Fast Molecular Compression by a Hyperthermal Collision Gives Bond-Selective Mechanochemistry

Using electrospray ion beam deposition, we collide the complex molecule Reichardt’s Dye (C41H30NO+) at low, hyperthermal translational energy (2 - 50 eV) with a Cu(100) surface and image the outcome at single-molecule level by scanning tunneling microscopy. We observe bond-selective reaction induced by the translational kinetic energy. The collision impulse compresses the molecule and bends specific bonds, prompting them to react selectively. This dynamics drives the system to seek thermally inaccessible reactive pathways, since the compression timescale (sub-ps) is much shorter than the thermalization timescale (ns), thereby yielding reaction products that are unobtainable thermally

Beneficial Effects of Three-Dimensional Structured Electrodes for the Fast Charging of Lithium-Ion Batteries

Lithium-ion batteries are the dominating electrochemical energy storage technology for battery electric vehicles. However, additional optimization is needed to meet the requirements of the automotive industry regarding energy density, cost, safety, and fast charging performance. In conventional electrode designs, there is a trade-off between energy density and rate capability. Recently, three-dimensional (3D) structuring techniques, such as laser perforation, were proposed to optimize both properties at the same time and remarkable improvements in fast-charging performance have been demonstrated. In this work, we investigate the effect of structuring techniques on the thermal properties and electrochemical performance of the battery using microstructure-resolved simulations. Particular attention will be paid to the heat evolution and lithium plating during fast charging of the batteries. According to our results, 3D structuring is able to reduce the overall cell resistance by improving the electrolyte transport. This has a positive impact on the fast charging capability of the cell and, moreover, reduces the danger of lithium plating

High-Performance Computing in Battery Development: From Pore Scale to Continuum

An application for high-performance computing (HPC) is shown that is relevant in the field of battery development. Simulations of electrolyte wetting and flow are conducted using pore network models (PNM) and the lattice Boltzmann method (LBM), while electrochemical simulations are conducted using the tool BEST. All aforementioned software packages show an appropriate scaling behavior. A workflow for optimizing battery performance by improving the filling of battery components is presented. A special focus is given to the unwanted side effect of gas entrapment encountered during filling. It is also known to adversely affect the electrochemical performance of batteries and can be partially prevented by appropriate microstructure design such as electrode perforation