scholarly journals Quasi-3D Modeling of Li-ion Batteries Based on Single 2D Image

2021 ◽  
Author(s):  
Yoichi Takagishi ◽  
Tatsuya Yamaue ◽  
Takumi Yamanaka
Keyword(s):  
3D Model ◽  
Ion Beam ◽  
Active Material ◽  
3D Structure ◽  
Simulation Method ◽  
Ion Concentration ◽  
Discharge Process ◽  
Li Ion Batteries ◽  
Li Ion ◽  
Charge Discharge

In this work, we developed an advanced electrochemical physics-based simulation method for Li-ion batteries that enabled a quasi-3D simulation of charge/discharge using only a single 2D slice image. The governing equations are based on typical theories of electrochemical reactions and ion transport. From referencing the 2D plane, the model was able to simulate both the Li concentration in the active material and the Li-ion concentration in the electrolyte for their subsequent consideration in a virtual 3D structure. To confirm the validity of our proposed model, a full 3D discharge simulation with randomly packed active material particles was performed and compared with the results of the quasi-3D model and a simple-2D model. Results indicated that the quasi-3D model properly reproduced the sliced Li and Li-ion concentrations simulated by the full 3D model in the charge/discharge process, whereas the simple-2D simulation partially overestimated or underestimated these concentrations. Finally, we applied the model to an actual Scanning Electron Microscopy equipped with a Focused Ion Beam (FIB-SEM) image of a positive electrode.

scholarly journals Quasi-3D Modeling of Li-ion Batteries Based on Single 2D Image

2021 ◽  
Author(s):  
Yoichi Takagishi ◽  
Tatsuya Yamaue ◽  
Takumi Yamanaka
Keyword(s):  
3D Model ◽  
Ion Beam ◽  
Active Material ◽  
3D Structure ◽  
Simulation Method ◽  
Ion Concentration ◽  
Discharge Process ◽  
Li Ion Batteries ◽  
Li Ion ◽  
Charge Discharge

In this work, we developed an advanced electrochemical physics-based simulation method for Li-ion batteries that enabled a quasi-3D simulation of charge/discharge using only a single 2D slice image. The governing equations are based on typical theories of electrochemical reactions and ion transport. From referencing the 2D plane, the model was able to simulate both the Li concentration in the active material and the Li-ion concentration in the electrolyte for their subsequent consideration in a virtual 3D structure. To confirm the validity of our proposed model, a full 3D discharge simulation with randomly packed active material particles was performed and compared with the results of the quasi-3D model and a simple-2D model. Results indicated that the quasi-3D model properly reproduced the sliced Li and Li-ion concentrations simulated by the full 3D model in the charge/discharge process, whereas the simple-2D simulation partially overestimated or underestimated these concentrations. Finally, we applied the model to an actual Scanning Electron Microscopy equipped with a Focused Ion Beam (FIB-SEM) image of a positive electrode.

scholarly journals Quasi-3D modeling of Li-ion batteries based on single 2D image

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Yoichi Takagishi ◽  
Takumi Yamanaka ◽  
Tatsuya Yamaue
Keyword(s):  
3D Model ◽  
Ion Beam ◽  
Active Material ◽  
3D Structure ◽  
Porous Electrodes ◽  
Ion Concentration ◽  
Discharge Process ◽  
Li Ion Batteries ◽  
Li Ion ◽  
Charge Discharge

Abstract Electrochemical physics-based simulations of Li-ion batteries using a mesoscale 3D structure of porous electrodes are one of the most effective approaches for evaluating the local Li concentration in active materials and the Li-ion concentration in electrolytes. However, this approach requires considerable computational resources compared with a simple 2D or 1D homogeneous simulation. In this work, we developed an advanced electrochemical physics-based simulation method for Li-ion batteries that enabled a quasi-3D simulation of charge/discharge using only a single 2D slice image. The governing equations were based on typical theories of electrochemical reactions and ion transport. From referencing the 2D plane, the model was able to simulate both the Li concentration in the active material and the Li-ion concentration in the electrolyte for their subsequent consideration in a virtual 3D structure. To confirm the validity of our proposed model, a full 3D discharge simulation with randomly packed active material particles was performed and compared with the results of the quasi-3D model and a simple-2D model. Results indicated that the quasi-3D model properly reproduced the sliced Li and Li-ion concentrations simulated by the full 3D model in the charge/discharge process, whereas the simple-2D simulation partially overestimated or underestimated these concentrations. In addition, the quasi-3D model made it possible to dramatically decrease the computation time compared to the full-3D model. Finally, we applied the model to an actual scanning electron microscopy equipped with a focused ion beam (FIB-SEM) image of a positive electrode. Graphic abstract

scholarly journals Lithium-Rich Cobalt-Free Manganese-Based Layered Cathode Materials for Li-Ion Batteries: Suppressing the Voltage Fading

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3487
Author(s):  
Ashraf Abdel-Ghany ◽  
Ahmed M. Hashem ◽  
Alain Mauger ◽  
Christian M. Julien
Keyword(s):  
Layered Structure ◽  
Performance Enhancement ◽  
Electrochemical Impedance ◽  
Discharge Process ◽  
High Porosity ◽  
Li Ion Batteries ◽  
Hydrothermal Route ◽  
Li Ion ◽  
Fading Rate ◽  
Charge Discharge

