Search

Your search keyword '"Cao, Dianxue"' showing total 1,172 results
Start Over Author "Cao, Dianxue"
1,172 results on '"Cao, Dianxue"'

406. Three-demensional porous carbon framework coated with one-demensional nanostructured polyaniline nanowires composite for high-performance supercapacitors

Author

Wang, Bin, primary, Zhao, Jing, additional, Zhang, Dongming, additional, Zhang, Hongquan, additional, Cheng, Kui, additional, Ye, Ke, additional, Zhu, Kai, additional, Yan, Jun, additional, Cao, Dianxue, additional, Jiao, Weizhou, additional, Liu, Youzhi, additional, and Wang, Guiling, additional

Published
2019
Full Text
View/download PDF

432. Synthesis and electrochemical studies of carbon-modified LiNiPO4 as the cathode material of Li-ion batteries

Author

Liu Jia, Cao Dianxue, Pan Yue, Zhang Ying, and Wang Guiling

Subjects
Lithium vanadium phosphate battery, Scanning electron microscope, Inorganic chemistry, Analytical chemistry, chemistry.chemical_element, General Chemistry, Electrochemistry, Lithium-ion battery, Cathode, law.invention, chemistry, Transmission electron microscopy, law, Lithium, Particle size
Abstract

Well-crystallized olivine LiNiPO4 and carbon-modified LiNiPO4(LiNiPO4/C) were synthesized by a combined solvothermal and solid state reaction method using water-benzyl alcohol two-phase solvent. The structure and morphology of the prepared LiNiPO4 were systematically characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The LiNiPO4 particles are up to around 2 μm in diameter while the particle size of LiNiPO4/C is about 100–200 nm. At a current rate of 0.05 C(1.00 C=167 mA/g, corresponding to one Li+ intercalation/deintercalation), LiNiPO4 and LiNiPO4/C presented a high initial specific capacity of 157 and 220 mA·h/g, respectively. The capacity of LiNiPO4/C is 72% larger than that of LiNiPO4 at 0.1 C. The LiNiPO4/C cathode exhibits a superior electrochemical performance in comparison with LiNiPO4, revealing that carbon modifying is an effective method to improve the ionic diffusion and electronic conductivity of cathode material LiNiPO4. Furthermore, lithium ion diffusion coefficients of LiNiPO4 and LiNiPO4/C are 1.80×10−15 and 1.91×10−14 cm2/s, respectively, calculated via the data from electrochemical impedance spectra.

Published
2015

433. High‐performance all‐solid‐state supercapacitor with binder‐free binary transition metal sulfide array as cathode.

Author

Li, Yanan, Gong, Junwei, Xing, Xiaolin, Du, Jialiang, Xu, Panpan, Cheng, Kui, Ye, Ke, Zhu, Kai, Yan, Jun, Cao, Dianxue, and Wang, Guiling

Subjects
SUPERCAPACITOR electrodes, SUPERCAPACITORS, ENERGY storage, METAL sulfides, TRANSITION metals, ENERGY density, NEGATIVE electrode
Abstract

Summary: Transition metal sulfides show excellent performance in an aqueous supercapacitor. However, all‐solid‐state supercapacitors are attracting more and more interest because of thinner, lighter, and more flexible. Binary sulfides Ni3Co6S8 nanowire arrays (NCS) are directly grown on a nitrogen‐doped carbon foam (NCF) through hydrothermal reaction, which is applied as a binder‐free electrode for all‐solid‐state supercapacitor. The unique needlelike structure assembled by nanosheet effectively increases the utilization efficiency of active materials and promotes electrochemical performance. The NCS‐NCF electrode shows promising application potential for wearable electronic devices due to the flexibility of NCF. A high‐specific capacitance of 243 mAh g−1is delivered by NCS‐NCF electrode, which also exhibits good rate behavior along with outstanding cycle stability. The NCS‐NCF electrode (positive electrode) and NCF electrode (negative electrode) are employed to assemble asymmetric all‐solid‐state supercapacitor. When the high power density is 675 W kg−1, the energy density of supercapacitor reaches the maximum of 28.31 Wh kg−1. The specific capacitance of supercapacitors could maintain 84%, after 10 000 cycles of galvanostatic charge and discharge under 4 A g−1, indicating the potential application of NCS‐NCF electrode as an excellent supercapacitor electrode material in flexible, wearable energy storage systems. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

434. Aggregation‐Resistant 3D Ti3C2Tx MXene with Enhanced Kinetics for Potassium Ion Hybrid Capacitors.

Author

Fang, Yong‐Zheng, Hu, Rong, Zhu, Kai, Ye, Ke, Yan, Jun, Wang, Guiling, and Cao, Dianxue

Subjects
POTASSIUM ions, CAPACITORS, ENERGY density, POWER density, ACTIVATED carbon, SUPERCAPACITORS, ANODES
Abstract

