NB/T 42007-2013 in English

Bipolar plate for vanadium flow battery - Test method

1 Scope

This standard specifies the general requirements and test methods of bipolar plate for vanadium flow battery, mainly including thickness uniformity test, warpage test, corrosion current density test, resistivity test, gas permeability test, bending strength test, tensile strength test and compressive strength test.

This standard is applicable to all bipolar plate materials for vanadium flow battery.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 13465.2-2002 Test method for flexure strength of impermeable graphite materials

3 Terms and definitions

For the purpose of this standard, the following terms and definitions apply.

3.1
vanadium flow battery; VFB
energy storage device that realizes the mutual conversion of electric energy and chemical energy through the electrochemical reaction of vanadium ions at different valence states in positive and negative electrolytes, also known as vanadium flow battery system

Note: The vanadium flow battery is mainly composed of power unit (electric pile or module), energy storage unit (electrolyte and storage tank), electrolyte delivery unit (pipeline, valve, pump, heat exchanger, etc.) and battery management system, etc.

3.2
bipolar plate
conductive separator used for collecting conduction current and separating positive and negative electrolytes

3.3
corrosion current density
current value generated by the damage caused by electrochemical action of bipolar plate of battery per unit area on corrosion potential under specified conditions, in μA/cm2

Note: The magnitude of corrosion current density, as a physical quantity characterizing the corrosion resistance of bipolar plate materials on corrosion potential, reflects the corrosion rate of bipolar plates.

3.4
volume resistivity
resistivity per unit sectional area per unit length of bipolar plate, in Ω·cm

3.5
interface contact resistance
resistance generated by the contact part between two materials, in Ω·cm2

Note: It is characterized by the contact resistance between bipolar plate material and electrode material (usually carbon felt).

3.6
gas permeability
amount of gas passing through the sample per unit area per unit time under the test conditions, in cm3/(cm2·s)

3.7
bending strength
maximum bending stress that the material can bear during bending under specified conditions, in MPa

3.8
tensile strength
maximum tensile stress that the material can bear before fracture during tension under specified conditions, in MPa

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Test method
Bibliography