Fuel CellElectric Vehicles,part 1

EV-310a

This course is presented as part of Evannex Universitya free, open learning environment that presents concise, video-based mini-courses for those who have interest in electric vehicles (EVs)

Fuel Cell Vehiclesfuel cells have been touted as the future of automotive transportationfirst wave of a hydrogen economy?the fuel cell vehicle as part of the EV landscape

>> For many years, fuel cells have been touted as the future of automotive transportation. >> In fact, some proponents suggest that they are the first wave of a hydrogen economy.But others arent so sure.

>> In this EVU mini-course well examine the fuel cell vehicle, how it can be considered part of the EV landscape, and how fuel cell vehicles compare to BEVs

The Fuel Cellfuel cells are like a batterythey have the same componentsan electrolyte, electrodes, and a separatorautomotive applications use a polymer exchange membrane fuel cell (PEMFC)

>> a fuel cells is like a batteryBy the way, if youre unfamilar with EV battery concepts, you might want to view EVU course EV-210 before continuing with this presentation.>> fuel cells have the same componentsan electrolyte, electrodes, and a separator>> in most automotive applications, the polymer exchange membrane fuel cell (PEMFC) is used

The PEMFC hydrogen is forced through a platinum catalyst under pressurethe catalyst splits hydrogen into 2 ions and 2 electronsthe electrons can be used to power the EV motors directly or they can be used to charge a battery that provide power to the motorthe hydrogen combines with oxygen to form water which exists as steameach PEMFC is combined into a stack to provide sufficient voltage

Let explore the basic elements of the polymer exchange membrane fuel cell

>> hydrogen is forced through a platinum catalyst under pressure

>> the catalyst splits hydrogen into 2 ions and 2 electrons

>> the flow of electrons that is, electricity can be used to power the EV motor directly or it can be used to charge a battery that provides power to the motor

>> the hydrogen combines with oxygen to form water which exists as steam

>> each polymer exchange membrane fuel cell is combined into a stack to provide sufficient voltage to power the EV

HydrogenProduction Methodsone methodhydrogen electrolysiscurrent is passed through waterhydrogen and oxygen are separated outvery energy inefficientnatural gas reformingsteam is superheated to ~800 deg Ccombined with methaneproduces H2, along with carbon monoxide and CO2

But where does the hydrogen that feeds the fuel cell come from?

>>one method is hydrogen electrolysis>> current is passed through water>> and hydrogen and oxygen are separated out>> the problem is that this approach is very energy inefficient

>>another approach is called natural gas reforming>> steam is superheated to about 800 deg C>> it is then combined with methane>> the chemical reaction produces hydrogen, along with carbon monoxide and CO2

Still other methods have been investigated, including:

- Biological production- Photo-electrochemical water splitting- Solar thermal, and - Photo-electro-catalytic methods

but these have not been widely implemented to date.

HydrogenInput to the EVtransported by truck to a fueling stationspecialized fuel stations (very rare today, with fewer than 50 in the entire US))liquid hydrogen stored at -250 deg Cconverted to gas, pressurized and pumped into on-board FCEV fuel tanksfilling the tank takes 3 - 5 minutes

So once the hydrogen is produced, how does it get from the production facility into a fuel cell vehicle?

>>first, it is liquified and transported by tanker trunk to a hydrogen refueling station>> these specialized fueling stations are currently very rare, with fewer than 50 in the entire US>> at the station, liquid hydrogen is stored at -250 deg C>> as it is needed, iquid hydrogen is converted to gas, pressurized and pumped into on-board fuel tanks>> the good news is that filling the tank takes 3 - 5 minutes

FCEV Diagram

Unlike PHEV, the fuel cell electric vehiclean FCEVdoes not charge its battery from the grid. As we just discussed, it makes use of a fuel cell (shown schematically in red) that initiates an electro-chemical reaction with a fuel, in this case hydrogen, to create electricity that charges the battery.The fuel cell can also provide direct power for the electric motor.An FCEV has one or more on-board fuel tanks (in orange) that contain pressurized hydrogen.As we just noted, the vehicle must be refueled at a hydrogen refueling station, an infrastructure element that is quite rare today.

In the next part of the EVU mini-course, we compare FCEVs with BEVs.

a free study guide for all EVU mini-courses is available for download from our website For a complete list of mini-courses and the study guide, visit: www.evannex.com

OlharesRouletBeats d'Amor, track 12014-05-18T14:02:41118051.055OlharesRouletBeats d'Amor, track 12014-05-18T14:02:41118051.055