A kind of pole piece group that is used for lithium rechargeable battery
Technical field
The utility model relates to the pole piece structure in a kind of battery, particularly relates to a kind of pole piece group that is used for lithium rechargeable battery.
Background technology
Secondary lithium battery generally adopts the takeup type structure at present, as shown in Figure 1; The both positive and negative polarity that is battery all has only a pole piece, after the both positive and negative polarity pole piece is separated by with barrier film during moulding together (mould of reeling) coiling can obtain the pole piece group of battery.Though adopt the lithium ion battery CURRENT DISTRIBUTION of this structure even, heat radiation is slow, is unfavorable for that high capacity lithium ion battery inner row who produces heat when high current charge-discharge looses, and reduces and has limited the maximum charging and discharging currents density that battery is allowed.In addition, the lug of the pole piece of takeup type structure is welded on the pole piece, pole piece is long, then must be on the basis of the lug on pole piece top the also soldering polar ear at the middle part of pole piece again, the lug at pole piece middle part can influence the smooth of the barrier film that is adjacent and pole piece layer, when reeling, also expose the barrier film of battery easily, cause short circuit.
The patent No. is that ZL00228494.4 also discloses a kind of lithium rechargeable battery, constitute by battery pole piece, electrolyte and battery case thereof, the rectangular cell pole piece is stacked in the battery case arranges, be separated by with barrier film between battery pole piece, the battery pole piece two ends are by corrosion resistant plate or copper coin or nickel plate connection and fixing, electrolyte is full of battery case substantially, and barrier film adopts the barrier film of polypropylene diaphragm or polyethylene film and polypropylene screen lamination.During assemble, battery positive and negative electrode pole piece is separated and align with the barrier film of polypropylene diaphragm or polypropylene and polyethylene lamination, arrange by stacked, the also corresponding marshalling of the lug on pole piece top, the pole piece two ends that to arrange then add with corrosion resistant plate or copper coin or nickel plate that Rusty Nail or nickel nail etc. are fixing, and the lug of the neat positive and negative electrode of arranging also adds stainless steel nail or the fastening back connection of fastener outer conductor with stainless steel substrates, nickel plate or copper sheet respectively.The pole piece that fixes is put into battery case, after under 80-100 ℃ dry 40-100 hour, in drying box, inject an amount of electrolyte, again with the complete good seal of battery case.Though the large-capacity battery of this folded formula structure can dispel the heat by the edge of each battery pole piece when heavy-current discharge, inner the lost of heat that produce when helping the battery high current charge-discharge, thereby improve the maximum charging and discharging currents density that battery is allowed, and the large-capacity battery of takeup type structure is because entire electrode is a pole piece, the size of pole piece is very long, can only be behind the coiling by the upper and lower side heat radiation of pole piece, heat dispersion is corresponding relatively poor, has also influenced the macrocell charge-discharge performance of battery.But it does not tackle the problem at its root.In addition, the pole piece group of this laminated structure can only be made by hand, and whole pole piece composition is as a whole, and entire cell is an one, can not be divided into a plurality of unit, and the security performance of battery can not guarantee like this.
One of the purpose of this utility model is in order to improve the overall security of battery; Two of purpose is in order to reduce the internal resistance of cell, and can adjust the multiplying power of battery easily, adopts list/bipolar ear mode to connect and have the pole piece group that is used for lithium rechargeable battery of serpentine folding mode composition on a kind of pole piece thereby provide.
The purpose of this utility model is achieved in that
The pole piece group that is used for lithium rechargeable battery that the utility model provides comprises the positive plate 1 of being with lug, the negative plate 2 of band lug, and barrier film 3 is wherein separated by barrier film 3 between the negative pole 2 and anodal 1; It is characterized in that: described positive plate 1 is for to be coated with positive electrode in the place of a carrier surface except that lug, and positive pole ear 4 is made in a side top of positive plate 1; Described negative plate 2 is for to be coated with negative material in the place of a carrier surface except that lug, and another side is coated with insulating material, the side top that its negative lug 4 ' be made in and negative plate 2 are opposite; Negative plate 2 be coated with insulating material towards outside, it is overlapping with positive plate 1 that its negative plate 2 is coated with the one side of negative material, and between positive and negative plate, insert a slice barrier film 3, and then on positive plate, stack a barrier film 3, and barrier film 3 is outer to stack a negative plate 2 again, and it is coated with in negative material faces, be coated with insulating material and face outer stacking, its positive and negative lug interlaces out, and is rolled into the lamination pole piece group of " S " type, is the electrode cores that is used for lithium rechargeable battery.
