Design, Development and Thermal Analysis of Reusable Li-Ion Battery Module for Future Mobile and Stationary Applications

open access articleThe performance, energy storage capacity, safety, and lifetime of lithium-ion battery cells of different chemistries are very sensitive to operating and environmental temperatures. The cells generate heat by current passing through their internal resistances, and chemical reactions can generate additional, sometimes uncontrollable, heat if the temperature within the cells reaches the trigger temperature. Therefore, a high-performance battery cooling system that maintains cells as close to the ideal temperature as possible is needed to enable the highest possible discharge current rates while still providing a sufficient safety margin. This paper presents a novel design, preliminary development, and results for an inexpensive reusable, liquid-cooled, modular, hexagonal battery module that may be suitable for some mobile and stationary applications that have high charge and or discharge rate requirements. The battery temperature rise was measured experimentally for a six parallel 18650 cylindrical cell demonstrator module over complete discharge cycles at discharge rates of 1C, 2C and 3C. The measured temperature rises at the hottest point in the cells, at the anode terminal, were found to be 6, 17 and 22 °C, respectively. The thermal resistance of the system was estimated to be below 0.2 K/W at a coolant flow rate of 0.001 Kg/s. The proposed liquid cooled module appeared to be an effective solution for maintaining cylindrical Li-ion cells close to their optimum working temperature

Failure prediction of adhesively bonded lap joints between metal and composite adherends

Most of the modern civilian or military aircrafts use advanced composite materials for their primary structural components, in addition to metals. The components are joined together by using either fastener or adhesively bonded joints. But with the introduction of composite materials in aircraft industries, adhesively bonded lap joints are most preferred. This is due to the fact that they develop smooth load transfer and fewer points of stress concentration as compared to fastener joints. The failure prediction of such joints is extremely important, to avoid catastrophic failures during aircraft service period. In the present investigation, an adhesively bonded lap joint between metal-composite (i.e., Al 2024-T3/CFRP) adherends bonded with Redux 319-A adhesive has been analyzed using finite element method considering geometric non-linearity and incorporating adhesive material nonlinear behavior. The failure has been predicted using plastic zone size criterion of adhesive material, which is innovative approach of this study. Also, experimental program is carried out on such joints to correlate with the predicted failure load obtained from numerical model. In this study, the failure of joint is assumed to take place due to adhesive failure only. Plastic zone size in adhesive at failure load of joint is taken as 15 % of the lap length as established from the previous work of the authors. It is observed that the failure load of the adhesively bonded lap joint between composite-metal adherends as obtained from numerical model is well compared with that obtained from experimental study. Results are discussed

RuCl3 Catalyzed and Uncatalyzed Oxidative Decolorization of Acid Orange 7 Dye with Chloramine-B in Acid Medium: Spectrophotometric, Kinetic and Mechanistic Study

Acid orange 7, chemically known as sodium 4-[(2E)-2-(2-oxonaphthalen-1-ylidene)hydrazinyl]benzenesulfonate, is extensively used for dyeing textiles, paper and leather. The discharge of wastewater containing this dye, causes environmental and health related problems. Therefore, in the present research, we have developed optimum conditions for the facile oxidative decolorization of this dye with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB). The kinetics and mechanism of oxidative decolorization of acid orange 7 dye with CAB in acidic medium have also been studied spectrophotometrically at 303 K in the presence and absence of RuCl3 catalyst. Under similar experimental conditions, the reaction exhibits a first-order dependence of rate each on [CAB]o and [dye]o, and an inverse-fractional-order dependence on [H+] for both the RuCl3 catalyzed and uncatalyzed reactions. The order with respect to RuCl3 is fractional. Activation parameters have been computed. Dielectric effect is negative in both the cases. Oxidation products of the acid orange 7 dye are identified as 1,2-naphthoquinone and benzenesulfonic acid by GC–MS data. The RuCl3 catalyzed reaction is about four fold faster than the uncatalyzed reaction. The chemical oxygen demand value of the dye was determined. The mechanistic pathways and kinetic modelings have been computed based on experimental results. The developed oxidative decolorization method is expected to be helpful to treat acid orange 7 dye present in wastewater after suitable modifications