NB/T 11203-2023Technical specification of carbon plastic bipolar plate for vanadium flow battery (English PDF)

3.1 Carbon-plastic composite bipolar plate

A bipolar plate for a vanadium flow battery made of carbon and plastic (polymer or polymer derivative).

4.1 Test conditions and requirements

--- Temperature: 25°C±5°C;

--- Pressure: 86 kPa~106 kPa;

--- Air humidity: 10%~96%.

4.2 Structural dimensions

4.2.1 Thickness uniformity requirements

The thickness dimensional deviation shall comply with the following provisions: when the average thickness d<=0.4 mm, the difference between the maximum and minimum thickness values <=6%d; when 0.4< d<=1.0 mm, the difference between the maximum and minimum thickness values <=5%d; when d >1.0 mm, the difference between the maximum and minimum thickness values <=4%d. See 5.2 a) for the test method.

4.2.2 Dimensional deviation

Dimensional deviation in length and width shall be <= ±1 mm. Measure the length and width of the material with a steel ruler. The specific dimensional requirements of products of different specifications shall be negotiated by the supplier and the purchaser.

4.3 Electrical properties

Volume resistivity shall be <=0.15 ohm·cm, and the surface resistance in the direction perpendicular to the bipolar plate panel shall be <=0.1 ohm·cm2; the pressure range is 0.5 MPa~0.6 MPa, and the contact resistance with the carbon felt surface shall be <=0.1 ohm·cm2. See 5.2 b) for the test method.

4.4 Mechanical properties

4.4.1 Bending strength requirements

Bending strength shall be >=20 MPa. See 5.2 c) for the test method.

4.4.2 Tensile strength requirements

Tensile strength shall be >=10 MPa. See 5.2 d) for the test method.

4.4.3 Compressive strength requirements

Compressive strength shall be >=20 MPa. See 5.2 e) for the test method. […]