Thermal runaway mechanism of lithium ion battery for electric vehicles: A review

A review of lithium ion battery failure mechanisms and fire prevention strategies

Calibration and finite element simulation of pouch lithium-ion batteries for mechanical integrity

Homogenized mechanical properties for the jellyroll of cylindrical Lithium-ion cells

This research reports on an experimental and numerical study of material failure in the electrode assemblies (i.e. “jelly roll” and/or “electrode stack”) of lithium-ion batteries after local mechanical loading. Deformed cylindrical and pouch cells (i.e. lithium-ion polymer cells) were subjected to X-ray computed tomography (CT scanning) to detect location, size, and orientation of cracks that developed in the electrode assemblies at onset of short-circuit. An experimental program was completed to acquire properties of electrode–separator micro components of electrode assemblies in tension. This data was used for calibration of an anisotropic material model. Finite element models were developed for both cell types and a maximum strain criteria was used for element failure and deletion at short circuit. The models developed here predict the location of cracks in both pouch and cylindrical cells. The finite element models corroborated the CT scan regarding location and orientation of cracks formed in the electrode assemblies. In both pouch and cylindrical cells, cracks were found to initiate perpendicular to the transverse direction of the separator.

Modelling of cracks developed in lithium-ion cells under mechanical loading

Determination of welding pressure in the non-steady-state porthole die extrusion of improved Al7003 hollow section tubes

Investigation on blanking of thin sheet metal using the ductile fracture criterion and its experimental verification

This paper describes a numerical analysis of non-steady state porthole die extrusion, which is useful for manufacturing long tubes with a hollow section. Materials divided through several portholes are gathered within a chamber and are then welded under high pressure. This weldability classifies the quality of tube products and is affected by process variables and die shapes. However, porthole die extrusion has been executed based on the experience of experts, due to the complicated die assembly and the complexity of metal flow. To better assist the design of die and to obtain improvement of productivity, non-steady 3D FE simulation for porthole die extrusion is required. Therefore, the objective of this study is to analyze the behavior of metal flow and to determine the welding pressure of hot extrusion products according to various billet temperatures, bearing length, and tube thickness by FE analysis. The results of FE analysis are compared with those of experiments.

Prediction of welding pressure in the non-steady state porthole die extrusion of Al7003 tubes

https://cyberleninka.org/article/n/213278.pdf

Genetic characteristics of Sasang typology: a systematic review.

Temperature-sensitive hybrid films were synthesized with a concentration gradient by casting and UV curing of N-isopropylacrylamide (NIPAAm) monomers (0%–70%) on the free surface of waterborne polyurethane (WPU) films on a Teflon substrate. The surface hardness and contact angle of the free surface with a water drop increased asymptotically with the addition of NIPAAm, whereas those on the substrate side were virtually unchanged. The diffusion coefficient (D), rates of swelling at 20°C (below the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM)) and deswelling at 50°C (above the LCST) increased with increasing NIPAM content, showing favorable thermosensitivity. In addition, the glassy state modulus and glass transition temperature (Tg) of the film increased with increasing NIPAM content, whereas the rubbery modulus decreased due to the increased molecular weight between the crosslinks. In addition, as the NIPAM content increased, the film showed a positive yield with an i...

S.K Lee

Papers

Determination of welding pressure in the non-steady-state porthole die extrusion of improved Al7003 hollow section tubes

Investigation on blanking of thin sheet metal using the ductile fracture criterion and its experimental verification

Prediction of welding pressure in the non-steady state porthole die extrusion of Al7003 tubes

Genetic characteristics of Sasang typology: a systematic review.

Synthesis and Properties of Thermosensitive Poly(N-Isopropylacrylamide)/Waterborne Polyurethane Graded Concentration Hybrid Films