Unifying Chemical and Electrochemical Thermodynamics of Electrodes

Authors: Archie Mingze Yao, Amal Sebastian, Venkatasubramaian Viswanathan

Published: July 14, 2025

Batteries are critical for electrified transportation and aviation, yet
thermodynamic understanding of electrode materials remains lacking, as
indicated by the often-seen violation of the second law of thermodynamics of
open-circuit voltage (OCV) models. On the other hand, thermodynamic modeling
rarely utilizes electrochemical data such as OCV, entropic heat (dOCV/dT),
which contains rich thermodynamic information. This work introduces a framework
of thermodynamic modeling of materials for electrochemical energy storage,
using differentiable programming and gradient-based optimization of
thermodynamic parameters. Using a modified Debye model that accounts for the
phonon density of states, the thermodynamics of pure substances is modeled from
experimental measurements of specific heat ($c_p$) as well as the phonon
density of states $g(\omega)$. Thermodynamics of mixing is modeled with
measured entropic heat and OCV data. We demonstrate the differentiable
thermodynamic modeling framework with forward and inverse problems. In the
forward problem, i.e. determining phase diagram of graphite anode given
thermochemical and electrochemical data, we show that in addition to accurate
reproduction of phase diagram of LixC6, the fitted temperature-dependent OCV of
graphite reaches 3.8 mV mean absolute error (MAE) for test set data measured at
10$^\circ$C, compared with 2.9-3.6 mV MAE for training set data measured at
25$^\circ$C - 57$^\circ$C. In the inverse problem, i.e. determining OCV of
lithium iron phosphate (LFP) cathode from phase diagram constrained by
thermochemical and electrochemical data, we demonstrate accurate reproduction
of LFP OCV as well as phase diagram. This framework offers a unified treatment
of chemical and electrochemical thermodynamic data for electrode materials.

Temperature-Tunable Entangled Photon Source for Multiplexed Time-Resolved Fluorescence on a Nanophotonic Platform

Authors: Ayantika Sengupta, Nathan A. Harper, Emily Y. Hwang, Scott K. Cushing

Published: July 11, 2025

Compact, scalable, and multiplexed fluorescence lifetime sensors are of great
interest for point-of-care diagnostics. However, current solutions either lack
broad-range wavelength-tuning capabilities or involve complex optical setups
that hinder miniaturization. On-chip entangled photon sources offer a promising
alternative for time-resolved spectroscopy with their strong temporal
correlations, tunable spectral characteristics, and small footprints. Here, we
develop a temperature-tunable, visible quantum light source on thin-film
lithium niobate (TFLN) with a continuous tuning range greater than one octave,
spanning 564.5~nm to 1.494~$\mu$m using only one waveguide. The tunability is
enabled by utilizing type-I phase matching. We measured an on-chip efficiency
of \boldmath$(3.88\pm0.20)\times10^{9}$ pairs/s/mW, comparable to the most
efficient type-0 bulk lithium niobate sources. These results show that the TFLN
platform is ideal for on-chip integrated photonic and multiplexed lifetime
imaging and sensing.

Placing the Solar System in its Astrophysical Context

Authors: Guillermo Gonzalez

Published: July 11, 2025

We examine recent astronomical data to assess whether the sun and Solar
System possess anomalous properties compared to other stars and exoplanetary
systems, providing context for astrobiology research. Utilising data primarily
from large surveys like {\it Gaia}, {\it Kepler}, {\it TESS}, and ground-based
spectroscopy (e.g., GALAH, LAMOST, HARPS), we construct comparison samples
(e.g., nearby stars, solar analogues and twins within 20-200 pc) and employ
statistical methods, including regression analysis, to account for parameter
dependencies. We find that the sun is modestly metal-rich compared to nearby
solar-age stars. More anomalous solar properties include its mass (top $\sim$8
percent locally), low photometric variability on short timescales ($\sim$0.2
percent), specific light and heavy element abundance patterns (high beryllium,
low lithium, low carbon/oxygen and nitrogen/oxygen ratios, and low heavy
neutron capture and refractory elements), slow rotation, and low superflare
rate. The sun has average $\alpha$/iron, phosphorus/iron, and Ytterbium/iron
abundance ratios. It also has average chromospheric activity as measured by
R$^{\rm '}_{\rm HK}$(T$_{\rm eff}$), R$^{\rm +}_{\rm HK}$, and H$\alpha$
indices. The Solar System is unusual in its lack of super-Earths despite
hosting a cold Jupiter ($\sim$3 percent), the low eccentricities of its planets
(especially considering detectability, $<2$ percent), its large size scale for
a multi-planet system ($\sim$6 percent), and potentially the sun's obliquity.
The sun's galactic orbit is less eccentric and has lower vertical excursions
than $\sim$95 percent of nearby solar analogues. Its current position is near
perigalacticon and minimum distance from the Galactic plane, resulting in a
higher local star density than 98.8 percent of randomly chosen times from
$-0.5$ to $+0.5$ Gyrs.

