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1.
Hiroyuki Shinka Takeshi Yamamoto Hiroaki Komatsu Takeshi Hongakiuchi 《Electronics and Communications in Japan》2015,98(1):1-8
Hollow porcelain insulators are widely used in gas‐insulated power apparatus and oil‐filled power apparatus. Previously, it was thought that hollow porcelain insulators are not subject to aging deterioration. However, gas and oil leaks caused by the alkali–silica reaction in the porcelain where it is in contact with cementing parts have been reported in recent years. We experimentally verified the generation process of the alkali–silica reaction by using a hollow porcelain insulator removed from the substation, and examined an inhibition method of alkali–silica reaction based on the use of lithium nitrite. It was found that the alkali–silica reaction occurs in the hollow porcelain insulator and that lithium nitrite is effective for inhibition of the alkali–silica reaction. 相似文献
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Zhe Li Yan Zhang Yi Feng Chuan‐Qi Cheng Kang‐Wen Qiu Cun‐Ku Dong Hui Liu Xi‐Wen Du 《Advanced functional materials》2019,29(36)
Ultrasmall size and abundant defects are two crucial factors for improving the performance of catalysts. However, it is a big challenge to introduce defects into ultrafine catalysts because of the surface tension and self‐purification effect of the nanoparticles. In the present work, physical laser fragmentation with chemical oxidization reaction is combined to synthesize Co3O4 nanoparticles (L‐CO) with ultrasmall size (≈2.1 nm) as well as abundant oxygen vacancies, thus providing an effective solution to the long‐standing contradiction between the size reduction and defect generation. The ultrasmall particle size allows more catalytic sites to be exposed. The surficial oxygen vacancies enhance the intrinsic activity, while the internal oxygen vacancies improve the electron transfer, and all of these benefits make L‐CO an active and durable bifunctional catalyst for oxygen reduction/evolutions. As the air cathode of zinc–air battery, L‐CO displays excellent rechargeable performance with a power density of ≈337 mW cm?2, outperforming the commercial noble metal couple (Pt/C+RuO2). 相似文献
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Chang‐Xin Zhao Jia‐Ning Liu Bo‐Quan Li Ding Ren Xiao Chen Jia Yu Qiang Zhang 《Advanced functional materials》2020,30(36)
Zinc–air batteries deliver great potential as emerging energy storage systems but suffer from sluggish kinetics of the cathode oxygen redox reactions that render unsatisfactory cycling lifespan. The exploration on bifunctional electrocatalysts for oxygen reduction and evolution constitutes a key solution, where rational design strategies to integrate various active sites into a high‐performance air cathode remain insufficient. Herein, a multiscale construction strategy is proposed to rationally direct the fabrication of bifunctional oxygen electrocatalysts for long‐lifespan rechargeable zinc–air batteries. NiFe layered double hydroxides and cobalt coordinated framework porphyrin are selected as the active sites considering their high intrinsic activity at the molecular level, and the active sites are successively integrated on three‐dimensional conductive scaffolds at mesoscale to strengthen ion transportation. Consequently, the multiscale constructed electrocatalyst exhibits excellent bifunctional performance (ΔE = 0.68 V), which is even better than that of the noble metal based benchmarks. The corresponding air cathodes endow zinc–air batteries with a reduced voltage gap of 0.74 V, a high power density of 185.0 mW cm?2, and an ultralong lifespan of more than 2400 cycles at 5.0 mA cm?2. This work demonstrates a feasible strategy to rationally integrate various active sites to construct multifunctional electrocatalysts for energy‐related processes. 相似文献
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Zhihao Wang Huihui Jin Tian Meng Ke Liao Wenqian Meng Jinlong Yang Daping He Yuli Xiong Shichun Mu 《Advanced functional materials》2018,28(39)
