An electrostatic potential study of LiFePO4 cathode material for lithium-ion battery

Choe, Yong-Su; Han, Sun-Bom; Ahn, Jong-Hun; Kim, Chang-Il

doi:10.1016/j.ssc.2021.114231

“…The cycling process is one of the highest conditioning factors when handling an LFP-based battery [45,46]. It is mandatory to understand the limits for these two processes, which are linked with LiFePO 4 and FePO 4 phases [47] and, depending on the rates, Li 0.25 FePO 4 . Aiming to understand this problem, DFT simulations were performed to associate the average total local potentials, from which the chemical potentials were calculated, the charge carriers' density (figures 3(c)-(f)), and the differential capacitance due to the accumulation of charged species.…”

Section: However Here It Is Shown For the First Time That The 'Workin...mentioning

confidence: 99%

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO₄ case study

Maia,

Gomes,

Guerreiro

et al. 2024

J. Phys. Mater.

0

View full text Add to dashboard Cite

There are still essential aspects regarding cathodes requiring a comprehensive understanding. These include identifying the underlying phenomena that prevent reaching the theoretical capacity, explaining irreversible losses, and determining the cut-off potentials at which batteries should be cycled. We address these inquiries by investigating the cell’s capacity, and phase dynamics by looking into the transport properties of electrons. This approach underlines the crucial role of electrons in influencing battery performance, similar to their significance in other materials and devices such as transistors, thermoelectrics, or superconductors. We use LFP as a case study to demonstrate that understanding the electrochemical cycling behavior of a battery cell, particularly a Li//LFP configuration, hinges on factors like the total local potentials used to calculate chemical potentials, electronic density of states (DOS), and charge carrier densities. Our findings reveal that the stable plateau potential difference is 3.42 V, with maximum charge and minimum discharge potentials at 4.12 V and 2.80 V, respectively. The study illustrates the dynamic formation of metastable phases at a plateau voltage exceeding 3.52 V. Moreover, we establish that determining the working chemical potentials of elements like Li and Al can be achieved through a combination of their work function and DOS analysis. Additionally, we shed light on the role of carbon black beyond its conductivity enhancement. Through Density Functional Theory (DFT) calculations and experimental methods involving Scanning Kelvin Probe (SKP) and electrochemical analysis, we comprehensively examine various materials, including Li, C, Al, Cu, LFP, FePO4, Li0.25FePO4, polyvinylidene fluoride (PVDF), and Li6PS5Cl (LPSCl). The insights derived from this study, which solely rely on electrical properties, have broad applicability to all cathodes and batteries. They provide valuable information for efficiently selecting optimal formulations and conditions for cycling batteries.

show abstract

“…However, the large computational overhead of the DFT methods prohibits high-throughput studies, why future work will target development of faster approximative methods to enable screening for improved battery components. In this direction, a few promising descriptors correlating with the 𝜆, 𝜔 𝐿𝑖 +, 𝛽, and 𝐻 DA charge transfer properties are highlighted below: first, 𝜆 is known to correlate with the static and optical dielectric constants of the medium; 70,71 second, the electrostatic potential (ESP), [72][73][74] oxygen/lithium pDOS centers, 63,75 charge population analysis, 76 and the Crystal Orbital Hamilton Population (COHP) 76,77 are promising for estimations of 𝛽; and, third, 𝜔 Li + could be evaluated from solvation or ion-pairing energies. 78,79 Last, estimating HDA is challenging, but positive results based on neural network models have been shown for molecular systems based on atomic orbital overlap and geometric descriptors.…”

mentioning

confidence: 99%

Computational Insights into Electrolyte-Dependent Li-ion Charge-Transfer Kinetics at the LixCoO2 Interface