Corner-Sharing PS$_4$-BS$_4$ Modes Facilitate Fast Ion Conduction in Lithium Thioborophosphate Iodide Glassy Solid Electrolytes

Authors: Yun An

Published: July 10, 2025

Glassy solid electrolytes (GSEs), with their amorphous nature and the absence
of grain boundaries, make them highly attractive for applications in
all-solid-state lithium batteries (ASSLBs), a leading candidate for
next-generation energy storage technologies. A recently developed lithium
thioborophosphate iodide GSE, composed of
30Li$_2$S-25B$_2$S$_3$-45LiI-5P$_2$S$_5$ (LBPSI), has demonstrated excellent
room-temperature ionic conductivity and low activation energy. Despite this
exciting finding, the underlying mechanism behind this ultrafast ion transport
remains ambiguous. Here, we accurately fine-tune the foundational MACE-MP-0
model and perform large-scale machine learning molecular dynamics simulations
to investigate the structural and ion dynamics in LBPSI GSE. Our results reveal
that B$_2$S$_3$ glass formers primarily form multi-bridged B$_x$S$_y$
long-chain networks that impede Li$^+$ conduction. In contrast, P$_2$S$_5$
gives rise to mono-tetrahedral PS$_4$$^{3-}$ and di-tetrahedral
P$_2$S$_7$$^{4-}$ tetrahedra, which engage in distinctive corner-sharing modes
with BS$_4$$^{5-}$ tetrahedra, effectively disrupting the B$_x$S$_y$ chains and
enhancing Li$^+$ mobility. Furthermore, the polyhedral anion rotations of
PS$_4$$^{3-}$ and BS$_4$$^{5-}$ in the corner-sharing PS$_4$-BS$_4$ motifs may
further promote fast Li$^+$ conduction.

In situ impedance spectroscopy tests of Li$_{4-x}$Ge$_{1-x}$P$_x$O$_4$ as potential solid state electrolyte for Micro Li ion Batteries

Authors: Mohammadhossein Montazerian, Kyle J. Stephens, Vladimir Roddatis, Christof Vockenhuber, Arnold Müller, Anders J. Barlow, Thomas Lippert, Nick A. Shepelin, Daniele Pergolesi

Published: July 10, 2025

Lithium-ion batteries employing solid-state electrolytes (SSEs) are emerging
as a safer and more compact alternative to conventional batteries using liquid
electrolytes, especially for miniaturized energy storage systems. However, the
industry-standard SSE, LiPON, imposes limitations due to its incompatibility
with high-temperature processing. In this study, we investigate
Li$_{4-x}$Ge$_{1-x}$P$_x$O$_4$ (LGPO), a LISICON-type oxide, as a promising
alternative thin-film SSE. LGPO thin films are fabricated using pulsed laser
deposition under four distinct deposition conditions, with in situ impedance
spectroscopy enabling precise conductivity measurements without ambient
exposure. We systematically correlate deposition temperature, background
pressure, chemical composition, crystallinity, and morphology with ionic
transport properties. Polycrystalline LGPO films grown at high temperature (535
$^\circ$C) and low oxygen pressure (0.01 mbar) exhibited the highest
room-temperature ionic conductivity ($\sim 1.2 \times 10^{-5}$ S cm$^{-1}$),
exceeding that of LiPON by an order of magnitude, with an activation energy of
0.46 eV. In contrast, amorphous films show significantly lower conductivity
($\sim 5.2 \times 10^{-8}$ S cm$^{-1}$) and higher activation energy (0.72 eV).
The results reveal that crystallinity, chemical composition, and grain boundary
density critically affect ion transport, highlighting the importance of
microstructural control. This work establishes LGPO as a viable,
high-performance oxide SSE compatible with high-temperature processing for
next-generation microbattery architectures.

