GB/T 34870.1-2017Super capacitors—Part 1:General (English PDF)

3.1 Capacitance

The ability to store electric charge.

Note: Modify GB/T 2900.16-1996, definition 2.3.1.

6.2.2 Measuring instruments and meters

The accuracy of measuring instruments and meters shall meet the following requirements:

a) Voltage measuring device: Accuracy is not less than level 0.5;

b) Current measuring device: Accuracy is not less than level 0.5;

c) Temperature measuring device: It shall have an appropriate measuring range. The division value is not more than 1 °C. The calibration accuracy is not less than 0.5 °C;

d) Timer: Divide by hour, minute and second. The accuracy is ±0.1%;

e) Measuring tool for measuring dimensions: Division value is not more than 1 mm;

f) Weighing instrument for weighing mass: Accuracy is above ±0.05%.

6.2.3 Charging and discharging current

Unless otherwise specified, the charging and discharging current of this Part is selected according to the constant current I, as follows:

a) Hybrid capacitor: I=5I1 or 8C (or a current not lower than 5I1 provided by the manufacturer), whichever is greater;

b) Electric double-layer capacitor: I=40I1 or 66C (or a current not lower than 40I1 provided by the manufacturer), whichever is the greater;

c) Battery capacitor: 3C.

Note 1: C represents the ratio of the current magnitude when the capacitor is charged and discharged. 3C is discharge at 3 times the current.

Use the measuring tool and weighing instrument to check the boundary dimensions and mass of the capacitor cell. It shall meet the technical conditions provided by the manufacturer.

6.4.1.3 Capacitance measurement

6.4.1.3.1 Capacitance

Follow the steps below to test the capacitance of capacitor cell:

a) At a constant current I, the capacitor cell is charged to the rated voltage UR;

b) At a constant current I, the capacitor cell is discharged to the minimum operated voltage Umin;

c) Repeat steps a)~b) 3 times. Record the discharge time t of the capacitor voltage from 90% of the rated voltage to the minimum operated voltage Umin;

d) According to formula (1), calculate the capacitance of the capacitor cell in each cycle. Take the average value.

Where:

C - Capacitance, in farad (F);

I - Charging and discharging current, in amperes (A); t - Charging time, in seconds (s);

UR - Rated voltage, in volts (V);

Umin - Minimum operated voltage, in volts (V).

The capacitance deviation shall not exceed ±10% of the rated capacitance.

6.4.1.3.2 Storage energy

Follow the steps below to test the storage energy and mass energy density of the capacitor cell:

a) At a constant current I, the capacitor cell is charged to the rated voltage UR;

The internal resistance shall not be greater than the nominal internal resistance.

6.4.1.5 Measurement of maximum mass power density

After measuring the internal resistance of the capacitor cell according to the method in 6.4.1.4, according to formula (5), calculate the maximum mass power density of the capacitor cell.

Where:

Pdm - Maximum mass power density, in watts per kilogram (W/kg);

UR - Rated voltage, in volts (V);

R - Internal resistance, in ohms (ohm);

M - Mass of capacitor cell, in kilograms (kg).

The maximum mass power density shall not be less than the nominal value.

6.4.1.6 Short-circuit discharge test

At a constant current I, charge the capacitor to the rated voltage UR; keep the constant voltage for 1 h. At 25 °C±5 °C, place it for 1 h. The super capacitor is externally short-circuited for 10 min. The external circuit resistance shall be less than 5 mohm. Record the short-circuit discharge current value and actual resistance.

During and after the test, the sample shall not explode, fire or leak.

6.4.1.7 Test of voltage holding characteristics

Follow the steps below to test the voltage holding characteristics of the capacitor:

a) At a constant current I, the capacitor cell is charged to the rated voltage UR;

b) The capacitor cell is charged at the constant rated voltage for 30 min;

c) After standing in open circuit for 24 h at test temperature, measure the terminal voltage of the capacitor cell. Calculate the ratio of the terminal voltage to the rated voltage, as its voltage holding characteristics.

After the test, the voltage across the capacitor shall not be less than 85% of the - The storage energy is not less than 70% of the initial value;

- The internal resistance is less than 2 times the initial value.

6.4.1.11 Steady-state damp heat test

Store the super capacitor at 40 °C±2 °C, 90%~95%RH for 240 h; then, place it at room temperature for 24 h. Test its capacitance, leakage current and internal resistance. The test values shall meet the requirements for specified values.

And the performance of the capacitor remains unchanged.

During and after the test, the sample shall not explode, fire or leak.