Zeolitic imidazole frameworks (ZIFs) offer rich platforms for rational design and construction of high‐performance nonprecious‐metal oxygen reduction reaction (ORR) catalysts owing to their flexibility, hierarchical porous structures, and high surface area. Herein, an Fe, Cu‐coordinated ZIF‐derived carbon framework (Cu@Fe‐N‐C) with a well‐defined morphology of truncated rhombic dodecahedron is facilely prepared by introducing Fe2+ and Cu2+ during the growth of ZIF‐8, followed by pyrolysis. The obtained Cu@Fe‐N‐C, with bimetallic active sites, large surface area, high nitrogen doping level, and conductive carbon frameworks, exhibits excellent ORR performance. It displays 50 mV higher half‐wave potential (0.892 V) than that of Pt catalysts in an alkaline medium and comparable performance to Pt catalysts in an acidic medium. In addition, it also has excellent durability and methanol resistance ability in both acidic and alkaline solutions, which makes it one of the best Pt‐free catalysts reported to date for ORR. Impressively, when being employed as a cathode catalyst in zinc–air batteries, Cu@Fe‐N‐C presents a higher peak power density of 92 mW cm?2 than that of Pt/C (74 mW cm?2) as well as excellent durability. 相似文献
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CuCo Bimetallic Oxide Quantum Dot Decorated Nitrogen‐Doped Carbon Nanotubes: A High‐Efficiency Bifunctional Oxygen Electrode for Zn–Air Batteries 
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下载免费PDF全文 The large‐scale production of metal–air batteries, an appealing solution for next‐generation energy storage, requires low‐cost, earth‐abundant, and efficient oxygen electrode materials, yet insights into active catalyst structures and synergistic reactivity remain largely unknown. Here, a new bifunctional oxygen electrode based on nitrogen‐doped carbon nanotubes decorated by spinel CuCo2O4 quantum dots (CuCo2O4/N‐CNTs) is reported, outperforming the benchmark of state‐of‐the‐art noble metal catalysts. Combining spectroscopic characterization and electrochemical studies, a prominent synergetic effect between CuCo2O4 and N‐doped carbon nanotubes is uncovered: the high conductivity, large active surface area, and increase in the number of catalytic sites induced by Cu doping (i.e., Cu2+ and Cu?N) can be beneficial to the overall electrocatalytic activities. Remarkably, the native flexibility of CuCo2O4/N‐CNTs allows its direct use as reversible oxygen electrodes in Zn–air batteries either with liquid alkaline electrolyte or in the all‐solid‐state configuration. The prepared devices demonstrate excellent discharging/charging performance, large energy density (83.83 mW cm?2 in liquid state, 1.86 W g?1 in all‐solid‐state), and long lifetime (48 h in liquid state, 9 h in all‐solid‐state), holding great promise in the practical application of rechargeable metal–air batteries and other fuel cells. 相似文献
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《Advanced functional materials》2017,27(30)
The large‐scale production of metal–air batteries, an appealing solution for next‐generation energy storage, requires low‐cost, earth‐abundant, and efficient oxygen electrode materials, yet insights into active catalyst structures and synergistic reactivity remain largely unknown. Here, a new bifunctional oxygen electrode based on nitrogen‐doped carbon nanotubes decorated by spinel CuCo2O4 quantum dots (CuCo2O4/N‐CNTs) is reported, outperforming the benchmark of state‐of‐the‐art noble metal catalysts. Combining spectroscopic characterization and electrochemical studies, a prominent synergetic effect between CuCo2O4 and N‐doped carbon nanotubes is uncovered: the high conductivity, large active surface area, and increase in the number of catalytic sites induced by Cu doping (i.e., Cu2+ and Cu? N) can be beneficial to the overall electrocatalytic activities. Remarkably, the native flexibility of CuCo2O4/N‐CNTs allows its direct use as reversible oxygen electrodes in Zn–air batteries either with liquid alkaline electrolyte or in the all‐solid‐state configuration. The prepared devices demonstrate excellent discharging/charging performance, large energy density (83.83 mW cm?2 in liquid state, 1.86 W g?1 in all‐solid‐state), and long lifetime (48 h in liquid state, 9 h in all‐solid‐state), holding great promise in the practical application of rechargeable metal–air batteries and other fuel cells. 相似文献
7.
