Glossary of fuel cell terms
The Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this fuel cell glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but a few.
A
Activation loss
Adsorption
Alkali
Alkali anion exchange membrane
An alkali anion exchange membrane is a semipermeable membrane generally made from ionomers and designed to conduct anions while being impermeable to gases such as oxygen or hydrogen.Alkaline fuel cell
Alloy
Alternator
Alternating current
Ambient Air
Ambient temperature
Ampere
Anion
Anode
Aqueous phase reforming
Artificial membrane
Atmospheric pressure
Atom
Autothermal reforming
Auxiliary power unit
Availability factor
B
Back pressure
Baffle
Balance of plant
Battery
Biofuel
Biogas
Bioreactor
Biosensor
Bipolar plate
Black start
Beta-alumina solid electrolyte
Boiling point
Borax
British thermal unit
Busbar
C
Capacity
Capacity factor
Capital cost
Carbon
Carbon black
Carbon dioxide
Carbon dioxide sensor
Carbon monoxide
Carbon monoxide detector
Carbon paper
Carnot cycle
Catalysis
Catalyst
Catalyst poisoning
Catalytic partial oxidation
Cathode
Cation
Celsius
Centimeter
Centrifugal governor
Ceramic
Cermet
Chemical thermodynamics
Circuit
Circuit diagram
Circulation
Climate change
Cogeneration
Combustion
Combustion chamber
Composite material
Compressed hydrogen
Compressed natural gas
Concentration
Condensate
Condensation
Condenser
Contamination
Coulomb
Countercurrent exchange
Cryogenic liquefaction
Current
Current collector
D
DC to DC converter
Density
Desiccant
Detection limit
Dew point
Diffusion
Direct borohydride fuel cell
Direct carbon fuel cell
Direct current
Direct-ethanol fuel cell
Direct methanol fuel cell
Dispersion
Distributed Generation
Doping
Downtime
Dry basis
E
Effluent
Electrical Balance of Plant
Electricity
Electrical conductivity
Electrical efficiency
Electrical insulation
Electrical resistance
Electric circuit
Electric current
Electricity generation
Electric power conversion
Electrochemistry
Electrochemical cell
Electrochemical gas sensor
Electrode
Electro-galvanic fuel cell
Electroosmotic flow
Electroosmotic pump
Electrolysis
Electrolyte
Electron
Emission
Emission standard
Endothermic
Energy
Energy carrier
Energy content
Energy security
Energy storage
Engine
Energy conversion efficiency
Energy density
Energy transformation
Enthalpy
Enthalpy of vaporization
Ethanol
Evaporation
Exergy
Exergy efficiency
Exhaust gas
Exothermic
Expansion ratio
F
Fan
Fahrenheit
Failure mode and effects analysis
FCEV
FCV
Feedstock purification
Flammability
Flammability limit
Flash point
Float valve
Flow battery
Flow measurement
Flue gas
Flue-gas desulfurization
Fluid dynamics
Fluid mechanics
Flux
Formic acid
Formic acid fuel cell
Fossil fuel
Fouling
Frequency changer
Fuel
Fuel cell
Fuel cell poisoning
Fuel cell vehicle
Fuel efficiency
Fuel efficiency in transportation
Fuel processor
Fuel processing system
Fuel pump
Fusible plug
G
Gadolinium doped ceria
Gas
Gas compressor
Gas detector
Gas diffusion
Gas diffusion electrode
Gasification
Gasoline gallon equivalent
Gibbs free energy
Graphite
Greenhouse effect
Greenhouse gases
Grid connection
Grid-tied electrical system
Grid tie inverter
Guard bed
Guard catalyst bed
H
Half-reaction
Heat exchanger
Heat pipe
Heat transfer
Heating value
Heat of combustion
Higher heating value
High-temperature shift
Hybrid electric vehicle
Hydride
Hydride ion
Hydrocarbon
Hydrocarbon dew point
Hydrodesulfurization
Hydrogen
Hydrogen anion
Hydrogen purity
or hydrogen quality is the lack of impurities in hydrogen as a fuel gas.Hydrogen-rich fuel
Hydrogen sulfide sensor
A hydrogen sulfide sensor or H2S sensor is a gas sensor for the measurement of hydrogen sulfide in a gas stream.I
Impurity
Influent
Interlock
Internal combustion engine
Inverter
Ion
Ion exchange
Ion exchange resin
Ionomer
Islanding
J
K
Kröger–Vink notation
Kilogram
Kilowatt
Kilowatt hour
L
Landfill gas
Lanthanum carbonate
LH2
Life cycle assessment
Linear regulator
Liquid
Liquid hydrogen
Liquid–liquid extraction
Liquefied natural gas
Liquefied petroleum gas
Liquefaction
Liquefaction of gases
List of chemical purification methods in chemistry
Load following power plant
Load profile
Lower flammability limit
Lower heating value
Low temperature shift
M
Maintenance, repair and operation cost
Mass flow sensor
Maximum allowable operating pressure
Mean down time
