The electrode kinetics of Li-ion batteries, which are important for battery utilization in electric vehicles, are affected by the grain size, crystal orientation, and surface structure of electrode materials. However, the kinetic influences of the grain interior structure and element segregation are poorly understood, especially for Li-rich layered oxides with complex crystalline structures and unclear electrochemical phenomena. In this work, cross-sectional thin transmission electron microscopy specimens are "anatomized" from pristine Li1.2Mn0.567Ni0.167Co0.067O2 powders using a new argon ion slicer technique. Utilizing advanced microscopy techniques, the interior configuration of a single grain, multiple monocrystal-like domains, and nickel-segregated domain boundaries are clearly revealed; furthermore, a randomly distributed atomic-resolution Li2MnO3-like with an intergrown LiTMO2 (TM = transitional metals) "twin domain" is demonstrated to exist in each domain. Further theoretical calculations based on the Li2MnO3-like crystal domain boundary model reveal that Li(+) migration in the Li2MnO3-like structure with domain boundaries is sluggish, especially when the nickel is segregated in domain boundaries. Our work uncovers the complex configuration of the crystalline grain interior and provides a conceptual advance in our understanding of the electrochemical performance of several compounds for Li-ion batteries.
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http://dx.doi.org/10.1021/acs.nanolett.5b03933 | DOI Listing |
Science
January 2025
Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano), Hysitron Applied Research Center in China (HARCC) and Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China.
Higher strength and higher ductility are desirable for structural materials. However, ultrastrong alloys inevitably show decreased strain-hardening capacity, limiting their uniform elongation. We present a supranano (<10 nanometers) and short-range ordering design for grain interiors and grain boundary regions, respectively, in fine-grained alloys based on vanadium, cobalt, and nickel, with additions of tungsten, copper, aluminum, and boron.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001 China. Electronic address:
Nickel-rich cobalt-free layered oxide cathode with Ni contents no fewer than 90 % has received extensive attention in the field of lithium-ion batteries due to its excellent specific capacity and low cost, but serious capacity degeneration induced by structural deterioration and interfacial instability greatly hamper their further development. Herein, the Sb-modified LiNiMnO materials from the interface to interior have been designed and fabricated to overcome the above issues. On the one hand, the introduction of Sb-ion in interior of grains can generate Sb-O chemical bond with high dissociation energy, which contributes to reinforce the chemical and structural stability.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Institute of Photoelectronic Thin Film Devices and Technology, Tianjin Key Laboratory of Thin Film Devices and Technology, Nankai University, Tianjin 300350, China.
Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) has emerged as a promising photovoltaic material due to its low cost and high stability. The CZTSSe film for high-performance solar cells can be obtained by annealing the deposited CZTS precursor films with selenium (a process known as selenization). The design of the selenization process significantly affects the quality of the absorber layer.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Physics, Lehigh University, Bethlehem, Pennsylvania, 18015, USA.
Driven quantum materials often feature emergent topology, otherwise absent in static crystals. Dynamic bulk-boundary correspondence, encoded by nondissipative gapless modes residing near the Floquet zone center and/or boundaries, is its most prominent example. Here we show that topologically robust gapless dispersive modes appear along the grain boundaries, embedded in the interior of Floquet topological crystals, when the Floquet-Bloch band inversion occurring at a finite momentum ( ) and the Burgers vector ( ) of the constituting array of dislocations satisfy (modulo ).
View Article and Find Full Text PDFSensors (Basel)
December 2024
School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China.
Addressing the issue of excessive manual intervention in discharging fermented grains from underground tanks in traditional brewing technology, this paper proposes an intelligent grains-out strategy based on a multi-degree-of-freedom hybrid robot. The robot's structure and control system are introduced, along with analyses of kinematics solutions for its parallel components and end-effector speeds. According to its structural characteristics and working conditions, a visual-perception-based motion control method of discharging fermented grains is determined.
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