Yuan Teng Xu‐Dong Wang Jin‐Feng Liao Wen‐Guang Li Hong‐Yan Chen Yu‐Jie Dong Dai‐Bin Kuang 《Advanced functional materials》2018,28(34)
Engineering non‐noble metal–based electrocatalysts with superior water oxidation performance is highly desirable for the production of renewable chemical fuels. Here, an atomically thin low‐crystallinity Fe–Mn–O hybrid nanosheet grown on carbon cloth (Fe–Mn–O NS/CC) is successfully synthetized as an efficient oxygen evolution reaction (OER) catalyst. The synthesis strategy involves a facile reflux reaction and subsequent low‐temperature calcination process, and the morphology and composition of hybrid nanosheets can be tailored conveniently. The defect‐rich Fe–Mn–O ultrathin nanosheet with uniform element distribution enables exposure of more catalytic active sites; moreover, the atomic‐scale synergistic action of Mn and Fe oxide contributes to an enhanced intrinsic catalytic activity. Therefore, the optimized Fe–Mn–O hybrid nanosheets, with lateral sizes of about 100–600 nm and ≈1.4 nm in thickness, enable a low onset potential of 1.46 V, low overpotential of 273 mV for current density of 10 mA cm?2, a small Tafel slope of 63.9 mV dec?1, and superior durability, which are superior to that of individual MnO2 and FeOOH electrode, and even outperforming most reported MnO2‐based electrocatalysts. 相似文献
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Due to their high theoretical specific capacity and energy density, Li?O2 batteries are considered as candidates for next‐generation battery systems in place of conventional Li‐ion batteries for advanced applications such as electric vehicles. However, low energy efficiency, poor cycle life, and Li‐metal safety issues make the use of Li?O2 batteries yet impractical. In addition, actual cell capacities are very low, and since only small‐scale electrodes are currently tested, it is hard to predict the properties of large‐size electrodes and cells, thus evaluating and judging real practical challenges related to this battery technology. In this work, the behavior of pouch‐type Li?O2 cells using 3 × 5 cm2 sized electrodes is investigated and it is confirmed that Li‐metal is a key issue for the upscale of Li?O2 cells. This study can help to determine which parameters are the most important for developing practical Li?O2 batteries. 相似文献
11.
《Advanced functional materials》2017,27(11)
Due to their high theoretical specific capacity and energy density, Li? O2 batteries are considered as candidates for next‐generation battery systems in place of conventional Li‐ion batteries for advanced applications such as electric vehicles. However, low energy efficiency, poor cycle life, and Li‐metal safety issues make the use of Li? O2 batteries yet impractical. In addition, actual cell capacities are very low, and since only small‐scale electrodes are currently tested, it is hard to predict the properties of large‐size electrodes and cells, thus evaluating and judging real practical challenges related to this battery technology. In this work, the behavior of pouch‐type Li? O2 cells using 3 × 5 cm2 sized electrodes is investigated and it is confirmed that Li‐metal is a key issue for the upscale of Li? O2 cells. This study can help to determine which parameters are the most important for developing practical Li? O2 batteries. 相似文献
12.
Kan Mi Shunwei Chen Baojuan Xi Shuangshuang Kai Yong Jiang Jinkui Feng Yitai Qian Shenglin Xiong 《Advanced functional materials》2017,27(1)
The exploration of inexpensive, facile, and large‐scale methods to prepare carbon scaffolds for high sulfur loadings is crucial for the advancement of Li–S batteries (LSBs). Herein, the authors report a new nitrogen and oxygen in situ dual‐doped nonporous carbonaceous material (NONPCM) that is composed of a myriad of graphene‐analogous particles. Importantly, NONPCM could be fabricated on a kilogram scale via inexpensive and green hydrothermal‐carbonization‐combined methods. Many active sites on the NONPCM surface are accessible for the efficient surface‐chemistry confinement of guest sulfur and its discharge product; this confinement is exclusive of physical entrapment, considering the low surface area. Electrochemical examination demonstrates excellent cycle stability and rate performance of the NONPCM (K)/S composite, even with a sulfur loading of 80 or 90 wt%. Hence, the scaffolds for LSBs exhibit potential for industrialization through further optimization and expansion of the present synthesis. 相似文献
13.
Yiling Liu Fengjiao Chen Wen Ye Min Zeng Na Han Feipeng Zhao Xinxia Wang Yanguang Li 《Advanced functional materials》2017,27(12)
The development of nonprecious metal‐based electrocatalysts for the oxygen reduction reaction holds the decisive key to many energy conversion devices. Among several potential candidates, transition metal and nitrogen co‐doped carbonaceous materials are the most promising, yet their activity and stability are still insufficient to meet the needs of practical applications. In this study, a core–shell hybrid electrocatalyst is developed via the self‐polymerization of dopamine and cobalt on carbon nanotubes (CNTs), followed by high‐temperature pyrolysis. The polymer‐derived carbonaceous shell contains abundant structural defects and facilitates the formation of Co? N/C active sites, whereas the graphitic carbon nanotube core provides high electrical conductivity and corrosion resistance. These two components separately fulfill different functionalities, and jointly afford the catalyst with excellent electrochemical performance. In 1 m KOH, Co? N/CNT exhibits a positive half‐wave potential of ≈0.91 V, low peroxide yield of <7%, as well as great stability. When used as the air catalyst of primary Zn–air and Al–air batteries, this hybrid electrocatalyst enables large discharge current density, high peak power density, and prolonged operation stability. 相似文献
14.
