CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jingsheng Xu,Zhiyuan Wang,Runguo Zheng,Hongyu Sun,Yanguo Liu,Junhua You
Ni-rich cathodes especially with Ni content over 90 % are promising next-generation cathode materials for advanced high energy lithium − ion batteries. However, in comparison with Ni ≤ 80 % Ni-rich cathodes, these ultrahigh Ni-rich materials face more severe challenges in terms of harmful H2 − H3 phase transformations and structural degradation during cycling. Herein, we present a robust surface structure composted of defect-rich disordered structures and LiF/Li 2 SiO 3 coating for stabilizing the ultrahigh Ni-rich cathode LiNi 0.96 Co 0.03 Mn 0.01 O 2 (NCM96) by modification with (NH 4 ) 2 SiF 6 . The surface disordered structures including Li/TM mixing, spinel, and rock salt structure play a crucial role in inhibiting the irreversible H2-H3 phase transition and reducing lattice volume changes by lattice coherence effect. Moreover, the disordered surface in collaboration with the co-coating restrains the rapid growth of surface rock salt phase into the bulk, enhancing structural stability. The modified sample NSF-0.5 delivers a capacity of 238 mAh/g at 0.1C and maintains a capacity retention of 88.5 % at 0.5C after 100 cycles in half cell as well as 82.3 % at 1C after 300 cycles in full cell, significantly superior to the NCM96. The findings provide a simple and cost-effective surface modification strategy to enhance the structural stability and electrochemical performance of ultrahigh nickel cathodes for high-energy density LIBs.
研究领域:
材料科学
·
电化学
·
能源存储
·
锂离子电池
·
固态化学
·
表面工程
·
电池材料
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2016
·Vol. 28
·期 1
·49-54
·
IF 1.947
Qi-Feng Li,Chao Wang,Xiao-Zheng Lan
Latent heat storage performance of a layered perovskite-type compound, 1-C 14 H 29 NH 3 ) 2 ZnCl 4 (C 14 Zn), embedded in a series of silica gel (SG) with pore sizes of d = 15–200 nm is investigated using differential scanning calorimetry (DSC), and powder X-ray diffractions (XRD). C 14 Zn in the nanopores of silica gel shows size-dependent phase transition temperature, enthalpy change and supercooling. They have a stable transition temperature and heat capacity at each size in a short-term thermal cycling. Similar X-ray diffraction patterns are observed for the nano-sized and the bulk C 14 Zn. The encapsulation of a phase change material in nanopores is a new way of tuning its thermal energy storage properties for a wider range of temperature regulation.
研究领域:
材料科学
·
热力学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2011
·Vol. 110
·期 3
·1437-1442
·
IF 1.752
Lan X. Z.,Pei H. R.,Yan X.,Liu W. B.
Phase behavior of dodecane–tetradecane ( n -C 12 H 26 –C 14 H 30 , n -C 12 –C 14 ) binary system in bulk and confined in SBA-15 (pore diameters 8 nm; 15.9 nm) has been investigated by differential scanning calorimetry and transmission electron microscopy. The bulk system possesses some special phases relating to the rotator phase in normal alkanes. Dodecane–tetradecane mixtures confined in SBA-15 (8 nm) are a system miscible both in solid and liquid states with a phase diagram of a smooth curve. Dodecane–tetradecane system confined in SBA-15 (15.9 nm) exhibits not only solid–liquid (s–l) in all compositions but solid–solid transition in mole fractions of tetradecane 0.1–0.6, which forms a phase diagram of “loop line” shape. Melting temperatures of n -C 12 –C 14 /SBA-15 (8 nm) are lower than those of n -C 12 –C 14 /SBA-15 (15.9 nm) in all mole fractions. The evolution of the phase diagram of n -C 12 –C 14 confined in 8 nm, 15.9 nm pore sizes of SBA-15 and in bulk, respectively, shows a dramatic effect of confinement on phase behavior of normal alkane mixtures. The s–l phase boundary lines of n -C 12 –C 14 /SBA-15 (8, 15.9 nm) are fitted as \( T_{\text{m,r}}^{x} \) being [ \( xT_{{\text{m} ,r}}^{A} + \left( {1 - x} \right)T_{\text{m,r}}^{B} - D \) ], where D is a polynomial ∑ a
i
x
i , i = 1, 2,···, n ( A = C 14 , B = C 12 ).
