1. High-energy density subject to the limitation of the size of fuels torage tank
2. Constant power, unlike batteries where power density varies with
the state-of-charge
3. Fast refueling
The limitations presently faced are
1. Low-power density (kW/kg and kW/l)
2. High cost
3. Problems with fuel production and storage
A recent advancement in fuel-cell technologies has been the development of direct methanol fuel cells (DMFCs). Although DMFCs have made
Fuel Cells
325
15 km/l. It is mandatory that EVs meet these power and energy requirements.
Various aspects of FCVs are discussed in the following section.
11.3 Fuel-Cell Vehicles
Fuel-cell technology is not new and has a long history. The first fuel-cell was
invented in 1839 by Sir William Grove and an experimental vehicle powered
by an alkaline fuel-cell appeared in 1970. As indicated earlier, among the
fuel cells based on hydrogen as fuel, PEFC has been broadly accepted for
automotive applications. PEFC comprise a solid polymer electrolyte membrane sandwiched between an anode and a cathode, and end plates. A PEFC
stack has several cells stacked in series with electrically conducting bipolar
plates having flow fields to distribute hydrogen fuel and oxidant air at the
anodes and cathodes, respectively. Hydrogen fuel can be supplied either as
compressed gas from a cylinder or from a cryogenic tank, but both of these
have certain disadvantages. To overcome the difficulties of hydrogen storage and lack of hydrogen-distribution network, a methanol or gasoline-fuel
processor is incorporated to produce a hydrogen-rich gas stream onboard
the FCV.
Ballard in May 2005 emphasized four areas critical to commercial adaptation of automotive PEFC-stack technology; namely, durability, cost, freeze
start, and volumetric power density. The technical specifications for the
PEFC system were set as: power density ~2500 W/l, endurance of ~5000 h
in test driving cycle, freeze start capacity of 30 s to 50% power at –30°C, and
fuel cell stack cost of $30/kW e net at a volume of 500,000 units (Wee 2007).
The advantages of using fuel cells for automotive applications are
2. Constant power, unlike batteries where power density varies with
the state-of-charge
3. Fast refueling
The limitations presently faced are
1. Low-power density (kW/kg and kW/l)
2. High cost
3. Problems with fuel production and storage
A recent advancement in fuel-cell technologies has been the development of direct methanol fuel cells (DMFCs). Although DMFCs have made
Fuel Cells
325
15 km/l. It is mandatory that EVs meet these power and energy requirements.
Various aspects of FCVs are discussed in the following section.
11.3 Fuel-Cell Vehicles
Fuel-cell technology is not new and has a long history. The first fuel-cell was
invented in 1839 by Sir William Grove and an experimental vehicle powered
by an alkaline fuel-cell appeared in 1970. As indicated earlier, among the
fuel cells based on hydrogen as fuel, PEFC has been broadly accepted for
automotive applications. PEFC comprise a solid polymer electrolyte membrane sandwiched between an anode and a cathode, and end plates. A PEFC
stack has several cells stacked in series with electrically conducting bipolar
plates having flow fields to distribute hydrogen fuel and oxidant air at the
anodes and cathodes, respectively. Hydrogen fuel can be supplied either as
compressed gas from a cylinder or from a cryogenic tank, but both of these
have certain disadvantages. To overcome the difficulties of hydrogen storage and lack of hydrogen-distribution network, a methanol or gasoline-fuel
processor is incorporated to produce a hydrogen-rich gas stream onboard
the FCV.
Ballard in May 2005 emphasized four areas critical to commercial adaptation of automotive PEFC-stack technology; namely, durability, cost, freeze
start, and volumetric power density. The technical specifications for the
PEFC system were set as: power density ~2500 W/l, endurance of ~5000 h
in test driving cycle, freeze start capacity of 30 s to 50% power at –30°C, and
fuel cell stack cost of $30/kW e net at a volume of 500,000 units (Wee 2007).
The advantages of using fuel cells for automotive applications are