CN100490244C

CN100490244C - Method for fabricating electric core of lithium ion battery

Info

Publication number: CN100490244C
Application number: CNB2007100349934A
Authority: CN
Inventors: 邓凌峰; 肖军; 陈白珍
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2007-05-24
Filing date: 2007-05-24
Publication date: 2009-05-20
Anticipated expiration: 2027-05-24
Also published as: CN101093897A

Abstract

Method for fabricating battery core includes steps: aligning and superposing two negative pole (NP) pieces with same width and different lengths, and then soldering end point of two NP pieces to a NP ear so as to constitute NP piece set; soldering one end of longer positive pole (PP) piece to PP ear, and soldering one end of shorter PP piece to aluminum strip; before enwinding, using diaphragm paper to wrap shorter PP piece, and then inserting them between NP pieces in NP piece set; when enwinding, placing a layer of diaphragm paper (DP), and then placing NP piece set with PP piece being inserted to middle of DP; then, placing layer of DP on NP piece set, and finally, placing longer PP piece to middle of DP; aligning and enwinding each pole piece and DP to obtain roll core. Soldering PP ears of two PP pieces with aluminum strip so as to constitute an integrated battery core. Features are: high production efficiency, small internal resistance, and high capacity etc.

Description

A kind of manufacture method of lithium ion battery cell

Technical field

The present invention relates to a kind of manufacture method of lithium ion battery cell, particularly relate to a kind of manufacture method of polymer lithium ion battery electric core.

Background technology

At present, lithium ion battery cell has two kinds of manufacture methods: a kind of is to form with the overlapping coiling of monolithic positive pole, negative pole and barrier film, is commonly referred to the takeup type method; Another kind is that positive plate, negative plate are cut into the similar small pieces of size, and draws a lug on each pole piece, and is neat according to the order stack of negative plate-diaphragm paper-positive plate-diaphragm paper then, is commonly called laminating method.The shortcoming of first method is that the internal resistance of cell is big, and material is scrapped greatly when doing high power capacity, big specification battery, and production efficiency is low.Second method is manufactured volume core complex process, and same production efficiency is low.

Summary of the invention

Technical problem to be solved by this invention be for the shortcoming that overcomes above-mentioned technology with not enough, provide that a kind of makings is simple, the internal resistance of cell is little, production efficiency is high, be fit to high power capacity, the manufacture method of the lithium ion battery cell of specification greatly.

In order to solve the problems of the technologies described above, the present invention makes by following step:

Make two width unanimities earlier, short negative plate that length is different and long negative plate are made a short positive plate of a slice and a length of a film positive plate again, cut out first diaphragm paper and second diaphragm paper of 2 times of two negative plate length that thickness is identical, length is correspondence respectively;

Anode ear is gone up in long positive plate one end welding, and aluminium strip is gone up in short positive plate one end welding; To lack negative plate and long negative plate longitudinal end neat overlapping after, short negative plate and neat longitudinal end one end of long negative plate are welded on the negative electrode lug composition negative plate assembly; The short positive plate that is welded with aluminium strip is wrapped with first diaphragm paper, its aluminium strip exposed end is formed the positive plate assembly in the back, then this positive plate assembly is in a relative end with the relative negative electrode lug of aluminium strip and is inserted into composition positive/negative plate assembly between the short negative plate of negative plate assembly and the long negative plate;

During coiling, the positive/negative plate assembly is placed on the rear end of second diaphragm paper, front end with second diaphragm paper covers on the positive/negative plate assembly then, last on second diaphragm paper, be in same end and place the long positive plate that is welded with anode ear so that anode ear is corresponding with aluminium strip, will each pole piece, diaphragm paper is wound into electric core after aliging;

After electric core winding finished, the anode ear that will lack again on aluminium strip and the long positive plate on the positive plate welded together.

Adopt the manufacture method of the lithium ion battery cell of technique scheme, its advantage is:

1, the internal resistance of whole electric core is compared with the internal resistance of old winding method electricity core, has reduced by 20%～30%.Be suitable for reducing the improvement of lithium ion battery internal resistance.

2, the electric core of said method making adopts two positive plates, two negative plates, two diaphragm papers to form, compare with the electric core of old-fashioned monolithic positive pole, monolithic diaphragm paper, the overlapping coiling of monolithic negative pole, the pole piece and the diaphragm paper of battery all shorten, help improving raw-material utilance, reduce material cost.

3, present, the lithium battery industry often adopts stacked method to make electric core when making big specification, high inner capacities battery, but the method complex manufacturing technology, production efficiency are low.And because the method that the present invention makes electric core is to adopt two positive plates, two negative plate and two diaphragm papers to reel to form, making electric core with stacked method, to compare manufacture craft simple, and production efficiency can improve 30%～40%.

In sum, the present invention overcomes the shortcoming of above-mentioned technology with not enough, is that a kind of making is simple, the internal resistance of cell is little, production efficiency is high, is fit to the manufacture method of the lithium ion battery cell of high power capacity, big specification.

Description of drawings

Below in conjunction with the drawings and specific embodiments invention is described further.