研究领域:
物理化学
·
材料科学
·
纳米限域效应
·
热分析
·
软物质物理
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2018
·
IF 4.374
Xiuli Wang,Xiaomin Cheng,Yuanyuan Li,Ge Li,Jun Xu
A self-assembly method is introduced to prepare composite phase change materials (PCMs) consisting of 1-octadecanol (OD) and graphene. The shape stability and thermal properties of 1-octadecanol/graphene composite PCMs with three-dimensional network structure are investigated. Graphene is dispersed evenly in OD matrix and the three-dimensional network structure is getting tighter with increasing ratio of graphene. OD is completely encapsulated at relatively low amount of graphene about 1.5 wt%. XRD and Raman results show that the combination between OD and graphene is physical adsorption. The 1-octadecanol/graphene (OG) composite phase change materials possess excellent shape stability, which can prevent the leakage of molten OD during phase transition. In addition, around 99.3% phase change enthalpy of pure OD is maintained by connected network structure of graphene while the melting and solidifying temperature merely have small fluctuations. The thermal conductivity of composite phase change material with 1.5 wt% graphene increases to 0.358 W/(m K), which is 1.5 times higher than that of pure OD. Furthermore, the porous network of graphene can delay the evaporation and thermal decomposition point of the composite phase change materials, thus extending the operating temperature of OD efficiently. This work provides a promising way to encapsulate low-temperature organic phase change materials with little carbon additives, and enhance the thermophysical properties of base materials simultaneously.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2016
·Vol. 127
·期 3
·1889-1895
·
IF 1.781
Yuan Kangkang,Gan Xinzhu,Wang Xinqiang,Zhu Luyi,Zhang Guanghui,Xu Dong
The present study fully reports the decomposition of polyacetylacetonatozirconium (PAZ) in air with thermogravimetry–differential scanning calorimetry and Fourier transform infrared spectroscopy. The influence of water vapor on the decomposition of PAZ was characterized with the Fourier transform infrared spectroscopy. Crystallization and phase transformation of PAZ were studied by X-ray diffraction and Raman spectroscopy. The experimental results show that water vapor promotes the decomposition of PAZ and crystallization of zirconia compared with air. Furthermore, the effect of different amount of stabilizer Y(NO 3 ) 3 ·6H 2 O on the pyrolysis and phase stabilization of PAZ shows that NO 3
− was beneficial to the oxidation of organic components and the formation of Y 2 O 3 could stabilize tetragonal zirconia and hinder grain growth.
研究领域:
材料化学
·
无机化学
·
纳米材料
·
热分析
·
光谱学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 21
·30039-30042
·
IF 4.527
Leihao Feng,Qiwei Hu,Li Lei,Lei Qi,Leilei Zhang,Meifang Pu,Zili kou,Fang Peng,Duanwei He,Yohei Kojima,Hiroaki Ohfuji,Tetsuo Irifune
High-hardness TaN compacts with a diameter and height of 6 mm were synthesized through the phase transformation of CoSn-type into WC-type TaN under experimental conditions of high temperature and high pressure . The Vickers hardness of WC-type TaN compacts obtained at the pressure of 5 GPa and the temperature of 1873 K is found to be ~21.5 ± 1.5 GPa with a load of 3 Kg, which is comparable to that of the pure tungsten carbide compact (~20 GPa) and higher than those of ultrahigh temperature ceramics ZrB 2 and HfB 2 under the same load. The high hardness of WC-type TaN compacts presented in this work is attributed to the deviatoric strain and well-bonded nanograins . The synthesized WC-type TaN compacts also possess a high oxidation temperature (1072 K). These results suggest that the WC-type TaN with high hardness and high thermal stability holds great promise for industrial applications.
