Reduced Order Impedance Models of Lithium Ion Batteries

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Githin K. Prasad ◽  
Christopher D. Rahn
Keyword(s):  
Lithium Ion Batteries ◽  
Transfer Functions ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Lithium Ion ◽  
Particle Model ◽  
Simulation Design ◽  
Material Particle ◽  
Reduced Order ◽  
Cell Parameters

This paper develops reduced order, linear models of lithium ion batteries that can be used for model-based power train simulation, design, estimation, and controlling in hybrid and electric vehicles (HEV). First, a reduced order model is derived from the fundamental governing electrochemical charge and Li+ conservation equations that are linearized at the operating state of charge and low current density. The equations are solved using analytical and numerical techniques to produce the transcendental impedance or transfer function from input current to output voltage. This model is then reduced to a low order state space model using a system identification technique based on least squares optimization. Given the prescribed current, the model predicts voltage and other variables such as electrolyte and electrode surface concentration distributions. The second model is developed by neglecting electrolyte diffusion and modeling each electrode with a single active material particle. The transcendental particle transfer functions are discretized using a Padé Approximation. The explicit form of the single particle model impedance can be realized by an equivalent circuit with resistances and capacitances related to the cell parameters. Both models are then tuned to match experimental electrochemical impedance spectroscopy (EIS) and pulse current-voltage data.

Electrochemical Properties of Carbon-Coated NbO2 as a Negative Electrode for Lithium-Ion Batteries

2016 ◽  
Vol 724 ◽  
pp. 87-91 ◽  
Author(s):  
Chang Su Kim ◽  
Yong Hoon Cho ◽  
Kyoung Soo Park ◽  
Soon Ki Jeong ◽  
Yang Soo Kim
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Ball Milling ◽  
Carbon Coating ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Carbon Coated

We investigated the electrochemical properties of carbon-coated niobium dioxide (NbO2) as a negative electrode material for lithium-ion batteries. Carbon-coated NbO2 powders were synthesized by ball-milling using carbon nanotubes as the carbon source. The carbon-coated NbO2 samples were of smaller particle size compared to the pristine NbO2 samples. The carbon layers were coated non-uniformly on the NbO2 surface. The X-ray diffraction patterns confirmed that the inter-layer distances increased after carbon coating by ball-milling. This lead to decreased charge-transfer resistance, confirmed by electrochemical impedance spectroscopy, allowing electrons and lithium-ions to quickly transfer between the active material and electrolyte. Electrochemical performance, including capacity and initial coulombic efficiency, was therefore improved by carbon coating by ball-milling.

scholarly journals Electrical Response of Mechanically Damaged Lithium-Ion Batteries

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4284
Author(s):  
Damoon Soudbakhsh ◽  
Mehdi Gilaki ◽  
William Lynch ◽  
Peilin Zhang ◽  
Taeyoung Choi ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Electrical Response ◽  
Mechanical Damage ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Battery Management System ◽  
Battery Cell ◽  
Cell Parameters

Lithium-ion batteries have found various modern applications due to their high energy density, long cycle life, and low self-discharge. However, increased use of these batteries has been accompanied by an increase in safety concerns, such as spontaneous fires or explosions due to impact or indentation. Mechanical damage to a battery cell is often enough reason to discard it. However, if an Electric Vehicle is involved in a crash, there is no means to visually inspect all the cells inside a pack, sometimes consisting of thousands of cells. Furthermore, there is no documented report on how mechanical damage may change the electrical response of a cell, which in turn can be used to detect damaged cells by the battery management system (BMS). In this research, we investigated the effects of mechanical deformation on electrical responses of Lithium-ion cells to understand what parameters in electrical response can be used to detect damage where cells cannot be visually inspected. We used charge-discharge cycling data, capacity fade measurement, and Electrochemical Impedance Spectroscopy (EIS) in combination with advanced modeling techniques. Our results indicate that many cell parameters may remain unchanged under moderate indentation, which makes detection of a damaged cell a challenging task for the battery pack and BMS designers.

scholarly journals Utilizing the Intrinsic Thermal Instability of Swedenborgite Structured YBaCo4O7+δ as an Opportunity for Material Engineering in Lithium-Ion Batteries by Er and Ga Co-Doping Processes

