scholarly journals Temperature Control to Reduce Capacity Mismatch in Parallel-Connected Lithium Ion Cells

2019 ◽  
Author(s):  
Mayank Garg ◽  
Tanvir R. Tanim ◽  
Christopher D. Rahn ◽  
Hanna Bryngelsson ◽  
Niklas Legnedahl
Keyword(s):  
Temperature Control ◽  
Current Distribution ◽  
Lithium Iron Phosphate ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Premature Aging ◽  
Battery Pack ◽  
Different Temperatures ◽  
Uniform Current

Abstract The temperature and capacity of individual cells affect the current distribution in a battery pack. Non uniform current distribution among parallel-connected cells can lead to capacity imbalance and premature aging. This paper develops models that calculate the current in parallel-connected cells and predict their capacity fade. The model is validated experimentally for a nonuniform battery pack at different temperatures. The paper also proposes and validates the hypothesis that temperature control can reduce capacity mismatch in parallel-connected cells. Three Lithium Iron Phosphate cells, two cells at higher initial capacity than the third cell, are connected in parallel. The pack is cycled for 1500 Hybrid Electric Vehicles cycles with the higher capacity cells regulated at 40°C and the lower capacity cell at 20°C. As predicted by the model, the higher capacity and temperature cells age faster, reducing the capacity mismatch by 48% over the 1500 cycles. A case study shows that cooling of low capacity cells can reduce capacity mismatch and extend pack life.

scholarly journals Material Characterization and Analysis on the Effect of Vibration and Nail Penetration on Lithium Ion Battery

2019 ◽  
Vol 10 (4) ◽  
pp. 69
Author(s):  
Ajeet Babu K. Parasumanna ◽  
Ujjwala S. Karle ◽  
Mangesh R. Saraf
Keyword(s):  
Surface Morphology ◽  
Lithium Iron Phosphate ◽  
Electrochemical Impedance ◽  
Dynamic Stiffness ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Internal Resistance ◽  
Chemical Degradation ◽  
Battery Pack ◽  
A Cell

Battery packaging in a vehicle depends on the cell chemistry being used and its behavior plays an important role in the safety of the entire battery pack. Chemical degradation of various parts of a cell such as the cathode or anode is a concern as it adversely affects performance and safety. A cell in its battery pack once assembled can have two different mechanical abuse condition. One is the vibration generated from the vehicle and the second is the intrusion of external elements in case of accident. In this paper, a commercially available 32,700 lithium ion cell with lithium iron phosphate (LFP) chemistry is studied for its response to both the abuse conditions at two different states of charge (SoC). The primary aim of this study is to understand their effect on the surface morphology of the cathode and the anode. The cells are also characterized to study impedance behavior before and after being abused mechanically. The cells tested for vibration were also analyzed for dynamic stiffness. A microscopy technique such as scanning electron microscopy (SEM) was used to study the surface morphology and electrochemical impedance spectroscopy (EIS) characterization was carried out to study the internal resistance of the cell. It was observed that there was a drop in internal resistance and increase in the stiffness after the cells subjected to mechanical abuse. The study also revealed different morphology at the center and at the corner of the cell subjected to nail penetration at 50% SoC.

scholarly journals Research on the Capacity of Li-ion Battery Packer Based on Capacity Incremental Curve

2021 ◽  
Vol 237 ◽  
pp. 02018
Author(s):  
Yu Tian ◽  
Zhengyuan Zhu ◽  
Shuangyu Liu ◽  
Dongpei Qian ◽  
Xiao Yan ◽  
...  
Keyword(s):  
Single Cell ◽  
Electric Vehicles ◽  
Lithium Iron Phosphate ◽  
Characteristic Point ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Battery Pack ◽  
Analysis Tool ◽  
In Series ◽  
Battery Technology

Lithium ion battery is the most widely used and reliable power source for electric vehicles. With the development of electric vehicles, the safety, energy density, life and reliability of lithium ion batteries have been continuously improved. However, in the field of vehicle power battery technology, battery monomers are combined in series and parallel to provide enough energy, but one of the major problems faced by group batteries is the consistency between battery monomers. Taking the capacity increment curve (IC curve) of lithium iron phosphate battery as the analysis tool, it is found that the characteristic peak of IC curve of different monomers in battery pack can reflect the relationship of monomer capacity. On this basis, the mathematical model is established, and the IC curve II peak characteristic point of a single cell are used as the reference to characterize the capacity of the single cell one by one. The results show that the method can be used in the normal charging process of the battery pack, and the capacity of the single cell in the battery pack can be characterized in real time during the whole life of the battery pack. It has certain research value for the ladder utilization and accurate management of battery pack.

scholarly journals Optimize Thermal Management And Experiment Of Lifepo4 Battery Pack For Hybrid Electrical Vehicle

2021 ◽  
Vol 2 (6) ◽  
pp. 1922-1933
Author(s):  
Abdul Muchlis ◽  
Moh. Yamin
Keyword(s):  
Thermal Management ◽  
Lithium Iron Phosphate ◽  
Fuel Efficiency ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Battery Pack ◽  
Gasoline Engines ◽  
Electrical Vehicle ◽  
Fan Speed ◽  
Comparison Of The Results

Hybrid Electric Vehicles (HEV) combines the benefits of gasoline engines and electric motors which can be configured for improving fuel efficiency. Lithium Iron Phosphate (LiFePO4) Phosphate based technology possesses superior thermal and chemical stability which provides better safety characteristics than those of Lithium-ion technology made with other cathode materials. This research conducted by two methods , methods of part 1 is a comparison of the results with the thermal management simulation and experiment, part 2 is a method of optimizing the thermal management for battery pack by using solidwork software. When the fan is on, the forced air flow over the cells removes some of the generated heat. Results of method part 1 is simulation more heat than experiment in the amount of  0.11% – 1.56%. The results of the method part 2 is simulated using the fan 4 fan with a speed of 415 rad/s and battery gap 30mm most efficient compared with 4 fans the other , while the simulation using 6 fan, fan speed 415 rad/s and battery gap 30mm most efficient for all.

