The innovation engine for new materials

Samuel Alcantar

Samuel Alcantar

University: 

University of California, Santa Barbara

Major: 

Chemistry

Site Abroad: 

Leibniz Institute for New Materials, Saarbruecken, Germany

Mentor(s): 

Aura Tolosa

Faculty Sponsor(s): 

Volker Presser

Faculty Sponsor's Department: 

Materials

Project Title: 

VAPOR DEPOSITION OF ALUMINUM ON CARBON FIBER ELECTRODES FOR HIGH POWER SUPERCAPACITORS

Project Description: 

Supercapacitors enable high specific power and a long cycling lifetime, but a rather low specific energy. While most research focuses on optimizing the synthesis of electrode materials of a supercapacitor, recent interest peaked in modifying the fabrication of the electrode material via electrospinning. Among the different electrode materials proposed, non-woven fiber mats are attractive as freestanding, binder-free electrodes. Electrospun electrodes present a free pathway for electron transport without the dead mass of polymer binder in the system. Our work focused on enhancing the device performance via physical vapor deposition of aluminum directly on the fiber mat electrode instead of adding a carbon coated metal foil as a current collector. The integration of sputtered aluminum allows for lower electric resistance between the electrode and current collector, thus improving the rate handling of the device. The sputtered current collector measured an 11000% decrease in mass and a 3790% decrease in volume. Electrochemical characterization of the electrodes showed an 857% increase in specific capacitance (F/g) at 500mV/s. The rate handling performance was characterized by galvanostatic cycling with potential limitation, but no significant difference in capacitance retention was observed at 100A/g. Electrochemical measurements were complimented with impedance spectroscopy, showing a consistency in the equivalent series resistance value at 1.8Ω•cm2. The sputtering of aluminum onto non-woven mat fiber electrodes as a current collector exhibits vast reduction of mass and volume while retaining the electrochemical performance of a supercapacitor.