Isothermal calorimeter heat measurements of a 20Ah lithium iron phosphate battery cell

2017 ◽  
Author(s):  
Lluis Millet ◽  
Maximilian Bruch ◽  
Peter Raab ◽  
Stephan Lux ◽  
Matthias Vetter
Keyword(s):  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Battery Cell ◽  
Isothermal Calorimeter

scholarly journals Morphology and Electrical Conductivity of Carbon Nanocoatings Prepared from Pyrolysed Polymers

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Marcin Molenda ◽  
Michał Świętosławski ◽  
Marek Drozdek ◽  
Barbara Dudek ◽  
Roman Dziembaj
Keyword(s):  
Electrical Conductivity ◽  
Electrode Materials ◽  
Lithium Iron Phosphate ◽  
Solid Phase ◽  
Scale Up ◽  
Iron Phosphate ◽  
Battery Cell ◽  
Pyromellitic Acid ◽  
Specific Morphology ◽  
Precursor Composition

Conductive carbon nanocoatings (conductive carbon layers—CCL) were formed onα-Al2O3model support using three different polymer precursors and deposition methods. This was done in an effort to improve electrical conductivity of the material through creating the appropriate morphology of the carbon layers. The best electrical properties were obtained with use of a precursor that consisted of poly-N-vinylformamide modified with pyromellitic acid (PMA). We demonstrate that these properties originate from a specific morphology of this layer that showed nanopores (3-4 nm) capable of assuring easy pathways for ion transport in real electrode materials. The proposed, water mediated, method of carbon coating of powdered supports combines coating from solution and solid phase and is easy to scale up process. The optimal polymer carbon precursor composition was used to prepare conductive carbon nanocoatings on LiFePO4cathode material. Charge-discharge tests clearly show that C/LiFePO4composites obtained using poly-N-vinylformamide modified with pyromellitic acid exhibit higher rechargeable capacity and longer working time in a battery cell than standard carbon/lithium iron phosphate composites.

Entropy Coefficient and Thermal Time Constant Estimation From Dynamic Thermal Cycling of a Cylindrical LiFePO4 Battery Cell

2014 ◽  
Author(s):  
Sergio Mendoza ◽  
Hosam K. Fathy
Keyword(s):  
Time Constant ◽  
Lithium Iron Phosphate ◽  
Lithium Ion ◽  
Iron Phosphate ◽  
Temperature Cycling ◽  
Thermal Time ◽  
Quasi Equilibrium ◽  
Battery Cell ◽  
Thermal Time Constant ◽  
Time Required

This paper presents a method for estimating (i) the reciprocal of the thermal time constant of a lithium-ion battery cell and (ii) the cell’s entropy coefficients for different states of charge. The method utilizes dynamic battery temperature cycling for parameter estimation. The paper demonstrates this method specifically for a cylindrical lithium iron phosphate (LiFePO4) cell. Identifying battery thermal parameters is important for accurate thermo-electrochemical modeling and model-based battery management. Entropy coefficients have been identified in previous research for various battery chemistries using calorimetric and potentiometric measurements requiring quasi-equilibrium conditions. This work, in contrast, fits the entropy coefficients and the reciprocal of the thermal time constant of a first-order thermal model to datasets collected in a noninvasive, dynamic experiment. This reduces the time required for parameter identification by a factor of 3 compared to traditional quasi-equilibrium experiments.

scholarly journals Determining the Limits and Effects of High-Rate Cycling on Lithium Iron Phosphate Cylindrical Cells

Batteries ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 57
Author(s):  
Justin Holloway ◽  
Faduma Maddar ◽  
Michael Lain ◽  
Melanie Loveridge ◽  
Mark Copley ◽  
...  
Keyword(s):  
High Performance ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
High Rate ◽  
Catastrophic Failure ◽  
Safety Factors ◽  
Battery Cell ◽  
Capacity Loss ◽  
Maximum Current ◽  
Current Operation

The impacts on battery cell ageing from high current operation are investigated using commercial cells. This study utilised two tests–(i) to establish the maximum current limits before cell failure and (ii) applying this maximum current until cell failure. Testing was performed to determine how far cycling parameters could progress beyond the manufacturer’s recommendations. Current fluxes were increased up to 100 C cycling conditions without the cell undergoing catastrophic failure. Charge and discharge current capabilities were possible at magnitudes of 1.38 and 4.4 times, respectively, more than that specified by the manufacturer’s claims. The increased current was used for longer term cycling tests to 500 cycles and the resulting capacity loss and resistance increase was dominated by thermal fatigue of the electrodes. This work shows that there is a discrepancy between manufacturer-stated current limits and actual current limits of the cell, before the cell undergoes catastrophic failure. This presumably is based on manufacturer-defined performance and lifetime criteria, as well as prioritised safety factors. For certain applications, e.g., where high performance is needed, this gap may not be suitable; this paper shows how this gap could be narrowed for these applications using the testing described herein.

scholarly journals Large Prismatic Lithium Iron Phosphate Battery Cell Model Using PSCAD

2014 ◽  
Vol 02 (02) ◽  
pp. 21-26
Author(s):  
Garo Yessayan ◽  
Dipesh D. Patel ◽  
Ziyad M. Salameh
Keyword(s):  
Lithium Iron Phosphate ◽  
Cell Model ◽  
Iron Phosphate ◽  
Battery Cell

scholarly journals Thermal Behaviour of a Cylindrical Li-Ion Battery

2021 ◽  
Vol 65 (2-4) ◽  
pp. 218-223
Author(s):  
Luca Giammichele ◽  
Valerio D’Alessandro ◽  
Matteo Falone ◽  
Renato Ricci
Keyword(s):  
Surface Temperature ◽  
Heat Generation ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Open Circuit ◽  
Operating Conditions ◽  
Battery Cell ◽  
Cell Potential ◽  
Discharge Rates ◽  
Wide Range

This paper presents an experimental evaluation of thermal and electrical performances of a 26650 cylindrical Lithium Iron Phosphate/graphite battery cell. Thermal management of Lithium batteries is a fundamental issue of electric mobility, where batteries are subjected to severe operating conditions. Therefore, battery heat generation is a very important characteristic to be studied. In this work cell performances were assessed during battery discharge at ambient temperature over a wide range of discharge rates. The cell surface temperature was measured both with thermocouples and infrared thermography. Furthermore, also the open circuit potential and entropic heat coefficient were experimentally measured. Based on this experimental data, a simplified battery thermal model was used to evaluate the battery heat generation. The results show a substantial increase of battery surface temperature especially at high discharge rates. During discharge, the heat generated is greater at low battery state of charge due to the sudden decrease of cell potential. The contributions to heat generation are also carefully evaluated.

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