Potassium‐ion hybrid capacitors have attracted increasing attention due to good energy density, high power density, and low cost. Ti3C2Tx‐MXene is considered as a promising anode material for K ion storage. However, undesirable stacking issues decrease its exposed area and breeds sluggish K ion transport. Herein, a facile spray‐lyophilization strategy is proposed to construct stacking‐resistant Ti3C2Tx with 3D structures. As‐prepared Ti3C2Tx hollow spheres/tubes present stack resistance, a large specific surface area, and a short ion diffusion pathway. When serving as an anode material, it shows enhanced capacity and thickness‐independent rate performance compared to 2D Ti3C2Tx. After 10 000 cycles, a specific capacity of 122 mAh g−1 is obtained at 1 A g−1. Systematic kinetics analyses demonstrate the significance of concentration polarization on the electrode's rate ability. Furthermore, a 3D Ti3C2Tx‖hierarchical porous activated carbon (HPAC) K‐ion hybrid capacitor is assembled and displays remarkable energy and power densities with energy retention of 100% after 10 000 cycles at 1 A g−1. Following this strategy, other 3D structures from nanosheets can also be obtained, such as 3D Ti3C2Tx microtubes and graphene oxide nanoscrolls. This study provides a viable approach to solve the stacking issues of 2D nanosheets to promote the application of 2D materials. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

435. Versatile Interfacial Self-Assembly of Ti3C2TxMXene Based Composites with Enhanced Kinetics for Superior Lithium and Sodium Storage

Author

Zou, Zhengguang, Wang, Qian, Yan, Jun, Zhu, Kai, Ye, Ke, Wang, Guiling, and Cao, Dianxue

Abstract

Exploring nanostructured transition-metal sulfide anode materials with excellent electrical conductivity is the key point for high-performance alkali metal ion storage devices. Herein, we propose a powerful bottom-up strategy for the construction of a series of sandwich-structured materials by a rapid interfacial self-assembly approach. Oleylamine could act as a functional reagent to guarantee that the nanomaterials self-assemble with MXene. Benefiting from the small size of Co-NiS nanorods, excellent conductivity of MXene, and sandwiched structure of the composite, the Co-NiS/MXene composite could deliver a high discharge capacity of 911 mAh g–1at 0.1 A g–1for lithium-ion storage. After 200 cycles at 0.1 A g–1, a high specific capacity of 1120 mAh g–1could be still remaining, indicating excellent cycling stability. For sodium-ion storage, the composite exhibits high specific capacity of 541 mAh g–1at 0.1 A g–1and excellent rate capability (263 mAh g–1at 5 A g–1). This work offers a straightforward strategy to design and construct MXene-based anode nanomaterials with sandwiched structure for high-performance alkali metal ion storage and even in other fields.

Published
2021
Full Text
View/download PDF

436. Co‑MOF-Derived Flake-Like Co3O4Supported Pd Nanoparticles as High-Performance Hydrogen Peroxide Electroreduction Catalysts

Author

Yang, Yuheng, Gao, Yimin, Yao, Jiaxin, Yan, Jun, Zhu, Kai, Ye, Ke, Cao, Dianxue, Zhang, Dongming, and Wang, Guiling

Abstract

Development of highly efficient catalysts for the hydrogen peroxide reduction reaction (HPRR) has been a focus of research for fuel cells using hydrogen peroxide (H2O2) as an alternative cathode oxidant. The carbon-doped flake-like cobalt oxide electrode (Co3O4@C NF) was prepared on nickel foam (NF) by annealing the metal organic framework (MOF). A Co3O4@C/Pd NF (CPNF) electrode was derived from Co3O4@C NF by supporting Pd nanoparticles. Half-cell tests demonstrated that the CPNF electrode exhibited outstanding catalytic performance. The CPNF electrode displayed a high current density of 932 mA cm−2at −0.8 V (vs Ag/AgCl). This aligns with its low activation energy (7392.8 J mol−1). The electron transfer numbers for the Co3O4@C NF and CPNF electrodes were 2.97 and 3.32, respectively. Incorporating CPNF as the cathode of Direct borohydride-hydrogen peroxide fuel cell (DBHPFC) yielded notable catalytic performance, with a peak power density of 68 mW cm−2. The CPNF electrode exhibited remarkable stability, sustaining continuous current discharge for over 20 h. These electrochemical properties result from the structural characteristics obtained through MOF annealing, which increases the number of exposed active sites and enhances ion transport. Therefore, CPNF stands as a promising cathode catalyst for DBHPFC.

