(6dp) Design and Development of Materials and Electrolytes for Energy: From Fundamental Mechanisms to Applications

The development of new solutions to satisfy the growing demand for energy in areas ranging from the portable electronics to grid energy storage is becoming increasingly important. Current research efforts are directed toward improvement in the device performance (i.e. charging times, energy, capacity, cycling stability), cost and safety. Traditional batteries require prolonged charging and therefore have a limited high rate energy harvesting capacity. Supercapacitors on the other hand can provide fast charging times of below one minute but require development of the new materials in order to achieve energy densities comparable with batteries at much higher rates.

My research interests focus on the design of new supercapacitor materials and electrolytes guided by understanding of the charge storage processes and mechanisms to push the performance of energy storage devices while ensuring their safety and low cost.

During my postdoc in Prof. Zhenan Bao group at Stanford University, I worked in two different research directions. First, I explored electrochemical behavior of the new conducting metal-organic frameworks and demonstrated exceptionally high areal and volumetric capacitance of these materials. This work showed for the first time that metal-organic frameworks (MOFs) can outperform traditional supercapacitor materials such as porous carbons, establishing a new research direction. Currently, I am studying fundamental principles underlying the charge storage mechanism in MOFs. The second direction that I developed is related to superconcentrated water-based electrolytes for green and safe energy storage. In particular, I demonstrated that potassium acetate-based highly concentrated electrolytes can provide the same benefits of the extended voltage window as imide-based electrolytes and, once combined with lithium acetate, demonstrate compatibility with traditional Li-ion battery electrode materials while being low-cost and environmentally benign.

The focus of my Ph.D. work in Prof. Yury Gogotsi group was on (1) the investigation of a new family of two dimensional materials, MXenes (2D transition metal carbides), for high-rate energy storage applications and (2) understanding the charge storage mechanism in them. My studies revealed that a variety of cations of various charges and sizes such as sodium, magnesium, potassium and even aluminum can readily intercalate from aqueous solutions into the MXenes and participate in charge storage. Moreover, I demonstrated that spontaneous chemical and electrochemically-assisted intercalation of cations in between the MXene layers leads to extremely high volumetric capacitances. Volumetric capacitance is proportional to the amount of energy stored for a unit of volume of electrode and its high values are particularly crucial for portable electronics applications, where device volume is a main constraint. Also, combining in situ characterization techniques, I provided strong evidence that the mechanism of the electrochemical charge storage in MXenes is pseudocapacitive, i.e. due to changes in the oxidation state of transition metal during charge/discharge. Using the knowledge of the mechanism of charge storage, I demonstrated that the rate performance of MXenes can be pushed to extreme limits with charging times of just a fraction of a second.

Teaching Interests:

At Stanford University, I served as an instructor for a laboratory class as a part of the Chemical Engineering Laboratory course and mentored undergraduate and MS students. During my PhD, at Drexel University I served as a recitation and laboratory instructor in a number of undergraduate courses, mentored several students, led a Senior Design project and participated in the STEM outreach activities. I am interested in teaching various courses in Chemical Engineering at both the graduate and undergraduate levels, and in particular to teach/develop course in the field of electrochemistry.

Selected publications:

1. R. Lukatskaya, B. Dunn, Y. Gogotsi, “Multidimensional materials and device architectures for future hybrid energy storage”, Nature Communications, 2016, 7, 12647
2. Feng*, T. Lei*, M.R. Lukatskaya*, J. Park, Z. Huang, M. Lee, L. Shaw, S. Chen, A.A. Yakovenko, A. Kulkarni, J. Xiao, K. Fredrickson, J.B. Tok, X. Zou, Y. Cui, Z. Bao, “Robust and Conductive Two-Dimensional Metal−Organic Frameworks with Exceptionally High Volumetric and Areal Capacitance”, Nature Energy, 2018, 3, 30–36
3. R. Lukatskaya*, S. Kota*, Z. Lin*, M.-Q. Zhao, N. Shpigel, M.D. Levi, J. Halim, P.-L. Taberna, M.W. Barsoum, P. Simon, Y. Gogotsi, “Ultra-high-rate pseudocapacitive energy storage in two-dimensional transition metal carbides”, Nature Energy, 2017, 6, 17105
4. R. Lukatskaya*, S.M. Bak*, X. Yu, X.Q. Yang, M.W. Barsoum, Y. Gogotsi, “Probing the mechanism of high capacitance in two-dimensional titanium carbide using in-situ X-Ray absorption spectroscopy”, Advanced Energy Materials, 2015, 5 (15), 1500589
5. Ghidiu*, M. R. Lukatskaya*, M.Q. Zhao, Y. Gogotsi, M. W. Barsoum, “Conductive two-dimensional titanium carbide clay with high volumetric capacitance”, Nature, 2014, 516, 78-81
6. R. Lukatskaya, O. Mashtalir, C.E. Ren, Y. Dall’Agnese, P. Rozier, P. L. Taberna, M. Naguib, P. Simon, M.W. Barsoum, Y. Gogotsi, “Cation Intercalation and High Volumetric Capacitance of Two-dimensional Titanium Carbide”, Science, 2013, 341 (6153), 1502-1505.