JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Xiaofang Liu,Hengyang Wang,Bin Zhang,Sikang Zheng,Yao Chen,Hong Zhang,Xianhua Chen,Guoyu Wang,Xiaoyuan Zhou,Guang Han
SnSe, possessing strong lattice anharmonicity and structural anisotropy, has attracted massive attention in thermoelectric conversion. Herein, we demonstrate that simultaneously optimized electrical and thermal transport properties are achieved in SnS 2 -alloyed SnSe polycrystalline materials , which were fabricated via sintering the mixture of solution-synthesized SnSe microplates and SnS 2 nanoplates. Resulting from the increased carrier concentration, p-type (SnSe) 1– x (SnS 2 ) x ( x = 0.5%, 1%) samples obtain much-improved power factor between 300 K and 373 K, e.g. 0.72 mW m –1 K –2 at 300 K for (SnSe) 0.99 (SnS 2 ) 0.01 , which is enhanced by 53% compared to that of SnSe. Additionally, the existing point defects and planar defects effectively strengthen phonon scattering, thus reducing the lattice thermal conductivity , for example, 0.47 W m –1 K –1 at 773 K for the x = 0.02 sample. Eventually, a maximum zT of 0.80 at 823 K and an average zT of 0.52 over 300 – 823 K are obtained in the (SnSe) 0.99 (SnS 2 ) 0.01 sample, which are increased by 33% and 45% compared to those of SnSe, respectively. This study demonstrates a secondary phase alloying strategy to synergistically optimize the electrical and thermal properties of polycrystalline SnSe.
研究领域:
材料科学
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Physics
·
2023
·
IF 11.5
Lin Chen,Mingyu Hu,Jing Feng
Thermal transport management is of great significance for materials such as thermal barrier coatings , photovoltaics , and thermoelectrics . In particular, tremendous efforts have been made to tailor phonon thermal transport to improve performance. This work elucidated origins of low thermal conductivity of ferroelastic (Sm 1-X Yb X )TaO 4 solid solutions from defect-dominated phonon scattering processes. We estimated the influences of point defects (misfits in atomic weight and ionic radius , and oxygen vacancies), ferroelastic domains, and the Umklapp process on thermal transports via the corresponding phonon relaxation time ( τ ). The phonon relaxation time caused by point defects ( τ D ), ferroelastic domains ( τ F ), and the Umklapp process ( τ U ) exhibited a trend of τ D − 1 > τ U − 1 > τ F − 1 , indicating that point defects dominated the thermal transports. The effects of ferroelastic domains on thermal conductivity were estimated according to domain widths and space mismatches between neighboring domains. The approximately parallel relationship between the neighboring domains was beneficial for reducing ferroelastic t - m transition energy. Furthermore, a model was developed to derive the high-temperature thermal conductivity, and the contributions of radiative thermal conductivity were separated from the total thermal conductivity. The analysis of thermal transports can be used in other materials to estimate the contributions of different thermal transport mechanisms to the total thermal conductivity at both low and high temperatures, and to effectively tailor thermal transports according to specific applications.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Xiaotong Yu,Zhijun Wang,Pei Cai,Kai Guo,Junyan Lin,Shuankui Li,Juanjuan Xing,Jiye Zhang,Xinxin Yang,Jing-Tai Zhao
