Wednesday, May 09, 2018

KGSP Student Eman Alhajji Wins BASF Competition

KAUST Gifted Student Program (KGSP) student Eman Alhajji has won the Best Poster Award at an event sponsored by the German Company BASF.

​BASF is the largest chemical company in the world based on revenue. Eman, who is currently an undergraduate student in Materials Science & Engineering at North Carolina State University, received a plaque and a cheque for $3,000.00.  The competition was held in the Research Triangle Park in Raleigh, NC at the site of BASF Bioscience Research Laboratories.  Nearly 40 posters were presented by undergraduate and graduate students from local universities (e.g., NC State, UNC), Virginia, and Georgia. Participants in the competition were pre-selected after submitting school transcripts, CV, and abstract of the poster to be presented. 

Eman presented her research on developing hard carbon anodes for Na ion batteries which she carried out during a summer internship last year in the laboratory of Prof. Husam N. Alshareef at KAUST. This work is currently under review for publication in Wiley's journal Advanced Energy Materials.

Na ion batteries are being considered as replacement for Li ion batteries since Na is cheaper and more abundant. This is especially true in Saudi Arabia, since Na can be extracted from water desalination byproducts.  Normal graphite (the dominant anode material use in Li ion batteries) can hardly intercalate any Na ions due to their larger size compared with Li ions.

Eman co-developed a process for "hard carbon" anodes, which is a type of disordered graphite that can intercalate more Na ions, thereby increasing battery capacity.  "We turned the thin film of polyimide into 3D hard carbon layer with expanded inter-atomic spacing, hence we could easily accommodate more Na ions than we could in graphite", said Alhajji.

The hard carbon is formed directly on current collectors by laser irradiation of polyimide films.  By preparing polyimide solutions rich in nitrogen, the final hard carbon had unexpectedly high level of nitrogen doping (nearly 13 atomic %).  This improved conductivity resulted in anodes with one of the best reported capacity values in Na ion batteries (450 mAh/g).

Eman worked jointly with PhD student Fan Zhang where she was trained and mastered the process of making and testing Li and Na ion batteries. 

"Eman is an intelligent and highly dedicated student. I am proud of her and glad she has decided to join our group next Fall"
,  said Prof. Alshareef.