APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Limin Chang,Zheng Yi,Zhaomin Wang,Limin Wang,Yong Cheng
SnO 2 is regarded to be promising for both Li-ion and Na-ion batteries. Thus, it is imperative to fabricate SnO 2 -based anode with improved lithiation reaction kinetics using simple but effective method. Herein, we develop a one-pot hydrothermal route to fabricate two-dimensional SnO 2 nanosheets and the graphene supported SnO 2 nanosheet composite with decreased SnO 2 nanosheet of about 5–10 nm. The ultrathin nanosheet structure anchored on graphene supporting can effectively accelerate the conversion/alloying reaction. Electrochemical researches demonstrate that the reaction kinetics of the lithiation/delithiation reaction can be significantly enhanced by the graphene supported SnO 2 nanosheets. As a result, a capacity of 817.2 mAh g −1 after 100 cycles in the potential window of 0.01 to 3 V are achieved at 500 mA g −1 . The full cell performance and the sodium storage performance are both demonstrated to be good. These promising results suggest that such strategy to fabricate two-dimensional SnO 2 -based anode is of great interest for next-generation Li-ion and Na-ion batteries.
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高影响因子
TRIBOLOGY LETTERS
·
2019
·Vol. 67
·期 3
·1-11
·
IF 2.235
Zeng M. Q.,Hu R. Z.,Song K. Q.,Dai L. Y.,Lu Z. C.
An in situ displacement reaction was used to prepare an Al–12 wt% Sn nanocomposite alloy from mechanically alloyed Al–SnO 2 –MgH 2 . The nanoscaled Sn phase was mostly 30–50 nm in size and was distributed uniformly in the Al matrix. The wear properties of the Al–SnO 2 –MgH 2 composite were enhanced significantly compared to those of an Al–Sn–MgH 2 composite. These improvements stemmed from the high-strength and nanoconfined Sn-phase lubrication, which moved the peak stress far below the surface, released strain localization at the uppermost sliding surface layer, and suppressed cracking and surface roughening. The dispersion strengthening of the Al–SnO 2 –MgH 2 composite favored the maintenance of a stable tribolayer, which resulted in an integrated worn surface and an excellent wear performance.
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高影响因子
ACS Applied Energy Materials
·
2019
·
IF 0
Tiancun Liu,Jiulin Hu,Chilin Li,Yong Wang
Li metal anode is deemed the most promising candidate anode for high-energy battery systems such as Li-sulfur and Li-fluoride batteries. However, some severe challenges, for example, facile formation and growth of Li dendrites, large volume evolution of hostless Li ,and low Coulombic efficiency of Li plating/stripping, still hinder the commercialization of Li-metal batteries (LMBs). Herein, a free-standing and highly flexible 3D current collector made of carbon nanofibers (CNFs) conformally coated by continuous Sn layer is synthesized by electrospinning method. Sn layer enables a lithiophilic and alloyable carbon skeleton surface and provides uniform and continuous Li nucleation sites, leading to unusual conformal Li plating behavior and effective inhibition of Li dendrites. The spatial confinement of Li plating mitigates the volume expansion and network distortion of CNFs. The electric contact reinforced by Sn interlayer achieves highly reversible Li stripping for more than 850 h for CNF-Sn@Li symmetric cell. The small nucleation overpotential (28 mV) and potential polarization (14 mV for symmetric cell) benefit from the low energy barrier of Li–Sn alloying and following Li nucleation on Li–Sn layer. For CNF-Sn@Li-LiFePO4 full cell, the capacity retention ratio is as high as 92.2% after 150 cycles at 0. 5C and the reversible capacities are maintained at 134.3 and 106.7 mAh g–1 at 2C and 5C respectively. The design of 3D lithiophilic current collector instead of planar Cu is a potential solution to highly safe LMBs.
