摘要：
There has been an ongoing effort in pursuing high-energy-density supercapacitor to facilitate its practical applications in energy storage devices. Currently, constructing a composite electrode using multiple battery-type materials or battery-like capacitive materials has been perceived as a promising solution. On one hand, the rational composition/microstructure design is highly desirable to improve the volumetric stress distribution and enhance the overall electrical conductivity. Accordingly, we develop a battery-like (Co(OH)(2)/Co9S8)@NiTe/Ni composite electrode, in which the continuous NiTe network skeleton running throughout Co(OH)(2)/Co9S8 nanohybrid acts as the fast electron transfer channel and the buffer against volumetric strain. The electrode delivers a high areal capacitance of 5.28 F cm(-2) at a current density of 10 mA cm(-2) and demonstrates a super-long cycle life of 50,0 0 0 cycles due to the good electrical conductivity, buffer effect of NiTe skeleton and the capacitance contributions from multiple constituents. Thereafter, the assembled aqueous or quasi-solid-state (Co(OH)(2)/Co9S8)@NiTe/Ni//AC asymmetric supercapacitor demonstrates high areal energy density exceeding 0.88 mWh cm(-2) as well as long cycle life exceeding 35,000 cycles. The fabricated battery-like supercapacitor electrode can be engineered to satisfy the long-term, high-power and high-energy-density application requirements. (c) 2020 Elsevier Ltd. All rights reserved.
期刊：
Road Materials and Pavement Design,2020年21(5):1426-1438 ISSN：1468-0629
通讯作者：
Liu Qi-Cheng
作者机构：
[Liu Peng; Zeng Qing; Chen Chuan-Sheng; Liu Qi-Cheng] Changsha Univ Sci & Technol, Sch Mat Sci & Engn, Changsha, Peoples R China.;[Kong Jiang-Rong] Cent South Univ, Coll Chem & Chem Engn, Changsha, Peoples R China.
通讯机构：
[Liu Qi-Cheng] S;School of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, People’s Republic of China
关键词：
nano-ZnO;polymerised styrene butadiene;modified asphalt;modification mechanism;density functional theory
摘要：
The modification mechanism between nano-zinc oxide (nano-ZnO), polymerised styrene butadiene (PSB) and asphalt were studied by first-principles calculation, revealed the modification mechanism from the molecular scale. The asphalt was divided into four components: saturate, aromatic, resin and asphaltene, used nano-ZnO and PSB as modifiers for asphalt, constructed systems of asphalt modifiers and asphalt components, then geometric optimisation of each system. Density functional theory (DFT) was used to calculate the binding energy and the number of charges transferred between saturate, aromatic, resin and nano-ZnO, PSB. Calculated results show that nano-ZnO has chemical modification of hydroxylation to asphalt. Meanwhile, the nano-ZnO has a physical adsorption effect based on van der Waals force for each component of asphalt, which can be stably combined with asphalt. PSB can form aromatic-ring stacking with asphalt, making PSB combined with asphalt, the interaction of this accumulation is not strong, and the combination of PSB and asphalt is unstable. When nano-ZnO and PSB were simultaneously added into the asphalt, the absolute value of the binding energy between saturate, aromatic, resin and PSB all increased, nano-ZnO acts as a medium for attracting asphalt and PSB, the addition of nano-ZnO can effectively enhance the binding stability of PSB and asphalt.
摘要：
Transition metal compounds are attractive for their significant applications in supercapacitors and as non-noble metal catalysts for electrochemical water splitting. Herein, we develop Ni_3S_2 nanorods growing directly on Ni foam, which act as multifunctional additive-free Ni_3S_2@Ni electrode for supercapacitor and overall water splitting. Based on PVA-KOH gel electrolyte, the assembled all-solid-state Ni_3S_2@Ni//AC asymmetric supercapacitor delivers a high areal energy density of 0.52 mWh cm~(–2) at an areal power density of 9.02 mW cm~(–2), and exhibits an excellent cycling stability with a capacitance retention ratio of 89% after 10000 GCD cycles at a current density of 30 mA cm~(–2). For hydrogen evolution reaction and oxygen evolution reaction in 1 M KOH, Ni_3S_2@Ni electrode achieves a benchmark of 10 mA cm~(–2) at overpotentials of 82 mV and 310 mV, respectively. Furthermore, the assembled Ni_3S_2@Ni||Ni_3S_2@Ni electrolyzer for overall water splitting attains a current density of 10 mA cm~(–2) at 1.61 V. The in-situ synthesis of Ni_3S_2@Ni electrode enriches the applications of additive-free transition metal compounds in high-performance energy storage devices and efficient electrocatalysis.
摘要：
Carbon materials with a high specific surface area are usually preferred to construct the air cathode of lithium-air batteries due to their abundant sites for oxygen reduction and discharge product growth. However, the high surface area also amplifies electrolyte degradation during charging, which would become the threshold of cyclability after addressing the issue of electrode passivation and pore clogging, but is usually overlooked in relevant research. Herein, it is proven that the critical influence of cathode surface area on electrolyte consumption by adopting carbon-ceramic composites to reduce the surface area of the air cathode. After screening several potential ceramic materials, an optimal composite of Ketjenblack (KB) and La0.7 Sr0.3 MnO3 (LSM) delivered a discharge capacity that was even higher than that of pure KB. This composite effectively mitigated the parasitic reaction current by 45 % if polarized at 4.4 V versus Li(+) /Li. Correspondingly, this composite prolonged the cycle life of the cell by 156 %. The results demonstrate that electrolyte consumption during charging is one of the critical boundary conditions to restrain the cyclic stability of lithium-air batteries.
摘要：
Ni3S2@Ni composite electrode for supercapacitor is synthesized via a one-step solvothermal treatment of Ni foam at 120 degrees C, exhibiting a 3D meso/macroporous network structure. The structure contains Ni3S2 nanosheets with 15-20 nm in thickness and meso/macropores with an average pore size of 24.69 nm, and its formation is regulated through the slow release of S2- ions and the solid/liquid interfacial reactions in absolute ethanol. At a current density of 17.15 A g(-1), the composite electrode demonstrates a high specific capacitance of 945.71 F g(-1), and at various current densities below 17.15 A g(-1), it retains capacitance retention ratios above 100% after 2000 charge/discharge cycles. A two-step oxidation and three-step reverse reduction process occurs during the reversible Faradaic reaction of Ni3S2 in KOH aqueous solution, which is due to the valence transitions of Ni-0 in Ni3S2 between Ni-0 and Ni3+. The homogeneous cracking in Ni3S2 layer is a critical factor for achieving its long-term cycling stability, however, the cycling results in its amorphization. An asymmetric supercapacitor is assembled using Ni3S2@Ni composite electrode as the positive electrode and Ni foam as the negative electrode, which delivers an energy density of 55.79 Wh kg(-1) at the power density of 938.98 W kg(-1). (c) 2018 Elsevier Ltd. All rights reserved.
摘要：
Mesoporous carbon is constructed by monolithic polyaromatic mesophase deriving from the hexane insoluble of coal-tar pitch. This carbon material exhibits spherical morphology and layered crystallite, and thereby can be graphitized at 900 degrees C without destroying the mesoporous structure. Electrochemical measurements indicate that graphitic mesoporous carbon (GMC) support not only improves the activity of Pt electrocatalyst to oxygen reduction reaction (ORR), but also shows higher corrosion resistance than commercial XC-72 carbon black in the acid cathode environment (C) 2014 Elsevier B.V. All rights reserved.
