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GB/T 20042 consists of the following seven parts under the general title Proton exchange membrane fuel cell:
——Part 1: Terminology;
——Part 2: General technical specification of fuel cell stacks;
——Part 3: Test method for proton exchange membrane;
——Part 4: Test method for electrocatalysts;
——Part 5: Test method for membrane electrode assembly;
——Part 6: Test method of bipolar plate properties;
——Part 7: Test method of carbon paper properties.
This is Part 1 of GB/T 20042.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 20042.1-2005 Proton exchange membrane fuel cell - Terminology. The following main technical changes have been made with respect to GB/T 20042.1-2005:
——The categories of terms are adjusted from the original seven categories to five categories and eleven subcategories;
——The terms and definitions are supplemented from 93 to 219.
This part was proposed by the China Electrical Equipment Industrial Association.
This part is under the jurisdiction of the National Technical Committee on Fuel Cell and Flow Battery of Standardization Administration of China (SAC/TC 342).
The previous edition of this standard is as follows:
——GB/T 20042.1-2005.
Proton exchange membrane fuel cell - Part 1: Terminology
1 Scope
This part specifies the terms and definitions used in proton exchange membrane fuel cell technology and its application fields.
This part is applicable to all types of proton exchange membrane fuel cells.
2 Physical objects and abstracts
2.1 Materials
2.1.1
hydrogen storage material
material that can absorb, store and release hydrogen when needed under certain conditions
2.1.2
electrocatalyst
a substance that accelerates the electrode reaction process without being consumed itself
2.1.3
non-precious metal catalyst
catalyst without any precious metal component
Note: The precious metal elements include osmium (Os), iridium (Ir), ruthenium (Ru), rhodium (Rh), platinum (Pt), palladium (Pd), gold (Au) and silver (Ag).
2.1.4
alloy catalyst
catalyst consisting of an alloy of two or more metals
2.1.5
core-shell catalyst
catalyst consisting of a core and a shell coated on the core
2.1.6
electrocatalyst support
substance, as a component of the electrode, used for supporting the electrocatalyst
2.1.7
electrolyte
liquid or solid substance containing mobile ions and thus having ionic conductivity
2.1.8
polymer electrolyte
polymer containing mobile ions and thus having ionic conductivity
2.1.9
proton exchange membrane; PEM
polymer electrolyte membrane with protons as conductive charges
2.1.10
non-fluorinated PEM
proton exchange membrane containing no fluorine atoms
2.1.11
sulfonated PEM
proton exchange membrane that conducts protons through sulfonic acid groups
2.1.12
perfluorinated PEM
proton exchange membrane in which all hydrogen atoms in the polymer chain are replaced by fluorine atoms
2.1.13
composite membrane
Membrane consisting of two or more kinds of materials
2.1.14
carbon cloth
porous cloth woven with carbon fibers
2.1.15
carbon paper
porous paper profile formed by bonding the evenly dispersed carbon fibers together (with carbonizable adhesive)
2.1.16
fuel
substance that can be oxidized at the anode to produce free electrons
2.1.17
raw fuel
unreformed fuel supplied from an external source to the fuel cell power system
2.1.18
reformate
hydrogen-rich gas obtained by the conversion of the raw fuel through the fuel reforming system
2.1.19
oxidant
substance whose electrons can be reduced at the cathode
2.1.20
clean gaseous reactant
gaseous reactant that contains no gaseous pollutants or contains gaseous pollutants at a content low enough not to have any impact on the performance and life of the fuel cell
2.1.21
contaminant
substance (other than water) present in the gaseous reactant or electrolyte at a very low concentration that can affect the catalytic activity of hydrogen oxidation or oxygen reduction of the electrode or the proton conductivity of the electrolyte, thus affecting the performance or life of the cell
2.2 Components and functional zones
2.2.1
end plate
component located on either end of the fuel cell stack in the current flow direction, serving to transmit the required compression to the stacked components
2.2.2
current collector
conductive plate on either end of the stack, serving to conducting the current generated by the stack
2.2.3
polar plate
conductive plate for isolating single cells, guiding fluid flow and conducting electrons in the cell stack
2.2.4
monopolar plate
polar plate containing the flowfield for reactant (fuel or oxidant) supply and distribution and product discharge on one side only
2.2.5
bipolar plate
polar plate containing the flowfield for reactant (with fuel on one side and oxidant on the other side) supply and distribution and product discharge on both sides
2.2.6
flowfield
