Flexible packing lithium ion battery core that a kind of fail safe is high and preparation method thereof
Technical field
The present invention relates to field of cell preparation, be specifically related to lithium ion battery preparation field.
Background technology
At present, the production method of lithium ion battery mainly contains winding-structure and lamination, and stack type lithium ion battery is simple with its preparation technology, the low favor being subject to people of cost of manufacture, and becomes the major way of current lithium ion battery making.And current laminated battery plate mainly stacks gradually making by negative pole, barrier film, positive pole, but the shortcoming such as short circuit that it exists that qualification rate is low, poor product quality and dust thereof cause.
Summary of the invention
The invention discloses high flexible packing lithium ion battery core of a kind of fail safe and preparation method thereof, not only can the security performance improving lithium ion battery and products thereof qualification rate, avoid overshoot, clash into, fall abnormal condition and to heat up the short circuit problem caused.
The invention provides high flexible packing lithium ion battery core of a kind of fail safe and preparation method thereof, include: pocket type negative plate 1 and positive plate 2, pocket type negative plate 1 inside is provided with negative plate 12, negative plate 12 be surrounded by diaphragm bag 13, negative plate 12 top is provided with negative pole nickel lug 11, the lower part of negative pole nickel lug 11 is coated with negative electrode lug gluing 14, described positive plate 2 top is provided with positive pole aluminium pole ears 21, positive pole aluminium pole ears 21 lower part is coated with anode ear gluing 23, described pocket type negative plate 1 and positive plate 2 juxtaposition multilayer, wherein ground floor and last one deck are all pocket type negative plates 1, positive pole aluminium pole ears 21 and negative pole nickel lug 11 are positioned at the homonymy of battery core.
The material of described diaphragm bag 13 is ceramic diaphragm, and described ceramic diaphragm is formed by following material mixture ratio: aluminium oxide 1 ~ 5%, lithium compound 0.1 ~ 1%, binding agent 1 ~ 20%, solvent 80 ~ 95%;
The particle diameter of described aluminium oxide is 0.1 ~ 10 μm;
The material mixture ratio of described lithium compound is: Li
5la
3ta
2o
1210 ~ 15%, Li
5la
3nb
2o
1220 ~ 25%, Li
6baLa
2ta
2o
1245 ~ 68%, Li
6mgLa
2ta
2o
1210 ~ 20%;
The material mixture ratio of described binding agent is: polyacrylamide 5 ~ 15%, polyvinyl alcohol 50 ~ 65%, polyethylene glycol 2 ~ 25%, polyethylene glycol oxide 11 ~ 16%;
The material mixture ratio of described solvent is: oxolane 19 ~ 25%, dimethyl formamide 75 ~ 81%.
The present invention adopts bag formula lamination process, can prevent cathode pole piece dust from falling and cause battery short circuit at positive electrode surface, improve its security performance; Meanwhile, cathode pole piece bag can prevent barrier film under contraction situation, causing battery short circuit.
The uncoated district of both positive and negative polarity pole piece and nickel lug/aluminium pole ears apply tab and can prevent battery in an abnormal situation, and anode pole piece contacts with cathode pole piece and causes battery short circuit, and improves the security performance of its lithium ion battery.
Ceramic diaphragm protection core of lithium ion cell in overshoot, clash into, the abnormal condition such as to fall under cause temperature to become large instantaneously, ceramic diaphragm then has the characteristics such as high temperature resistant, heat dispersion is excellent, improves the security performance of its battery.
Accompanying drawing explanation
Fig. 1 is pocket type negative plate schematic diagram of the present invention.
Fig. 2 is positive plate schematic diagram of the present invention.
Fig. 3 is pocket type negative plate of the present invention and positive plate lamination schematic diagram.
Symbol description in Fig. 1-3: pocket type negative plate 1, negative pole nickel lug 11, negative plate 12, diaphragm bag 13, negative electrode lug gluing 14, positive plate 2, aluminium pole ears 21, anode ear gluing 23.
Embodiment
As Figure 1-3, flexible packing lithium ion battery core that a kind of fail safe is high and preparation method thereof, pocket type negative plate 1 and positive plate 2, pocket type negative plate 1 inside is provided with negative plate 12, negative plate 12 be surrounded by diaphragm bag 13, negative plate 12 top is provided with negative pole nickel lug 11, the lower part of negative pole nickel lug 11 is coated with negative electrode lug gluing 14, described positive plate 2 top is provided with positive pole aluminium pole ears 21, positive pole aluminium pole ears 21 lower part is coated with anode ear gluing 23, described pocket type negative plate 1 and positive plate 2 juxtaposition multilayer, wherein ground floor and last one deck are all pocket type negative plates 1, positive pole aluminium pole ears 21 and negative pole nickel lug 11 are positioned at the homonymy of battery core.
The lamination number that pocket type negative plate is conventional has 13 layers, 31 layers, 41 layers, corresponding positive plate 12 layers, 30 layers, 40 layers.
The material of described diaphragm bag 13 is ceramic diaphragm, and described ceramic diaphragm is formed by following material mixture ratio: aluminium oxide 3.3%, lithium compound 0.7%, binding agent 12%, solvent 84%;
The particle diameter of described aluminium oxide is 0.1 ~ 10 μm;
The material mixture ratio of described lithium compound is: Li
5la
3ta
2o
1212%, Li
5la
3nb
2o
1222%, Li
6baLa
2ta
2o
1250%, Li
6mgLa
2ta
2o
1216%;
The material mixture ratio of described binding agent is: polyacrylamide 8%, polyvinyl alcohol 58%, polyethylene glycol 21%, polyethylene glycol oxide 13%;
The material mixture ratio of described solvent is: oxolane 22%, dimethyl formamide 78%.
The Performance comparision of the present invention and traditional battery core:
Implementation method | DC internal resistance | Safety loading coefficient |
Pocket type negative plate 31 layers and positive plate 30 layers | 0.23 mΩ | 9/10 |
Pocket type negative plate 13 layers and positive plate 12 layers | 0.56 mΩ | 8/10 |
Pocket type negative plate 41 layers and positive plate 40 layers | 0.11 mΩ | 8/10 |
The stacked battery core of tradition | 0.39 mΩ | 4/10 |
The present invention adopts bag formula lamination process, is obviously better than traditional stacked battery core in security performance, can prevent cathode pole piece dust from falling and cause battery short circuit at positive electrode surface, improve its security performance; Meanwhile, cathode pole piece bag can prevent barrier film under contraction situation, causing battery short circuit.
The uncoated district of both positive and negative polarity pole piece and nickel lug/aluminium pole ears apply tab and can prevent battery in an abnormal situation, and anode pole piece contacts with cathode pole piece and causes battery short circuit, and improves the security performance of its lithium ion battery.
Ceramic diaphragm protection core of lithium ion cell in overshoot, clash into, the abnormal condition such as to fall under cause temperature to become large instantaneously, ceramic diaphragm then has the characteristics such as high temperature resistant, heat dispersion is excellent, improves the security performance of its battery.
Last it is noted that obviously, above-described embodiment is only for example of the present invention is clearly described, and the restriction not to execution mode.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without the need to also giving all execution modes.And thus the apparent change of amplifying out or variation be still among protection scope of the present invention.