Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XIX: Phase Stability of Energy Materials
Sponsored by: TMS Functional Materials Division, TMS: Alloy Phases Committee
Program Organizers: Hiroshi Nishikawa, Osaka University; Shi-Kang Lin, National Cheng Kung University; Chao-Hong Wang, National Chung Cheng University; Chih-Ming Chen, National Chung Hsing University; Jaeho Lee, Hongik University; Zhi-Quan Liu, Shenzhen Institutes of Advanced Technology; Ming-Tzer Lin, National Chung Hsing University; Dajian Li, Karlsruhe Institute of Technology; Yu Zhong, Worcester Polytechnic Institute; Yee-wen Yen, National Taiwan University of Science and Technology; Song-Mao Liang, Clausthal University of Technology; A.S.Md Abdul Haseeb, Bangladesh University of Engineering and Technology (BUET); Ligang Zhang, Central South University; Sehoon Yoo, Korea Institute of Industrial Technology
Tuesday 8:30 AM
February 25, 2020
Room: Marina Ballroom E
Location: Marriott Marquis Hotel
Session Chair: Shih-Kang Lin, National Cheng Kung University; Shien Ping Feng, The University of Hong Kong
8:30 AM
Full Battery Design for Li-ion Batteries Using CALPHAD Technique: Dajian Li1; Song-Mao Liang2; Yuan Yuan3; Weibin Zhang4; 1Karlsruhe Institute of Technology; 2University of Wisconsin Madison; 3Chongqing University; 4Shandong University
CALculation of PHAse Diagrams (CALPHAD) approach has been widely applied for developing phase diagrams as well as property diagrams for many systems. This enable the possibility for a predication of full cell behaviour of Li-ion batteries from the viewpoint of thermodynamics and phase diagrams. Here we briefly summarize the assessed relating phase diagrams. Afterwards, we demonstrate the predication and design routine of a full Li-ion battery using CALPHAD technique with following steps: (1) Predication of the behaviour mixed-conductor anode from Si-Sn system; (2) calculation of the Li-(Ni)-Mn-O properties; (3) take selected Si-Sn conductor and combine with LiMn2O4 cathode to form a full cell. With this routine, the development for future electrode materials as well as battery manage system can be more efficient.
8:50 AM
Challenges and Solutions for Experimental Investigation of Air and Moisture Sensitive Li Alloys: Joel Fels1; Thomas Reichmann2; Hans Flandorfer3; Hans Seifert1; 1Karlsruhe Institute of Technology; 2G-Technology GmbH; 3University of Vienna
The use of metallic anode materials in Li-ion batteries is beneficial due to the higher energy density compared to conventional carbonaceous negative electrodes. However, determining experimental data of metallic anode materials is challenging. Metallic Lithium and its alloys are air and moisture sensitive already at ambient temperatures. At elevated temperatures, side reactions with the crucible and evaporation of the high volatile Li occur. Using the example of the ternary Ga-Li-Sn system, the choice of an appropriate crucible material as well as heating programs for alloy preparation will be presented. Experimental methods, such as thermal analysis to determine phase transition temperatures or structure analysis experiments, require careful prearrangements. Crucible design and experimental details were adapted to the highly reactive alloys. Results from thermal- and crystal structure analysis are then used for phase diagram evaluation.
9:10 AM
An Ab-initio Study on the Structural and Electrochemical Propeties of Na3V2(PO4)2F3 as Cathode Materials for Hybrid-ion Batteries: Kuei-Hsi Chen1; Ngoc Thanh Thuy Tran1; Shih-kang Lin1; 1National Cheng Kung University
Na3V2(PO4)2F3, one type of sodium-vanadium fluorophosphates, is considered as a promising cathode material for Na-ion batteries and hybrid Na/Li-ion batteries due to their low cost, cycling stability, and high working potentials. In this work, the stoichiometric Na3V2(PO4)2F3 with various space group structures have been successfully optimized by mean of ab-initio calculations. This has not been previously reported so far due to the complicated phase transformation during cycling according to the in-situ experiment result. The optimistic models of Na3V2(PO4)2F3 are further investigated with different ratios of Na and Li intercalation/deintercalation in the Na sites. The calculated charge and discharge curves under different state of charge by the use of computational thermodynamics are compared with available experimental data to fulfill the reaction pathway and cycling mechanism for hybrid-ion batteries application. This work is expected to provide a better understanding on the complex Na3V2(PO4)2F3 structure as well its electrochemical properties.
