Materials Today Communications
·
2021
·
IF 3.383
Daifeng Wu,Rui Li,Tai Sun,Renheng Tang,Fangming Xiao
Mg/MgH 2 as a thermochemical energy storage (TCES) material suffers from a slow hydrogenation-dehydrogenation kinetic and poor reversibility. Addition of metal oxide is an effective way to improve the kinetic properties of Mg/MgH 2 . However, there is little study on the effects of complex oxides . Thus, the catalytic effects of complex metal oxides and its catalytic mechanism were investigated in this paper. Results show that the dehydrogenation peak temperature and apparent activation energy of MgH 2 -Ta 2 O 5 are 320.8 °C and 128.54 kJ/mol. Combined with complex metal oxide, MgH 2 -Ta 2 O 5 -Nd 2 O 3 could further reduce the dehydrogenation peak temperature (307.2 °C) and apparent activation energy (95.33 kJ/mol). MgO and NdH 2.61 are found in the dehydrogenated MgH 2 -Ta 2 O 5 -Nd 2 O 3 , indicating that n-typed oxide Ta 2 O 5 and p-typed oxide Nd 2 O 3 are formed and improved the kinetics properties of MgH 2 . Furthermore, Nd 2 O 3 /Ta 2 O 5 interface is formed and acted as “p-n junction”. When heating, the “p-n junction” is exposed to thermal radiation and produce electrons and holes, and then the kinetics properties of MgH 2 are further enhanced.
研究领域:
材料科学
·
能源化学
·
物理化学
·
无机功能材料
·
热能存储
✓ 已验证
DOI
高影响因子
MethodsX
·
2019
·
IF 0
Chengyuan Liu,Zhiwei Liu,Hongkun Niu,Cong Wang,Zhaowen Wang,Bingliang Gao,Jingjing Liu,Mark Taylor
We provide a method for preparation of binder-free cathode for rechargeable aluminum-ion batteries (AIBs). Ultrasonicated natural graphite (u-NG) flakes in N-methylpyrrolidone (NMP) is drop-casted to a carbon fiber cloth (CFC) to obtain binder-free u-GF@CFC cathode for AIBs. We also provide an in-situ Raman spectral technology and the corresponding in-situ Raman cell to determine the mechanism of intercalation/deintercalation reactions of the chloroaluminate ions at cathode of AIBs. The in-situ Raman spectra are recorded using a Raman spectrometer combined with a potentiostat/galvanostat model electrochemical workstation. • A simple preparation method of a binder-free u-GF@CFC cathode is suggested. • The u-GF@CFC cathode is obtained by drop-casting ultrasonicated graphite flakes on the surface and internal gaps of the carbon fiber cloth. • The method includes the in-situ Raman spectral technology and the corresponding in-situ Raman cell.
研究领域:
电化学
·
能源材料
·
纳米材料
·
电池技术
·
原位表征
✓ 已验证
DOI
RSC Advances
·
2015
·Vol. 5
·期 82
·67247-67257
·
IF 3.84
Huilong Guo,Yinwen Li,Jian Zheng,Jianqun Gan,Liyan Liang,Kun Wu,Mangeng Lu
In this work, a novel epoxy monomer denoted as 3,5′-di-t-butyl-5,3′-dimethyl biphenyl diglycidyl ether (t-BuMBPDGE) was synthesized and applied into in situ composites with 3,3′,5,5′-tetramethyl-4,4′-biphenyl diglycidyl ether (TMBPDGE), accompanied with curing agent aromatic amines. The liquid crystalline phase structure and the crosslink density of substituted biphenyl epoxies were determined by polarized optical microscopy, wide angle X-ray diffraction measurements and dynamic storage moduli data. The samples showed good mechanical properties and could recover quickly from a second state to their initial states with a shape fixity ratio higher than 98% and shape recovery ratio higher than 99%, owing to the oriented structure and increased crosslink network density caused by the orientation of biphenyl mesogenic. The high glass transition temperatures ranging from 160 to 178 °C and good water resistance could contribute to a stable fixed shape. The water resistance is analyzed by contact angles test. The samples exhibited contact angles of 92–98 degrees, which indicated that the water resistance was apparently better than that of conventional epoxy systems.