Zintl compounds have continuously received significant attention, primarily due to their structural characteristics that align with the properties of the electron crystal and phonon glass. In this study, the crystal structure and thermoelectric properties of the quaternary Zintl chalcogenide BaScCuTe3 are investigated. The band structure calculations for BaScCuTe3 reveal a slight energy split of 0.08 eV between the second valence band and the valence band maximum, suggesting the presence of multiband-transport behaviors. Substitution of rare earth Gd for Sc is conducted, which significantly increases the hole concentration from 4.1 × 1019 cm–3 to 8.2 × 1019 cm–3 at room temperature. Meanwhile, the Seebeck coefficient increases because of the participation of the second valence band. A maximum power factor of 6.56 μW/cm·K2 at 773 K is obtained, which is 72% higher than that of the pristine sample. Moreover, the lattice thermal conductivity decreases from 0.57 W/m·K for BaScCuTe3 to 0.48 W/m·K for BaSc0.97Gd0.03CuTe3 at 773 K, owing to the introduction of point-defect scattering. As a result, there is a noteworthy improvement in the thermoelectric figure of merit zT, increasing from 0.44 for the undoped sample to 0.85 for BaSc0.98Gd0.02CuTe3. Considering these findings, BaScCuTe3 exhibits great potential and holds promise for further investigation in the field of thermoelectric materials.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
npj Computational Materials
·
2022
·Vol. 8
·期 1
·1-9
·
IF 12.256
Sha Wuxin,Guo Yaqing,Cheng Danpeng,Han Qigao,Lou Ping,Guan Minyuan,Tang Shun,Zhang Xinfang,Lu Songfeng,Cheng Shijie,Cao Yuan-Cheng
LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) has become one of the most popular cathode materials for current lithium-ion batteries due to its high-energy density and cost performance. However, the rapid capacity fading of NCM severely hinders its development and applications. Here, the single crystal NCM523 materials under different degradation states are characterized using scanning transmission electron microscopy (STEM). Then we developed a neural network model with a two-sequential attention block to recognize the crystal structure and locate defects in STEM images. The number of point defects in NCM523 is observed to experience a trend of increasing first and then decreasing in the degradation process. The space between the transition metal columns shrinks obviously, inducing dramatic capacity decay. This analysis sheds light on the defect evolution and chemical transformation correlated with layered material degradation. It also provides interesting hints for researchers to regenerate the electrochemical capacity and design better battery materials with longer life.
研究领域:
材料科学
·
电化学
·
人工智能
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2024
·
IF 9
Huajing Zhou,Tiancheng Li,Fawen Zhang,Faze Chen,Zilian Liu,Rongrong Miao,Qingqing Guan,Lingxiang Zhao,Liang He
Intrinsic point defects in metal core-shell materials can regulate electron redistribution, thereby reducing catalytic energy barriers and enhancing their ORR activity. However, their specific contributions to electron transfer and mass transport pathways remain unclear. In this study, defect-rich hollow O Co @Co 3 O 4 nanoparticles were successfully synthesized using ZIF-67(Co) as a sacrificial template through controlled annealing and internal electric field substitution reactions. High-resolution electron microscopy analysis and density functional theory (DFT) calculations co-revealed the growth mechanism of Co and O vacancies, as well as antisite defects. The formation of oxygen vacancies significantly lowered the energy barrier for Co vacancy formation, playing a crucial bridging role in the development of antisite defects. The electric field polarization induced by Co-O atomic displacement resulted in asymmetric charge distribution, optimizing the adsorption of active hydrogen (H*) and oxygen atoms and facilitating the generation and release of reactive oxygen species (ROS). Electrocatalytic experiments demonstrated that under the combined action of singlet oxygen ( 1 O 2 ) and H*, bisphenol A (BPA) can be efficiently degraded. This study successfully bridges the knowledge gap between atomic defects and advanced electrocatalysis, providing a new perspective and insight for the in-depth analysis of the structure-performance relationship of electrocatalyst materials in the future.
