non-aqueous-electrode-processing-construction-lithium-ion-coin

Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells

Research into new and improved materials to be utilized in lithium-ion batteries (LIB) necessitates an experimental counterpart to any computational ...

three-electrode-coin-cell-preparation-electrodeposition-analytics-for

Three-electrode Coin Cell Preparation and Electrodeposition Analytics for Lithium-ion Batteries

As lithium-ion batteries find use in high energy and power applications, such as in electric and hybrid-electric vehicles, monitoring the degradation and ...

Texas A&M University

Purdue University

We are reporting a newborn male who had injury of the penis probably due to rat bite. The baby was brought to the hospital within 3 h of the injury. The urethra was completely transected. Macroscopic repair was performed. The patient had an uneventful recovery and was discharged after 2 weeks. The patient is doing well 3 months after the operation.

Animal bite of penis in a neonate and macroscopic repair.

The high-rate, high-capacity potential of LiFePO(4)-based lithium-ion battery cathodes has motivated numerous experimental and theoretical studies aiming to realize such performance through nano-sizing, tailoring of particle shape through synthesis conditions, and doping. Here, a granular mechanics study of microstructures formed by dense jammed packings of experimentally and theoretically inspired LiFePO(4) particle shapes is presented. A strong dependence of the resultant packing structures on particle shapes is observed, in which columnar structures aligned with the [010] direction inhibit diffusion along [010] in anisotropic LiFePO(4). Transport limitations are induced by [010] columnar order and lead to catastrophic performance degradation in anisotropic LiFePO(4) electrodes. Further, judicious mixing of nanoplatelets with additive nanoparticles can frustrate columnar ordering and thereby enhance the rate capability of LiFePO(4) electrodes by nearly an order of magnitude.

Columnar order in jammed LiFePO(4) cathodes: ion transport catastrophe and its mitigation.

Using a microfabricated porous media mimic platform, we investigated how fluid flow influences the formation of filamentous structures, known as streamers, between porous media structures. We demonstrate how hydrodynamics govern the formation, morphology and the distribution of these biofilm streamers in the device. Our work establishes that, under favorable hydrodynamic conditions, streamers can often act as precursors to mature microbial structures found in complex geometries, such as those involved in porous media.

A web of streamers: biofilm formation in a porous microfluidic device.

Mixing sequence during electrode processing affects the internal microstructure and resultant performance of a lithium-ion battery. In order to fundamentally understand the microstructure evolution during electrode processing, a mesoscale model is presented, which investigates the influence of mixing sequence for different evaporation conditions. Our results demonstrate that a stepwise mixing sequence can produce larger conductive interfacial area ratios than that via a one-step mixing sequence. Small-sized cubical nanoparticles are beneficial for achieving a high conductive interfacial area ratio when a stepwise mixing sequence is employed. Two variants of multistep mixing have been investigated with constant temperature and linearly increasing temperature conditions. It is found that the temperature condition does not significantly affect the conductive interfacial area ratio. The homogeneity of binder distribution in the electrode is also studied, which plays an important role along with the solvent evaporation condition. This study suggests that an appropriate combination of mixing sequence and active particle size and morphology plays a critical role in the formation of electrode microstructures with improved performance.

Mesoscale elucidation of the influence of mixing sequence in electrode processing.

Li intercalation and diffusion in pristine and modified SnS2 interlayer are studied by a first-principles approach. The results predict that the octahedral interstitial site is energetically favored for Li intercalation. The minimum energy path of Li diffusion in SnS2 interlayer is investigated by climbing image nudged elastic band method. It is found that Li atom diffuses from one energetically favored octahedral interstitial site to the neighbor one via tetrahedral interstitial site. The expansion of interlayer spacing is beneficial for decreasing the diffusion barrier. Ce dopant negatively impacts the Li diffusivity although it can optimize the interlayer spacing. Geometric structures of LixSnS2 (0 < x ≤ 3) are investigated to understand the lithiation-induced volume expansion and atomic structure change. The lithiation process can be divided into two stages. When Li content (x in LixSnS2) is less than 1, the volume expansion is not dramatic and only S atoms capture electrons from Li atoms. When Li content is larger than 1, Sn(4+) cations are significantly reduced, S-Sn-S trilayer gradually decomposes, and LixS2 (1 ≤ x ≤ 3) layer forms between two Sn monolayers. The mechanism of volume expansion is elucidated in this study.