Fig. 1 is in the electric core manufacturing process, the overlay order schematic diagram of two positive plates, two diaphragm papers, two negative plates;

Fig. 2 is the explosion views of whole electric core;

Fig. 3 is the charging and discharging curve figure of this example;

Fig. 4 is the cycle life resolution chart of this example.

Among the figure: 1 is short negative plate, and 2 are long negative plate, and 3 is negative electrode lug, and 4,5 is the same size diaphragm paper, and 6 are short positive plate, and 7 are long positive plate, and 8 is aluminium strip, and 9 is anode ear.

Embodiment

Make the polymer Li-ion battery 052030 electric core of a 250mAh:

Referring to Fig. 1 and Fig. 2, making two thickness earlier is that 0.136mm, length are respectively the short negative plate 1 of 115mm and the long negative plate 2 of 121mm, making two thickness again is that 0.133mm, length are respectively the short positive plate 6 of 115mm and the long positive plate 7 of 141mm, it is identical to cut out two thickness, and length is first diaphragm paper 4 and second diaphragm paper 5 of 254mm;

Anode ear 9 is gone up in long positive plate 7 one ends welding, and aluminium strip 8 is gone up in short positive plate 6 one ends welding; To lack negative plate 1 and long negative plate 2 longitudinal ends neat overlapping after, short negative plate 1 and long negative plate 2 neat longitudinal end one ends are welded on the negative electrode lug 3 composition negative plate assembly; Short positive plate 6 usefulness first diaphragm paper 4 that is welded with aluminium strip 8 is wrapped, its aluminium strip 8 exposed ends are formed the positive plate assembly in the back, then this positive plate assembly are in a relative end with aluminium strip 8 relative negative electrode lugs 3 and are inserted into composition positive/negative plate assembly between the short negative plate 1 of negative plate assembly and the long negative plate 2;

During coiling, the positive/negative plate assembly is placed on the rear end of second diaphragm paper 5, front end with second diaphragm paper 5 covers on the positive/negative plate assembly then, last on second diaphragm paper 5, be in same end and place the long positive plate 7 that is welded with anode ear 9 so that anode ear 9 and aluminium strip 8 are corresponding, will each pole piece, diaphragm paper is wound into electric core after aliging;

After electric core winding finished, the aluminium strip 8 that will lack again on the positive plate 6 welded together with anode ear 9 on the long positive plate 7.

Referring to Fig. 3 and Fig. 4, the internal resistance of whole electric core is compared with the internal resistance of old winding method electricity core, has reduced by 20%～30%.Be suitable for reducing the improvement of lithium ion battery internal resistance.The electric core that said method is made adopts two positive plates, two negative plates, two diaphragm papers to form, compare with the electric core of old-fashioned monolithic positive pole, monolithic diaphragm paper, the overlapping coiling of monolithic negative pole, the pole piece and the diaphragm paper of battery all shorten, help improving raw-material utilance, reduce material cost.At present, the lithium battery industry often adopts stacked method to make electric core when making big specification, high inner capacities battery, but the method complex manufacturing technology, production efficiency are low.And because the method that the present invention makes electric core is to adopt two positive plates, two negative plate and two diaphragm papers to reel to form, making electric core with stacked method, to compare manufacture craft simple, and production efficiency can improve 30%～40%.

Claims

A kind of manufacture method of lithium ion battery cell is characterized in that: it is made by following step:

(A), make two width unanimities, the short negative plate (1) that length is different and long negative plate (2), making a slice is lacked a positive plate (6) and a length of a film positive plate (7), cuts out first diaphragm paper (4) and second diaphragm paper (5);

(B), long positive plate (7) one ends welding goes up anode ear (9), aluminium strip (8) is gone up in short positive plate (6) one ends welding; To lack negative plate (1) and long negative plate (2) longitudinal end neat overlapping after, will lack neat longitudinal end one end of negative plate (1) and long negative plate (2) and be welded on the negative electrode lug (3), composition negative plate assembly; The short positive plate (6) that will be welded with aluminium strip (8) wraps with first diaphragm paper (4), its aluminium strip (8) exposed end is formed the positive plate assembly in the back, then with this positive plate assembly with aluminium strip (8) relatively negative electrode lug (3) be in a relative end and be inserted into composition positive/negative plate assembly between the short negative plate (1) of negative plate assembly and the long negative plate (2);

When (C), reeling, put one deck second diaphragm paper (5) earlier, the positive/negative plate assembly is placed on the centre of second diaphragm paper (5), the negative electrode lug of positive/negative plate assembly (3) is preceding, front end with second diaphragm paper (5) covers on the positive/negative plate assembly then, go up so that anode ear (9) is corresponding with aluminium strip (8) at second diaphragm paper (5) at last and be in same end and place the long positive plate (7) that is welded with anode ear (9), will each pole piece, diaphragm paper is wound into electric core after aliging;

(D), after electric core winding finishes, the aluminium strip (8) that will lack again on the positive plate (6) welds together with anode ear (9) on the long positive plate (7).