On November 9th DIFFER PhD researcher Xuan Zhou will defend her thesis, titled 'High-throughput computational screening of organic molecules for organic ion battery cathodes'.
The research described in this thesis is aimed at accelerating the speed of organic-based candidate material discovery for Li-ion and Na-ion battery cathodes. We firstly design a multiscale computational scheme in order to predict the redox potential of organic electroactive molecules efficiently yet accurately. Then we tap into a molecular space of 211,311 organic molecules that includes quinones and conjugated sulfonamides by using the quantum chemistry methods and newly developed machine-learning algorithms. The top-performing leads from chemical space are gradually down-selected by using the high-throughput computational screening approaches and the cutoffs of application-specific properties, such as synthetic complexity, molecular stability, redox potential, and energy density.
In the thesis, it can be concluded that (1) the lowest unoccupied molecular orbital energy of reactant molecules is the best descriptor at all levels of the considered theory; (2) the hybrid scheme of low-level optimizations and DFT-based energy calculations show the similar prediction accuracy as the full DFT simulations with an almost thousandfold increase in computational efficiency; (3) a total of 349 quinones and 52 conjugated sulfonamides that are easy-to-synthesize and high-potential are identified for Li-ion battery cathodes; (4) a top group of 21 promising and commercially available quinones are recommended for Na-ion battery cathodes. The accompanied calculation dataset of molecules is anticipated to be a useful resource for both as a reference and a training data source for the development of new materials and predictive models, respectively.
Promotor: prof.dr.ir. R.A.J. Janssen
Copromotor: dr. S. Er
Members: prof.dr. P.A. Bobbert
prof.dr. G.H.L.A. Brocks
prof.dr.ir. M. Huijben (Universiteit Twente)
dr. E.M. Kelder (Technische Universiteit Delft)
Link to the public event can be found here