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Materials
·
2019
·Vol. 12
·期 9
·1501
·
IF 2.972
Hongdan Zhang,Ludan Zhu,Jun Cheng,Long Chen,Chuanqi Liu,Shuanglong Yuan
In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [SnSn4+2++VCl] defect complex in the crystal is formed by Sn2+substituting Sn4+. The number of defects formed by Sn2+in the crystal decreases with Ce3+content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [SnSn4+2++VCl] decreased. When Ce3+is incorporated into the crystals, the defects of [Ce3+Sn4++VCl] and [SnSn4+2++VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6double perovskite crystals.Keywords:lead-free perovskite;Cs2SnCl6;doping;photoluminescence
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PubMed
高影响因子
Aerospace
·
2019
·Vol. 6
·期 4
·47
·
IF 0
Suhang Chen,Yue Tang,Wei Zhang,Ruiqi Shen,Hongsheng Yu,Yinghua Ye,Luigi T. DeLuca
The low regression rates for hydroxyl-terminated polybutadiene (HTPB)-based solid fuels and poor mechanical properties for the alternative paraffin-based liquefying fuels make today hybrid rocket engines far from the outstanding accomplishments of solid motors and liquid engines. In this paper, a survey is conducted of several innovative methods under test to improve solid fuel properties, which include self-disintegration fuel structure (SDFS)/paraffin fuels, paraffin fuels with better mechanical properties, high thermal conductivity fuels and porous layer combustion fuels. In particular, concerning HTPB, new results about diverse insert and low-energy polymer particles enhancing the combustion properties of HTPB are presented. Compared to pure HTPB, regression rate can be increased up to 21% by adding particles of polymers such as 5% polyethylene or 10% oleamide. Concerning paraffin, new results about self-disintegrating composite fuels incorporating Magnesium particles (MgP) point out that 15% 1 μm- or 100 μm-MgP formulations increase regression rates by 163.2% or 82.1% respectively, at 335 kg/m2·s oxygen flux, compared to pure paraffin. Overall, composite solid fuels featuring self-disintegration structure appear the most promising innovative technique, since they allow separating the matrix regression from the combustion of the filler grains. Yet, the investigated methods are at their initial stage. Substantial work of refinement in this paper is for producing solid fuels to fulfill the needs of hybrid rocket propulsion.Keywords:hybrid;regression rate;self-disintegration;HTPB;paraffin;low-energy polymer;magnesium
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ADVANCED FUNCTIONAL MATERIALS
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2019
·Vol. 29
·期 47
·1807696
·
IF 15.621
Hongyu Xu,Yuanzhi Jiang,Tingwei He,Saisai Li,Huanhua Wang,Yu Chen,Mingjian Yuan,Jun Chen
Tin-based perovskites have exhibited high potential for efficient photovoltaics application due to their outstanding optoelectrical properties. However, the extremely undesired instabilities significantly hinders their development and further commercialization process. A novel tin-based reduced-dimensional (quasi-2D) perovskites is reported here by using 5-ammoniumvaleric acid (5-AVA + ) as the organic spacer. It is demonstrated that by introducing appropriate amount of ammonium chloride (NH 4 Cl) as additive, highly vertically oriented tin-based quasi-2D perovskite films are obtained, which is proved through the grazing incidence wide-angle X-ray scattering characterization. In particular, this approach is confirmed to be a universal method to deliver highly vertically oriented tin-based quasi-2D perovskites with various spacers. The highly ordered vertically oriented perovskite films significantly improve the charge collection efficiency between two electrodes. With the optimized NH 4 Cl concentration, the solar cells employing quasi-2D perovskite, AVA 2 FA n −1 Sn n I 3 n +1 (< n > = 5), as light absorbers deliver a power conversion efficiency up to 8.71%. The work paves the way for further employing highly vertically oriented tin-based quasi-2D perovskite films for highly efficient and stable photovoltaics.
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高影响因子
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN
·
2018
·Vol. 126
·期 11
·900-905
·
IF 0.887
Shuai LU,Xiaoqiang LI,Youfu ZHOU,Wentao XU,Junrong LING,Wei PAN
TiB2/Ti2AlN composites with different proportions were successfully fabricated through solid state reaction of Ti/Al/AlN/BN powders and subsequent hot pressing sintering. The reaction mechanism, microstructures and mechanical properties of the composites were investigated. The Vickers hardness of the samples ascended with increases in the TiB2 content and reached the highest value of 11.32 ± 0.12 GPa at a TiB2/Ti2AlN mole ratio of 1:2 (M2T1). TiB2/Ti2AlN composites with a mole ratio of 1:3 (M3T1) and 1:4 (M4T1) exhibited the maximum flexural strength of 497 ± 15 MPa and the highest fracture toughness of 9.52 ± 0.14 MPa·m1/2, respectively, which are 1.3 times and 1.8 times that of pure Ti2AlN (MT0) ceramic.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Zhaomin Wang,Lu Yu,Limin Chang,Limin Wang,Yong Cheng
Owing to its high capacity of 994 mAh g −1 , low cost, and environmental friendliness , tin (Sn) is considered as an advanced anode material for high-capacity lithium-ion batteries (LIBs). Here, a facile strategy to fabricate core-shell structured Sn@NC composites with one-step and large-scale production is introduced in a liquid-phase reaction under room temperature . When used as anode materials for LIBs, the optimal Sn@NC composite delivers a high reversible discharge capacity of 761.2 and 476 mAh g −1 at a current density of 200 and 1000 mA g −1 after 200 cycles, respectively. A high capacity of 328.3 mAh g −1 can also be obtained even at a current density of 2000 mA g −1 . The excellent cycling stability and rate performance of the composite can be ascribed to the synergistic effect of the nanometer size of Sn powder and porous structure of the carbon shell, both of which can effectively reduce the absolute volume change of electrode during the repeated charge-discharge cycles, and thus lead to excellent electrochemical performances at both rate capability and cycling life.
