Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 8
    Citation - Scopus: 9
    Experimental Investigation of Air Cooling With/Out Tab Cooling in Cell and Module Levels for Thermal Uniformity in Battery Packs
    (ASME, 2023) Göçmen, Sinan; Çetkin, Erdal
    Catastrophic effects of global warming and environmental pollution are becoming more evident each day, and reduction in fossil fuel consumption is an urgent need. Thus, electric vehicles powered by sustainable energy sources are becoming a major interest. However, there are some challenges such as safety, limited range, long charging times, and battery life which are inhibitory to the adaptation of them. One of the biggest reasons for these challenges is the relationship between battery degradation and temperature which can be eliminated if batteries can be kept at the optimum temperature range. Here, the effects of three distinct (natural convection, forced convection, and tab cooling) methodology were experimentally compared at both the cell and module levels (six serial 7.5 Ah Kokam pouch cells, 1P6S) for thermal management of lithium-ion cells. The experiments were conducted at a discharge rate of 3C with ambient temperatures of 24 ◦C and 29 ◦C. The cell-level test results show that the tab cooling yields 32.5% better thermal uniformity in comparison to the other techniques. Furthermore, tab cooling yields better temperature uniformity with and without air convection as the hot spots occurring near the tabs is eliminated. For the module level, the forced air convection method stands out as the best option with a 4.3% temperature deviation between cells and maximum cell temperature of 39 ◦C. Overall, the results show that a hybrid approach with tab cooling would be beneficial in terms of temperature homogeneity especially in high capacity electric vehicle battery cells.
  • Article
    Citation - WoS: 75
    Citation - Scopus: 85
    Thermal Management System for Air-Cooled Battery Packs With Flow-Disturbing Structures
    (Elsevier, 2022) Şahin, R. Cagtay; Göçmen, Sinan; Çetkin, Erdal
    Lithium-ion battery packs are preferred in electrical vehicles (EVs) due to their efficient and stable characteristics. Battery thermal management systems (BTMS) have vital importance in EVs to keep batteries in the desired temperature range to maximize performance and lifetime. BTMS with air cooling is simpler and lighter relative to competing methods; however, low thermal conductivity and heat capacity of air necessitate thermal performance and pressure drop adjustments. This work offers a novel design method for cylindrical cells by evaluating the effect of various baffles (cylindrical, triangular, diamond and winglet) on the cooling performance and pressure drop of an air-cooled battery module with 12 21700 cylindrical cells. Thermal characteristics are simulated by the electrochemical-thermal battery model, the P3D multiscale model (modelling parameters for a commercial 21700 cell are documented) in COMSOL Multiphysics 5.5 and their accuracy is validated by experiments. As a result, baffles reduce the maximum temperature and temperature difference by 5% (1.8 °C) and 40% (1.7 °C), respectively, consuming 3.5 times more power than the base design. Delta winglets offer the optimum solution, reducing the maximum temperature and temperature difference by 2% (0.6 °C) and 15% (0.7 °C), respectively, with a 44% (0.12 W) rise in parasitic power consumption.