Halldin Stenlid,

Žguns,

Vivona

et al. 2024

Preprint

0

View full text Add to dashboard Cite

Interface engineering remains a largely underexplored area and yet it holds the keys to high performance Li-ion batteries. It is the charge transfer across electrode-electrolyte interfaces, its inefficient energetics and sluggish kinetics that are oftentimes significant obstacles for achieving fast charging and high power regimes without compromising battery lifespan. This work propose a Boltzmann-averaged first principles workflow based on constant potential and constrained density functional theory for estimation of atomic scale factors influencing coupled ion-electron charge transfer kinetics across battery electrode-electrolyte interfaces. The approach estimates diabatic Li+ interface energy landscapes as function of the interface character and operational conditions, needed to simulate charging/discharging currents. Experimental trends for the LixCoO2 (0.5≤x≤1.0) electrode in varied organic electrolytes with LiPF6 and LiClO4 salts are reproduced, identifying Li+ transfer energy and Li+ adsorption energy as decisive factors influencing the enhanced kinetics in LiClO4-based electrolytes over LiPF6, rationalized by a stronger surface interaction of ClO4-.

show abstract

“…However, the large computational overhead of the DFT methods prohibits high-throughput studies, why future work will target development of faster approximative methods to enable screening for improved battery components. In this direction, a few promising descriptors correlating with the 𝜆, 𝜔 𝐿𝑖 +, 𝛽, and 𝐻 DA charge transfer properties are highlighted below: first, 𝜆 is known to correlate with the static and optical dielectric constants of the medium; 70,71 second, the electrostatic potential (ESP), [72][73][74] oxygen/lithium pDOS centers, 63,75 charge population analysis, 76 and the Crystal Orbital Hamilton Population (COHP) 76,77 are promising for estimations of 𝛽; and, third, 𝜔 Li + could be evaluated from solvation or ion-pairing energies. 78,79 Last, estimating HDA is challenging, but positive results based on neural network models have been shown for molecular systems based on atomic orbital overlap and geometric descriptors.…”

mentioning

confidence: 99%

Computational Insights into Electrolyte-Dependent Li-ion Charge-Transfer Kinetics at the LixCoO2 Interface

Halldin Stenlid,

Žguns,

Vivona

et al. 2024

Preprint

0

View full text Add to dashboard Cite

Interface engineering remains a largely underexplored area and yet it holds the keys to high performance Li-ion batteries. It is the charge transfer across electrode-electrolyte interfaces, its inefficient energetics and sluggish kinetics that are oftentimes significant obstacles for achieving fast charging and high power regimes without compromising battery lifespan. This work propose a Boltzmann-averaged first principles workflow based on constant potential and constrained density functional theory for estimation of atomic scale factors influencing coupled ion-electron charge transfer kinetics across battery electrode-electrolyte interfaces. The approach estimates diabatic Li+ interface energy landscapes as function of the interface character and operational conditions, needed to simulate charging/discharging currents. Experimental trends for the LixCoO2 (0.5≤x≤1.0) electrode in varied organic electrolytes with LiPF6 and LiClO4 salts are reproduced, identifying Li+ transfer energy and Li+ adsorption energy as decisive factors influencing the enhanced kinetics in LiClO4-based electrolytes over LiPF6, rationalized by a stronger surface interaction of ClO4-.

show abstract

An electrostatic potential study of LiFePO4 cathode material for lithium-ion battery

Cited by 6 publications

References 22 publications

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO₄ case study

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO₄ case study

Computational Insights into Electrolyte-Dependent Li-ion Charge-Transfer Kinetics at the LixCoO2 Interface

Computational Insights into Electrolyte-Dependent Li-ion Charge-Transfer Kinetics at the LixCoO2 Interface

Contact Info

Product

Resources

About

An electrostatic potential study of LiFePO4 cathode material for lithium-ion battery

Cited by 6 publications

References 22 publications

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO4 case study

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO4 case study

Computational Insights into Electrolyte-Dependent Li-ion Charge-Transfer Kinetics at the LixCoO2 Interface

Computational Insights into Electrolyte-Dependent Li-ion Charge-Transfer Kinetics at the LixCoO2 Interface

Contact Info

Product

Resources

About

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO₄ case study

Cathodes pinpoints for the next generation of energy storage devices: the LiFePO₄ case study