Hydrogen 101 with Shawn Litster

Hydrogen is the most abundant element in the universe and sometimes hailed as “the fuel of the future” for its impressive efficiency as a green energy carrier. Over the last two decades, Shawn Litster, Professor of Mechanical Engineering, has worked to advance the critical energy technologies required to electrify heavy-duty transportation using hydrogen fuel cells. 

Q: Why is hydrogen referred to as “the fuel of the future?”

A: When hydrogen is referred to as a fuel, it’s most often in reference to hydrogen fuel cells. Hydrogen fuel cells are a promising power source because they are much more efficient than traditional combustion engines. Unlike combustion engines that burn fuel to generate energy, fuel cells turn hydrogen into electricity via an electrochemical reaction, so the fuel goes directly to electricity. The only emission from a fuel cell is pure, drinkable, water. 

Q: What is the advantage of using a hydrogen fuel cell instead of a battery?

A: A battery and a fuel cell have very similar structures - both have two electrodes with an electrolyte in the middle, but in a battery there are particles that are responsible for both energy storage and energy conversion. To make a battery power something longer we have to increase the weight of the whole battery system. This is problematic when it comes to electrifying vehicles, especially heavy-duty trucks, because increasing the weight of the battery takes away from the payload a truck can carry. In a fuel cell, we decouple energy storage and energy conversion. A fuel cell handles the energy conversion - the acceleration capabilities of the vehicle, and a separate, lightweight fuel tank stores the lightweight fuel. We can even adjust the size of the tank depending on the range requirements of the vehicle without the full weight penalty that batteries present.

Q: How do we get hydrogen? 

A: We would like to decarbonize the hydrogen production process that currently relies on fossil fuels by using something called electrolysis. Electrolysis uses electricity to split water directly into hydrogen and oxygen, consequently reducing carbon emissions. Electrolysis further enables us to convert renewable electricity into a versatile fuel and industrial feedstock.

Q: What obstacles do we need to overcome for hydrogen to truly fuel the future?

A: Heavy duty trucking companies are looking at the total cost of ownership for a fuel cell vehicle, this includes the upfront and lifetime costs. For widespread hydrogen fuel cell adoption, we need to reduce what it costs to make fuel cells and make them more durable. 

Q: How is your lab addressing these challenges?  

A: The materials used in fuel cells and electrolyzers are expensive and scarce. My lab is focused on translating developments in materials including catalysts and polymers for high-performance fuel cells and electrolyzers. Our goal is to develop materials that enable scalable and affordable hydrogen fuel cells.