Biaohua Chen Xiaobo He Fengxiang Yin Hao Wang Di‐Jia Liu Ruixing Shi Jinnan Chen Hongwei Yin 《Advanced functional materials》2017,27(37)
A highly efficient bifunctional oxygen catalyst is required for practical applications of fuel cells and metal–air batteries, as oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are their core electrode reactions. Here, the MO‐Co@N‐doped carbon (NC, M = Zn or Co) is developed as a highly active ORR/OER bifunctional catalyst via pyrolysis of a bimetal metal–organic framework containing Zn and Co, i.e., precursor (CoZn). The vital roles of inactive Zn in developing highly active bifunctional oxygen catalysts are unraveled. When the precursors include Zn, the surface contents of pyridinic N for ORR and the surface contents of Co–Nx and Co3+/Co2+ ratios for OER are enhanced, while the high specific surface areas, high porosity, and high electrochemical active surface areas are also achieved. Furthermore, the synergistic effects between Zn‐based and Co‐based species can promote the well growth of multiwalled carbon nanotubes (MWCNTs) at high pyrolysis temperatures (≥700 °C), which is favorable for charge transfer. The optimized CoZn‐NC‐700 shows the highly bifunctional ORR/OER activity and the excellent durability during the ORR/OER processes, even better than 20 wt% Pt/C (for ORR) and IrO2 (for OER). CoZn‐NC‐700 also exhibits the prominent Zn–air battery performance and even outperforms the mixture of 20 wt% Pt/C and IrO2. 相似文献
15.
Zehui Sun Yuankun Wang Libo Zhang Hu Wu Yachao Jin Yuhan Li Yuchuan Shi Tianxiang Zhu Heng Mao Jiamei Liu Chunhui Xiao Shujiang Ding 《Advanced functional materials》2020,30(15)
Fundamental understanding of constructing elevated catalysts to realize fast electron transfer and rapid mass transport in oxygen reduction reaction (ORR) chemistry by interface regulation and structure design is important but still ambiguous. Herein, a novel jellyfish‐like Mott–Schottky‐type electrocatalyst is developed to realize fast electron transfer and decipher the structure–mass transport connection during ORR process. Both spectroscopy techniques and density functional theory calculation demonstrate electrons spontaneously transfer from Fe to N‐doped graphited carbon at the heterojunction interface, thus accelerating electron transfer from electrode to reactant. Dynamic analysis indicates unique structure can significantly improve mass transport of oxygen‐species due to two factors: one is electrolyte streaming effect caused by tentacle‐like carbon nanotubes; the other is effective collision probability in the semi‐closed cavity. Therefore, this Mott–Schottky‐type catalyst delievers superior ORR performance with high onset potential, positive half wave potential, and large current density. It also exhibits low overpotential when serving as an air cathode in Zn–air batteries. This work deepens understanding of the two key factors—electron transfer and mass transport—on determining the kinetic reaction of ORR process and offers a new avenue in constructing efficient Mott–Schottky electrocatalysts. 相似文献
16.
Junxing Han Xiaoyi Meng Liang Lu Juanjuan Bian Zhipeng Li Chunwen Sun 《Advanced functional materials》2019,29(41)
Highly efficient non‐noble metal electrocatalysts are vital for metal–air batteries and fuel cells. Herein, a noble‐metal–free single‐atom Fe‐N x‐C electrocatalyst is synthesized by incorporating Fe‐Phen complexes into the nanocages in situ during the growth of ZIF‐8, followed by pyrolysis at 900 °C under inert atmosphere. Fe‐Phen species provide both Fe2+ and the organic ligand (Phen) simultaneously, which play significant roles in preparing single‐atom catalysts. The obtained Fe‐Nx‐C exhibits a half‐wave potential of 0.91 V for the oxygen reduction reaction, higher than that of commercial Pt/C (0.82 V). As a cathode catalyst for primary zinc–air batteries (ZABs), the battery shows excellent electrochemical performances in terms of the high open‐circuit voltage (OCV) of 1.51 V and a high power density of 96.4 mW cm?2. The rechargeable ZAB with Fe‐Nx‐C catalyst and the alkaline electrolyte shows a remarkable cycling performance for 300 h with an initial round‐trip efficiency of 59.6%. Furthermore, the rechargeable all‐solid‐state ZABs with the Fe‐Nx‐C catalyst show high OCV of 1.49 V, long cycle life for 120 h, and foldability. The single‐atom Fe‐Nx‐C electrocatalyst may function as a promising catalyst for various metal–air batteries and fuel cells. 相似文献
17.