6.4.1.12 Cyclic life test

6.4.1.12.1 Ambient temperature

The test shall be carried out at an ambient temperature of 25 °C±5 °C.

6.4.1.12.2 Test steps

Perform the test as follows:

a) At a constant current I, charge the capacitor cell to the rated voltage UR; let it stand for 5 s;

b) At a constant current I, discharge the capacitor cell to the minimum operated voltage Umin; let it stand for 5 s;

c) Repeat steps a)~b) 2000 times;

d) Let stand for 12 h;

e) According to 6.4.1.3.1 and 6.4.1.4, detect the capacitance and internal resistance of the capacitor. If they meet:

- The capacitance of hybrid super capacitor is greater than 80% of the initial value; the internal resistance is less than 2 times the initial value;

- The capacitance of electric double-layer super capacitor is greater than 90% of the initial value; the internal resistance is less than 1.5 times the initial value;

- There is no electrolyte leakage.

Then skip to the next step. Otherwise it will be determined as nonconformity; and the test will end;

b) Use a phi5 mm~phi8 mm high-temperature-resistant steel needle (the needle tip angle is 60°; the needle surface is smooth, free of rust, oxide layer and oil), at a speed of 20 mm/s~30 mm/s, to penetrate in the direction perpendicular to the capacitor plate (the steel needle stays in the capacitor cell).

During and after the test, the sample shall not explode or fire.

6.4.1.17 Squeeze test

Perform the test as follows:

a) At a constant current I, charge the capacitor cell to the rated voltage;

b) Test according to the following conditions:

- Squeeze direction: Perpendicular to the direction of the capacitor lead wire;

- Form of squeezing plate: A semi-cylinder with a radius of 75 mm. The length of the semi-cylinder is greater than the dimension of the capacitor to be squeezed;

- Squeeze degree: Stop squeezing when the voltage reaches 0 V or the cell ruptures.

c) Observe for 1 h.

During and after the test, the sample shall not explode, fire or leak.

6.4.1.18 Heating test

Perform the test as follows:

a) At a constant current I, charge the capacitor cell to the rated voltage;

b) Place the capacitor cell in a temperature box. At a rate of 5 °C/min, the temperature box is heated to 130 °C±2 °C. Keep this temperature for 30 min;

c) Observe for 1 h.

During and after the test, the sample shall not explode, fire or leak.

6.4.1.19 Seawater immersion test

Perform the test as follows:

Use the measuring tool and weighing instrument to check the boundary dimensions and mass of the capacitor module. It shall meet the technical conditions provided by the manufacturer.

6.4.2.4 Capacitance measurement

6.4.2.4.1 Capacitance

Follow the steps below to test the capacitance of capacitor module:

a) At a constant current I, the capacitor module is charged to the rated voltage UR;

b) At a constant current I, the capacitor module is discharged to the minimum operated voltage Umin;

c) Repeat steps a)~b) 3 times. Record the discharge time t of the capacitor voltage from 90% of the rated voltage to the minimum operated voltage Umin;

d) According to formula (6), calculate the capacitance of the capacitor module in each cycle. Take the average value.

The capacitance deviation shall not exceed ±10% of the rated capacitance.

6.4.2.4.2 Storage energy

Follow the steps below to test the storage energy and mass energy density of the capacitor module:

a) At a constant current I, the capacitor module is charged to the rated voltage UR;

b) Keep the constant voltage for 30 min;

c) After the capacitor module is left standing for 5 s, at a constant current I, it is discharged to the minimum operated voltage Umin. Record the waveform of capacitor voltage U and time t in real time;

d) Repeat steps a)~c) 3 times;

e) Respectively according to formula (7), formula (8) and formula (9), calculate the storage energy, mass energy density and volumetric energy density of the capacitor module. Take the average values.

The test voltage shall be applied between connected terminals and case for 1 min. The test voltage value is 3000 V.

There shall be no breakdown or flashover in the test.

6.4.2.7 Short-circuit discharge test

Perform the test as follows:

a) At a constant current I, charge the capacitor module to the rated voltage;

b) The super capacitor is externally short-circuited for 10 min. The external circuit resistance shall be less than 5 mohm.

During and after the test, the sample shall not explode, fire or leak.

6.4.2.8 Test of voltage holding characteristics

Follow the steps below to test the voltage holding characteristics of the capacitor:

a) At a constant current I, the capacitor module is charged to the rated voltage UR;

b) The capacitor module is charged at the constant rated voltage for 30 min;

c) After standing in open circuit for 24 h at test temperature, measure the terminal voltage of the capacitor module. Calculate the ratio of the terminal voltage to the rated voltage, as its voltage holding characteristics.

