Chaoqun Shang

One dimensional MnO2/titanium nitride nanotube coaxial arrays for high performance electrochemical capacitive energy storage

One dimensional MnO2/titanium nitride nanotube coaxial arrays have been designed for a high performance electrochemical capacitive energy storage system based on the concept of fabricating an efficient, fast charge separation network. This nanostructured composite material was prepared by electrodepositing mesoporous MnO2 into TiN nanotube arrays (TiN NTA), which are prepared by anodization of a Ti foil substrate and subsequent nitridation using ammonia annealing. The electrodeposited mesoporous MnO2 inside the electrically conductive framework of a TiN nanotube has been found to show high specific capacitance (681.0 F g−1 at 2 A g−1), excellent rate capability (55% capacitance retention from 2 to 2000 mV s−1), and a long cycle life (3% capacitance loss after 1000 cycles). These results demonstrate that this coaxial composite nanostructure is very promising for high performance supercapacitors.

Coaxial NixCo2x(OH)(6x)/TiN Nanotube Arrays as Supercapacitor Electrodes

NixCo2x(OH)6x, as a precursor of intensively studied NiCo2O4, has been directly deposited into self-standing titanium nitride nanotube array (TiN NTA) grid monolithic supports to form a coaxial nanostructured electrode for supercapacitors. With TiN NTA substrates providing a large surface area, fast electron transport, and enhanced structure stability, this NixCo2x(OH)6x/TiN electrode exhibits superior pseudocapacitive performance with a high specific capacitance of 2543 F g(-1) at 5 mV s(-1), remarkable rate performance of 660 F g(-1) even at 500 mV s(-1), and promising cycle performance (about 6.25% capacitance loss for 5000 cycles). Interestingly, the NixCo2x(OH)6x/TiN NTA electrode outperforms the NiCo2O4/TiN NTA electrode, indicating that this self-standing NixCo2x(OH)6x/TiN NTA monolith is a promising candidate for high-performance supercapacitor applications.

Mesoporous Coaxial Titanium Nitride-Vanadium Nitride Fibers of Core–shell Structures for High-Performance Supercapacitors

In this study, titanium nitride-vanadium nitride fibers of core-shell structures were prepared by the coaxial electrospinning, and subsequently annealed in the ammonia for supercapacitor applications. These core-shell (TiN-VN) fibers incorporated mesoporous structure into high electronic conducting transition nitride hybrids, which combined higher specific capacitance of VN and better rate capability of TiN. These hybrids exhibited higher specific capacitance (2 mV s(-1), 247.5 F g(-1)) and better rate capability (50 mV s(-1), 160.8 F g(-1)), which promise a good candidate for high-performance supercapacitors. It was also revealed by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) characterization that the minor capacitance fade originated from the surface oxidation of VN and TiN.

Molybdenum nitride based hybrid cathode for rechargeable lithium-O2 batteries

Molybdenum nitride/nitrogen-doped graphene nanosheets (MoN/NGS) are synthesized and used as an alternative O(2) electrode for Li-O(2) batteries. In comparison with electrocatalysts proposed previously, this hybrid cathode exhibits a high discharge potential (around 3.1 V) and a considerable specific capacity (1490 mA h g(-1), based on carbon + electrocatalyst).

Compatible interface design of CoO-based Li-O 2 battery cathodes with long-cycling stability

Lithium-oxygen batteries with high theoretical energy densities have great potential. Recent studies have focused on different cathode architecture design to address poor cycling performance, while the impact of interface stability on cathode side has been barely reported. In this study, we introduce CoO mesoporous spheres into cathode, where the growth of crystalline discharge products (Li2O2) is directly observed on the CoO surface from aberration-corrected STEM. This CoO based cathode demonstrates more than 300 discharge/charge cycles with excessive lithium anode. Under deep discharge/charge, CoO cathode exhibited superior cycle performance than that of Co3O4 with similar nanostructure. This improved cycle performance can be ascribed to a more favorable adsorption configuration of Li2O2 intermediates (LiO2) on CoO surface, which is demonstrated through DFT calculation. The favorable adsorption of LiO2 plays an important role in the enhanced cycle performance, which reduced the contact of LiO2 to carbon materials and further alleviated the side reactions during charge process. This compatible interface design may provide an effective approach in protecting carbon-based cathodes in metal-oxygen batteries.