a combination of flow channels of various shapes processed on the polar plate for the purposes of input and discharge and (reasonable) distribution of reactants, reaction products or cooling media
2.2.7
electrode
electronic conductor (or semiconductor) that is in contact with electrolyte to provide electrochemical reaction zone and leads the current generated by the electrochemical reaction into or out of the electrochemical reaction tank
2.2.8
anode
electrode at which the oxidation of the fuel takes place
2.2.9
cathode
electrode at which the reduction of the oxidant takes place
2.2.10
catalyst layer
a thin layer containing an electrocatalyst, typically with ionic and electronic conductivity
Note: In a fuel cell, one side of the catalyst layer is adjacent to the electrolyte membrane, forming a spatial zone where electrochemical reactions can occur
2.2.11
gas diffusion layer; GDL
a porous base layer placed between the catalyst layer and the polar plate to form electric contact, allowing reactants to enter the catalyst layer and reaction products to leave the catalyst layer
2.2.12
supporting layer
a porous base layer with mechanical supporting function in gas diffusion layer
2.2.13
microporous layer; MPL
a porous thin layer between the catalyst layer and the supporting layer to promote effective transfer and distribution of gaseous reactants and reaction products
2.2.14
gas diffusion electrode; GDE
porous electrode obtained by directly preparing the catalyst layer on the gas diffusion layer
2.2.15
catalyst-coated membrane; CCM
proton exchange membrane with catalyst layers on both surfaces to form cathode and anode reaction zones respectively
2.2.16
membrane-electrode assembly; MEA
an assembly consisting of an electrolyte membrane and the gas diffusion electrodes respectively arranged on two sides of the electrolyte membrane or a catalyst-coated membrane and the gas diffusion layers respectively arranged on two sides of the catalyst-coated membrane through a certain process, which is mostly called membrane electrode for short
2.2.17
three-phase boundary
a zone of microstructural space which can be reached simultaneously by the electrons, ions, and reactants in the catalyst layer and in which the electrochemical reactions may occur
2.2.18
stack wiring lead
the output terminal of the fuel cell stack that supplies power to the outside, which is also called the cell stack power terminal
2.2.19
manifold
a pipeline which supplies fluid to or collects and discharges fluid from the fuel cell or the fuel cell stack
Note 1: The external manifold is designed for the stacking of single cells, with which the gas mixture is supplied from a central source to a large fuel and oxidant inlet covering the adjacent side of the cell stack and sealed with a properly designed gasket. The waste gas is collected on the opposite side with similar system.
Note 2: The internal manifold is an internal channel of the stack formed by assembling bipolar plate, MEA and gasket, which is used for transporting and/or discharging reactants and/or reaction products for each single cell. The stacks of some structures also include the internal manifolds for transporting and discharging coolant.
2.3 Cells/systems
2.3.1
single cell or unit cell
the basic unit of a fuel cell, consisting of a group of membrane-electrode assemblies and corresponding unipolar or bipolar plates
Note: Generally, a single cell in the stack is called unit cell, and a single cell with an independent structure is called single cell.
2.3.2
fuel cell
an electrochemical device that directly converts chemical energy of externally supplied fuel and oxidant into electric energy (DC power) and generates heat and reaction products
2.3.3
regenerative fuel cell
an electrochemical device capable of generating electric energy and products by using fuel and oxidant and also generating the fuel and the oxidant by electrolyzing the aforementioned products by using external electric energy
2.3.4
direct alcohol fuel cell
fuel cell that directly oxidizes alcohols at the anode of a stack
2.3.5
direct methanol fuel cell
fuel cell that directly oxidizes methanol at the anode of a stack
2.3.6
proton exchange membrane fuel cell; PEMFC
fuel cell provided with proton exchange membrane as electrolyte
2.3.7
stack/fuel cell stack
a combination of two or more single cells and other necessary structural members with uniform electrical output
Note: The necessary structural members include: polar plate, current collector, end plate, sealing element, etc.
2.3.8
short stack
a stack that has the structural characteristics of a stack with the rated power but in which the number of single cells is significantly smaller than that of single cells in a stack designed according to the rated power
Foreword I
1 Scope
2 Physical objects and abstracts
3 Physical quantities and parameters
4 Reaction processes, phenomena and properties
5 Experimental methods and conditions
Index