研究领域:
材料科学
·
无机非金属材料
·
超硬材料
·
高温材料
·
固态化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 19
·26869-26876
·
IF 4.527
Shao-Min Lin,Ya-Ling Yu,Ming-Feng Zhong,Huan Yang,Chen-Yang Zhang,Zhi-Jie Zhang,Wei Xu,Jiong-Yan Xie,Yu-Chun Qiu
Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al 2 O 3 ), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al 2 O 3 was activated by oxalic acid . XRD , 27 Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al 2 O 3 decreased to 1029 °C for oxalic acid activated γ-Al 2 O 3 , and the α-fraction was 100% for activated γ-Al 2 O 3 at 1300 °C. After oxalic acid activation , the diffraction peak intensity of γ-Al 2 O 3 decreased significantly; the results of 27 Al-MAS-NMR suggested that octahedral [AlO 6 ] in γ-Al 2 O 3 was easier than tetrahedral [AlO 4 ] to be attacked by oxalic acid , and the formation of pentavalent [AlO 5 ] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al 2 O 3 . The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al 2 O 3 and extracted Al as three complexes of [Al(C 2 O 4 )] + , [Al(C 2 O 4 ) 2 ] - and [Al(C 2 O 4 ) 3 ] 3- . Oxalic acid activated γ - Al 2 O 3 with a lower phase transformation temperature has broad application prospects in the alumina industry.
研究领域:
材料化学
·
无机化学
·
固态化学
·
工业催化
·
陶瓷材料
✓ 已验证
DOI
高影响因子
Results in Physics
·
2022
·
IF 4.565
Yige Du,Qilong Gao,Andrea Sanson,Hengli Xie,Yangming Hu,Gaojie Zeng,Juan Guo,Xiao Ren,Erjun Liang
Negative thermal expansion (NTE) is an intriguing physical phenomenon, which is of great significance for the high precision application. In this work, we have realized to broaden the NTE temperature zone in Mg 2 P 2 O 7 -based bulk material by doping Cu atom on the Mg site. A joint study of Raman scattering and X-ray diffraction (XRD) indicates that there are double phases in the NTE temperature zone, and the NTE of Mg 1.9 Cu 0.1 P 2 O 7 bulk material comes from the phase transition of α - and β -phase. The present work provides a way to optimize negative thermal expansion property in phase transition typed materials.
研究领域:
材料科学
·
凝聚态物理
·
无机化学
·
功能材料
·
热学性能
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 47
·期 5
·6842-6847
·
IF 3.83
Shunjin Xiong,Rongxia Huang,Congfei Peng,Yejing Dai,Jiajiu Li,Wen Bai,Hua-Tay Lin
A series of HfO 2 -modified (Bi 0 .475 Na 0 . 405 K 0 . 055 Li 0.015 ) 0.95 Ba 0 . 05 Ti (1- x ) Hf x O 3 ( x = 0–0.015) lead-free ceramics were prepared. Results of detailed characterizations showed that the addition of HfO 2 had little influence on the grain size, and all of the samples showed the pure perovskite structure. As the Hf 4+ content increases, the samples changed from the normal ferroelectric phase to the ergodic relaxor state at room temperature, and the ceramics with x = 0.01 showed a high electro-strain of 0.295% at 6 kV/mm. Therefore, this study provides a new insight into of how the HfO 2 addition influences the ferroelectric property of the BNT-based ceramics by B-site substitution.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
铁电材料
·
压电材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2020
·Vol. 44
·期 11
·8555-8566
·
IF 3.741
Li Yang,Yanping Yuan,Nan Zhang,Yanfang Dong,Yafen Sun,Wenhui Ji
Summary To make better use of solar energy, lauric acid/expanded graphite (LA/EG) composite phase change materials (PCMs) were synthesized to collect and store solar energy as latent heat thermal energy. The results of thermal characteristics show that when the mass fraction of EG is 5%, 10%, and 15%, the latent heat of LA/EG is 164.5, 156.9, and 148.0 J/g, and the thermal conductivity is 2.73, 7.98, and 10.54 W/(m·K). Leakage test shows that LA/EG PCMs with EG mass fraction of 10% and 15% are form stable after phase change. One thousand thermal cycles prove good thermal reliability of LA/EG. TG analysis indicates LA/EG PCMs have good thermal stability within operating temperature range. The Ultraviolet-visible spectra reveal that the absorbance of LA/EG composite PCMs would increase as the mass fraction of EG increases. Photothermal conversion experiment results indicate that the photothermal conversion efficiency of LA/EG composite PCMs increases as the mass fraction of EG increases, and the efficiency can reach 95% when the mass fraction of EG is 15%. Moreover, it was also found that the process of photothermal conversion can be accelerated with stronger illumination intensity or smaller heat transfer size. All the results show that the prepared LA/EG PCMs can convert solar energy into thermal energy and store it in the form of latent heat at the same time, which indicates it has promising prospect in the application of solar energy conversion and storage.