In-situ SHG microscopy investigation of the domain-wall-conductivity enhancement procedure in lithium niobate

Authors: Iuliia Kiseleva, Boris Koppitz, Elke Beyreuther, Matthias Roeper, Samuel D. Seddon, Lukas M. Eng

Published: July 10, 2025

Conductive domain walls (CDWs) in the uniaxial ferroelectric lithium niobate
(LiNbO$_3$, LN) have attracted a lot of interest as potential elements in 2D
nanoelectronics, due to their orders-of-magnitude larger electronic AC and DC
conductivities as compared to the host material. On the way towards generating
standardized CDWs into z-cut bulk LN crystals with controllable geometry and
electrical properties, we have encountered setbacks recently: Although the
first preparation step, i.e., the established UV-light-assisted
liquid-electrode poling, reliably creates fully penetrating hexagonal domains
with the DWs being aligned almost parallel to the polarization axis, the second
step in the DW 'conductivity-enhancement' process through post-growth voltage
ramping, resulted in randomly-shaped DWs as reflected in their different
current-voltage (I-V) characteristics even after having applied the same
process parameters. To clarify this phenomenon, we present here an
\textit{in-situ} and time-resolved second-harmonic-generation (SHG) microscopy
investigation of DW samples of different sizes, monitoring the DW evolution
during that critical voltage ramping, which allowed us to reconstruct the 3D DW
shapes both prior to and after the enhancement process. As a result, we are
able to map the temporal changes of the local DW inclination angle $\alpha$,
and to quantify the DW velocity. As a consequence, we need to re-assess and
re-think the origin of the DW conductivity (DWC) in LN: The hitherto assumed
simple connection between $\alpha$ and the DWC can not be generalized, since
point defects accumulating along DWs act as extra sources for charge carrier
trapping/release, significantly contributing to the DW current.

Machine-Learned Force Fields for Lattice Dynamics at Coupled-Cluster Level Accuracy

Authors: Sita Schönbauer, Johanna P. Carbone, Andreas Grüneis

Published: July 9, 2025

We investigate Machine-Learned Force Fields (MLFFs) trained on approximate
Density Functional Theory (DFT) and Coupled Cluster (CC) level potential energy
surfaces for the carbon diamond and lithium hydride solids. We assess the
accuracy and precision of the MLFFs by calculating phonon dispersions and
vibrational densities of states (VDOS) that are compared to experiment and
reference ab initio results. To overcome limitations from long-range effects
and the lack of atomic forces in the CC training data, a delta-learning
approach based on the difference between CC and DFT results is explored.
Compared to DFT, MLFFs trained on CC theory yield higher vibrational
frequencies for optical modes, agreeing better with experiment. Furthermore,
the MLFFs are used to estimate anharmonic effects on the VDOS of lithium
hydride at the level of CC theory.

Real-time monitoring of the SoH of lithium-ion batteries

Authors: Bruno Jammes, Edgar Hernando Sepúlveda-Oviedo, Corinne Alonso

Published: July 8, 2025

Real-time monitoring of the state of health (SoH) of batteries remains a
major challenge, particularly in microgrids where operational constraints limit
the use of traditional methods. As part of the 4BLife project, we propose an
innovative method based on the analysis of a discharge pulse at the end of the
charge phase. The parameters of the equivalent electrical model describing the
voltage evolution across the battery terminals during this current pulse are
then used to estimate the SoH. Based on the experimental data acquired so far,
the initial results demonstrate the relevance of the proposed approach. After
training using the parameters of two batteries with a capacity degradation of
around 85%, we successfully predicted the degradation of two other batteries,
cycled down to approximately 90% SoH, with a mean absolute error of around 1%
in the worst case, and an explainability score of the estimator close to 0.9.
If these performances are confirmed, this method can be easily integrated into
battery management systems (BMS) and paves the way for optimized battery
management under continuous operation.

Probing Binary Architectures of Lithium-Rich Giants in GALAH with COSMIC and Stellar Models

Authors: Maryum Sayeed, Selina Yang, Giulia Cinquegrana, Melissa K. Ness, Katelyn Breivik, Andrew R. Casey, Sven Buder, Amanda I. Karakas

