Dr. Cai has a core competency in chemical engineering, with a focus toward electrochemistry and materials science. Dr. Cai specializes in synthesis, fabrication and testing of composite oxide/ceramic systems for electrochemical energy storage applications. She has extensive academic and industrial experience in developing and characterizing electrode materials for fuel cells and lithium-ion batteries. She is also experienced in employing design of experiments and failure analysis to resolve process, product and performance issues. This broad engineering background enables her to provide support to clients from a variety of markets.
Dr. Cai is skilled in a variety of electrochemical analyses including cyclic voltammetry (CV), impedance (EIS), and cycle life testing. She also has extensive experience in ceramic thin film and bulk material characterization techniques including chemical spectroscopy (XPS, AES, EDS, Raman), Focused Ion Beam (FIB), Electron Microscopy (TEM/SEM), scanning probe microscopy (AFM, STM, and MFM), X-ray diffraction (XRD), N2 Adsorption (BET) and Thermogravimetric Analysis (TGA). Dr. Cai has more than ten years of direct hands-on experience in thin film deposition (e.g. sputtering, pulsed laser deposition, and molecular beam epitaxy) and micro-fabrication (lithography, reactive ion etching, lift-off, and wet etching). Dr. Cai is also proficient in fuel cell and lithium-ion cell fabrication techniques including powder/slurry preparation, ball milling, drying, tape casting, calendaring, calcination, sintering and screen-printing.
Prior to joining Exponent, Dr. Cai worked as research scientist in Prof. Yet-Ming Chiang’s group at MIT developing low cost electrolyzers. She also worked as Senior Process Engineer and R&D Engineer in SiEnergy Systems and 24M Technologies respectively, where she developed new structures of ceramic oxides for high temperature fuel cell electrodes and optimized manufacturing processes for making lithium-ion batteries. She routinely employed root cause analysis to understand the fundamental degradation and failure mechanisms for high temperature solid oxide fuel cells (SOFC). Dr. Cai also previously worked as a Postdoctoral Associate in Prof. Bilge Yildiz’s group at MIT to improve the efficiency and durability of SOFCs by developing highly active cathode materials and nano-structures.
CREDENTIALS & PROFESSIONAL HONORS
- Ph.D., Chemical Engineering, Northeastern University, 2010
- B.S., Chemical Engineering, East China University of Science and Technology, 1999
- Mandarin Chinese
Kubicek M, Cai Z, Ma W, Yildiz B, Fleig J. Tensile lattice strain accelerates oxygen surface exchange and diffusion in La1–xSrxCoO3−δ thin films. ACS Nano 2013; 7:3276-3286.
Chen Y, Cai Z, Kuru Y, Ma W, Tuller HL, Yildiz B. Electronic activation of cathode superlattices at elevated temperatures – source of markedly accelerated oxygen reduction kinetics. Advanced Energy Materials 2013; 3:1221-1229.
Lee W, Han JW, Chen Y, Cai Z, Yildiz B. Cation size mismatch and charge interactions drive dopant segregation on the surfaces of manganite perovskites. Journal of the American Chemical Society 2013; 135:7909-7025.
Cai Z, Kubicek M, Fleig J, Yildiz B. Chemical heterogeneities on La0.6Sr0.4CoO3-δ thin films—Correlations to cathode surface activity and stability. Chemistry of Materials 2012; 24:1116-1127.
Chen Y, Jung W, Cai Z, Kim J, Tuller HL, Yildiz B, Impact of Sr segregation on the electronic structure and oxygen reduction activity of SrTi1-xFexO3 surfaces, Energy & Environmental Science 2012; 5:7979-7988.
Cai Z, Kuru Y, Han JW, Chen Y, Yildiz B. Surface electronic structure transitions at high temperature on perovskite oxides: The case of strained La0.8Sr0.2CoO3 thin films. Journal of the American Chemical Society 2011; 133:17696-17704.
Kuru Y, Jalili H, Cai Z, Yildiz B, Tuller HL. Direct probing of nano-dimensioned oxide multilayers with aid of focused ion beam milling. Advanced Materials 2011; 23:4543-4548.
Jalili H, Han JW, Kuru Y, Cai Z, Yildiz B. New Insights into the strain coupling to surface chemistry, electronic structure and reactivity of La0.7Sr0.3MnO3. The Journal of Physical Chemistry Letters 2011; 2:807-810.
Cai Z, Kubicek M, Fleig J, Yildiz B. Influence of lattice strain on the oxygen exchange kinetics and oxide ion diffusion in (La,Sr)CoO3-δ, Oral Presentation, Material Research Society Conference, Boston, MA, 2012.
Cai Z, Chen Y, Yildiz B. Cation segregation and electrochemical activity of ruddlesden popper phase cobalt oxides in oxygen reduction and oxygen evolution. Oral Presentation, 222nd Electrochemical Society Meeting, Honolulu, Hawaii, 2012.
Cai Z, Kubicek M, Januschewsky J, Fleig J, Yildiz B. Effect of temperature on the surface cation chemistry of La0.6Sr0.4CoO3 Thin Films - correlations to cathode performance. Poster Presentation, 18th International Conference on Solid State Ionics, Warszawa, Poland, 2011.
Cai Z, Sun B, Ziemer KS. Integration of barium hexaferrite on wide bandgap semiconductor 6H-SiC by molecular beam epitaxy, Poster Presentation, North American Molecular Beam Epitaxy Conference, Princeton, NJ, 2009.
Cai Z, Chen Z, Harris VG, Ziemer KS. Molecular beam epitaxy integration of barium hexaferrite on wide bandgap semiconductor 6H-SiC. Oral Presentation, American Vacuum Society Meeting, Boston, MA, 2008.
Cai Z, Goodrich TL, Ziemer KS. Understanding the role of the magnesium oxide interlayer on heteroepitaxial growth of barium hexaferrite on 6H-SiC, Oral Presentation, North American Molecular Beam Epitaxy Conference, Albuquerque, NM, 2007.
Research Scientist, MIT, 2016-2017
Senior Process Engineer, 24M Technologies, 2016
Senior R&D Engineer, SiEnergy Systems, 2013-2015
Postdoctoral Associate, MIT, 2010-2012
Materials Research Society—MRS
The Electrochemical Society—ECS
American Institute of Chemical Engineers-AICHE