After the test, the voltage across the capacitor shall not be less than 85% of the rated voltage.

6.4.2.9 Cyclic life test

6.4.2.9.1 Ambient temperature

The test shall be carried out at an ambient temperature of 25 °C±5 °C.

6.4.2.9.2 Test steps

Perform the test as follows:

a) At a constant current I, charge the capacitor module to the rated voltage UR; let it stand for 5 s;

b) At a constant current I, discharge the capacitor module to the minimum operated voltage Umin; let it stand for 5 s;

During and after the test, the sample shall not explode, fire or leak.

6.4.2.12 Puncture test

Perform the test as follows:

a) At a constant current, charge the capacitor module to the rated voltage;

b) Use a phi6 mm~phi10 mm high-temperature-resistant steel needle; at a speed of 20 mm/s~30 mm/s, in the direction perpendicular to the capacitor plate, until at least 3 capacitor cells are penetrated (the steel needle stays in the capacitor);

c) Observe for 1 h.

During and after the test, the sample shall not explode or fire.

6.4.2.13 Squeeze test

Perform the test as follows:

a) At a constant current I, charge the capacitor module to the rated voltage;

b) Test according to the following conditions:

- Form of squeezing plate: A semi-cylinder with a radius of 75 mm. The length of the semi-cylinder is greater than the dimension of the squeezed capacitor, but not more than 1 m;

- Squeeze direction: The same as the direction where the capacitor module is most susceptible to squeezing in the use layout. If the direction most susceptible to squeezing is not available, apply pressure perpendicular to the arrangement direction of the capacitor cells;

- Squeeze degree: The squeeze force reaches one of the following conditions; keep for 10 min. The deformation of the capacitor module reaches 30%. Or the squeeze force reaches 1000 times the mass of the capacitor module, or reaches 500 kN, whichever is greater.

c) Observe for 1 h.

During and after the test, the sample shall not explode, fire or leak.

6.4.2.14 Vibration test

Unless otherwise specified, the vibration test shall be carried out in accordance with class 1, level A in IEC 61373:2010.

7.1 Safety requirements for case connection

The capacitor case shall be equipped with bolts for connection (if applicable); so that the potential of the capacitor metal case can be fixed; and it can withstand the fault current when the case is broken down.

7.2 Other safety requirements

When there are special requirements in relevant national safety regulations, the purchaser shall explain them during the inquiry.

8.1 Cell

The following information shall be given on the nameplate of each capacitor cell:

a) Manufacturer (abbreviation of company name) or registered trademark;

b) Rated voltage (V);

c) Capacitance (F);

d) Polarity mark;

e) Product number;

f) Date of production.

Note: For small capacitor cells, if all the items listed above cannot be marked on the nameplate, some items can be given in the manual.

8.2 Module

The following information shall be given on the nameplate of each capacitor module:

a) Manufacturer (abbreviation of company name) or registered trademark;

b) Product model or specification;

c) Capacitance (F);

d) Rated voltage (V);

In the process of loading-unloading, it shall handle with care and avoid falling, rolling, and heavy pressure.

9.2.2 Storage

The capacitor shall be stored in a dry, clean, and naturally-ventilated place at - 30 °C~40 °C.

The capacitor shall not be exposed to direct sunlight. The distance from the heat source must not be less than 2 m.

Do not drop any metal debris between the positive and negative electrodes of the capacitor. It shall avoid contact with any liquid or harmful substances.

The capacitor must not be placed upside down or lying down, to avoid mechanical shock or heavy pressure.

9.2.3 Installation

The capacitor shall be placed in a place, where the heat generated by the loss of the capacitor can be fully dissipated by convection, conduction and radiation.

By the radiation from the sun or any high-temperature surface, the temperature of the capacitor will increase.

According to the cooling air temperature, cooling efficiency, and the intensity and duration of radiation, one of the following precautions may need to be taken:

- Prevent the capacitor from being radiated;

- Choose a capacitor designed for higher working air temperature; or use a capacitor with a rated voltage higher than the specified voltage.

10.1 Prevention of environmental pollution by chemicals

If the super capacitor contains substances that can pollute the environment or have other hazards, in accordance with relevant regulations, it shall be marked with corresponding signs on the equipment and devices. The purchaser shall inform the manufacturer of these relevant regulations.

When the capacitor is impregnated with materials, which are not allowed to be diffused into the environment, in accordance with China's legal requirements in this regard, preventive measures must be taken.