Browsing by Author "Kausthubharam, n."

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Combined influence of concentration-dependent properties, local deformation and boundary confinement on the migration of Li-ions in low-expansion electrode particle during lithiation
(Elsevier Ltd, 2022) Kausthubharam, n.; Koorata, P.K.; Panchal, S.; Fraser, R.; Fowler, M.
In this article, a low expansion electrode particle is investigated for mechanical stresses during lithiation with intrinsic and extrinsic factors included. The stress states are estimated with local deformation, concentration dependent properties, and external constraints. It is observed that lithiation of an unconstrained electrode particle lead to reduced concentration gradient of Li-ions with increase in stress magnitude for a case where the particle show concentration dependent stiffening response. Whereas, the constrained expansion of the same electrode particle result in reduced and elevated concentration gradient at near-field and far-field locations, respectively. Influence of charging rate is also reported wherein limiting stress (threshold limit) is observed with increasing charging rate. Further, at elevated charging rates, a drastic reduction in concentration gradient is observed at the surface of the electrode particle. © 2022 Elsevier Ltd
Impact of mechanical stiffening and softening on the spatial distribution of lithium ions in spherical electrode particle under galvanostatic charging
(John Wiley and Sons Ltd, 2021) Kausthubharam, n.; Koorata, P.K.; Chandrasekaran, N.
This article investigates the lithiation of low-expansion electrode particles with concentration-dependent properties. The conventional electrochemical coupled stress equations do not take into account concentration dependency, especially for particles with a low volume of expansion, as they are assumed to have no impact on the lithium-ion (Li-ion) migration. However, considerable changes are observed in the present study when this factor is included. The Li-ion concentration gradient is observed to decrease with stiffening and increase with softening in an electrode particle. The stresses at the center of the particle increase with stiffening and reduce with the softening. It is observed that the effect of concentration-dependent elastic modulus on the concentration gradient of lithium ions at the surface of the particle is more prominent at higher charging rates. The stresses in the electrode particle are observed to increase in proportion to an increase in the charging rate up to a critical limit beyond which its magnitude reduces. © 2021 John Wiley & Sons Ltd.
Investigation of the thermal performance of biomimetic minichannel-based liquid-cooled large format pouch battery pack
(Elsevier Ltd, 2024) Kausthubharam, n.; Koorata, P.K.; Panchal, S.; Fraser, R.; Fowler, M.
This article presents a diagonal-type minichannel-based thermal management system for a 20 Ah pouch cell battery. An optimal thermal strategy is suggested by numerically investigating the cooling performance of the proposed design for various structural and operational parameters. Besides the design, mini-channel optimization is observed to have played a significant role in pressure drop and temperature. An operational parametric study recommends an inlet temperature of 25 °C and a flow rate of 12.5 cm3/s for the liquid coolant for optimal pouch cell performance. The enhancement of temperature distribution uniformity is noted to diminish at higher cooling fluid flow rates. Further, a comparison with existing literature revealed a 75 % increase in temperature homogeneity across the pouch cell. The feasibility of the proposed design with an optimized cooling framework at the module level is demonstrated for the 43 V battery pack. The thermal system maintained the maximum temperature in the pack 20 % below the upper limit of the recommended range for Li-ion cells. © 2024 Elsevier Ltd
Numerical investigation of cooling performance of a novel air-cooled thermal management system for cylindrical Li-ion battery module
(Elsevier Ltd, 2021) Kausthubharam, n.; Koorata, P.K.; Chandrasekaran, N.
Batteries strongly influence the performance of electric vehicles. Therefore it is crucial to develop a battery thermal system that is highly efficient in removing the battery pack's heat during its operation. In this paper, a numerical analysis of a lumped thermal model coupled with fluid flow equations is employed to investigate the novel air-cooled battery thermal management system (BTMS). The cooling efficiency of the proposed battery thermal system with commercial thermal interface material (3M™) is investigated by comparing it with a standard battery pack at different discharge rates. The proposed solution offers a 25% reduction in peak temperature when compared to the standard one. The thickness of the thermal interface material is found to have an insignificant impact on the battery pack's thermal performance. Introducing forced air-cooling in the battery pack reduced the maximum temperature considerably but increased the temperature difference compared to the battery pack without forced convection. Then the effect of various structural and operational parameters on the performance of the BTMS is investigated. Moving the air inlet-outlet boundaries to a central location increased the uniformity of temperature distribution in the battery pack. Although the increase in the inlet airflow velocity reduces the maximum temperature, it comes at the cost of an increase in temperature difference and power consumption. It is further observed that a reduction in ambient temperature reduces the peak temperature and makes the temperature distribution in the battery pack more homogeneous. The discharge voltage curves indicate a slight reduction in cell potential as a reducing function of temperature. © 2021 Elsevier Ltd
Thermal management of large-sized LiFePO4 pouch cell using simplified mini-channel cold plates
(Elsevier Ltd, 2023) Kausthubharam, n.; Koorata, P.K.; Panchal, S.
An efficient, simplified mini-channel cooling plate-based thermal management system is presented for LiFePO4 pouch cell. The proposed design improves the uniformity in surface temperature difference by more than 100% compared to existing literature data on similar designs. The proposed coolant design is tested for temperature distribution and cooling efficiency parameters by varying the cooling fluid volume flow rate and inlet temperatures from 15 ml/min to 150 ml/min and 5 °C to 35 °C, respectively. The proposed design maintains the maximum temperature in the cell well below 40 °C even under a 4C discharge rate and a high coolant inlet temperature of 35 °C. Increasing the coolant temperature is observed to positively impact the temperature homogeneity in the pouch cell. Further, an increase in the cooling liquid flow rate is observed to have a reduced impact on the maximum temperature reduction at all discharge rates. In comparison with the existing minichannel-based study, the proposed cooling system improved the temperature uniformity of the pouch cell by more than 140%. The proposed simple design is easily scalable to modular packs of pouch cells. © 2023 Elsevier Ltd