Science Journey: Addressing Energy Storage Challenges: Making Electrolytes That Can Help Batteries Store More Energy

The challenges presented by climate change require that humanity begin the transition to more sustainable sources of energy like wind and solar, in addition to adopting more environmentally friendly transportation solutions like electric vehicles. Energy storage is a crucial part of this equation, but the current standard-bearer, the lithium-ion battery, is at the limit of its energy storage ability because of a component between the battery terminals known as the electrolyte. These electrolytes are made from liquid solutions that can combust, and they are not stable in the presence of pure metal lithium, which if used as a battery terminal, could allow batteries to store more energy in a smaller space. Villafuerte's research focuses on a novel material known as a solid polymer electrolyte, which is similar to the plastics used to make rubber, but can be used as the electrolyte in a battery. Solid polymer electrolytes are more stable against lithium than their liquid cousins, and do not combust. However, they suffer from low ionic conductivity, which is the ability to shuttle the atoms that give up the electricity we use, known as ions, between the battery terminals, which results in a low power output. Villafuerte aims to understand the mechanism by which ions move in a solid polymer electrolyte system, so that we better understand how to improve its conductivity and potentially tailor it for future application in actual rechargeable batteries.

About the Speaker

Fernando Villafuerte is a fifth-year PhD candidate in materials science at Caltech. He investigates materials derived from a common ingredient in rubber for use as electrolytes in lithium-ion and lithium batteries. Born to parents with roots in Latin America and raised in Brooklyn, New York, Villafuerte first studied German and International Relations at Cornell University, after which he spent a number of years working in the non-profit legal sector. With an eye toward pursuing a profession with meaningful social and technological impact, he enrolled at Hunter College in New York to study physics. While at Hunter, Villafuerte worked in the lab of Professor Steven Greenbaum on investigating energy storage materials. He secured a summer fellowship at the Jet Propulsion Laboratory, where he worked on verifying experimental data from batteries with potential application in deep space probes. These experiences eventually led Fernando to Caltech and the group of Professor Julia R. Greer, where he currently undertakes his research.

Outside of research, Villafuerte has been a tutor to local Pasadena high school students through the RISE program at the Caltech Y for four years. He is interested in housing and energy policy. He also enjoys reading, hiking, and the occasional game of pool.