Kanyaporn Adpakpang Seung Mi Oh Daniel Adjei Agyeman Xiaoyan Jin Nutpaphat Jarulertwathana In Young Kim Thapanee Sarakonsri Yong‐Mook Kang Seong‐Ju Hwang 《Advanced functional materials》2018,28(17)
Holey 2D nanosheets of low‐valent Mn2O3 can be synthesized by thermally induced phase transition of exfoliated layered MnO2 nanosheets. The heat treatment of layered MnO2 nanosheets at elevated temperatures leads not only to transitions to low‐valent manganese oxides but also to the creation of surface hole in the 2D nanosheet crystallites. Despite distinct phase transitions, highly anisotropic 2D morphology of the precursor MnO2 material remains intact upon the heat treatment whereas the diameter of surface hole becomes larger with increasing heating temperature. The obtained holey 2D Mn2O3 nanosheets show promising electrocatalyst performances for oxygen evolution reaction, which are much superior to that of nonporous Mn2O3 crystal. Among the present materials, the holey Mn2O3 nanosheet calcined at 500 °C displays the best electrocatalyst functionality with markedly decreased overpotential, indicating the importance of heating condition in optimizing the electrocatalytic activity. Of prime importance is that this material shows much better catalytic activity for Li–O2 batteries than does nonporous Mn2O3, underscoring the critical role of porous 2D morphology in this functionality. This study clearly demonstrates the unique advantage of holey 2D nanosheet morphology in exploring economically feasible transition metal oxide‐based electrocatalysts and electrodes for Li–O2 batteries. 相似文献
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Yangyang Xu Peilin Deng Guangda Chen Jinxi Chen Ya Yan Kai Qi Hongfang Liu Bao Yu Xia 《Advanced functional materials》2020,30(6)
The rational construction of efficient bifunctional oxygen electrocatalysts is of immense significance yet challenging for rechargeable metal–air batteries. Herein, this work reports a metal–organic framework derived 2D nitrogen‐doped carbon nanotubes/graphene hybrid as the efficient bifunctional oxygen electrocatalyst for rechargeable zinc–air batteries. The as‐obtained hybrid exhibits excellent catalytic activity and durability for the oxygen electrochemical reactions due to the synergistic effect by the hierarchical structure and heteroatom doping. The assembled rechargeable zinc–air battery achieves a high power density of 253 mW cm?2 and specific capacity of 801 mAh gZn?1 with excellent cycle stability of over 3000 h at 5 mA cm?2. Moreover, the flexible solid‐state rechargeable zinc–air batteries assembled by this hybrid oxygen electrocatalyst exhibits a high discharge power density of 223 mW cm?2, which can power 45 light‐emitting diodes and charge a cellphone. This work provides valuable insights in designing efficient bifunctional oxygen electrocatalysts for long‐life metal–air batteries and related energy conversion technologies. 相似文献
20.
Shang Hu Ting Han Chao Lin Weikai Xiang Yonghui Zhao Peng Gao Fuping Du Xiaopeng Li Yuhan Sun 《Advanced functional materials》2017,27(18)
3D graphene aerogel (GA) integrated with active metal or its derivatives has emerged as a novel class of multifunctional constructs with range of potential applications. However, GA fabricated by self‐assembly in the liquid phase still suffers from low conductivity and poor knowledge related to spatial active phase distribution and 3D structure. To address these issues, a facile approach involving in situ integration of 1D silver nanowire (AgNW) during gelation of graphene oxide flakes is presented. AgNWs prevent the restacking of graphene sheets and act as an efficient electron highway and Ag source for deposition of ultrasmall Ag nanocrystals (AgNCs). When applied as the cathodic electrocatalyst in a zinc–air battery, the 3D GA integrated with 0D AgNCs and 1D AgNWs permit ultrahigh discharge rates of up to 300 mA cm?2. Moreover, for the first time, with the help of phase‐contrast X‐ray computed microtomography, the interconnected porous network of millimeter‐sized GA and a full‐field view of the macrodistribution of Ag is delivered, offering the vitally complementary macroscopic structure information, which has been missing in previous reports. 相似文献