Lithium-rich layered oxides are recognized as promising materials for Li-ion batteries, owing to higher capacity than the currently available commercialized cathode, for their lower cost. However, their voltage decay and cycling instability during the charge/discharge process are problems that need to be solved before their practical application can be envisioned. These problems are mainly associated with a phase transition of the surface layer from the layered structure to the spinel structure. In this paper, we report the AlF3-coating of the Li-rich Co-free layered Li1.2Ni0.2Mn0.6O2 (LLNMO) oxide as an effective strategy to solve these problems. The samples were synthesized via the hydrothermal route that insures a very good crystallization in the layered structure, probed by XRD, energy-dispersive X-ray (EDX) spectroscopy, and Raman spectroscopy. The hydrothermally synthesized samples before and after AlF3 coating are well crystallized in the layered structure with particle sizes of about 180 nm (crystallites of ~65 nm), with high porosity (pore size 5 nm) determined by Brunauer–Emmett–Teller (BET) specific surface area method. Subsequent improvements in discharge capacity are obtained with a ~5-nm thick coating layer. AlF3-coated Li1.2Ni0.2Mn0.6O2 delivers a capacity of 248 mAh g−1 stable over the 100 cycles, and it exhibits a voltage fading rate of 1.40 mV per cycle. According to the analysis from galvanostatic charge-discharge and electrochemical impedance spectroscopy, the electrochemical performance enhancement is discussed and compared with literature data. Post-mortem analysis confirms that the AlF3 coating is a very efficient surface modification to improve the stability of the layered phase of the Li-rich material, at the origin of the significant improvement of the electrochemical properties.

scholarly journals Structure and Electrochemical Properties of a Mechanochemically Processed Silicon and Oxide-Based Nanoscale Composite as an Active Material for Lithium-Ion Batteries

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Norihiro Shimoi ◽  
Kazuyuki Tohji
Keyword(s):  
Active Material ◽  
Lithium Ion ◽  
Silicon Monoxide ◽  
Li Ion Batteries ◽  
Discharge Characteristics ◽  
High Charge ◽  
Cu Alloy ◽  
Li Ion ◽  
Anode Active Material ◽  
Charge Discharge

Si is essential as an active material in Li-ion batteries because it provides both high charge and optimal cycling characteristics. A composite of Si particles, Cu particles, and pure H2O was realized to serve as an anode active material and optimize the charge–discharge characteristics of Li-ion batteries. The composite was produced by grinding using a planetary ball mill machine, which allowed for homogenous dispersion of nanoscale Cu3Si as Si–Cu alloy grains and nanoscale Si grains in each poly-Si particle produced. Furthermore, some Si particles were oxidized by H2O, and oxidized Si was distributed throughout the composite, mainly as silicon monoxide. As a result, each Si particle included silicon monoxide and conductive Cu3Si materials, allowing for effective optimization of the recharging and charge-discharge characteristics. Thus, a new and simple process was realized for synthesizing a Si active material composited with silicon oxides, including silicon monoxide. This Si-rich conductive material is suitable as an anode for Li-ion batteries with high charge and optimized cycling properties.

scholarly journals Improvement of Charge-Discharge Characteristics of the Mg-Ni Powder Electrodes at 55°C

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Kuan-Jen Chen ◽  
Fei-Yi Hung ◽  
Truan-Sheng Lui ◽  
Ren-Syuan Xiao
Keyword(s):  
Anode Materials ◽  
Room Temperature ◽  
Ion Concentration ◽  
Li Ion Batteries ◽  
Sei Layer ◽  
Ni Powder ◽  
Li Ion ◽  
Discharge Capacities ◽  
Cycling Life ◽  
Charge Discharge

Magnesium-nickel (Mg-Ni) powders are used as the anode materials for secondary lithium (Li) ion batteries. Mg-Ni powders with ratios of 1 : 1 (Mg : Ni) are prepared and their structure and electrochemical behavior at room temperature and 55°C are investigated. The results show that adding Ni powders to Mg powders can reduce the charge-discharge capacities and improve cycling life. In charge-discharge cycle testing at 55°C, the Li ion concentration gradually increased with increasing the duration of electrochemical reactions, indicating that the charge-discharge capacities increase with increment of cycling number. The formation of a solid electrolyte interface (SEI) layer restrains Mg ions from dissolving into the electrolyte and thus improves the charge-discharge capacities at high temperature.

scholarly journals Analysis of processes in Li-ion batteries by time-of-flight neutron diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C359-C359
Author(s):  
Ivan Bobrikov ◽  
Anatoly Balagurov ◽  
Chih-Wei Hu ◽  
Chih-Hao Lee ◽  
Sangaa Deleg
Keyword(s):  
Neutron Diffraction ◽  
Time Of Flight ◽  
Ex Situ ◽  
Discharge Process ◽  
Li Ion Batteries ◽  
Pulsed Reactor ◽  
In Situ Experiments ◽  
Li Ion ◽  
Charge Discharge

Ex-situ and in-situ neutron diffraction experiments were performed at HRFD time-of-flight (TOF) diffractometer (IBR-2 long-pulsed reactor, JINR) to characterize the entire battery system based on LiFePO4 and V-added LiFePO4 electrodes during electrochemical cycling and to find additional information about crystal structure of electrodes. Another purpose of this work was checking possibilities for in-situ experiments with real Li-ion batteries at the IBR-2 pulsed reactor. An important advantage of TOF method is the possibility to work at the fixed geometry of the experiment, which allows selecting the optimal battery orientation relative to the directions of the incident and scattered neutron beams and, thus, to minimize the difficulties associated with complex internal structure of the battery. It was shown that charge/discharge process of Li-based real Li-ion battery can be effectively studied by TOF technique at the IBR-2 pulsed reactor. Three full charge/discharge cycles were realized at room temperature (~170C) with slow rate. The step-like appearance of several LiCn phases was observed and the volume fractions of LiFePO4 and FePO4 structural phases at different states of charge were determined. The analysis of changes in cathode material microstructure when doped with vanadium showed a significant increase in the density of defects, which correlates with better electrochemical properties of V-added LiFePO4 compared to pure LiFePO4.

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