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Author

Hui Zhang

Bio: Hui Zhang is an academic researcher from Anhui University. The author has contributed to research in topics: Reflection loss & Anode. The author has an hindex of 21, co-authored 62 publications receiving 1103 citations.


Papers
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Journal ArticleDOI
Hui Zhang1, Miao Hong1, Ping Chen1, Anjian Xie1, Yuhua Shen1 
TL;DR: In this paper, the authors synthesize 3D and ternary composite hydrogels containing reduced graphene oxide, multi-walled carbon nanotubes and Fe3O4 nanoparticles via hydrothermal process.

145 citations

Journal ArticleDOI
Ping Yan1, Qian Liu2, Hui Zhang1, Luchun Qiu1, Hao Bin Wu2, Xin-Yao Yu1 
TL;DR: In this paper, hollow nanostructured Ni5P2/FeP4 nanoboxes (NiFeP NBs) are designed and synthesized as pre-catalysts.
Abstract: Transition metal phosphides (TMPs) have been reported as efficient pre-catalysts for the oxygen evolution reaction (OER) in alkaline media. In situ generated metal oxyhydroxides on the surface of TMPs serve as real active sites. However, the reconstruction of most of the reported TMPs is incomplete and the active components cannot be fully used. Herein, hollow nanostructured Ni5P2/FeP4 nanoboxes (NiFeP NBs) are designed and synthesized as pre-catalysts. During the OER, the NiFeP NBs deeply reconstruct into low-crystalline and ultrathin NiOOH/FeOOH nanosheet assembled nanoboxes (NiOOH/FeOOH NBs). In situ Raman spectroscopy and ex situ characterization studies provide evidence that the hollow nanostructure facilitates the deep reconstruction of NiFeP NBs. Benefiting from the hierarchical hollow structure, the abundant interface between NiOOH and FeOOH, and plentiful defects, the reconstructed NiOOH/FeOOH NBs exhibit superior OER activity and excellent stability. Density functional theory (DFT) calculations reveal that the Fe–Ni dual sites in the NiOOH/FeOOH interface may be the possible active sites.

123 citations

Journal ArticleDOI
Sheng Zhu1, Wang Zidan1, Fangzhi Huang1, Hui Zhang1, Shikuo Li1 
TL;DR: In this article, a well-aligned hierarchical hierarchical Cu(OH)2@Ni2(OH)-2CO3 core/shell nanowire arrays were prepared on conductive copper foam via a simple in situ oxidation reaction and subsequent hydrothermal method for highperformance solid-state supercapacitors.
Abstract: Well-aligned hierarchical Cu(OH)2@Ni2(OH)2CO3 core/shell nanowire arrays were prepared on conductive copper foam via a simple in situ oxidation reaction and subsequent hydrothermal method for high-performance solid-state supercapacitors. Such novel hierarchical architectures integrate the merits of macroporous copper foam and the core/shell nanowire arrays such as superior electrical conductivity, enlarged surface area, and fast charge transport and ion diffusion. The areal capacitance of this typical hierarchical Cu(OH)2@Ni2(OH)2CO3 core/shell nanowire array reaches 1.09 F cm−2 at a current density of 1.0 mA cm−2, much higher than that of pristine Cu(OH)2 nanowire arrays (0.36 F cm−2). In addition, a remarkable rate capability (0.91 F cm−2 at a current density of 25 mA cm−2) and excellent cycling stability (86.1% after 10 000 cycles) were observed. Moreover, the hierarchical Cu(OH)2@Ni2(OH)2CO3 core/shell nanowire arrays were also used as the positive electrodes to fabricate solid-state asymmetric supercapacitor devices, exhibiting a high cell voltage of 1.6 V and largely enhanced energy density up to 1.01 W h cm−2. The improvement in electrochemical behaviors is attributed to the unique hierarchical architecture and the component synergistic effect. This work provides a scalable and promising strategy for the synthesis of well-defined core/shell nanoarrays as energy storage and conversion devices.

116 citations

Journal ArticleDOI
TL;DR: In this paper, a facile method was proposed to assemble a hierarchical and interconnected reduced graphene oxide/β-MnO2 (rGO/βmnO 2) nanobelt hybrid hydrogel by dispersion of presynthesized ultrathin β-MmO2 nanobelts (NBs) in graphene oxide (GO) precursor solution by a hydrothermal reaction.
Abstract: We report a facile method to assemble a hierarchical and interconnected reduced graphene oxide/β-MnO2 (rGO/β-MnO2) nanobelt hybrid hydrogel by dispersion of presynthesized ultrathin β-MnO2 nanobelts (NBs) in graphene oxide (GO) precursor solution by a hydrothermal reaction. The microscopic structure of the three-dimensional (3D) hybrid hydrogel can be controlled by adjusting the content of the ultrathin β-MnO2 NBs, which exhibits the properties of low density, large specific surface area, and high compressive strength for the corresponding aerogel. Importantly, a typical hybrid hydrogel with 54.2% ultrathin β-MnO2 NBs displays a specific capacitance as high as 362 F g−1 at a current density of 1.0 A g−1, and even 282 F g−1 at 20 A g−1, which is three times higher than that of the pure rGO hydrogel (118 F g−1). Meanwhile, the typical hybrid hydrogel also shows outstanding cycling stability with 96.3% capacitance retention after 10 000 cycles of cyclic voltammetry (CV) scans. These findings open up the use of ultrathin NBs for the self-assembly of hybrid hydrogels as high performance supercapacitor devices in energy storage and conversion.

