its performance is superior to most current MoS2 electrocatalysts. In addition to the charge transfer benefits of the RGO substrate, the vanadium and nitrogen dopants trigger defect sites on the basal/edge planes, and an optimized electronic structure and expanded interlayer distance are also responsible for the enhancement in catalysis. This contribution may offer a potential way to design advanced MoS2 catalysts by modulating the defect sites and interlayer distance for efficient electrochemical water splitting.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源转换
·
表面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yue Du,Zhiyi Zhong,Zhixian Shi,Lina Zhou,Song Pan,Xiaonan Xu,Yisi Liu,Dongbin Xiong,Kai Wang
The development of carbon-encapsulated alloy catalysts, through a rational design that integrates highly active Me-N-C sites, is essential for improving the reaction kinetics of both oxygen reduction (ORR) and oxygen evolution reactions (OER). This advancement is pivotal for the progression of efficient rechargeable zinc-air batteries (RZABs). In this study, we investigates a CoNi alloy decorated N-doped carbon nanotube (CoNi-NCNT) electrocatalyst using a dual-ligand strategy. Experimental characterizations and theoretical calculations reveales that the electronic modulation of the 3 d orbitals of the CoNi alloy by the CoN 3 sites enhances electronic conductivity during the ORR/OER process, leading to exceptional bifunctional activity. Electrochemical evaluations demonstrates the outstanding performances of CoNi-NCNT, with a half-wave potential of 0.81 V (versus RHE) for ORR and a low overpotential of 1.52 mV for OER at 10 mA cm −2 . Moreover, the CoNi-NCNT catalyzed Zn-air battery exhibits a remarkable specific capacity of 780 mAh g −1 and an exceptionally extended lifespan exceeding 800 h. This underscores the potential of this alloy strategy in the development of high-performance bifunctional ORR/OER electrocatalysts.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）