Research

Overview  


Batteries, fuel cells, and supercapacitors are the technologies that meet society’s growing need for energy storage and conversion. Inkjet and aerosol jet printing of these devices provides the opportunity to improve their performance by optimizing their structures at the micro and meso scales. Printing also permits integration of energy storage devices directly into the systems they power. Our research focuses on the four areas necessary to transform the idea of printed energy storage into a manufacturing reality: 1) printable electroactive materials; 2) functional inks containing electroactive materials; 3) inkjet and aerosol jet printing methods for layer by layer construction of electrochemical devices; 4) post-printing processing protocols to optimize device performance. 
 

Printable Electroactive Materials


Active and selective electrocatalysts and conductive support materials are the functioning components of electrochemical devices for energy conversion and storage. Our recent work in this area focuses on synthesis and mechanistic studies of a printable Ni(OH)2/graphene oxide catalyst for the oxygen reduction reaction, and on mechanochemical synthesis of printable high surface area, high porosity graphite-based support material.

Ink Formulation


The high conductivity and surface area of graphene make it a potentially useful support material and conductive additive in electrodes. To enable environmentally friendly printing of graphene, we are working on formulating a high concentration aqueous graphene ink. Our approach is to synthesize a graphene material with a low density of edge functionalities. These edge functionalities allow the graphene material to attain a zeta potential such that it is self-dispersible in pH-tuned aqueous solution. 

Digital Fabrication of Electrocatalytic Devices


Lithium ion batteries are the dominant energy storage technology for mature applications like portable electronics, and emerging applications like electric vehicles. Our research in this area focuses on aerosol jet printing of high capacity, rate capable Li-ion battery cathodes. Our research also focuses on aerosol jet printing solid electrolyte materials for the next generation of all solid Li-ion batteries.

Post-Printing Processing


A crucial step in fabricating electrochemical devices is consolidation of material from the form of an ink dispersion in which it is deposited to the solid form of a functioning device. Consolidation always includes evaporation of solvent, and can also include higher temperature sintering steps. Our research in this area focuses on understanding the interfaces formed when Li-ion battery cathode materials are co-sintered with solid electrolyte materials like ceramics and glasses.