Mean time between failures
Mean time between outages
Mechanical energy
Mechanical Balance of Plant
Membrane
Membrane electrode assembly
Megawatt
Meter
Methanation
Methane
Methane reformer
Methanol
Methanol reformer
MicroCHP
Microbial fuel cell
Micropump
Miles per gallon equivalent
Millimeter
Milliwatt
Molten-carbonate fuel cells
N
Nafion
Nano iron powder
Nanowire
Natural gas
Nernst equation
Net energy gain
Nickel
Nitrogen
Nitrogen oxide
Nitrogen oxide sensor
O
Off board reforming
Ohm
Onboard reforming
Open-circuit voltage
Original equipment manufacturer
Output impedance
Overpotential
Overpressure
Overvoltage
Oxidant
Oxidation
Oxygen
Oxygen sensor
P
Palladium
Parallel circuit
Partial oxidation
Partial pressure
Particulate
Parts per million
Parts per million by volume
Pascal
Peak load
PEDOT
Permeation
Phase transition
Phosphoric acid
Phosphoric acid fuel cell
Photoelectrochemical cell
Platinum
Polybenzimidazole fiber
Polyethylene
Polymer
Polymer electrolyte membrane
Polytetrafluoroethylene
Polymer electrolyte membrane fuel cell
Potential difference
Portable fuel cell applications
Potassium hydroxide
Power
Power density
Power factor
Power supply
Power-to-weight ratio
Power per unit of mass
PReferential OXidation
Pressure regulator
Pressure relief valve
Pressure sensor
Pressure swing adsorption
Pressure vessel
Propane
Proton
Proton exchange membrane
Proton exchange membrane fuel cell
Protonic ceramic fuel cell
Q
R
Reactor
Reagent
Rectifier
Redox
Reformate
Reformed Methanol Fuel Cell
Reformer
Reforming
Reformulated gasoline
Regenerative fuel cell
Relief valve
Renewable energy
Reservoir
Response time
Reversible fuel cell
Reynolds number
Rupture disc
Ruthenium
S
Safety shutoff valve
Safety valve
Salt bridge
Scrubber
Sensor
Series circuit
Service life
Short circuit
Sodium borohydride
Solenoid valve
Solid oxide electrolyser cell
A solid oxide electrolyser cell is a solid oxide fuel cell set in regenerative mode for the electrolysis of water with a solid oxide, or ceramic, electrolyte to produce oxygen and hydrogen gas.Solid oxide fuel cell
Solubility
Sorbent
Sorption
Specific gravity
Specific heat capacity
Specific power
Specific weight
Stack
Standard cubic foot
Standard electrode potential
Stationary fuel cell applications
Steady state
SMR
Steam reforming
Switched-mode power supply
Syngas
T
Tafel equation
Tail gas combustor
Tar
Technology assessment
Technology life cycle
Technology readiness level
Technology validation
Temperature
Terbium
Thermal
Thermal conductivity
Thermal efficiency
Thermal expansion
Thermal partial oxidation
Thermoelectricity
Thermoplastic
A thermoplastic is a plastic that melts to a liquid when heated and freezes to a brittle, very glassy state when cooled sufficiently.Thermoplastic elastomer
Transducer
Transfer switch
A transfer switch allows switching from a primary power source to a secondary or tertiary power source and are employed in some electrical power distribution systems.Transformer
Triple phase boundary
Triple point
Turbine
Turbocharger
Turbocompressor
U
Ullage
Uninterruptible power supply
Unitized regenerative fuel cell
A unitized regenerative fuel cell is a fuel cell based on the proton exchange membrane which can do the electrolysis of water in regenerative mode and function in the other mode as a fuel cell recombining oxygen and hydrogen gas to produce electricity.V
Vacuum pump
Vapor–liquid equilibrium
Vapor pressure
Vapor recovery
Voltage
Voltage converter
Voltage drop
Voltage regulator
Volumetric energy density
Volumetric flow rate
Volumetric heat capacity
W
Water
Water gas shift reaction
Water purification
Water vapor
Watt
Wet basis
W/kg
Wt.%
X
Y
Yttria-stabilized zirconia
Z
Zinc-air battery
Zinc oxide
Acronyms
| Acronym | – |
| AAEM | alkali anion exchange membrane |
| AC | alternating current |
| AFC | alkaline fuel cell |
| ATR | autothermal reforming |
| APU | auxiliary power unit |
| BASE | beta-alumina solid electrolyte |
| BOP | balance of plant |
| BTU | British thermal unit |
| °C | celsius |
| C | carbon |
| C | coulomb |
| ca. or c. | circa |
| CGH2 | compressed hydrogen |
| CH4 | methane |
| CH3CH2OH | ethanol |
| CH3OH | methanol |
| CHP | combined heat and power |
| CI | chloride ion |
| CNG | compressed natural gas |
| CNT | carbon nanotube |
| CO2 | carbon dioxide |
| CO | carbon monoxide |
| CPOX | catalytic partial oxidation |