Evaluating pristine and modified SnS2 as a lithium-ion battery anode: a first-principles study.

In lithium-sulfur batteries, the growth of insulating discharge product Li2S film affects the cathode microstructure and the related electron as well as lithium ion transport properties. In this study, chemical reactions of insoluble lithium polysulfides Li2Sx (x = 1, 2) on crystal Li2S substrate are investigated by a first-principles approach. First-principles atomistic thermodynamics predicts that the stoichiometric (111) and (110) surfaces are stable around the operating cell voltage. Li2Sx adsorption is an exothermic reaction with the (110) surface being more active to react with the polysulfides than the stoichiometric (111) surface. There is no obvious charge transfer between the adsorbed molecule and the crystal Li2S substrate. Analysis of the charge density difference suggests that the adsorbate interacts with the substrate via a strong covalent bond. The growth mechanism of thermodynamically stable surfaces is investigated in the present study. It is found that direct Li2S deposition is energetically favored over Li2S2 deposition and reduction process.

Adsorption of insoluble polysulfides Li2S(x) (x = 1, 2) on Li2S surfaces.

Solid electrolyte interphase (SEI) formation, due to the electrochemical reaction between the salt and solvent in the electrolyte, is a key contributor to the electrode performance decay in lithium-ion batteries. The active particle morphology and electrode microstructure affect the side reaction rate and hence the SEI induced interfacial transport and impedance behavior. The change resistance due to the variation of SEI thickness can be inferred from electrochemical impedance spectroscopy. In this study, we proposed a microstructure-aware impedance model to predict the effect of electrode microstructure on impedance response. Our model successfully captures the influence of active particle morphology on the SEI formation and corresponding impedance characteristics. Different electrode realizations with microstructural and compositional variations have been considered. The critical influence of active material morphology, mean particle size, binder and electrolyte volume fractions on the SEI formation and impedance behavior reveals the underlying interdependences of the interfacial and transport resistance modes.

Probing the morphological influence on solid electrolyte interphase and impedance response in intercalation electrodes.

The present work discusses the implications of wall wettability and inclination of the surface on droplet dynamics. In this work, mesoscopic illustration of droplet dynamics in a duct with different inclination angles, based on the two-phase lattice Boltzmann model, is reported. Temporal evolution of wetted length, wetted area, and maximum height of the droplet for surfaces with different inclination angles and wettabilities is furnished in detail in order to elucidate the droplet displacement dynamics. It has been observed that the effect of inclination of the surface on droplet dynamics is more pronounced on a hydrophobic surface as compared to a hydrophilic surface. The time evolution of height and contact line motion of the droplet shows that higher angle of inclination of substrate affects the dynamics strongly irrespective of wettability.

Wettability effects on contact line dynamics of droplet motion in an inclined channel.

Lithium-ion battery electrodes exhibit complex interplay among multiple electrochemically coupled transport processes, which rely on the underlying functionality and relative arrangement of different constituent phases. The electrochemically inactive solid phases (e.g., conductive additive and binder, referred to as the secondary phase), while beneficial for improved electronic conductivity and mechanical integrity, may partially block the electrochemically active sites and introduce additional transport resistances in the pore (electrolyte) phase. In this work, the role of mesoscale interactions and inherent stochasticity in porous electrodes is elucidated in the context of short-range (interface) and long-range (transport) characteristics. The electrode microstructure significantly affects kinetically and transport-limiting scenarios and thereby the cell performance. The secondary-phase morphology is also found to strongly influence the microstructure-transport-kinetics interactions. Apropos, strategies have been proposed for performance improvement via electrode microstructural modifications.

Partha P. Mukherjee

Department of Mechanical Engineering

Texas A&M University

Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells

Three-electrode Coin Cell Preparation and Electrodeposition Analytics for Lithium-ion Batteries

Partha P. Mukherjee

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Mechanical Engineering

Texas A&M University

Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells

Three-electrode Coin Cell Preparation and Electrodeposition Analytics for Lithium-ion Batteries

Department of Mechanical Engineering