研究领域:
材料科学
·
环境科学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Yingbo Deng,Zengzhu Li,Honghao Wang,Lunhua He,Bingkai Zhang,Mingjian Zhang
Extending the lower cutoff potential of spinel LiNi0.5Mn1.5O4 to 2 V holds the potential to significantly increase the energy density from approximately 600 to around 900 W h/kg by utilizing an extra ∼2.7 V plateau. However, precisely adjusting the length of the ∼2.7 V plateau has proven to be a challenging task, and the decisive structural factor has remained elusive. In this study, a thorough and comparative investigation employing time-of-flight neutron powder diffraction, aberration-corrected scanning transmission electron microscopy, combined with theoretical calculations, has unveiled, for the first time, the key structural feature influencing the length of the ∼2.7 V plateau, a specific point defect, that is, Ni occupation at the 16c octahedral site. It drives Li ions at the neighboring 8a tetrahedral site to move to the 16c site and accelerates the T1 → T2 phase transition, resulting in a shorter ∼2.7 V plateau. Ultimately, the cathode material with the vacant 16c site exhibits a prolonged ∼2.7 V plateau, achieving a higher energy density of approximately 900 W h/kg than that of the cathode material with ∼5.4% Ni at the 16c site (around 800 W h/kg). These findings offer valuable insights for achieving high-energy-density and cost-effective spinel cathodes through meticulous microstructure regulation.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Physics
·
2020
·
IF 10.443
Juan Li,Shuai Zhang,Fei Jia,Shuqi Zheng,Xiaolei Shi,Daqiang Jiang,Siyu Wang,Guiwu Lu,Liming Wu,Zhi-Gang Chen
Approaching practical thermoelectric devices require high-performance and machinable thermoelectric materials . However, the currently available materials are usually brittle. In this work, Nd-doped Mg 3 Sb 2 -based compounds exhibit not only excellent thermoelectric performance but also superior machinability . Mg 3.2 Nd 0.03 Sb 1.5 Bi 0.5 exhibits a high power factor of 20.6 μW cm −1 K −2 at 725 K and a peak zT of 1.8, which mainly originates from the increased n of ~8 × 10 19 cm −3 by Nd/Mg substitutional defects. Defect calculations predict that other rare earth elements (Sm, Gd, Tb, Dy and Ho) have the same effect as Nd on Mg 3 Sb 2 and the predicted highest achievable electron concentrations at 700 K are ~10 20 cm −3 . The measured hardness, Young's modulus and fracture toughness of Mg 3.2 Nd 0.03 Sb 1.5 Bi 0.5 are 1.1 GPa, 49.8 GPa and 1.4 MPa m 1/2 , respectively. In addition, the sample can be easily machined into the dog-bone shape with external thread at both ends, indicating the excellent machinability of Mg 3 Sb 2 -based materials. This work suggests a bright future of Mg 3 Sb 2 -based thermoelectric materials for practical applications and device fabrication .
研究领域:
材料科学
·
热电材料研究
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Chi Zhang,Xiumin Yao,Yinsheng Li,Hanqin Liang,Jian Chen,Jingxian Zhang,Jian Yang,Xiaoyun Li,Tai Qiu,Zhongming Chen,Xuejian Liu,Zhengren Huang
Dense silicon carbide ceramics with 0.5–10 wt% AlN additions were pressureless densified by two steps sintering using B 4 C and C as sintering additives. The effects of AlN content on density, microstructure and thermal conductivity of SiC–AlN composites were investigated. SiC ceramics can be well densified in the presence of AlN. The phonon scattering mechanism and the Klemens–Callaway theory were used to calculate the thermal conductivity evolution of SiC ceramics result from the dissolved Al and N atoms. The main reason for the degradation of thermal conductivities is the point defect scattering dominated by the differences in size and interatomic forces between impurity and host atoms.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2022
·
IF 3.752
Shenghao Zeng,Zhoufu Wang,Yan Ma,Xitang Wang,Hao Liu,Yunjie Dong,Yueying Li,Entao Qiao,Weilun Qian
A series of lanthanum-cerium oxides with different lanthanum content were synthesized by low-temperature solid-state method, and the effect of lanthanum content on the thermal conductivity and near-infrared reflectance of lanthanum-cerium oxide ceramics was systematically investigated. The results indicated that the thermal conductivity of lanthanum-cerium oxide ceramics decreased significantly with the increase of lanthanum content, which was mainly due to the non-negligible phonon scattering caused by the increased point defects in the structure. Lanthanum-cerium oxide ceramics with different lanthanum content had high near-infrared reflectivity (82%) between 1200 and 2200 nm. The lanthanum-cerium oxide ceramics prepared in this work has lower thermal conductivity and higher near-infrared reflectivity, which has broad application prospects in the field of high-temperature energy saving as thermal insulation material.