| CPS | continuous power supply |
| DBFC | direct borohydride fuel cell |
| DC | direct current |
| DCFC | direct carbon fuel cell |
| DEFC | direct-ethanol fuel cell |
| DER | distributed energy resource |
| DFAFC | formic acid fuel cell |
| DMFC | direct methanol fuel cell |
| E0 | standard electrode potential |
| EBOP | electrical balance of plant |
| EGFC | electro-galvanic fuel cell |
| EOF | electroosmotic flow |
| EOP | electroosmotic pump |
| °F | fahrenheit |
| FB | flow battery |
| FC | fuel cell |
| FGD | flue-gas desulfurization |
| FMEA | failure mode and effects analysis |
| FPS | fuel processing system |
| GDC | gadolinium doped ceria |
| GEG | gasoline-equivalent gallon |
| GGE | gasoline gallon equivalent |
| GHSV | gas hourly space velocity |
| H2 | hydrogen |
| H2O | water |
| HC | hydrocarbon |
| HCDP | hydrocarbon dew point |
| HCOOH | formic acid |
| HDP | hydrocarbon dew point |
| HDS | hydrodesulfurization |
| HEV | hybrid electric vehicle |
| HHV | higher heating value |
| HTS | high temperature shift |
| ICE | internal combustion engine |
| IMFC | indirect methanol fuel cell |
| KG | kilogram |
| KOH | potassium hydroxide |
| kW | kilowatt |
| kWh | kilowatt hour |
| kW/kg | Kilowatts per kilogram |
| kW/m3 | Kilowatts per cubic meter |
| kW/sq.m | Kilowatts per square meter |
| LCA | life cycle assessment |
| LDH | layered double hydroxide |
| LEL | lower explosive limit |
| LFG | landfill gas |
| LFL | lower flammable limit |
| LH2 | liquid hydrogen |
| LHSV | liquid hourly space velocity |
| LHV | lower heating value |
| LNG | liquefied natural gas |
| LOD | limit of detection |
| LPG | liquefied petroleum gas |
| LSM | lanthanum strontium manganite |
| LTS | low temperature shift |
| MAF | mass flow sensor |
| MAOP | maximum allowable operating pressure |
| MBOP | mechanical balance of plant |
| MCFC | molten-carbonate fuel cell |
| mCHP | micro combined heat and power |
| MDT | mean down time |
| MEA | membrane electrode assembly |
| MeOH | methanol |
| MFC | microbial fuel cell |
| mm | millimeter |
| MPGe | miles per gallon of gasoline equivalent |
| MRO | maintenance, repair and operations |
| MSR | methanol steam reforming |
| MTBF | mean time between failures |
| MTBO | mean time between outages |
| MW | megawatt |
| mW | milliwatt |
| N2 | nitrogen |
| NEG | net energy gain |
| NOx | nitrogen oxide |
| O | oxygen |
| OCV | open-circuit voltage |
| OEM | original equipment manufacturer |
| Pa | pascal |
| PAFC | phosphoric acid fuel cell |
| PBI | polybenzimidazole fiber |
| PCFC | protonic ceramic fuel cell |
| Pd | palladium |
| p.d. | potential difference |
| PEC | photoelectrochemical cell |
| PEDOT | poly |
| PEDT | poly |
| PEFC | polymer electrolyte membrane fuel cell |
| PEM | polymer electrolyte membrane or proton exchange membrane |
| PEMFC | polymer electrolyte membrane fuel cell or proton exchange membrane fuel cell |
| PM | particulate matter |
| POX | partial oxidation |
| ppm | parts per million |
| ppmv | parts per million volume |
| PROX | preferential oxidation |
| PRV | pressure relief valve |
| PSA | pressure swing adsorption |
| PSU | power supply unit |
| Pt | platinum |
| PTFE | polytetrafluoroethylene |
| Pv | power density |
| Re | reynolds number |
| RESS | rechargeable energy storage system |
| RFC | reversible fuel cell |
| RMFC | reformed methanol fuel cell |
| RWGS | reversed water-gas shift reaction |
| s/c | short circuit or steam to carbon ratio |
| SFC | standard cubic foot or sometimes solid oxide fuel cell |
| SMPS | switched-mode power supply |
| SMR | steam methane reforming |
| SOEC | solid oxide electrolyser cell |
| SOFC | solid oxide fuel cell |
| SR | steam reforming |
| TA | technology assessment |
| TGC | tail-gas combustor |
| TOF | turnover frequency |
| TOS | time on stream |
| TPB | triple-phase boundary |
| TPE | thermoplastic elastomers |
| TPOX | thermal partial oxidation |
| TRL | technology readiness level |
| UEL | upper explosive limit |
| UPS | uninterruptible power supply |
| URFC | unitized regenerative fuel cell |
| VHC | volumetric heat capacity |
| VLE | vapor–liquid equilibrium |
| W | watt |
| WGS | water–gas shift reaction |
| WHSV | weight hourly space velocity |
| Wt.% | weight percent |
| YSZ | yttria-stabilized zirconia |
| ZnO | zinc oxide |