Conjugated microporous polymers with excellent electrochemical performance for lithium and sodium storage

Conjugated microporous polymers, which exhibit high specific capacity, superior cycle stability and remarkable rate capability, are explored as high-performance electrode materials for lithium and sodium storage. Their excellent electrochemical performance can be attributed to their conductive frameworks, plentiful redox-active units, high specific surface area and homogeneous microporous structure.

A Carbon- and Binder-Free Nanostructured Cathode for High-Performance Nonaqueous Li-O2 Battery

Operation of the nonaqueous Li–O2 battery critically relies on the reversible oxygen reduction/evolution reactions in the porous cathode. Carbon and polymeric binder, widely used for the construction of Li–O2 cathode, have recently been shown to decompose in the O2 environment and thus cannot sustain the desired battery reactions. Identifying stable cathode materials is thus a major current challenge that has motivated extensive search for noncarbonaceous alternatives. Here, RuOx/titanium nitride nanotube arrays (RuOx/TiN NTA) containing neither carbon nor binder are used as the cathode for nonaqueous Li–O2 batteries. The free standing TiN NTA electrode is more stable than carbon electrode, and possesses enhanced electronic conductivity compared to TiN nanoparticle bound with polytetrafluoroethylene due to a direct contact between TiN and Ti mesh substrate. RuOx is electrodeposited into TiN NTA to form a coaxial nanostructure, which can further promote the oxygen evolution reaction. This optimized monolithic electrode can avoid the side reaction arising from carbon material, which exhibits low overpotential and excellent cycle stability over 300 cycles. These results presented here demonstrate a highly effective carbon‐free cathode and further imply that the structure designing of cathode plays a critical role for improving the electrochemical performance of nonaqueous Li–O2 batteries.

A biocompatible titanium nitride nanorods derived nanostructured electrode for biosensing and bioelectrochemical energy conversion

In this study, a facile method is proposed to fabricate biocompatible TiN nanorod arrays through solvent-thermal synthesis and subsequent nitridation in ammonia atmosphere. The TiN nanorod arrays are potential excellent nanostructured electrodes owing to their good electronic conductivity and large surface area. These nanostructured electrodes not only deliver superior electrocatalytic activity (the limit of detection, LOD is 0.5 μM) and highly selective sensing towards H(2)O(2), but also exhibit excellent biocompatibility with horseradish peroxidase (HRP) in a highly sensitive enzymatic biosensor for H(2)O(2) (the LOD can reach to 0.05 μM). Furthermore, a novel biocatalytic cathode based Li air fuel cell (bio-Li-air fuel cell) is explored based on the combination of TiN nanorod arrays and laccase (LAC) for electrochemical energy conversion. These results demonstrate that TiN nanorod arrays can be served as excellent nanostructured electrodes for multifunctional bioelectrochemical applications.

Cu 2 GeS 3 derived ultrafine nanoparticles as high-performance anode for sodium ion battery

Germanium based sulfides are potentially attractive as anode material for sodium ion batteries but rarely investigated. Herein, we firstly investigated Na+ storage properties of pristine Cu2GeS3 (PCGS) and found an effective strategy to improve its performance by a single lithiation/delithiation cycle obtaining ultrafine nanoparticle copper germanium sulfide (NCGS). The lithiation/delithiation process leads to the formation of a stable Li-containing solid electrolyte interphase film and a significant improvement of sodiation kinetics. Therefore, the NCGS anode delivers favorable capacity retention and better rate capability compared with that of a PCGS whether in the half cell or in the full cell, showing great promise for energy storage application.摘要锗基硫化物作为钠离子电池负极具有潜在的吸引力, 但相关报道甚少. 为此, 我们研究了Cu2GeS3 (PCGS)的储钠性能, 发现通过单次 嵌锂/脱锂循环获得超细纳米微粒铜锗硫(NCGS)是一种改善其储钠性能的有效策略. 嵌锂/脱锂过程能够在材料表面形成一层稳定的含锂 固态电解质相界面膜, 并提高材料的嵌钠动力学. 因此, 与PCGS相比, NCGS在半电池和全电池中都显示出良好的循环性能和倍率性能, 在 能源存储领域具有广阔的应用前景.