9:30 AM
Thermodynamic Modeling of the Cu-Mg-Si-Sn Quaternary System and Interpretation of Mg2(Si0.3Sn0.7)/Cu Thermoelectric Interconnections: Silvana Tumminello1; Sahar Ayachi1; Suzana Fries2; Eckhard Müller1; Johannes de Boor1; 1German Aerospace Center (DLR); 2ICAMS-Ruhr University Bochum
The recent development on thermoelectric energy conversion shows magnesium silicide stannide solid solutions as prominent materials, owing to high values of the thermoelectric figure of merit zT, elemental abundance, and non-toxicity. The operation of thermoelectric generators, however, relies as well upon long-term stable contacts with low thermal and electrical resistivity, similar thermal expansion coefficient and good adhesion to Mg2(Si,Sn).Mg2(Si0.3Sn0.7)/Cu joints were investigated showing good contacting and no delamination as well as low specific electrical contact resistances. Phase designation combined SEM/EDX analysis and calculated phase diagrams. To the best of our knowledge, no quaternary description is available, therefore, the aim of this work is to develop an open thermodynamic database to complement the experimental observations of thermoelectric joints and bring understanding to diffusion-reaction mechanisms in the interconnection zone (IZ). The modeling of τ1-Cu3Mg2Si and γ’-Cu51.7Mg33.3Sn15 phases are of particular interest since they are observed to grow in the IZ.
9:50 AM Break
10:20 AM
CALPHAD-assisted Analyses of BOF Slag Modification and Reduction: Han-Yu Wang1; Wan-Yu Huang1; Yung-Chang Liu2; Kuan-Ju Lin2; Shih-kang Lin1; 1National Cheng Kung University; 2China Steel Corporation
Basic-oxygen furnace (BOF) slag is a byproduct during the steelmaking process, composed of high free-CaO (unreacted CaO), FeO, and P2O5 contents. BOF slag has been used as aggregates for road and hydraulic construction. However, free-CaO hydrolyzes coming in contact with water and its volume increases which causes safety issue. In this study, a new approach for recycling BOF slag is to apply it on construction as BF slag cement which could substitute for Portland cement. It involves materials modification with multicomponent complex reactions at high temperatures. With the aid of CALPHAD thermodynamic modeling, we optimize the reaction path of BOF slag which satisfied all the criteria for low melting temperature and no solid phase precipitation in order to lower the CaO, FeO, and P2O5 contents during an entire process. Reaction path of BOF slag is carefully investigated and an optimized reaction path is found.
10:40 AM
High-throughput CALPHAD-type Calculation in Design of Coherent Precipitate-strengthening AlCuFeNiTi Multi-principal Element Alloys: Shao-Yu Yen1; Hao-che Wang1; Shih-kang Lin1; 1National Cheng-Kung University
Multi-principal element alloys (MPEAs), also known as complex concentrated alloys (CCAs) and high entropy alloys (HEAs), are alloys composed of multiple elements with equal or near equal atomic composition, which exhibit outstanding mechanical properties. By definition, numerous combinations of elements with a large variety of compositions can form a MPEA. However, alloy design with trial-and-error experiments is costly and time-consuming. CALPHAD method combined with high-throughput calculation (HTC) provides an efficient way to design MPEAs. In this work, Pandat software with reliable database are employed to perform high-throughput CALPHAD-type calculation. Considering density and cost, Al-Cu-Fe-Ni-Ti quinary system with γ/γ' coherent precipitates is selected after a rough screening in PanHEA database. Experiments were carried out for verification, and the results showed a good agreement with the calculations. We demonstrate that HTC CALPHAD-type calculation is a powerful and reliable method for next-generation material’s design.
11:00 AM
Study on the Phase Diagrams of Bi-Te Binary and Bi-Te-RE (Yb, La, Ce, Nd, Sm, Tb, Er) Ternary Systems: Cun Mao1; Mingyue Tan1; Libin Liu1; Ligang Zhang1; 1Central South University
Bi-Te based alloy is one of the most mature thermoelectric materials at present. Because of its special electronic structure, rare earth elements (RE) can be doped to effectively adjust the energy band structure of thermoelectric materials and reduce the thermal conductivity of the crystal lattice thus improve the thermoelectric properties. The solid solubility of rare earth elements in Bi-Te alloys, the formation of ternary compounds, phase stability, phase transition temperature and other phase diagram information can guide the design of thermoelectric materials via doping rare-earth elements. In this work, phase diagram and phase structures of Bi-Te system is carefully checked.The isothermal sections of Bi-Te-RE ternary systems were partly established by equilibrium alloy method. A ternary compound BiTeRE was found. It is found that the solid solubility of rare earth elements in Bi-Tematrix increases with the decrease of the atomic radius of rare earth elements.
11:20 AM Cancelled
Effects of Ge/Sb Intermixing on the Local Structures and Optical Properties of GeTe-Sb2Te3 Superlattice: Gang Han1; Furong Liu1; 1Beijing University of Technology
GeTe-Sb2Te3 based superlattice (GST-SL) is a new phase change film prepared with alternative GeTe and Sb2Te3 layers, showing strongly improved switching properties. However, the recent experiments showed that Ge/Sb atomic intermixing was hardly to be avoided. In this paper, the effects of Ge/Sb atomic intermixing on the local structure and phase change mechanism were investigated by first-principles simulations. The free energy evolution with temperatures indicated that Ge/Sb intermixing is helpful for phase change. The bond analysis and local order parameter showed that no obvious structure changes happened when lower than 1200 K and there were almost no 4-fold Ge tetrahedral structures even when quenched from 1500 K, different from the traditional GST materials. The Ge/Sb intermixing and its ratios can not only influence the structural transition, but also play a vital role on the optical properties. These findings enrich a deep understanding of Ge/Sb intermixing on GST-SL phase changes.