92 citations

Journal ArticleDOI
Sheng Zhu1, Mi Wu1, Mei-Hong Ge1, Hui Zhang1, Shikuo Li1, Chuanhao Li2 
TL;DR: In this article, a novel CuO-PANI-rGO ternary hybrid electrode self-assembles by an in situ polymerization method combined with hydrothermal route for electrochemical capacitor.

85 citations


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TL;DR: The two-step solution-phase reactions to form hybrid materials of Mn(3)O(4) nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications should offer a new technique for the design and synthesis of battery electrodes based on highly insulating materials.
Abstract: We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

1,587 citations

Journal ArticleDOI
TL;DR: The state-of-the-art advancements in FSSCs are reviewed to provide new insights on mechanisms, emerging electrode materials, flexible gel electrolytes and novel cell designs.
Abstract: Flexible solid-state supercapacitors (FSSCs) are frontrunners in energy storage device technology and have attracted extensive attention owing to recent significant breakthroughs in modern wearable electronics In this study, we review the state-of-the-art advancements in FSSCs to provide new insights on mechanisms, emerging electrode materials, flexible gel electrolytes and novel cell designs The review begins with a brief introduction on the fundamental understanding of charge storage mechanisms based on the structural properties of electrode materials The next sections briefly summarise the latest progress in flexible electrodes (ie, freestanding and substrate-supported, including textile, paper, metal foil/wire and polymer-based substrates) and flexible gel electrolytes (ie, aqueous, organic, ionic liquids and redox-active gels) Subsequently, a comprehensive summary of FSSC cell designs introduces some emerging electrode materials, including MXenes, metal nitrides, metal–organic frameworks (MOFs), polyoxometalates (POMs) and black phosphorus Some potential practical applications, such as the development of piezoelectric, photo-, shape-memory, self-healing, electrochromic and integrated sensor-supercapacitors are also discussed The final section highlights current challenges and future perspectives on research in this thriving field

1,210 citations

08 Jul 2010
TL;DR: Layer-by-layer techniques are used to assemble an electrode that consists of additive-free, densely packed and functionalized multiwalled carbon nanotubes, which had a gravimetric energy approximately 5 times higher than conventional electrochemical capacitors and power delivery approximately 10 timesHigher than conventional lithium-ion batteries.
Abstract: Energy storage devices that can deliver high powers have many applications, including hybrid vehicles and renewable energy. Much research has focused on increasing the power output of lithium batteries by reducing lithium-ion diffusion distances, but outputs remain far below those of electrochemical capacitors and below the levels required for many applications. Here, we report an alternative approach based on the redox reactions of functional groups on the surfaces of carbon nanotubes. Layer-by-layer techniques are used to assemble an electrode that consists of additive-free, densely packed and functionalized multiwalled carbon nanotubes. The electrode, which is several micrometres thick, can store lithium up to a reversible gravimetric capacity of approximately 200 mA h g(-1)(electrode) while also delivering 100 kW kg(electrode)(-1) of power and providing lifetimes in excess of thousands of cycles, both of which are comparable to electrochemical capacitor electrodes. A device using the nanotube electrode as the positive electrode and lithium titanium oxide as a negative electrode had a gravimetric energy approximately 5 times higher than conventional electrochemical capacitors and power delivery approximately 10 times higher than conventional lithium-ion batteries.

953 citations

Journal ArticleDOI
TL;DR: MnO2-based materials have been intensively investigated for use in pseudocapacitors due to their high theoretical specific capacitance, good chemical and thermal stability, natural abundance, environmental benignity and low cost as mentioned in this paper.
Abstract: MnO2-based materials have been intensively investigated for use in pseudocapacitors due to their high theoretical specific capacitance, good chemical and thermal stability, natural abundance, environmental benignity and low cost. In this review, several main factors that affect the electrochemical properties of MnO2-based electrodes are presented. Various strategic design and synthetic methods of MnO2-based electrode materials for enhanced electrochemical performance are highlighted and summarized. Finally, the challenges and future directions toward the development of MnO2-based nanostructured electrode materials for high performance supercapacitors (SCs) are discussed.

750 citations

Journal ArticleDOI
01 Dec 2018-Carbon
TL;DR: In this article, the authors discussed the factors of microstructural defects, filler concentration, filler alignment, filler inherent conductivity and the surrounding temperature of carbon nanostructures and their composites.

531 citations