Germanium-based superatom clusters as excess electron compounds with significant static and dynamic NLO response; a DFT study

Herein, the geometric, electronic, and nonlinear optical properties of excess electron zintl clusters Ge5AM3, Ge9AM5, and Ge10AM3 (AM = Li, Na, and K) are investigated.

Too Much of a Good Thing? Assessing Performance Tradeoffs of Two-Electron Compounds for Redox Flow Batteries

<p>Engineering redox-active compounds to support stable multi-electron transfer is an emerging strategy for enhancing the energy density and reducing the cost of redox flow batteries (RFBs). However, when sequential electron transfers occur at disparate redox potentials, increases in electrolyte capacity are accompanied by decreases in voltaic efficiency, restricting the viable design space. To understand these performance tradeoffs for two-electron compounds specifically, we apply theoretical models to investigate the influence of the electron transfer mechanism and redox-active species properties on galvanostatic processes. First, we model chronopotentiometry at a planar electrode to understand how the electrochemical response and associated concentration distributions depend on thermodynamic, kinetic, and mass transport factors. Second, using a zero-dimensional galvanostatic charge / discharge model, we assess the effects of these key descriptors on performance for a single half-cell. Specifically, we examine how different properties (i.e., average of the two redox potentials, difference between the two redox potentials, charging rate, mass transfer rate, and comproportionation rate) affect the electrode polarization and voltaic efficiency. Finally, we extend the galvanostatic model to include two-electron compounds in both half-cells, demonstrating compounding voltage losses for a full cell. These results evince limitations to the applicability of multi-electron compounds—as such, we suggest new directions for molecular and systems engineering that may improve the prospects of these materials within RFBs.<b></b></p>

Too Much of a Good Thing? Assessing Performance Tradeoffs of Two-Electron Compounds for Redox Flow Batteries

<p>Engineering redox-active compounds to support stable multi-electron transfer is an emerging strategy for enhancing the energy density and reducing the cost of redox flow batteries (RFBs). However, when sequential electron transfers occur at disparate redox potentials, increases in electrolyte capacity are accompanied by decreases in voltaic efficiency, restricting the viable design space. To understand these performance tradeoffs for two-electron compounds specifically, we apply theoretical models to investigate the influence of the electron transfer mechanism and redox-active species properties on galvanostatic processes. First, we model chronopotentiometry at a planar electrode to understand how the electrochemical response and associated concentration distributions depend on thermodynamic, kinetic, and mass transport factors. Second, using a zero-dimensional galvanostatic charge / discharge model, we assess the effects of these key descriptors on performance for a single half-cell. Specifically, we examine how different properties (i.e., average of the two redox potentials, difference between the two redox potentials, charging rate, mass transfer rate, and comproportionation rate) affect the electrode polarization and voltaic efficiency. Finally, we extend the galvanostatic model to include two-electron compounds in both half-cells, demonstrating compounding voltage losses for a full cell. These results evince limitations to the applicability of multi-electron compounds—as such, we suggest new directions for molecular and systems engineering that may improve the prospects of these materials within RFBs.<b></b></p>

From Electride-like Super Alkali Earth Atom to Superalkalide or Superalkali Electride: M(HF)3M (M = Na or Li) as Field-Induced Excellent Inorganic NLO Molecular Switches

Exploring novel molecular switch is an ongoing hot issue in molecular electronics. Alkalide and electride are two typical representatives of excess electron compounds. It was found that M(HF)3M (M =...

Designing a new class of excess electron compounds with unique electronic structures and extremely large non-linear optical responses

New Ca+-1-M′− (M′ = Li, Na, and K) compounds with typical alkalide features and electride-like characteristics have been obtained.

Remarkable second and third order nonlinear optical properties of organometallic C6Li6–M3O electrides

Electrides are excess electron compounds with excellent nonlinear optical properties.

Coinage metalides: a new class of excess electron compounds with high stability and large nonlinear optical responses

A new class of NLO molecules, termed coinage metalides, was designed by using coinage metal atoms as excess electron acceptors.