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Prof. Dr. George John
Foto: Prof. Dr. George JohnCurriculum Vitae
George John is recognized for his active research in the field of functional molecular materials from renewable resources and their potential utility in food materials/energy technologies and materials science. After receiving his Ph.D. from NIIST-CSIR (India) in Chemistry, he held research positions in the Netherlands, Japan, and the United States before joining the City College of New York (CCNY). Currently he is a Professor of Chemistry and Biochemistry at CCNY. The research in John’s laboratory is highly interdisciplinary, and is focused on molecular design of synthetic lipids (biobased), membrane mimics, soft materials, trans fat alternatives, food materials and food chemistry, and organic materials chemistry. Current research thrusts are on (i) oleogel technology, (ii) green battery components from biomass, and the mechanistic understanding to design a future throw-away battery and (iii) molecular gel based organic scintillators for cancer imaging (iv) amphiphilic molecules, assembly and surfactants from biomass. His group has successfully developed environmentally benign antibacterial paints, oil spill recovery materials, molecular gel technologies, vegetable oil thickening agents, and trans-fat alternatives. He is a Fellow of the Royal Society of Chemistry (FRSC), a senior Fulbright Scholar to India, and was a recipient of the Tokyo University of Sciences (TUS) President Award, the Pfizer Visiting Professorship at (IISc) Bangalore, and the Kerala Center Award. He holds more than a dozen patents on inventions related to value-added chemicals/surfactants from renewable resources and their potential utility in food and materials.
Abstract
Molecular Electrode Materials from Nature – Design of a Green Battery
George John
Department of Chemistry and Center for Discovery and Innovation, The City College of New York, New York, NY 10031, and Ph.D. Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 10016, USA. E-mail: gjohn@ccny.cuny.edu
Current lithium ion battery technologies suffer from challenges derived from the eco-toxicity, cost, and energetic inefficiency of contemporary inorganic materials used in these devices. Organic molecules, including polyaromatic carbonyl compounds such as quinones, can be utilized as environmentally friendly alternatives to transition metal oxide-based intercalation cathodes due to their lithium and sodium ion binding capability for LIB/SIB electrodes. Here we demonstrate reversible Na/Li-ion coordination with quinones through the electrochemical reduction of the carbonyl and/or the replacement of hydroxyl group protons with Na/Li. Previous works on stable organic cathodes have mostly focused on the interaction of alkali metal ions with the C=O groups of quinones, which marginalizes the influence of neighboring hydroxyl, amine, and thiol functional groups. Organic molecule-based batteries1-3 previously exhibited precipitous capacity fading and poor cycling lifetimes due to their solubility in organic electrolytes. We report here that a tetramer (TL) derived from natural henna dye, exhibits stable gravimetric capacities exceeding 100 mAh g-1 for over 300 charge/discharge cycles due to coordination with multiple Na/Li ions, as well as the unique stability of metallated salts of TL in electrolytes. The mechanism and chemistry of metal ion binding in the TL were probed using solid-state/solution NMR studies and DFT computations, in conjunction with other spectroscopic methods, reveals that the molecule adopts a nonplanar eight-membered coordination geometry. The new LIB/SIB cathode provides avenues to build fast, stable, high capacity electrodes using organic molecular systems. In addition to the functional utility of these materials, they will be inherently designed to be safe, economic, and environmentally benign. Being constructed from plant derived chemicals to afford smart, throw away batteries to meet the demands of a greener future.
References
- Larcher, D. & Tarascon, J. Towards greener and more sustainable batteries for electrical energy storage. Nat. Chem. 2015, 7, 19–29.
- Shen, L. & Yu, Y. Greener and cheaper. Nat. Energy 2017, 2, 836–837.
- Miroshnikov, M. et al. Power from nature: designing green battery materials from electroactive quinone derivatives and organic polymers. J. Mater. Chem. 2016, A 4, 12370–12386.