Cylindrical battery protection block
Technical field
The utility model relates to technical field of lithium ion, is a kind of when cell internal pressure is too high, and the safety guard that battery can not be discharged and recharged is especially blocked a shot at the security protection of cylindrical lithium ion secondary battery.
Background technology
Development along with modern society, mobile device such as video camera, notebook computer, mobile DVD and digital camera etc. have obtained application more and more widely, thereby formed wilderness demand to high-energy battery, column lithium ion battery is as 18650,26650, and 14430 batteries are because high energy density has obtained application widely.So owing to there is the very high lithium/carbon compound of pair water activity good sealing to be arranged, generally will adds glue to battery seal ring and seal in order to solve the cell sealing problem in the industry in the lithium ion battery with the external world.Lithium ion battery can make the excessive danger that blast is arranged of inner pressure of battery because of electrolyte decomposition produces gas when improper use simultaneously, so lithium ion battery needs power-off protection and protector when interior pressure is excessive.The combination cover cap that possesses the outage protection is arranged on the market, solve sealing problem but these combination cover caps can not add glue, and its complex structure, fail safe is not high.
Summary of the invention
Technical problem to be solved in the utility model just is to overcome the not high and baroque defective of combination cover cap fail safe of present lithium ion battery, and a kind of column lithium ion battery security protection block with higher-security energy is provided.
For solving the problems of the technologies described above, the utility model has adopted following technical scheme: this protection block comprises: one has the explosion-proof valve of ring-type indentation, and along this indentation towards outer formation one lug boss; One power-off protection apparatus, this power-off protection apparatus center and the lug boss welding that is positioned at its top explosion-proof valve also offer one or more pressure conduction hole on the power-off protection apparatus; One is positioned at positive temperature coefficient (PTC) ring plate of explosion-proof valve top ring-type; One has the top cover of air vent hole; Seal in one, this seal loads top cover, ring plate, explosion-proof valve and power-off protection apparatus successively.
When using the utility model, it is installed in the upper end of cylindrical battery, and a lug of battery is welded in the power-off protection apparatus center gets final product.After the utility model adopted said structure, it had the advantage of the following aspects:
Positive temperature coefficient ring plate resistance raises and reduces input current when 1, overcharging overcurrent;
2, cell internal pressure is high when setting numerical value, and explosion-proof valve overturns, and the lug that connects with explosion-proof valve is come off and opens circuit;
3, after the explosion-proof valve upset, cell internal pressure still raises, and when reaching set point, explosion-proof valve will be opened pressure release, and promptly pressure is washed explosion-proof valve open by the indentation place, and pressure is discharged.
The utility model can effectively avoid battery to blast and pyrophoricity accident, and its method for making is simple, is convenient to produce in batches.
Description of drawings:
Fig. 1 is a structural representation of the present utility model;
Fig. 2 is the cutaway view of the utility model explosion-proof valve;
Fig. 3 is the stereogram of the utility model power-off protection apparatus;
Fig. 4 is the schematic diagram that adopts cylindrical battery of the present utility model.
Specific embodiment:
See Fig. 1~3, the utility model comprises: explosion-proof valve 1, power-off protection apparatus 2, positive temperature coefficient (PTC) ring plate 3, top cover 4 and seal 5.
Explosion-proof valve 1 has ring-type indentation 11, and this explosion-proof valve 1 along this indentation 11 towards outer formation one circular-arc lug boss 12.It is that 0.2~2mm aluminium flake strikes out that explosion-proof valve adopts thickness 1 quarter.These explosion-proof valve 111 lug bosses 12 centre punch are molded to have platform 121, this platform 121 to be used for and power-off protection apparatus 2 welding.Explosion-proof valve 1 is to control its eversion pressure and the pressure that pops by the degree of depth of adjusting indentation 11 and diameter.Usually eversion pressure is 1-2Mpa, and the pressure that pops is 1~3Mpa.
Power-off protection apparatus 2 is the metallic plate of a circle, and there is the circular groove 21 of 2~5 millimeters of diameters at its center, and also offers a plurality of pressure conduction holes 22 that are used for exitting on it, and electric in-core portion pressure can conduct the hole by these and pass on the explosion-proof valve.During installation, the platform 121 of explosion-proof valve 1 welds with the center of this power-off protection apparatus 2, and this weld part lower surface correspondence is offered groove 21, to help welding.When adjusting explosion-proof valve 1 upset and the pressure that comes off between the power-off protection apparatus 2 by the weld strength between explosion-proof valve 1 and the power-off protection apparatus 2.When power-off protection apparatus 2 is installed, should be at its edge a sheathed insulating washer 23.
Positive temperature coefficient ring plate 3 adopts PTC (Positive Temperature Coefficient thermistor special material) to make.The internal diameter of this positive temperature coefficient ring plate is than protection indentation 11 slightly larger in diameter of explosion-proof valve 1, can not pushed down by this ring plate 3 and influences the pressure that pops with the protection indentation 11 of guaranteeing to assemble back explosion-proof valve 1.
This positive temperature coefficient ring plate 3 is positioned at explosion-proof valve 1 top, and the top cover 4 with air vent hole 41 is positioned at the top of this ring plate 3, and power-off protection apparatus 2 is positioned at the below of explosion-proof valve 1.
Hollow insulator 5 is used to load top cover 4, ring plate 3, explosion-proof valve 12 and power-off protection apparatus 2.This power-off protection apparatus 5 is the sealing ring of electrolyte resistance, and it is by making in about about the 100 microns sealant layer drying of immersion thickness in the fluid sealant solution.
See Fig. 4; top cover 4, ring plate 3, explosion-proof valve 12 and power-off protection apparatus 2 are installed in the power-off protection apparatus 5; obtain combination cover cap 6; power-off protection apparatus 2 laser welding in electric core 7 positive pole ears 71 of having annotated electrolyte and the combination cover cap 6 together, weld 6 the electric core 7 of blocking a shot and seals through mechanical riveted again after i.e. formation assemble battery 8.
During use, if when electric core 7 external short circuits or charging and discharging currents surpass the operating current of positive temperature coefficient ring plate 3, this positive temperature coefficient ring plate 3 by temperature raise, resistance increases and reduces electric current, to protect electric core; When electric core 7 causes internal gas pressure to increase to the protection pressure of setting because of inefficacy; explosion-proof valve 1 will be by the upwards upset of indentation 12 places; be that whole lug boss 12 will upwards overturn; this moment, power-off protection apparatus 2 came off with platform 121 welding portions; cause forming between lug 71 and the explosion-proof valve 1 and open circuit; so electric core 7 is in the failure state that opens circuit and can not discharges and recharges, thereby also uses continuing when avoiding electric core 7 to lose efficacy.If electric in-core portion air pressure after opening circuit, also continue to rise, when reaching set point, explosion-proof valve 1 pops and pressure release, avoids the battery accident of blasting.