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4565
Author(s):  
Sanghyuk Park ◽  
Kwangho Park ◽  
Ji-Seop Shin ◽  
Gyeongbin Ko ◽  
Wooseok Kim ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Phase Stability ◽  
Electrochemical Impedance ◽  
Coulombic Efficiency ◽  
Structural Phase ◽  
Active Material ◽  
Rate Capability ◽  
Lithium Ion ◽  
Ion Migration ◽  
Co Doping

We firstly introduce Er and Ga co-doped swedenborgite-structured YBaCo4O7+δ (YBC) as a cathode-active material in lithium-ion batteries (LIBs), aiming at converting the phase instability of YBC at high temperatures into a strategic way of enhancing the structural stability of layered cathode-active materials. Our recent publication reported that Y0.8Er0.2BaCo3.2Ga0.8O7+δ (YEBCG) showed excellent phase stability compared to YBC in a fuel cell operating condition. By contrast, the feasibility of the LiCoO2 (LCO) phase, which is derived from swedenborgite-structured YBC-based materials, as a LIB cathode-active material is investigated and the effects of co-doping with the Er and Ga ions on the structural and electrochemical properties of Li-intercalated YBC are systemically studied. The intrinsic swedenborgite structure of YBC-based materials with tetrahedrally coordinated Co2+/Co3+ are partially transformed into octahedrally coordinated Co3+, resulting in the formation of an LCO layered structure with a space group of R-3m that can work as a Li-ion migration path. Li-intercalated YEBCG (Li[YEBCG]) shows effective suppression of structural phase transition during cycling, leading to the enhancement of LIB performance in Coulombic efficiency, capacity retention, and rate capability. The galvanostatic intermittent titration technique, cyclic voltammetry and electrochemical impedance spectroscopy are performed to elucidate the enhanced phase stability of Li[YEBCG].

State Estimation for Lithium-Ion Batteries With Phase Transition Materials Via Boundary Observers

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Shumon Koga ◽  
Leobardo Camacho-Solorio ◽  
Miroslav Krstic
Keyword(s):  
Phase Transition ◽  
Lithium Ion Batteries ◽  
Lithium Iron Phosphate ◽  
Moving Boundary ◽  
Active Material ◽  
Lithium Ion ◽  
Estimation Algorithm ◽  
Iron Phosphate ◽  
Particle Model ◽  
Lithium Ions

Abstract Lithium iron phosphate (LiFePO4 or LFP) is a common active material in lithium-ion batteries. It has been observed that this material undergoes phase transitions during the normal charge and discharge operation of the battery. Electrochemical models of lithium-ion batteries can be modified to account for this phenomenon at the expense of some added complexity. We explore this problem for the single particle model (SPM) where the underlying dynamic model for diffusion of lithium ions in phase transition materials is a partial differential equation (PDE) with a moving boundary. We derive a novel boundary observer to estimate the concentration of lithium ions together with a moving boundary radius from the SPM via the backstepping method for PDEs, and simulations are provided to illustrate the performance of the observer. Our comments are stated on the gap between the proposed observer and a complete state-of-charge (SoC) estimation algorithm for lithium-ion batteries with phase transition materials.

State Estimation for Lithium Ion Batteries With Phase Transition Materials

2017 ◽  
Author(s):  
Shumon Koga ◽  
Leobardo Camacho-Solorio ◽  
Miroslav Krstic
Keyword(s):  
Phase Transition ◽  
Lithium Ion Batteries ◽  
Lithium Iron Phosphate ◽  
Moving Boundary ◽  
Active Material ◽  
Lithium Ion ◽  
Estimation Algorithm ◽  
Iron Phosphate ◽  
Particle Model ◽  
Lithium Ions

Lithium Iron Phosphate (LiFePO4 or LFP) is a common active material in lithium-ion batteries. It has been observed that this material undergoes phase transitions during the normal charge and discharge operation of the battery. Electrochemical models of lithium-ion batteries can be modified to account for this phenomena at the expense of some added complexity. We explore this problem for the single particle model (SPM) where the underlying dynamic model for diffusion of lithium ions in phase transition materials is a partial differential equation (PDE) with a moving boundary. An observer is derived for the concentration of lithium ions from the SPM via the backstepping method for PDEs in a rigorous way and simulations are provided to illustrate the performance of the observer. Our comments are stated on the gap between the proposed observer and a complete state-of-charge (SoC) estimation algorithm for lithium-ion batteries with phase transition materials.