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高影响因子
Solar RRL
·
2019
·Vol. 3
·期 10
·1900131
·
IF 0
Afei Zhang,Zhengji Zhou,Wenhui Zhou,Dongxing Kou,Yuena Meng,Yafang Qi,Shengjie Yuan,Sixin Wu
A back contact interface in a kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) photovoltaic device plays an important role in fabricating high quality semiconducting photoactive layers and improving carrier extraction efficiency. However, uncontrolled decomposition reactions between the CZTSSe absorber layer and Mo electrode result in high series resistance and recombination at the back interface. The insertion of high work function MoO 3 as an interfacial layer is considered as a promising way to engineer the back contact. This highlights the importance of elucidating the chemistry and dynamics of MoO 3 at the Mo/kesterite interface in the CZTSSe annealing process. Herein, A detailed investigation of the elemental diffusion and chemistry of the back contact with the MoO 3 intermediate layer during selenization is carried out. The results demonstrate that the presence of the MoO 3 interfacial layer largely suppresses the chemical reaction between Mo and CZTSSe in the annealing process, inducing high quality CZTSSe absorbing films with fewer voids and reducing the thickness of MoSe 2 from 209 to 84 nm when the optimized thickness of MoO 3 is 10 nm. This finally leads to the increase in device efficiency from 9.02% to 10.92%, and the best performance where an efficiency of 11.37% is achieved.
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Nano Energy
·
2019
·
IF 15.548
Bangsen Ouyang,Cheng Chang,Li-Dong Zhao,Zhong Lin Wang,Ya Yang
Self-powered photodetectors (PDs) have attracted great attentions due to energy shortage and the upcoming internet of things . However, the bottleneck of traditional methods to enhance the output performances of self-powered PDs are largely limited. Here, we report a dramatic coupling enhancement ("1 + 1>2") of the output signals in a bromine doped tin selenide (SnSe:Br) single crystal due to the thermo-photoelectric coupled effect for enhanced self-powered PDs. As compared with that of individually illuminating the device, both the output current and voltage signals of the PD can be enhanced by 38.1% and 81.9% under the simultaneous illumination at the top surface and cooling at the bottom surface, respectively. The coupling enhancement mechanism is associated with the same polarities of photoelectric and thermoelectric signals during the cooling process, where the photo-generated electrons can be accelerated by the driving force of the thermoelectric field under the cooling condition. This work offers a novel approach to enhance the output performances of self-powered PDs.
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高影响因子
Journal of the American Chemical Society
·
2019
·
IF 14.695
Xu-Dong Wang,Yu-Hua Huang,Jin-Feng Liao,Yong Jiang,Lei Zhou,Xiao-Yan Zhang,Hong-Yan Chen,Dai-Bin Kuang
Heterojunction engineering has played an indispensable role in the exploitation of innovative artificial materials with exceptional properties and has consequently triggered a new revolution in achieving high-performance optoelectronic devices. Herein, an intriguing halide perovskite (PVK) and metal dichalcogenide (MD) heterojunction, i.e., a lead-free Cs2SnI6 perovskite nanocrystal/SnS2 nanosheet hybrid, was fabricated in situ for the first time. Comprehensive investigations with experimental characterizations and theoretical calculations demonstrate that cosharing of the Sn atom enables intimate contact in the Cs2SnI6/SnS2 hybrid together with a type II band alignment structure. Additionally, ultrafast carrier separation between SnS2 and Cs2SnI6 has been observed in the Cs2SnI6/SnS2 hybrid by transient absorption measurements, which efficiently prolongs the lifetime of the photogenerated electrons in SnS2 (from 1290 to 3080 ps). The resultant spatial charge separation in the Cs2SnI6/SnS2 hybrid evidenced by Kelvin probe force microscopy (KPFM) significantly boosts the photocatalytic activity toward CO2 reduction and the photoelectrochemical performance, with 5.4-fold and 10.6-fold enhancements compared with unadorned SnS2. This work provides a facile and effective method for the in situ preparation of PVK-MD heterojunctions, which may significantly stimulate the synthesis of various perovskite-based hybrid materials and their further optoelectronic applications.
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PubMed
高影响因子
Nano Energy
·
2018
·
IF 13.12
Zhiwei Zhou,Junyou Yang,Qinghui Jiang,Xuesong Lin,Jiwu Xin,Abdul Basit,Jingdi Hou,Bingyang Sun
In this work, the co-doping in both the anion and cation sites of SnTe has been implemented by addition of BiCl 3 and the effect of co-doping on thermoelectric performance of SnTe-based materials has been studied detailedly. Benefitting from the sharp reduction of carrier concentration and the increase of density of states due to the electron donor contribution of Bi and Cl, the electrical transport properties have been improved greatly; moreover, the hierarchical architectures such as the point defects , dislocations, nano-particles and phase/grain boundaries act as multiscale phonon scattering centers and effectively suppress the transport of phonons in wide frequency range, thus reduced the thermal conductivity dramatically. Due to the synergistic regulation of cation-anion co-doping, a maximum ZT of ~1.27 at 873 K has been obtained in the sample of SnTe doping with 4% BiCl 3 , which enhances by 182% in comparison with the pristine sample.
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