Development of Aluminum Anodes for Lithium-ion Batteries Holding High Active Material Loadings

תמונה_סמינרים
27.01.2019
14:30
David Wang Auditorium, 3rd floor Dalia Maydan Bldg
MSc Candidate, Ms. Inbal Offen

MSc Candidate, Ms. Inbal Offen, M.Sc. Candidate (Haifa Campus)

Department of Materials Science and Engineering,
Technion – Israel Institute of Technology

Li-ion Batteries (LIBs) can be found in many electronic devices. Recent advances in electric vehicles raise the demand for high energy batteries, thus requiring the development of high-capacity anode materials. The low cost and abundant aluminum metal offer three times the theoretical capacity of a commercial graphite LIBs anode by forming LiAl alloys.  In this research, we developed Al powder anode with high active material loadings. Commonly, electrodes are manufactured by spreading a mixture of the active powder on a current collector. The mixture contains conductive carbonaceous additives, such as carbon black (CB) and a polymeric binder. Here, relying on the conductivity of the Al, we increased the active material content at the expense of the CB. The reduction in CB content caused a diminished adhesion to the current collector. To solve this, a self-healing polymer and other binders were studied, along with different current collectors. Essentially, higher Al loading allowed higher areal capacities to be obtained. However, the capacity decayed differently than traditional anodes, calling for further investigation. The primary capacity loss of Al resulted from mechanical stresses initiated by the alternating volume between the lithitated and delithiated states of the anode. The Al anode large volume fluctuations cause pulverization and loss of electrical contact, leading to a large irreversible capacity. We concluded that the conductive CB in the matrix mitigates the capacity decay by buffering the Al expansion and by maintaining conductivity to the current collector.

Prof. Yair Ein-Eli