GB/T 20042.1-2017Proton exchange membrane fuel cell—Part 1: Terminology (English PDF)

2.1 Materials

2.1.1 Hydrogen storage material

Materials that can absorb, store, and release hydrogen when needed under certain conditions.

2.1.2 Electrocatalyst

A substance that speeds up the electrode reaction process but is not consumed by itself.

2.1.3 Non-precious metal catalyst

Catalyst that does not contain any precious metal component.

Note: Precious metal elements include. Osmium (Os), Iridium (Ir), Ruthenium (Ru), Rhodium (Rh), Platinum (Pt), Palladium (Pd), Gold (Au), Silver (Ag).

2.1.4 Alloy catalyst

A catalyst consisting of an alloy of two or more metals.

2.1.13 Composite membrane

A membrane which consists of two or more materials.

2.1.14 Carbon cloth

A porous cloth woven from carbon fiber.

2.1.15 Carbon paper

A porous paper-like profile formed by bonding uniformly dispersed carbon fibers together (by the use a carbonizable binder).

2.1.16 Fuel

The substance which can be oxidized at the anode to produce free electrons.

2.1.17 Raw fuel

The unreformed fuel which is supplied from an external source to the fuel cell power generation system.

2.1.18 Reformate

The hydrogen-rich gas converted from the raw fuel through the fuel reforming system.

2.1.19 Oxidant

The substance which can get electrons at cathode to be reduced.

2.2.18 Stack wiring lead

The output terminal of the fuel cell stack that supplies power to the outside, which is also referred to as the cell stack terminal.

2.2.19 Manifold

A pipe that supplies fluids to the fuel cell or fuel cell stack or otherwise collects from the fuel cell or fuel cell stack and drain it.

Note 1. The design of the external manifold is for single cells that are stacked together. The gas mixture is sent from a central source to the inlet of large fuel and oxidant. The inlet covers the immediate end of the stack and is sealed with a properly designed gasket. Similar systems collect exhaust gas at the opposite end.

Note 2. The internal manifold is an internal channel formed by the assembly of bipolar plates, MEAs, and gaskets, which is used for the delivery and/or removal of reactants and/or reaction products for each cell. The stack of some structures also includes internal manifolds that deliver and remove coolant.

2.3 Battery/system

2.3.1 Single cell unit cell

The basic unit of a fuel cell which consists of a group of membrane electrode assemblies and corresponding unipolar or bipolar plates.

Note: In general, a single cell in a 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 the chemical energy of an externally supplied fuel and oxidant into electrical energy (direct current) and generates heat and reaction products.

2.4.7 Thermal management system/module

The system and module which is to provide cooling, heat dissipation and/or heating, and may also provide for excess heat reusing to ensure that the temperature of various internal modules is within normal range when the fuel cell system is in operation.

2.4.8 Water management system/module

A system or module that manages to maintain the water required for the relevant modules inside the fuel cell system to meet its normal operating requirements and may also be used to achieve the reuse of water.

2.4.9 Water treatment system/module

A system or module used to perform the necessary treatment of recycled or make-up water used in fuel cell systems.

2.4.10 Exhaust treatment system/module

The system or module for treating the exhaust gas discharged from the stack to achieve the relevant discharge standard, which is mainly to remove or dilute the non-reactive fuel in the anode exhaust gas.

2.4.11 Oxidant treatment system/module

The system or module that meters, regulates, and processes the input oxidant to facilitate the use by the fuel cell power system.

2.4.12 Balance of plant; BOP

The general term for all components of a fuel cell system other than the fuel […]

3.1.11 Proton conductivity

The proton conductivity of the membrane which is characterized by the current density that the membrane can conduct at a unit electric field strength, in units of S/cm.

3.1.12 Gas permeability

The amount of gas which passes through unit area and unit thickness of article under the unit pressure per unit time.

3.1.13 Porosity

The ratio of the volume of all holes in an article to the geometric volume of the article.

Note: In proton exchange membrane fuel cells, porosity is one of the characteristic parameters of the catalyst layer, microporous diffusion layer, and gas diffusion layer.

3.1.14 Internal resistance (fuel cell internal resistance)

The ohmic resistance inside the fuel cell caused by electronic and ion resistance.

Note: Ohmic means that the relationship between voltage drop and current obeys Ohm's law.

3.1.15 Lower flammable limit

The lowest concentration (volume fraction) of a combustible gas or steam that can be ignited in a homogeneous mixture with the combustion supporting gas and can transmit the flame.

3.2.19 Net power

The power generated by a fuel cell power system which can be used externally.

3.2.20 Minimum power

The minimum net electric power that the fuel cell power system can output under continuous stable operation.

3.2.21 Peak power

The maximum power not less than the rated power generated by the fuel cell stack or power generation system within a predetermined short time period.

3.2.22 Auxiliary electrical power

The external electrical power consumed by the fuel cell system.

3.2.23 Auxiliary thermal power

The external thermal power consumed by the fuel cell system.

3.2.24 (Electrode) area power density

The power generated by the active area of the unit electrode.

3.2.25 Volumetric power

The ratio of the rated power of a stack or fuel cell power system to its volume.

Note: Volumetric power is often referred to as power density.

3.3.3 Fuel consumption

The amount of fuel consumed by the power generation system within a specified period of time under certain conditions. […]