Assistant Professor Aims to Build Better Batteries
We use batteries in our cars, in our phones, in our computers, and in countless other common household objects. But the simple battery is a complex feat of chemistry and engineering, a feat that Dr. Jung-Hyun Kim, assistant professor in the Department of Mechanical and Aerospace Engineering, and his team at the Energy Innovation Lab perform every day.
Today, the leading type of battery is a lithium-ion battery. The three main parts of these batteries are a cathode, an anode, and an electrolyte that sits between them. Lithium-ion batteries are low-maintenance and provide high energy capacity, but even higher energy is needed to extend the driving distance of current electric vehicles (EVs). Also, their reduced performance at high and low temperatures, high price, limited fast-charging capability, and abuse tolerance make them less reliable in EVs. As the world turns to electric transportation, Kim is searching for a battery that can answer those problems.
The Energy Innovation Lab is a collaborative research lab from the Center for Automotive Research (CAR), the Institute for Materials Research (IMR), and Nanotech West. Researchers at the Lab synthesize and characterize materials, build batteries, and test those batteries’ longevity, capacity, and stability, all in pursuit of a better battery.
The process begins with design and material synthesis. Kim and his team design and synthesize cathode, anode, and electrolyte materials using various chemical or solid-state synthesis methods. The synthesized materials are analyzed by microscopies, spectroscopies, and diffractometers to examine if the team obtained the target materials. The materials are used to create experimental battery elements that can then be combined with industry-standard materials to build battery cells.
The cells are often constructed in moistureless glove boxes to maintain the integrity of the materials. Battery cells are very sensitive to moisture, so researchers fabricate them in a box filled with argon gas. Once cells are fabricated and sealed in the glove boxes, they move on to testing, the final step in the experimental process.
Small coin-type cells are tested first, and if they pass the performance criteria, a bigger pouch-type cell is fabricated and tested. Cells are tested at different temperatures and under different testing protocols, battery cyclers, and temperature-controlled environmental chambers. Because testing is automated, the battery cells are quickly and accurately assessed for success according to the Energy Innovation Lab’s goals.
“Our mission is to make a battery cell that lasts longer, for driving longer at high power and high energies,” says Kim. As the automotive industry moves toward electrification, better batteries are becoming more important to ensure reliable vehicles. The Energy Innovation Lab is up to the challenge.
Written by Georgia Drost, CAR writing intern