研究领域:
高分子材料
·
功能材料
·
化学工程
·
材料科学
·
纳米复合材料
·
智能材料
✓ 已验证
DOI
高影响因子
Nano Energy
·
2017
·
IF 12.343
Haoxiang Yu,Hua Lan,Lei Yan,Shangshu Qian,Xing Cheng,Haojie Zhu,Nengbing Long,Miao Shui,Jie Shu
Hollow microstructure always exhibits some special properties in the field of electrochemistry . Here, this study reports the rational design and preparation of TiNb 2 O 7 nanofibers with one dimensional hollow structure via co-electrospinning. The as-electrospun TiNb 2 O 7 hollow nanofibers show high intercalation potential, low charge-charge resistance and fast electrochemical kinetics . The electrochemical results exhibit that the TiNb 2 O 7 hollow nanofibers deliver a reversible capacity of 210.1 mAh g −1 after 150 cycles at a current rate of 0.4 C, and 158.4 mAh g −1 after 900 cycles even at a current rate of 10 C with an outstanding capacity retention of 80.6%. The excellent electrochemical performance of nanofibers can be related to the unique morphology of hollow structure. Furthermore, the lithium ions storage mechanism of TiNb 2 O 7 hollow nanofibers is also systematically analyzed, which is related to one two-phase coexistence and two solid-solution processes during the whole charge-discharge cycle. In addition, it is also demonstrated by in situ and ex situ observations that TiNb 2 O 7 hollow nanofibers have outstanding structural stability and electrochemical reversibility. Therefore, the TiNb 2 O 7 hollow nanofibers can be applied as an alternative promising electrode material for the next rechargeable lithium ions batteries .
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Chenyu Lin,Tianqi Yang,Haiyuan Zhang,Donghuang Wang,Wenkui Zhang,Yao Wang,Yang Xia,Hui Huang,Xinhui Xia,Yongping Gan,Xinping He,Xinyong Tao,Jun Zhang
Solid-state lithium metal batteries with high energy density and safety have gained increasing attention due to their potential applications. However, the practical use of solid electrolytes is hindered by several challenges. These include poor compatibility at the electrode–electrolyte interface, low ionic conductivity at room temperature, and fast capacity degradation. To address these issues, here we propose ternary strategies by in-situ cross-linked plastic crystal electrolyte (in-situ PCE) based on succinonitrile (SN). Through the in-situ polymerization of SN with polyacrylonitrile/poly(vinylidene difluoride) (PAN/PVDF) nanofibers separator, excellent mechanical strength and compatibility at the electrode–electrolyte interface are achieved. The cross-linked structure of thermally polymerized ethoxylated trimethylolpropane triacrylate (ETPTA) immobilizes the SN molecule, preventing its contact with the lithium metal and inhibiting irreversible side reactions. Additionally, a LiF-rich passivation layer is employed to further protect the SN at the electrolyte-lithium metal interface. The dual protection from ETPTA and LiF offers excellent stability to lithium. Hence, the in-situ PCE exhibits high ionic conductivity (0.79 mS cm −1 at 30 °C) and wide electrochemical window (4.56 V, vs Li + /Li). The cells exhibit excellent cycling stability and high-rate performance. LiFePO 4 //Li cells retain 96.6 % capacity after 1000 cycles at 10C rate. This study provides valuable insights into the development of high-performance solid-state electrolytes.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
固态离子学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 47
·期 7
·9083-9089
·
IF 3.83
Hongli Liu,Lantian Zhang,Jing Li,Hongyan Li,Guoqing An,Yajing Li,Zhong Chen
SiBCN ceramic aerogels have excellent properties such as ultra-high temperature stability, low density and high thermal insulation . The aerogels have better potential applications in aerospace and other fields. However, similar to inorganic aerogels , the low mechanical strength of SiBCN ceramic aerogels are the main limitation of its application. Based on the principle of inorganic double network enhancement, the first network was constructed by PVA and HNTs , and HNTs/SiBCN dual network aerogels were constructed by SiBCN ceramic aerogels as the second network. The structure and mechanical properties were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), specific surface area analyzer and pressure tester. Compared with SiBCN ceramic aerogels, 6 wt% HNTs-SiBCN ceramic hybrid aerogels have better microscopic properties (maintaining basic porous network structure and structural stability) and mechanical properties.The continuous HNTs first network can effectively transfer the stress load and enhance the strength of SiBCN ceramic aerogels.
