Rajlakshmi Purkayastha EDUCATION 2008 – Present Ph.D Candidate, Materials RESEARCH INTERESTS My main research interest is using computational methods to study materials, primarily in energy storage devices such as batteries and fuel cells. My expertise lies in the Finite Element Method, which is used for continuum scale calculations. I have been working on applying principles from structural mechanics to the electrochemical environment in order to study degradation of materials more effectively. Other research interests include defects in materials (dislocation theory) and thin films. EXPERIENCE Sep 2008 – Present Micro-Mechanical Modelling of Lithium-Ion BatteriesUniversity of California, Santa BarbaraSupervisor: Prof Robert M. McMeeking
A coupled stress-diffusion model for storage particles was developed to determine the contribution of stressto aging of lithium-ion batteries.
Three critical parameters which govern the stress response were identified and stress maps were developedfor a wide range of values and thus can be used for a variety of materials.
The model was extended to simulate the working of an entire battery with multiple components. Our workmatches experimental results showing that particle position also impacts the stress response with particlescloser to the battery separator experiencing higher stresses.
Our ongoing work involves non-spherical particles as well as inclusion of plasticity to model high-deformation materials such as Silicon. Research Intern, Applied Research MaterialsRobert Bosch GmbH, Stuttgart, GermanySupervisor: Dr N. Dorsch, Dr D. Rosato
The effect of transport properties, particle shape and particle arrangement on stress was analyzed using thecoupled stress-diffusion model and the integrated battery model.
Stresses for all the components of the cathode were considered to model the volume change of the battery
Model was extended to 3-D with particles of different aspect ratio. Research Intern, Dept of Applied MechanicsUniversity of Groningen, NetherlandsSupervisors: Prof E. Van der Giessen, University of Groningen and
An adaptive mesh for Dislocation Dynamics Simulations of micron-scale plasticity under multiple contactswas developed and was used to analyze both isolated contacts and interacting contacts i.e. indentation andrough surface contacts.
We could analyze much smaller indenter contact lengths and significantly reduce computational time. UROP fellow, Metallurgical Engineering and Materials Dept
An existing code for three dimensional Dislocation Dynamics (DDLab) was modified in order to studydifferent strengthening mechanisms present in Metal Multilayers.
Sponsored by the Industrial Research and Consultancy Centre (IRCC); part of the Undergraduate ResearchOpportunity Project (UROP), which is awarded to students who show aptitude towards research. TEACHING AND OUTREACH EXPERIENCE Jan – Mar 2012 Course Instructor (Selected), School for Scientific ThoughtCalifornia Nano Science Institute, UCSB
Designed a 10 hour course entitled ‘Sustainable Energy: Fact or Fiction? ‘for high school students.
Explored the concept of sustainability and developed metrics to evaluate if energy sources are sustainable. Teaching Assistant, Structural Evolution of Materials Materials 200 C
Materials Graduate student core class on kinetics and structure-property relationships.
As Teaching Assistant I held office hours and conducted problem solving sessions for a class of 30. PUBLICATIONS R. Purkayastha and R.M. McMeeking, A Linearized Model for Lithium-Ion Batteries and Maps for their Performance and Failure , Journal of Applied Mechanics, 2011 DOI : 10.1115/1.4005962 R. Purkayastha and R.M. McMeeking, An Integrated Two-Dimensional Model of a Lithium-Ion Battery: The effect of material parameters and particle morphology on storage particle stress, Computational Mechanics, 2012, 50(2), 209-227 R. Purkayastha and R.M. McMeeking, The Use of Non-Dimensional Parameters to Study Stress in Lithium-Ion Battery Electrode Storage Particles, Proceedings of the ASME 2012 International Mechanical Engineering Congress & Exposition, 2012 R. Purkayastha and R.M. McMeeking, A Parameter Study of Intercalation of Lithium into Storage Particles in a Lithium Ion Battery , Computational Materials Science, 2013 (Accepted) PRESENTATIONS R. Purkayastha and R.M. McMeeking, Effect of Particle Morphology on Stress in a Lithium-Ion Battery Using an Integrated Model in 2-D, Meeting of the Electrochemical Society, Fall 2012
R. Purkayastha and R.M. McMeeking, Integrated Model for Storage Particles, Interface Kineticsand Electrolyte in Lithium-Ion batteries, Gordon Conference on Thin Films and Small-Scale MechanicalBehavior, Colby College, Waterville, Maine, 2010.
R. Purkayastha and R.M. McMeeking, Single Particle Model for Lithium Storage Particles, Tony EvansMemorial Conference, University of California, July 2010
Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement Peter H Whincup, Julie A Gilg, Jonathan R Emberson, Martin J Jarvis, ColinFeyerabend, Andrew Bryant, Mary Walker and Derek G Cook 2004;329;200-205; originally published online 30 Jun 2004; BMJ doi:10.1136/bmj.38146.427188.55 Updated information and services can be found at: R
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