Also be included in welding one Metal Melting fracture of wire on the lug, wire fusing when temperature surpasses certain value is to guarantee not excess temperature of battery.
Also comprise the two-sided negative plate 2 that all scribbles negative material '; Negative plate 2 be coated with insulating material towards outside, it is overlapping with positive plate 1 that its negative plate 2 is coated with the one side of negative material, and just, insert a slice barrier film 3 between the negative plate, and then on positive plate, stack a barrier film 3, on barrier film 3, stack a negative plate 2 ', negative plate 2 ' on stack a positive plate 1, and can repeat poststack N time, after stacking a barrier film 3 on the positive plate 1, stack a negative plate 2 more again, it is coated with in negative material faces, and is coated with insulating material and faces outer stacking, and its positive and negative lug interlaces out, and be rolled into the lamination pole piece group of " S " type, be the electrode cores that is used for lithium rechargeable battery.
Anode ear is welded together when being assembled into battery, and the one end welds a Thermal Cutoffs (Metal Melting fracture of wire) series connection, and the Thermal Cutoffs other end is connected with the battery unit external connection; Negative electrode lug is cascaded, and is connected with the battery unit external connection; And a pole piece group put into the plastic-aluminum bellows, behind the filling electrolyte, and with behind the aluminum plastic film good seal, the formation battery unit.More than at least 2, or N above-mentioned battery unit, battery of positive and negative electrode formation in parallel.Wherein N=100
Advantage of the present utility model is:
1, general battery is to be wound in circle or manual operations is folded into square; The utility model can replace manual operations, realizes automatic industrial production, increases work efficiency greatly and has reduced labour cost.
2, welded a Temperature protection at the lug of every group of unit, when temperature surpasses certain value, can fuse, to guarantee not excess temperature of battery.
3, existing technology entire cell is as a whole, and the pole piece group of battery can not resolve into a plurality of unit; Utilize pole piece group of the present utility model, make that each unit has baby battery of one's own in the battery, the high capacity cell of danger can be divided into a plurality of small-capacity cells that have Temperature protection and be formed in parallel, improved the fail safe of battery, its a large amount of production is become a reality.
4. because folding with serpentine, and the list/bipolar ear mode of employing connects, and helps reducing the internal resistance of cell and reaches multiplying power adjustment flexibly and production technology.
5. for folding with " S " row or directly build up the pole piece group and can reduce that accumulation artificially causes dimensional problem because of degree of tightness when folding, reduce the defective products in giving birth to, improve quality.
6. the R angle of the folding position in folding is controlled easily, helped quality control.
7. be coated with etc. on dew metal edges or the face at the pole piece edge of necessity or single face and add insulating barrier, to improve its fail safe and life-span.
8. to contrast existing lithium manganate battery data as follows for the battery of making of the utility model pole piece group:
1, internal resistance: about 15 milliohms of the 10AH internal resistance of cell, the battery that the utility model pole piece group is made is about 6 milliohms.
2, efficient: can improve about 20 times.
3, safety: 25AH does not overcharge and can explode; Its some performances are just as shown in table 1.
