18650 Sodium ion Batteries for Sale

No.

Items

Test Methods and Conditions

Criteria

1

Standard
Charging Method

Charging the cell with constant current at 650mA and then with constant voltage at3.95V.

Limited Charge
Voltage=3.95V
Charge Current =650mA

2

Rapid
Charging Method

Charging the cell with constant current at 1300mA and then with constant voltage at3.95V till charge current declines to≤65mA.

Limited Charge Voltage = 3.95V
Charge Current =1300mA

3

Standard Discharge
condition

The capacity means the discharge capacity of the cell, which is measured with discharge current of 0.5C with 1.8V cut-off voltage after standard
charge.

Discharge Voltage =1.8V
Discharge Rate =0.5C
Charge Current =650mA

4

Initial Impedance

Internal resistance measured at AC 1KHz within 1 hour after standard charge.

≤30mΩ

5

Cell Voltage

Cell state upon shipment

2.5-3.0V

6

Capacity

(1)Prior to charging, the cell shall be discharged at a constant current of 0.5C down to the cut off discharge voltage 1.8V, rest for 10 minutes.
(2)The capacity means the discharge capacity of the cell, which is measured with discharge current of 0.2C with 1.8V cut-off voltage after
standard charge.
(3)If the discharge capacity fails to meet the standard requirements, this test is allowed to be repeated 3 times.

≥1300mAh

7

Rate Discharge
Performance

(1)Prior to charging, the cell shall be discharged at a constant current of 0.5C down to cutoff discharge voltage 1.8V,rest for 10 minutes.
(2)0.5C CC to 3.95V,and CV to 0.05C cut off, rest for 10 minutes.
(3) The capacity means the discharge capacity of the cell, which is measured with discharge current of 1C with 1.8V cut-off voltage.

≥98% Nominal capacity

8

Low Temperature
Performance

(1) The cell shall be charged in accordance with the standard charge.
(2) The cell shall be stored in the temperature of -20℃±2℃for 4h.
(3) Discharge at the constant current of 1C down to the end-of-discharge voltage 1.8V.

discharge capacity≥80

9

High Temperature
Performance

(1) The cell shall be charged in accordance with the standard charge.
(2) The cell shall be stored in the temperature of 55℃±2℃for 4h.
(3) Discharge at the constant current of 1C down to the end-of-discharge voltage 1.8V.

discharge capacity≥95%
Nominal capacity

10

Charge Retention and
Recovery at Room
Temperature

After the cell is fully charged according to the standard method, it is stored at 25℃ ±2℃for 30 days, and then discharged at 0.5C at 25℃ ±2℃until the discharge termination voltage is 1.8V. This discharge capacity is maintained by charge. After the cell is recharged, the cell is
discharged at a current of 0.5C at 25℃ ±2℃until the discharge termination voltage is 1.8V. This discharge capacity is restored by the charge.

Capacity Retention≥90%
Nominal capacity
Capacity Recovery≥95%
Nominal capacity

11

Standard Cycle Life

Temperature : 25°C±2°C
Relative Humidity : 65%±20%
Charge: Charging the cell with constant current at 0.5C and then with constant voltage at 3.9V till charge current declines to≤0.05C, rest for
30mins. Discharge:0.5C discharge to 2.0V, one cycle is finished, then rest for 30mins. Then repeat above steps, when capacity is less than 80% of nominal capacity, the cell life is over.

≥1000cycles

No.

Items

Test Methods and Conditions

Criteria

1

Overcharge Test

After standard charge, the cell shall be charged at 1C with cutoff voltage 5.5V or charging time reached 60min, observe 1h (one of the conditions is preferred to stop test).

No Fire, No Explosion.

2

Low Pressure Test

The full charged cells are to be stored for at least 6h at an vacuum environment with pressure of less than 11.6kPa, and temperature of 23℃±2℃.

No Fire, No Explosion.
The open circuit voltage of each test cell or battery after testing is not less than 90% of its voltage immediately prior to this procedure.

3

Heating Test

The cells are fully charged with standard charging method, and put into oven with nature air or cycled air convected, heat cell by velocity of 5℃/min±2℃/min to 130℃±2℃,and maintain for 30 minutes.

No Fire, No Explosion.

4

Temperature Cycling Test

The fully charged cells are placed in a test chamber and subjected to the following cycles:
a) Raising the temperature to 75℃±2℃and maintaining this temperature for at least 6 hours.
b) Reducing the temperature to -40℃ ±2℃within 30 minutes and maintaining this temperature for at least 6 hours.
c) Repeating the sequence for a further 9 cycles.
d) After the 10th cycle, storing the cells for 24 hours prior to examination, in the temperature of 20±5℃.

No Fire, No Explosion.

5

Short Test

The fully charged cells are placed in a test chamber and subjected to the following cycles: short the positive and negative terminals with wire resistance of 80mΩ±20mΩ.Tests are to be conducted at standard test conditions, keep 24h or surface temperature decline to 20% of max. temperature, test is end.

No Fire, No Explosion.
The surface temperature of samples shall not exceeding 150℃.

6

Forced Discharge
Test

The cell is discharged with standard discharging method.

Inverse charge current =1300mA

time:≥90minutes

No Fire, No Explosion.

No.

Items

Test Methods and Conditions

Criteria

1

Shock Test

The full charged cell is fixed on shock table. Each cell shall be subjected to a half-sine shock of peak acceleration of 150 gn and pulse duration of 6 milliseconds. Each cell shall be subjected to three shocks in the positive direction by three shocks in the negative direction of three mutually perpendicular mounting positions of the cell for a total of 18 shocks.

No Fire, No Explosion.
The open circuit voltage of each test cell or battery after testing is not less than 90% of its voltage immediately prior to this procedure.

2

Crush Test

A cell is crushed between two flat surfaces. The applied force is 13 kN±1kN by hydro cylinder. Once the maximum pressure has been obtained, or voltage decrease to 1/3 of nominal voltage sharply, or 10% of deformation has occurred compared

No Fire, No Explosion.

3

Free Drop Test

The fully charged cell drops on the concrete ground from 1m height, total 3 times, to obtain the shock of random directions. After the test, the cell shall rest for a minimum of one hour and then a visual inspection shall be performed.

No Fire, No Explosion.