研究领域:
材料科学
·
无机非金属材料
·
纳米复合材料
·
航空航天材料
·
高分子复合材料
✓ 已验证
DOI
高影响因子
Small
·
2019
·Vol. 15
·期 50
·1904854
·
IF 10.856
Junchao Zheng,Zhuo Yang,Alvin Dai,Linbo Tang,Hanxin Wei,Yunjiao Li,Zhenjiang He,Jun Lu
Although the high energy density and environmental benignancy of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) holds promise for use as cathode material in Li-ion batteries, present low rate capabilities, and fast capacity fade limit its broad commercial applications. Here, it is reported that surface modification of NCA cathode ( R-3m ) with 5 nm-thick nanopillar layers and Fm-3m structures significantly improves electrode structure, morphology, and electrochemical performance. The formation of nanopillar layers increases cycling and working voltage stability of NCA by shielding the host material from hydrofluoric acid and improves structural stability with the electrolyte. The modified NCA cathode exhibits an enhanced 89% capacity retention at a rate of 1 C over that of pristine NCA (75.2%) after 150 cycles and effectively suppresses working voltage fade (a drop of 0.025 V after 300 cycles) during repeated charge–discharge cycles. In addition, the diffusion barrier of Li ions in NCA crystals at 0.80 V is noticeably smaller than that of Li ions in pristine NCA (0.87 eV). These findings demonstrate that this unique surface structure design considerably enhances cycle and rate performance of NCA, which has potential applications in other Ni-rich layered cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
锂离子电池
·
纳米材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Zhanjian Liu,Huaiyuan Wang,Xiguang Zhang,Chijia Wang,Chongjiang Lv,Yanji Zhu
In this work, a novel bistratal gas layer structure has been used to enhance the long-term durability of a superhydrophobic surface. The design of this bistratal structure takes inspiration from the wings of the insect Notonecta glauca and a spider web. It is comprised of an underlying semi-interpenetrating array structure and a superficial microfiber network structure. On modification with 1 H ,1 H ,2 H ,2 H -perfluorooctyltriethoxysilane (POTS), the prepared surface demonstrates an excellent superhydrophobicity with a water contact angle (WCA) of 168 ± 1.4° and a sliding angle (SA) of 4 ± 0.5°. The underlying semi-interpenetrating array structure can capture more gas to form a stable underlying gas layer, which enhances its anti-static pressure capability. When the superhydrophobic surface was impacted by a high-pressure water column (250 kPa), the superficial micro fibers network structure acted as a buffer layer to disperse the impact force that spread over the network. The prepared surface with bistratal gas layer structure was thus able to high speed water jetting (22.4 m s −1 ), which is three times the speed of the heavy rain (7–9 m s −1 ) and four times that reported for polysiloxane/multiwalled carbon nanotubes (POS/MWCNTs) surfaces (5.4 m s −1 ). Furthermore, the superhydrophobic surface designed by this method was also shown to possess self-healing and hot-water-repellent (100 °C) capability. These features demonstrate the practical potential of superhydrophobic surfaces with a bistratal gas layer structure.
