Summary of the invention
The purpose of this invention is to provide a kind of method for detecting lithium ion battery airtightness, this method can judge quantitatively that whether battery leaks gas.
Technical scheme of the present invention: method for detecting lithium ion battery airtightness comprises the steps:
A, with subatmospheric air pressure m a plurality of not sealed batteries are carried out air-tightness and detect, and write down the gas leakage speed of each battery correspondence;
B, battery is toasted;
C, inject the electrolyte into battery;
D, envelope battery liquid-filling hole;
E, battery is immersed in the water;
F, taking-up battery;
G, measure each cell thickness, and judge whether its varied in thickness scope is qualified;
H, the battery qualified according to varied in thickness are determined detecting corresponding with it gas leakage velocity interval n when air-tightness detects.
I, with air pressure m down gas leakage velocity interval n be set at the air-tightness examination criteria;
J, with air pressure m down gas leakage velocity interval n battery carried out sealing detect, defective battery is eliminated, select qualified battery.
Further, described air pressure m is lower than atmospheric pressure.
Further, step b time remaining 2~30 hours, more preferably 8~20 hours; The temperature of step b is set at 50~85 ℃.
Further, between steps d and e, also have battery ageing placement, precharge step;
Further, the d step duration is not less than 3 minutes.
Further, before the g step battery was left standstill 30~60 minutes.
Beneficial effect of the present invention: battery air tightness method of testing provided by the present invention has the step of the testing standard of preestablishing, therefore can check accurately battery, promptly the qualified battery of flase drop does not cause waste, also can not cause defective battery to flow into subsequent processing even comes into the market.
Embodiment
Embodiment 1
Method for detecting lithium ion battery airtightness comprises the steps:
With the air pressure of 0.093MPa to 30 models be aluminum hull 423450 types not sealed battery carry out air-tightness and detect, and write down the gas leakage speed of each battery correspondence;
B, with 65 ℃ of temperature baking batteries 16 hours;
C, inject the electrolyte into battery;
D, envelope battery liquid-filling hole;
E, battery was immersed in the water 3 minutes;
F, take out battery, and battery was left standstill 30 minutes;
G, measure each cell thickness, and judge whether its varied in thickness scope is qualified, sees Table (1);
H, the battery qualified according to varied in thickness are that the time difference is not less than 3.5 seconds to bubble at interval detecting corresponding with it gas leakage velocity interval when determining that air-tightness detects.
I, at interval to be not less than 3.5 seconds as air pressure be that 0.93MPa detects the bubble-tight standard of this size battery down the time difference with bubble.
J, with above-mentioned standard battery is carried out sealing and detect, defective battery is eliminated, select qualified battery.
Experimental data is as follows:
Sequence number |
Bubbling is (second) at interval |
Thickness (millimeter) before the water logging |
Thickness after the water logging (left standstill 30 fens |
Whether qualified cell thickness is after the water logging |
|
|
|
Clock) |
|
1 |
0.85 |
4.49 |
4.87 |
Not |
2 |
2.93 |
4.22 |
5.24 |
Not |
3 |
1 |
4.33 |
4.24 |
Be |
4 |
3.15 |
4.4 |
4.83 |
Not |
5 |
1.2 |
4.26 |
5.04 |
Not |
6 |
1.23 |
4.29 |
4.31 |
Be |
7 |
1.26 |
4.62 |
4.73 |
Not |
8 |
1.3 |
4.24 |
4.17 |
Be |
9 |
1.5 |
4.46 |
4.47 |
Be |
10 |
1.55 |
4.3 |
4.35 |
Be |
11 |
1.6 |
4.3 |
4.72 |
Not |
12 |
1.8 |
4.29 |
4.3 |
Be |
13 |
1.85 |
4.28 |
4.24 |
Be |
14 |
2.1 |
4.26 |
4.9 |
Not |
15 |
2.3 |
4.5 |
4.56 |
Not |
16 |
2.38 |
4.28 |
4.36 |
Be |
17 |
2.54 |
4.24 |
4.29 |
Be |
18 |
2.56 |
4.47 |
4.53 |
Not |
19 |
2.9 |
4.23 |
4.24 |
Be |
20 |
3.12 |
4.3 |
4.44 |
Be |
21 |
3.5 |
4.33 |
4.35 |
Be |
22 |
3.6 |
4.32 |
4.36 |
Be |
23 |
3.8 |
4.27 |
4.29 |
Be |
24 |
4.21 |
4.27 |
4.26 |
Be |
25 |
5.1 |
4.3 |
4.34 |
Be |
26 |
2.7 |
4.22 |
4.29 |
Be |
27 |
3 |
4.2 |
4.25 |
Be |
28 |
3.3 |
4.28 |
4.33 |
Be |
29 |
3.6 |
4.28 |
4.26 |
Be |
30 |
3.96 |
4.27 |
4.3 |
Be |
Table (1)
Embodiment 2
Method for detecting lithium ion battery airtightness comprises the steps:
A, with the air pressure of 0.093MPa to 30 models be aluminum hull 423450 types not sealed battery carry out air-tightness and detect, and write down the gas leakage speed of each battery correspondence;
B, to 70 ℃ of temperature baking batteries 10 hours;
C, inject the electrolyte into battery, again with battery ageing placement, precharge
D, envelope battery liquid-filling hole;
E, battery was immersed in the water 10 minutes;
F, take out battery, and battery was left standstill 4 hours;
G, measure each cell thickness, and judge whether its varied in thickness scope is qualified, sees Table (2);
H, the battery qualified according to varied in thickness are that the time difference is not less than 3.5 seconds to bubble at interval detecting corresponding with it gas leakage velocity interval when determining that air-tightness detects.
I, at interval to be not less than 3.5 seconds as air pressure be that 0.93MPa detects the bubble-tight standard of this size battery down the time difference with bubble.
J, with above-mentioned standard battery is carried out sealing and detect, defective battery is eliminated, select qualified battery.
Experimental data is as follows:
Table (2)
Concrete technological parameter such as detected air pressure, stoving time and temperature etc. are all identical or approximate with the technology elaboration in the battery production process among the present invention, be not limited to embodiment pressure in one's power as detected air pressure, as long as consistent with detected air pressure in the normal testing process.