Potassium-ion batteries (PIBs) have been regarded as a competitive alternative for lithium-ion batteries, owing to the natural abundance, low cost, and similar rocking-chair working mechanism of potassium element. However, it is challenging to simultaneously prepare suitable potassium ion anode materials of low voltage plateau, high capacity, and long cycle life. In this work, onion-like soft carbon (OLSC) of high heteroatom content is prepared by using solvent-sensitive self-assembly properties of asphaltene molecules. The OLSC electrode exhibits a low voltage plateau because of a high degree of graphitization. Meanwhile, it possesses excellent cycling stability and rate capability due to the high stability of the onion-like structure and fast transport of potassium ions, the latter of which is caused by heteroatom-induced expanded interlayers as found by first-principle calculations. Compared with existing carbon materials, the OLSC synthesized in this study exhibits a high reversible capacity of 466 mAh g at 20 mA g , a reversible capacity of 222 mAh g and capacity retention of 95% after 1600 cycles at 1 A g . This work connects the nanostructure of carbon materials and electrochemical performance and provides new insights in improving carbon-based anodes for PIBs.
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http://dx.doi.org/10.1002/smll.202203494 | DOI Listing |
Soft Matter
December 2024
Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
The phase behavior of symmetric diblock copolymers under three-dimensional (3D) soft confinement is investigated using self-consistent field theory. Soft confinement is realized in binary blends composed of AB diblock copolymers and C homopolymers, where the copolymers self-assemble to form a droplet embedded in a homopolymer matrix. The phase behavior of the confined block copolymers is regulated by the degree of confinement and the selectivity of the homopolymers, resulting in a rich variety of novel structures.
View Article and Find Full Text PDFNat Commun
April 2024
Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
J Chem Phys
January 2024
Civil Engineering Institute, Materials Science and Engineering Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Atomistic simulations performed with a family of model potential with tunable hardness have proven to be a great tool for advancing the understanding of wear processes at the asperity level. They have been instrumental in finding a critical length scale, which governs the ductile to brittle transition in adhesive wear, and further helped in the understanding of the relation between tangential work and wear rate or how self-affine surfaces emerge in three-body wear. However, so far, the studies were mostly limited to adhesive wear processes where the two surfaces in contact are composed of the same material.
View Article and Find Full Text PDFMacromol Rapid Commun
September 2023
Center of Soft Matter Physics and its Applications, School of Physics, Beihang University, Beijing, 100191, China.
The kinetic paths of structural evolution and formation of block copolymer (BCP) particles are explored using dynamic self-consistent field theory (DSCFT). It is shown that the process-directed self-assembly of BCP immersed in a poor solvent leads to the formation of striped ellipsoids, onion-like particles and double-spiral lamellar particles. The theory predicts a reversible path of shape transition between onion-like particles and striped ellipsoidal ones by regulating the temperature (related to the Flory-Huggins parameter between the two components of BCP, χ ) and the selectivity of solvent toward one of the two BCP components.
View Article and Find Full Text PDFSmall
September 2022
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China.
Potassium-ion batteries (PIBs) have been regarded as a competitive alternative for lithium-ion batteries, owing to the natural abundance, low cost, and similar rocking-chair working mechanism of potassium element. However, it is challenging to simultaneously prepare suitable potassium ion anode materials of low voltage plateau, high capacity, and long cycle life. In this work, onion-like soft carbon (OLSC) of high heteroatom content is prepared by using solvent-sensitive self-assembly properties of asphaltene molecules.
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