scholarly journals Analysis of the Charging and Discharging Process of LiFePO4 Battery Pack

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4055
Author(s):  
Wiesław Madej ◽  
Andrzej Wojciechowski
Keyword(s):  
Lithium Iron Phosphate ◽  
Electronic Devices ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Power Source ◽  
Battery Pack ◽  
Correct Selection ◽  
Portable Devices ◽  
Major Drawback ◽  
Initial Charge

A serious issue relative to the construction of electronic devices is proper power source selection. This problem is of particular importance when we are dealing with portable devices operating in varying environmental conditions, such as military equipment. A serious problem in the construction of electronic devices is the correct selection of the power source. In these types of devices, lithium-ion batteries are commonly used nowadays, and in particular their variety—lithium iron phosphate battery—LiFePO4. Apart from the many advantages of this type of battery offers, such as high power and energy density, a high number of charge and discharge cycles, and low self-discharge. They also have a major drawback—a risk of damage due to excessive discharge or overcharge. This article studies the process of charging and discharging a battery pack composed of cells with different initial charge levels. An attempt was made to determine the risk of damage to the cells relative to the differences in the initial charge level of the battery pack cells. It was verified, whether the successive charging and discharging cycles reduce or increase the differences in the amount of energy stored in individual cells of the pack.

Graphenised Lithium Iron Phosphate and Lithium Manganese Silicate Hybrid Cathodes: Potentials for Application in Lithium‐ion Batteries

2020 ◽  
Vol 32 (12) ◽  
pp. 2982-2999
Author(s):  
Zolani Myalo ◽  
Chinwe Oluchi Ikpo ◽  
Assumpta Chinwe Nwanya ◽  
Miranda Mengwi Ndipingwi ◽  
Samantha Fiona Duoman ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Iron Phosphate ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Manganese Silicate ◽  
Lithium Manganese

scholarly journals A Novel Pyrometallurgical Recycling Process for Lithium-Ion Batteries and Its Application to the Recycling of LCO and LFP

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 149
Author(s):  
Alexandra Holzer ◽  
Stefan Windisch-Kern ◽  
Christoph Ponak ◽  
Harald Raupenstrauch
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Iron Phosphate ◽  
Process Development ◽  
Removal Rate ◽  
Continuous Process ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Recycling Process ◽  
Subsequent Step ◽  
Pre Treatment

The bottleneck of recycling chains for spent lithium-ion batteries (LIBs) is the recovery of valuable metals from the black matter that remains after dismantling and deactivation in pre‑treatment processes, which has to be treated in a subsequent step with pyrometallurgical and/or hydrometallurgical methods. In the course of this paper, investigations in a heating microscope were conducted to determine the high-temperature behavior of the cathode materials lithium cobalt oxide (LCO—chem., LiCoO2) and lithium iron phosphate (LFP—chem., LiFePO4) from LIB with carbon addition. For the purpose of continuous process development of a novel pyrometallurgical recycling process and adaptation of this to the requirements of the LIB material, two different reactor designs were examined. When treating LCO in an Al2O3 crucible, lithium could be removed at a rate of 76% via the gas stream, which is directly and purely available for further processing. In contrast, a removal rate of lithium of up to 97% was achieved in an MgO crucible. In addition, the basic capability of the concept for the treatment of LFP was investigated whereby a phosphorus removal rate of 64% with a simultaneous lithium removal rate of 68% was observed.

Modification of liquid-phase synthesis of lithium-iron phosphate, a cathode material for lithium-ion battery

2012 ◽  
Vol 85 (6) ◽  
pp. 879-882 ◽  
Author(s):  
E. N. Kudryavtsev ◽  
R. V. Sibiryakov ◽  
D. V. Agafonov ◽  
V. N. Naraev ◽  
A. V. Bobyl’
Keyword(s):  
Liquid Phase ◽  
Cathode Material ◽  
Lithium Ion Battery ◽  
Lithium Iron Phosphate ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Phase Synthesis

Iron Phosphates as Cathodes of Lithium-Ion Batteries

2006 ◽  
Vol 973 ◽  
Author(s):  
Shijun Wang ◽  
M. Stanley Whittingham
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Iron Phosphate ◽  
Low Cost ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Environmentally Benign ◽  
Iron Phosphates ◽  
Electrochemical Capacity ◽  
High Theoretical Capacity ◽  
Olivine Structure

ABSTRACTThis study focusses on optimizing the parameters of the hydrothermal synthesis to produce iron phosphates for lithium ion batteries, with an emphasis on pure LiFePO4 with the olivine structure and compounds containing a higher iron:phosphate ratio. Lithium iron phosphate (LiFePO4) is a promising cathode candidate for lithium ion batteries due to its high theoretical capacity, environmentally benign and the low cost of starting materials. Well crystallized LiFePO4 can be successfully synthesized at temperatures above 150 °C. The addition of a reducing agent, such as hydrazine, is essential to minimize the oxidation of ferrous (Fe2+) to ferric (Fe3+) in the final compound. The morphology of LiFePO4 is highly dependent on the pH of the initial solution. This study also investigated the lipscombite iron phosphates of formula Fe1.33PO4OH. This compound has a log-like structure formed by Fe-O octahedral chains. The chains are partially occupied by the Fe3+ sites, and these iron atoms and some of the vacancies can be substituted by other cations. Most of the protons can be ion-exchanged for lithium, and the electrochemical capacity is much increased.

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