研究领域:
材料科学
·
表面工程
·
纳米技术
·
仿生学
·
物理化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 65
·37417-37423
·
IF 2.936
Jihui Li,Kang Sun,Changyu Leng,Jianchun Jiang
Reasonable structure design and component selection are crucial to electrochemical performance of supercapacitor electrode materials. Sodium alginate (SA), with a novel structure which can immobilize multivalent metal cations, was used to coordinate with Fe3+ to fabricate a carbon and Fe3O4 composite by an easy sol–gel method. Due to the chelation effect between SA and Fe3+, the carbon composite was constructed into a two-dimensional sheet-like structure, and the Fe3O4 particles were nanosize and homogenously distributed on the surface of the carbon nanosheet. As an electrode material for supercapacitors, the composite electrode showed a high specific capacitance of 550 F g−1 at 1 A g−1 in the potential range from −1.1 to 0 V, and excellent cycling stability of 89% retention after 2000 cycles. The enhanced electrochemical performance could be attributed to the abundant exposed active sites, producing high pseudocapacitance, to the two-dimensional nanosheet structure, facilitating electrolyte transport and to the strong attachment strength, improving cycle life. This environmentally-friendly design can provide an alternative to existing methods, resulting in the development of a two-dimensional carbon/metal oxide composite for energy storage devices.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2016
·
IF 3.997
XinRong Liu,Ming Zhang,TingTing Yang,LiNa Wang,Han Zhu,ShunLi Wang,MingLiang Du
Carbon nanofibers served as nanoreactors for the design and construction of PtCo alloy carbon core-shell nanostructures with nitrogen doping (PtCo/NCNF) through a combination of electrospinning and nitrogen doping treatments. The PtCo/NCNF hybrid consists of PtCo alloy nanoparticles surrounded by a few of N-doped carbon layers , demonstrating a typical core-shell structures. The PtCo/NCNF hybrid can both served as electrode materials for electrocatalytic water splitting including hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For the HER performance, the PtCo/NCNF exhibits very small onset potential of 20 mV, an overpotential of 50 mV at a j (vs RHE) = 10 mA cm − 2 and Tafel slope of 30 mV dec − 1 . The PtCo/NCNF hybrid also exhibits high OER activity with an onset potential of 310 mV, an overpotential of 400 mV at a j of 10 mA cm − 2 and a small Tafel slope of 76 mV dec − 1 . The high catalytic activities of PtCo alloy for HER and OER originate from the 3D hierarchical structures, well-dispersed PtCo alloy, high conductivity of NCNF, protection from the carbon-encapsulated structure, and the introduction of nitrogen.
研究领域:
材料科学
·
纳米技术
·
电化学
·
能源化学
·
催化化学
·
功能材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 68
·38850-38859
·
IF 2.936
Yaozu Guo,Dong Zhao,Junhua You,Wenli Pei,Yingdong Qu,Xiaoyang Wang,Qingyu Meng
Nd2Fe14B nanoparticles were successfully prepared by using a low-energy chemical method. The microscopic characteristics and formation mechanisms of the phases were investigated at each stage during the preparation of Nd-Fe-B nanoparticles. The Nd-Fe-B intermediates, Nd-Fe-B oxides and reduced Nd-Fe-B nanoparticles were detected and analyzed by using TEM, STEM, XRD, SEM, VSM and Rietveld calculations. The results showed that the intermediate of Nd-Fe-B consisted of Fe3O4 and Nd and Fe elements surrounded by nitrile organic compounds. The Nd-Fe-B oxide was composed of NdFeO3 (48.619 wt%), NdBO3 (31.480 wt%) and α-Fe (19.901 wt%), which was formed by the reaction among Nd, Fe3O4 and B2O3. NdFeO3 and NdBO3 exhibited a perovskite-like lamellar structure, and the grain size was smaller than that of α-Fe. Nd-Fe-B particles were mainly composed of Nd2Fe14B and α-Fe phases. The small particles of NdFeO3 and NdBO3 and the interstitial position between oxide particles and α-Fe were more favorable for the formation of Nd2Fe14B particles. At the same time, the surface of α-Fe particles can also diffuse to form Nd2Fe14B nanoparticles. The coercivity of Nd-Fe-B particles was 5.79 kOe and the saturation magnetization was 63.135 emu g−1.
研究领域:
材料科学
·
纳米材料
·
磁性材料
·
无机非金属材料
·
固体化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Shunhang Wei,Rong Wu,Xiaoxiang Xu,Jikang Jian,Haixia Wang,Yanfei Sun
Black core-shelled anatase titania were successfully prepared using a simple one-step synthetic method by calcining colloid titania precursor in N 2 flow under atmospheric pressure. The physicochemical properties of the as-prepared samples were characterized by various techniques such as X-ray diffraction, high resolution transmission electron microcopy, etc. The samples demonstrate a unique core-shelled structure and electron paramagnetic resonance spectra reveal the presence of high concentration of Ti 3+ and oxygen vacancies at the surface, which accounts for their black appearance. A possible mechanism for the formation of such core–shell structure is proposed based on the results (X-ray photoelectron spectra, etc) of products prepared under different ration between urea and hydrochloric acid. Ethanol absolute is found to have critical effect in preventing phase transition of titania (from anatase to rutile) upon elevated temperatures. The black appearance of the sample powder (high visible light absorption) as well as slow electron/hole recombination rate after introducing oxygen vacancies/N species signify the core-shelled anatase titania as an efficient visible light active photocatalyst.
研究领域:
材料科学
·
光催化
·
纳米材料
·
表面化学
·
无机合成
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）