Published
2024
Full Text
View/download PDF

437. Surface modification boosting amorphous vanadium oxides anode toward stable and rapid sodium ion storage

Author

Zhang, Qidi, Liao, Shuqing, Yu, Huiying, Liu, Boya, Jiang, Kai, Gao, Yinyi, Cao, Dianxue, Wang, Guiling, and Zhu, Kai

Abstract

Sodium-ion batteries (SIBs) are receiving increasing attention for their flexibility and low cost, showing potential to replace the well-studied lithium-ion batteries (LIBs). Compared to lithium ion, sodium ion possesses larger radius, leading to the volume expansion during insertion/extraction. Therefore, amorphous anode materials with low volume expansion and fast ion diffusion are more suitable for the SIBs. Among them, vanadium-based oxides are regarded as promising alternatives according to their advantages of high theoretical capacity, abundance, and low cost. However, the shortcomings such as poor conductivity, aggregation, and pulverization restrict their development as the anode of SIBs. Herein, the vanadium oxide is modified by graphene sheets, and a VOx/rGO-5 % composite is reported as the anode material for SIBs, which has promising electrochemical performance. The VOx/rGO-5 % anode remains a discharge specific capacity of 185 mAh g−1over 400 cycles under 0.5 A g−1. Meanwhile, VOx/rGO-5 % anode also exhibits a rate capability of 189 mAh g−1at 2 A g−1. Moreover, the sodium ion storage kinetics in VOx/rGO-5 % is investigated. This work affirms the possibility of vanadium-based oxides being the anode materials of SIBs.

Published
2024
Full Text
View/download PDF

438. A heterogeneous interface on NiS@Ni3S2/NiMoO4 heterostructures for efficient urea electrolysis.

Author

Sha, Linna, Liu, Tianfu, Ye, Ke, Zhu, Kai, Yan, Jun, Yin, Jinling, Wang, Guiling, and Cao, Dianxue

Abstract

Urea electrolysis is an appealing energy conversion technology to produce hydrogen (H2) and alleviate the problem of urea-rich wastewater treatment concurrently. In particular, electrocatalytic performance can be dramatically enhanced by rationally modulating the surface charge distribution with a well-tuned heterostructure. Herein, a heterostructure is constructed by NiMoO4 nanosheets grown on an interior hollow NiS@Ni3S2 nanorods framework (NiS@Ni3S2/NiMoO4). Density functional theory (DFT) calculations demonstrate that the formed heterojunction structure leads to a tailored surface charge state of NiMoO4, with oxygen as the nucleophilic region and molybdenum as the electrophilic region, which facilitates the decomposition of urea molecules and thus significantly improves hydrogen evolution. As expected, the assembled NiS@Ni3S2/NiMoO4 system substantially expedites urea electrolysis activity with a cell voltage of 1.40 V at 10 mA cm−2, which is 200 mV less than the voltage of an overall water splitting system. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

443. MXene-Derived Defect-Rich TiO2@rGO as High-Rate Anodes for Full Na Ion Batteries and Capacitors.

Author

Fang, Yongzheng, Zhang, Yingying, Miao, Chenxu, Zhu, Kai, Chen, Yong, Du, Fei, Yin, Jinling, Ye, Ke, Cheng, Kui, Yan, Jun, Wang, Guiling, and Cao, Dianxue

Abstract

Highlights: A freestanding MXene-derived defect-rich TiO2@reduced graphene oxides (M-TiO2@rGO) foam electrode was fabricated. M-TiO2@rGO presents fast Na+ storage kinetics due to capacitive contribution. M-TiO2@rGO foam electrode displays a capacity retention of 90.7% after 5000 cycles.Sodium ion batteries and capacitors have demonstrated their potential applications for next-generation low-cost energy storage devices. These devices's rate ability is determined by the fast sodium ion storage behavior in electrode materials. Herein, a defective TiO2@reduced graphene oxide (M-TiO2@rGO) self-supporting foam electrode is constructed via a facile MXene decomposition and graphene oxide self-assembling process. The employment of the MXene parent phase exhibits distinctive advantages, enabling defect engineering, nanoengineering, and fluorine-doped metal oxides. As a result, the M-TiO2@rGO electrode shows a pseudocapacitance-dominated hybrid sodium storage mechanism. The pseudocapacitance-dominated process leads to high capacity, remarkable rate ability, and superior cycling performance. Significantly, an M-TiO2@rGO//Na3V2(PO4)3 sodium full cell and an M-TiO2@rGO//HPAC sodium ion capacitor are fabricated to demonstrate the promising application of M-TiO2@rGO. The sodium ion battery presents a capacity of 177.1 mAh g−1 at 500 mA g−1 and capacity retention of 74% after 200 cycles. The sodium ion capacitor delivers a maximum energy density of 101.2 Wh kg−1 and a maximum power density of 10,103.7 W kg−1. At 1.0 A g−1, it displays an energy retention of 84.7% after 10,000 cycles. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

444. High-performance asymmetric supercapacitor assembled with three-dimensional, coadjacent graphene-like carbon nanosheets and its composite

Author

Zhao, Jing, primary, Li, Yiju, additional, Huang, Fengguang, additional, Zhang, Hongquan, additional, Gong, Junwei, additional, Miao, Chenxu, additional, Zhu, Kai, additional, Cheng, Kui, additional, Ye, Ke, additional, Yan, Jun, additional, Cao, Dianxue, additional, Wang, Guiling, additional, and Zhang, Xianfa, additional

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results