Published: July 7, 2025

Surface lithium is depleted when a star goes through the first dredge-up
phase, yet $1\%$ of red giants are found to be Li-rich. The formation mechanism
for these remains uncertain. We combine observational constraints from GALAH
Li-rich giants, with the binary population synthesis code COSMIC to investigate
system properties of these objects assuming binary mass transfer. By evolving 9
million binary systems, we find that binary histories most consistent with
observational constraints are mass transfer from an intermediate-mass AGB donor
to a main-sequence star now observed as a Li-rich red giant. In GALAH, $9\%$ of
main-sequence stars have $\rm A(Li)=2.5-3.2$ dex making it plausible to create
red giants with $\rm A(Li)=1.5-2.2 \; dex$ via main-sequence mass transfer, but
cannot explain the more enriched giants $\rm A(Li) \gtrsim 2.2 \; dex$.
Nucleosynthetic yields from stellar models show that AGB stars with initial
masses of $4.25-5 \; \rm M_\odot$ and $8 \; \rm M_\odot$ contain the most Li in
their ejecta. Intermediate-mass AGB stars comprise $29\%$ of COSMIC results,
with present-day separations $s=3.3\pm0.5 \rm \; AU$ and mass ratios
$q=0.5-1.6$. We achieve $95\%$ agreement in mean enhancements in $\rm (Ba, Y)$
between GALAH observations and stellar models of 6 and $8 \rm \; M_\odot$ AGB,
assuming $1\%$ mass transfer efficiency. We find a low mass transfer efficiency
best reproduces GALAH observations suggesting that the preferred mass transfer
mechanism for Li-enrichment is via wind Roche Lobe Overflow. While we constrain
the most plausible binary parameters assuming AGB mass transfer creates Li-rich
giants, discrepancies in nucleosynthesis comparisons, and the small fraction of
Li-enhanced main-sequence stars suggests additional enrichment mechanisms are
likely.

Deciphering the interplay between wetting and chemo-mechanical fracture in lithium-ion battery cathode materials

Authors: Wan-Xin Chen, Luis J. Carrillo, Arnab Maji, Xiang-Long Peng, Joseph Handy, Sarbajit Banerjee, Bai-Xiang Xu

Published: July 6, 2025

Crack growth in lithium-ion battery electrodes is typically detrimental and
undesirable. However, recent experiments suggest that stabilized fracture of
cathode active materials in liquid electrolytes can increase electrochemically
active surfaces, shorten diffusion pathway, enhance (de)lithiation and improve
overall capacity. To decipher the fundamental couplings between electrolyte
wetting and fracture evolution and evaluate their influences on macroscopic
battery performance, we conducted an integrated experiment-simulation study on
$\alpha$-V2O5 single crystals and polycrystalline NCM as model cathode
materials. Despite synthesis challenges, single-crystal $\alpha$-V2O5 offers
clearer fundamental insights than polycrystalline counterparts with
grain-boundary complexities. Fracture patterns and lithiation heterogeneities
on the samples were mapped using advanced scanning techniques after chemical
(de)lithiation cycles, exhibiting excellent agreements with simulations by the
developed multiphysics model. Results reveal a mutually reinforcing interplay
between wetting and fracture: (i) electrolyte infiltration at fracture surfaces
enhances (de)lithiation and compositional heterogeneity; (ii) wetting
influences fracture dynamics, including fracture modes, propagation distance
and directionality. The validated modelling framework is further applied to
simulations on polycrystalline NCM particles under constant-current
(dis)charging, highlighting the critical role of wetting in promoting fracture
and improving overall capacity. This work bridges fundamental understanding of
wetting-fracture coupling with practical implications for battery performance
optimization via controlled fracture engineering.

Chemical Data for: Lithium

CID: 3028194

Properties:

Compound: 1
Compound Complexity: 0
Count: 0
Fingerprint:
IUPAC Name: lithium
InChI: InChI=1S/Li
InChIKey: WHXSMMKQMYFTQS-UHFFFAOYSA-N
Mass: 7.01600343
Molecular Formula: Li
Molecular Weight: 7.0
SMILES: [Li]
Topological: 0
Weight: 7.01600343

Synonyms:

LITHIUM
7439-93-2
Lithium element
CHEBI:30145
LI
DTXSID5036761
Lithium, metallic
Lithium, elemental
Lithium 7
LITHIUM METALLICUM
9FN79X2M3F
DTXCID101012138
231-102-5
lithium(1+) ion
Lithium-7

Lithium Fluoride Guide

Lithium Fluoride

arXiv Scientific Articles: "lithium fluoride"

Chemical Data for: Lithium

CID: 3028194

Properties:

Synonyms:

Lithium Fluoride in Nuclear Reactors and Radiation Shielding

Lithium Fluoride as a Flux in Glass and Ceramic Industry

SEARCH

Recent News

Lithium Fluoride in Batteries and Energy Storage

Physical and Chemical Properties of Lithium Fluoride

Production and Manufacturing of Lithium Fluoride