A Review of Design Strategies in SiO/C Composite Anodes for Rechargeable Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) are widely used in electric vehicles, portable electronic devices, clean energy storage, and other fields due to their long service life, high energy density, and low self-discharge rate, which also puts forward higher requirements for the performance of lithium-ion batteries. As an anode for lithium-ion batteries, SiO materials have garnered significant attention from researchers due to its high specific capacity (2400 mAh·g-1), abundance of raw materials, and simple preparation. However, its large volume change (~ 200%) and poor electrical conductivity hinder its large-scale commercial application. Researchers employ various methods to reduce the volume change of SiO during lithium intercalation and improve its structural stability during cycling. This work mainly reviews the chemical structure and lithium storage mechanism of SiO, as well as the latest research progress on the preparation methods of SiO/C anode materials, focusing on summarizing the following preparation strategies: chemical vapor deposition, mechanical ball milling, spray drying, and in-situ reduction/oxidation methods. The obtained SiO-based anode materials' structural characteristics and electrochemical properties are compared and summarized. Finally, this review discusses the advantages and disadvantages of the current preparation methods, the future research directions, and the development prospects of SiO-based anode materials.

Boosting the Cell Performance of the SiO/Cu and SiO/PPy Anodes via In-Situ Reduction/Oxidation Coating Strategies.

Silicon monoxide (SiO) has attracted great attention due to its high theoretical specific capacity as an alternative material for conventional graphite anode, but its poor electrical conductivity and irreversible side reactions at the SiO/electrolyte interface seriously reduce its cycling stability. Here, to overcome the drawbacks, the dicharged SiO anode coated with Cu coating layer is elaborately designed by in-situ reduction method. Compared with the pristine SiO anode of lithium-ion battery (293 mAh g-1 at 0.5 A g-1 after 200 cycles), the obtained SiO/Cu composite presents superior cycling stability (1206 mAh g-1 at 0.5 A g-1 after 200 cycles). The tight combination of Cu particles and SiO significantly improves the conductivity of the composite, effectively inhibits the side-reaction between the active material and electrolyte. In addition, polypyrrole-coated SiO composites are further prepared by in-situ oxidation method, which delivers a high reversible specific capacity of 1311 mAh g-1 at 0.5 A g-1 after 200 cycles. The in-situ coating strategies in this work provide a new pathway for the development and practical application of high-performance silicon-based anode.

3D Structure of Jet-Induced Diffusion Wake in an Expanding Quark-Gluon Plasma.

The diffusion wake accompanying the jet-induced Mach cone provides a unique probe of the properties of quark-gluon plasma in high-energy heavy-ion collisions. It can be characterized by a depletion of soft hadrons in the opposite direction of the propagating jet. We explore the 3D structure of the diffusion wake induced by γ-triggered jets in Pb+Pb collisions at the LHC energy within the coupled linear Boltzmann transport and hydro model. We identify a valley structure caused by the diffusion wake on top of a ridge from the initial multiple parton interaction (MPI) in jet-hadron correlation as a function of rapidity and azimuthal angle. This leads to a double-peak structure in the rapidity distribution of soft hadrons in the opposite direction of the jets as an unambiguous signal of the diffusion wake. Using a two-Gaussian fit, we extract the diffusion wake and MPI contributions to the double peak. The diffusion wake valley is found to deepen with the jet energy loss as characterized by the γ-jet asymmetry. Its sensitivity to the equation of state and shear viscosity is also studied.

From Hydrodynamics to Jet Quenching, Coalescence, and Hadron Cascade: A Coupled Approach to Solving the R_{AA}⊗v_{2} Puzzle.

Hydrodynamics and jet quenching are responsible for the elliptic flow v_{2} and suppression of large transverse momentum (p_{T}) hadrons, respectively, two of the most important phenomena leading to the discovery of a strongly coupled quark-gluon plasma in high-energy heavy-ion collisions. A consistent description of the hadron suppression factor R_{AA} and v_{2}, especially at intermediate p_{T}, however, remains a challenge. We solve this long-standing R_{AA}⊗v_{2} puzzle by including quark coalescence for hadronization and final state hadron cascade in the coupled linear Boltzmann transport-hydro model that combines concurrent jet transport and hydrodynamic evolution of the bulk medium. We illustrate that quark coalescence and hadron cascade, two keys to solving the puzzle, also lead to a splitting of v_{2} for pions, kaons, and protons in the intermediate p_{T} region. We demonstrate for the first time that experimental data on R_{AA}, v_{2}, and their hadron flavor dependence from low to intermediate and high p_{T} in high-energy heavy-ion collisions can be understood within this coupled framework.