研究领域:
材料科学
·
能源化学
·
热能工程
·
功能材料
·
可再生能源
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Zhiping Zhang,Yuenan Wang,Yang Lei,Fang Zhang,Xiaobing Chen,Hongfei Liu
Negative thermally expanded (NTE) (KMg) x Sc 2-x (WO 4 ) 3 (0 = x ≤ 1.5) ceramics have been prepared via solid-state reaction. X-ray diffraction (XRD) analysis reveals that (KMg) x Sc 2-x (WO 4 ) 3 undergoes a composition-induced phase transition as the (KMg) 3+ -substitution content increases. For x = 0.25, both hexagonal (KMg) x Sc 2-x (WO 4 ) 3 and orthorhombic Sc 2 (WO 4 ) 3 coexisted in the sample. For 0.25 < x ≤ 1, a single-phase, hexagonal (KMg) x Sc 2-x (WO 4 ) 3 , was obtained. When x is further increased to 1.25, monoclinic MgWO 4 impurity was detected in the sample. Meanwhile, as x increases, the grain size of (KMg) x Sc 2-x (WO 4 ) 3 ceramics grows up. Hexagonal (KMg) x Sc 2-x (WO 4 ) 3 ceramics show high densification and strong NTE property. Thermomechanical analysis indicates that the linear coefficients of thermal expansion (CTEs) of hexagonal (KMg) x Sc 2-x (WO 4 ) 3 ceramics decrease from −7.48 × 10 −6 °C −1 to −14.06 × 10 −6 °C −1 with the increase of x. High-temperature XRD analysis reveals that hexagonal (KMg) 0.5 Sc 1.5 (WO 4 ) 3 show an anisotropic NTE. The intrinsic linear CTEs are α a = α b = −6.74 × 10 −6 °C −1 , α c = 11.03 × 10 −6 °C −1 and the volumetric CTE is α v = −2.52 × 10 −6 °C −1 .
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
热学性能
·
结构与物性
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2021
·
IF 6.583
Tiantian Zhang,Shi Juan,Wang Yi,Zhenqian Chen
Halloysite nanotube (HNT), a natural and environmentally friendly low-cost material with significant reserves, has become one of promising candidates for preparation of form-stable composite PCM with satisfactory thermal properties owing to their hollow tubule structure and high surface area. The present work prepared the form-stable composite with HNTs and acid etching HNTs (A-HNTs) and compares the properties closely related to thermal energy storage application. Specifically, the micromorphology, thermal properties, shape-stabilized properties, as well as thermal conductivities of the composite materials were characterized by utilizing SEM, TEM, FTIR, DSC, BET, and Hot-disk wire methods, respectively. The results showed that the n-octadecane can both adhere on the inner lumen and the outer wall of HNTs and A-HNTs, while the A-HNTs possess significantly improved absorption thanks to the fact that the pore volume of A-HNTs was enlarged by 19.2% in comparison with HNT, which empowers the extra 5.8% phase transition enthalpy of n-octadecane@A-HNT. In addition, the composite PCMs have a good long-term thermal stability based on multi-cycle heat absorption and release further highlights the potentials in thermal storage application.
研究领域:
材料科学
·
纳米科技
·
能源材料
·
热力学
·
环境友好材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）