Description of drawings
Fig. 1 is the pole piece group schematic diagram that has laminated construction in the existing lithium rechargeable battery
Fig. 2 the utlity model has " S " type lamination pole piece group structural representation
1-positive plate, 2-single face is coated with the negative plate of negative material
2 '-the two-sided negative plate 3-barrier film that is coated with negative material
4-positive pole ear 4 '-negative lug
Embodiment
Embodiment 1
With reference to figure 1, make a 20AH lithium manganate battery, this 20AH lithium manganate battery by: 4 battery pole piece groups are formed in parallel, and wherein every battery pole piece group comprises:
A. the carrier of a 100mm (wide) * 600mm (length) * 0.385mm (thick), the place on it except that lug all is coated with and applies positive electrode as positive plate 1, and positive pole ear 4 is made in the top, left side of positive plate 1;
B, 2 101mm (wide) * 606mm (length) * 0.235mm (thick) copper pool is done the carrier of negative plate 2: be coated with negative material on the one side of flat copper pool, another side is coated with 0.01mm heavy insulation material; Its negative lug 4 ' be made on the right side of negative plate 2 tops; And another flat copper pool two sides all be coated with negative material do negative plate 2 '; Its negative lug 4 ' be made on the right side of negative plate 2 ' top;
The conventional barrier film 3 of C, barrier film 3:102mm (wide) * 612mm (length) * 0.025mm (thick), shared 6, each bar barrier film 3 places between positive plate 1, the negative plate 2;
D, positive and negative lug are 10mm (length) * 15mm (wide); Wherein existing with a negative plate 2 tape insulation layers towards outer placement, it is coated with and places a slice barrier film 3 on the face of negative material, place a slice positive plate 1 on the barrier film 3 again, on positive plate 1, place a slice barrier film 3 again, place negative plate 2 on the barrier film 3, these negative plate 2 tape insulation layers towards outer placement, lug on its two pole piece staggers mutually, then its lamination is rolled into " S " type lamination, as a pole piece group, i.e. battery unit.Anode ear is connected with Thermal Cutoffs (Metal Melting fracture of wire) when being assembled into battery, and the Thermal Cutoffs other end is connected with the battery unit external connection; Negative electrode lug is connected with the battery unit external connection; And a pole piece group put into the aluminum plastic film bag, behind the filling electrolyte, and with behind the aluminum plastic film good seal, the formation battery unit.With 4 above-mentioned battery units, the positive and negative electrode battery that forms a 20AH in parallel.
Perhaps on second barrier film 3, place again again a slice negative plate 2 ', its negative plate 2 ' on place on 3, the three barrier films 3 of a slice barrier film and place a positive plate 1 again, place on the positive plate 1 place on 3, the four barrier films 3 of the 4th barrier film negative plate 2 '; Lug on its two pole piece staggers mutually, as a pole piece group.Comprise also perhaps again and on the 4th barrier film 3, repeating again 10 times that make the overlapping battery unit of making of the multilayer positive/negative plate with 10 barrier films 3, its positive and negative lug interlaces out.Anode ear is welded together when being assembled into battery, and the one end welds a Thermal Cutoffs (Metal Melting fracture of wire) series connection, and the Thermal Cutoffs other end is connected with the battery unit external connection; Negative electrode lug is cascaded, and is connected with the battery unit external connection; And a pole piece group put into the aluminum plastic film bag, behind the filling electrolyte, and with behind the aluminum plastic film good seal, the formation battery unit.
Table 1 internal resistance relatively
Existing wound form pole piece group is made the internal resistance of cell (m Ω) | The folding pole piece group of the utility model S shape is made the internal resistance of cell (m Ω) |
15.2
|
5.3
|
16
|
5.1
|
16.5
|
6.3
|
16.1
|
6.1
|
Table 2 production efficiency relatively
Existing wound form pole piece group is made battery (/ hour) | The folding pole piece group of the utility model S shape is made battery (/ hour) |
60
|
1200
|
58
|
1250
|
65
|
1230
|
55
|
1210
|
Table 3 overcharges completeness relatively
Existing wound form pole piece group is made battery | The folding pole piece group of the utility model S shape is made split type battery |
Meeting quick-fried (20A filled 10 hours) | Can quick-fried (20A fill 50 hours) |
Meeting quick-fried (20A filled 8 hours) | Can quick-fried (20A fill 60 hours) |
Meeting quick-fried (20A filled 10 hours) | Can quick-fried (20A fill 65 hours) |
Meeting quick-fried (20A filled 12 hours) | Can quick-fried (20A fill 70 hours) |