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
CRYSTENGCOMM
·
2018
·Vol. 20
·期 47
·7729-7738
·
IF 3.304
Heng Quan Yang,Yong Jin Chen,Xiao Yang Wang,Lei Miao,Xiao Yan Li,Xiao Dong Han,Xu Lu,Guo Yu Wang,Xiao Yuan Zhou
The rational design and fabrication of nanostructures has become a fashionable strategy for pursing high thermoelectric performance in solid-state materials. Here we report nanostructured Te–Sb2Te3 composites with significantly enhanced thermoelectric performance through a scalable bottom-up method followed by a rapid sintering process. The power factor along with the carrier concentration could be significantly enhanced by increasing the number of point defects of . Meanwhile, a great number of boundaries and hetero-interfaces between the Te and Sb2Te3 nanoparticles could play an important role in blocking phonons, resulting in the evident suppression of lattice thermal conductivity. Ultimately, a highest zT value close to 1.0 could be achieved at 623 K in samples with components of 2.6 mol% Sb2Te3 and 97.4 mol% Te. Such a peak zT value is comparable to that of doped Te materials synthesized by the conventional solid-state reaction process. This work reveals that high thermoelectric performance could be realized in an intentionally designed nanocomposite by synergistically improving the power factor and suppressing the lattice thermal conductivity.
研究领域:
材料科学
·
热电材料
·
纳米结构工程
·
固态物理
·
能源转换
✓ 已验证
DOI
高影响因子
ACTA MATERIALIA
·
2024
·
IF 8.3
Wei Cao,Ziwei Chen,Maolin Yang,Hanxi Guan,Xing Cheng,Ming Zhang,Feng Lin,Yinguo Xiao,Min Ling,Chengdu Liang,Jun Chen
Point defect engineering has garnered widespread application for enhancing the dynamic behavior of anode materials and improving electrochemical performance. Herein, a hybrid point defect strategy is proposed in Ti-based oxide materials to achieve N doping induced oxygen vacancies (OVs) and subsequently accelerated electron mobility and perform better diffusion kinetics. This methodology culminates in the fabrication of self-supported nanotube arrays comprising N-doped OVs-rich TiO 2 (denoted as N-TNTs). Density functional theory (DFT) calculations and electrochemical characterizations validate that, hybrid point defects lead to high electron mobility and perform better diffusion kinetics, as well as higher Li + /Na + ions adsorption energy barrier and diffusion energy barrier, which in turn improves the rate performance and cycling stability. This research provides a forward-looking and feasible strategy for the application of point defect engineering in anode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Xinpeng Luan,Jianbo Li,Shipeng Wu,Guibin Zhang,Hexige Wuliji,Jun Wang
AgCuTe, a p-type medium-temperature thermoelectric material, exhibits great potential as a candidate for converting waste heat into electricity owing to its low thermal conductivity and high thermoelectric performance. However, an unstable phase structure of the material system has hindered the direct observation of various point defects contacting with high performance, despite their predicted possibilities solely based on first-principles calculations. Here, we present the novel observation of Te interstitial atoms together with other point defects, planar defects, and nanoscale atomic aggregation for the first time in the Zn-doped and Te non-stoichiometric AgCuTe system, employing a nanoscale perspective. Through our investigation, we disclose the remarkable coexistence of multidimensional defects, thereby resolving the previously conflicting opinions regarding point defects in this system. The effective control of these defects is crucial for achieving high thermoelectric performance. The Zn Cu point defects regulate carrier concentration and Seebeck coefficient by influencing phase proportion and carrier effective mass. While maintaining the material's inherently large power factor ( PF ), thermal conductivity is effectively reduced through grain refinement and multiscale defect scattering. As a result, the dimensionless thermoelectric figure of merit ( ZT ) of approximately ∼ 1.16 is achieved at 773 K. By altering Te content, a coexistence of diverse defects is introduced, leading to intricate microstructures and phase structures. Consequently, a significant reduction in thermal conductivity is observed. The coexistence of multidimensional defects, as well as their impact on microstructure and thermoelectric transport properties, holds significant implications for the performance control of functional materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）