Anode performances of mixed LiMn2O4 and carbon black toward lithium-ion battery

2014 ◽  
Vol 07 (02) ◽  
pp. 1450017 ◽  
Author(s):  
Kunfeng Chen ◽  
Dongfeng Xue
Keyword(s):  
Carbon Black ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Lithium Ion ◽  
Electrochemical Performances ◽  
Commercial Carbon ◽  
Utilization Ratio ◽  
Material Utilization ◽  
Charge Discharge

The mixed LiMn 2 O 4 and carbon black were served as anodes for lithium-ion batteries and the samples with high active material utilization ratio showed the highest capacity and cycling retention of 407.0 mAh/g after 50 charge/discharge cycles. The galvanostatic cycling and electrochemical impedance measurements were used to study their electrochemical performances. The commercial carbon black showed higher cycling retention, 162.0 mAh/g after 50 charge/discharge cycles. The present results confirmed that the capacity and cycling retention of LiMn 2 O 4 anodes can be improved by the increase of conductivity in lithium-ion batteries, which can increase the utilization ratio of active materials.

scholarly journals Characterization of the Compressive Load on a Lithium-Ion Battery for Electric Vehicle Application

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 71
Author(s):  
Seyed Saeed Madani ◽  
Erik Schaltz ◽  
Søren Knudsen Kær
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Electric Vehicles ◽  
Large Scale ◽  
Electrochemical Impedance ◽  
Applied Pressure ◽  
Lithium Ion ◽  
Battery Cells

Lithium-ion batteries are being implemented in different large-scale applications, including aerospace and electric vehicles. For these utilizations, it is essential to improve battery cells with a great life cycle because a battery substitute is costly. For their implementation in real applications, lithium-ion battery cells undergo extension during the course of discharging and charging. To avoid disconnection among battery pack ingredients and deformity during cycling, compacting force is exerted to battery packs in electric vehicles. This research used a mechanical design feature that can address these issues. This investigation exhibits a comprehensive description of the experimental setup that can be used for battery testing under pressure to consider lithium-ion batteries’ safety, which could be employed in electrified transportation. Besides, this investigation strives to demonstrate how exterior force affects a lithium-ion battery cell’s performance and behavior corresponding to static exterior force by monitoring the applied pressure at the dissimilar state of charge. Electrochemical impedance spectroscopy was used as the primary technique for this research. It was concluded that the profiles of the achieved spectrums from the experiments seem entirely dissimilar in comparison with the cases without external pressure. By employing electrochemical impedance spectroscopy, it was noticed that the pure ohmic resistance, which is related to ion transport resistance of the separator, could substantially result in the corresponding resistance increase.

scholarly journals Determination of the Distribution of Relaxation Times by Means of Pulse Evaluation for Offline and Online Diagnosis of Lithium-Ion Batteries

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 36
Author(s):  
Erik Goldammer ◽  
Julia Kowal
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Sampling Rate ◽  
Relaxation Times ◽  
Low Frequency ◽  
Lithium Ion ◽  
Battery Management ◽  
Time Constants ◽  
Time Domain Data ◽  
Aging Study

The distribution of relaxation times (DRT) analysis of impedance spectra is a proven method to determine the number of occurring polarization processes in lithium-ion batteries (LIBs), their polarization contributions and characteristic time constants. Direct measurement of a spectrum by means of electrochemical impedance spectroscopy (EIS), however, suffers from a high expenditure of time for low-frequency impedances and a lack of general availability in most online applications. In this study, a method is presented to derive the DRT by evaluating the relaxation voltage after a current pulse. The method was experimentally validated using both EIS and the proposed pulse evaluation to determine the DRT of automotive pouch-cells and an aging study was carried out. The DRT derived from time domain data provided improved resolution of processes with large time constants and therefore enabled changes in low-frequency impedance and the correlated degradation mechanisms to be identified. One of the polarization contributions identified could be determined as an indicator for the potential risk of plating. The novel, general approach for batteries was tested with a sampling rate of 10 Hz and only requires relaxation periods. Therefore, the method is applicable in battery management systems and contributes to improving the reliability and safety of LIBs.

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