Why Battery Electric Vehicles Have Overtaken Hydrogen Fuel Cells

The electric vehicle movement is yet to gather pace in India. 

(Photo: iStock)

While electric cars are still minuscule in number compared to fossil-fuel driven cars, they are steadily gaining ground. Since 2013, the number of electric cars has doubled, but yet the overall share is less than 4 percent. And companies like Tesla have been at the forefront in changing public perception towards electric vehicles.

Electric vehicles accounted for virtually zero lithium-ion demand a decade ago. Between 2014 and 2017, electric vehicles’ use of lithium-ion has more than quadrupled. 

According to Bloomberg, EV’s accounted for 50 percent of lithium-ion demand in 2016 to manufacture vehicle batteries. However, electrification has left out a potential alternative fuel – hydrogen, which was considered as a potential replacement to petrol and diesel until 2009.

How Do Hydrogen Fuel Cells Work?

Hydrogen fuel cells generate energy through a straightforward chemical reaction: Stored hydrogen is combined with oxygen from the air with the aid of a catalyst, producing electricity.

Hydrogen fuel-cell cars are almost as good as battery-powered electric cars in many ways. They are efficient, they have no emissions and the only byproduct they produce is water. Hydrogen also has a higher energy density than electric batteries.

The devices are about twice as efficient as internal combustion engines when it comes to converting chemical energy into power, and the only emissions they produce are air and water vapour. Hydrogen is mostly sourced from natural gas.

Essentially, hydrogen-powered cars are just electric cars that use fuel cells instead of batteries to power the cars’ electric motors. 

Some cars that are hydrogen fuel-cell powered are the Toyota Mirai, Hyundai Nexo and Honda’s FCX Clarity. These are niche products, sold in limited numbers only in certain markets.

Pros & Cons of Hydrogen Fuel Cells

Hydrogen is actually quite a practical option. A battery-powered electric car takes hours to charge and can achieve a range of about 200 Kms to 300 Kms at best. A hydrogen-powered car can travel the same distance within a few minutes of refueling, like a conventional petrol or diesel car.

Charging times and the capacity of electric batteries are affected by environment conditions like temperature and moisture, while hydrogen-powered cars are immune to this.

However, storing and distributing hydrogen is an issue.

Cost of building hydrogen fueling infrastructure, including the issue of producing hydrogen at such a scale is something where we have not achieved a breakthrough yet.  

Infrastructure wise, setting up hydrogen fueling stations is a big task. First comes the storage, it is very difficult to store hydrogen for a long period of time and to compress it to a high pressure and drying it is a very complicated task. However, a breakthrough with this issue has been made by making hydrogen within the fueling station.

Hydrogen fuel cell stacks that generate power are a complex design to build and are made by hand.

Hydrogen-powered cars produce more heat, requiring larger radiators to keep them cool whereas battery packs heat up less as they turn chemical energy into electric energy more efficiently.

When it comes to safety, hydrogen is highly flammable, but Toyota claims to have created a strong enough fuel cell for its Mirai that didn’t explode even when shot with a 0.50 calibre bullet.

And then there’s cost. The platinum used in making hydrogen fuel cell stacks is expensive. A kilo of platinum costs around $30,000 while a kilo of lithium carbonate (used to make lithium-ion batteries) costs $20 only.

Hydrogen fuel cells use 30 grams of platinum for one stack, while EV’s use about 60 Kg lithium carbonate for a sedan like the Tesla Model S, so the numbers are not very different.

Electric vehicles also have the convenience of charging wherever there’s electricity available, but hydrogen needs specific fuel stations.

Battery-electric vehicles and hydrogen-powered cars still have a lot of catching up to do. There are about millions of cars sold every week around the world while the highest number of electric cars sold was just over a million worldwide in 2017.