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A coiling lithium ion battery and its making method

The technology of a lithium-ion battery and its production method is applied in the field of lithium-ion batteries and its production, which can solve the problems of uneven end faces, easy distortion and small contact area of ​​wound-type batteries, and achieve economical production methods, uniform distribution, Good heat dissipation effect

Active Publication Date: 2008-01-16
SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the end face of the wound battery is generally not smooth, and the collector plate must be welded at multiple points, and there will be force between the solder points, which is easy to desolder
The connection between the current collecting plate and the pole piece in this end surface current collecting structure belongs to point contact, and the contact area is small
At the same time, the positive and negative current collectors of lithium-ion batteries usually use thin aluminum foil (15-30 μm) and copper foil (5-20 μm), which have poor strength and are easily distorted and deformed when welding under a certain pressure, causing welding failure. tight or short circuit

Method used

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  • A coiling lithium ion battery and its making method
  • A coiling lithium ion battery and its making method
  • A coiling lithium ion battery and its making method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] A 1.2Ah high-rate 18650 lithium-ion battery made by this method. Dissolve polyvinylidene fluoride in an appropriate amount of N-methylpyrrolidone to make a glue, and mix lithium iron phosphate and superconducting carbon black according to lithium iron phosphate: superconducting carbon black: polyvinylidene fluoride = 90:5:5 Add the proportion of the glue into the glue, stir it evenly, and apply it on both sides of the 20μm thick aluminum foil. When coating, reserve a 1mm wide blank on the front and back sides of one side, and cut it after drying and rolling to obtain a coating width of 57mm. A positive electrode sheet 1 with a blank width of 1 mm. Add mesocarbon microspheres, SBR, CMC and superconducting carbon black in deionized water at a ratio of 94.5:2.25:2.25:1, stir evenly, and coat on a 9 μm thick copper foil, with one side reserved The blank with a width of 1 mm was dried and rolled, and then cut to obtain a negative electrode sheet 2 with a coating width of 57...

Embodiment 2

[0016] The 2.3Ah high-rate 26650 lithium-ion battery made of this end-face current collection structure uses spinel lithium manganate as the positive active material, artificial composite graphite as the negative active material, lithium manganate in the positive electrode: superconducting carbon black: polybias The ratio of chlorofluoroethylene is 94:3:3, and the rest of the production process is the same as above. A blank current collector with a width of 6 mm is left along the length direction on one side of the positive and negative electrodes. A separator is sandwiched between the positive and negative electrodes and wound into a battery core. After the two end faces of the cell are edged, two 6mm wide nickel tabs are welded to the negative end, and one 6mm wide aluminum lug is welded to the positive end, and then welded to the cap. After the battery cell is installed in the case, the bottom point, rolling groove, welding cap, liquid injection and sealing are carried out...

Embodiment 3

[0018] In the 1.4Ah high-rate SC-type lithium-ion battery manufactured by adopting the end surface current collecting structure of the present invention, the positive electrode active material adopts lithium-nickel-cobalt-manganese-oxygen ternary material, and the negative electrode active material adopts mesophase carbon microspheres. The manufacturing process of the pole piece is the same as above, the coating width of the pole piece is 30mm, and the blank width is 10mm. After the blank current collector is folded in half twice, the width of the blank edge is 2.5mm. The positive and negative plates are staggered by 2.5mm along the width direction, exposing the blank folded edge, with a separator in the middle and then wound into a battery cell. Weld three 4mm wide nickel lugs on the negative end, weld a 15mm diameter current collector on the positive end, and then weld it to the cap. After the battery cell is installed in the case, the bottom point, rolling groove, welding ...

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Abstract

The invention provides a wound lithium-ion battery and the fabrication method thereof, which is characterized in that blanks of current collectors with certain width are reserved on the upper side of an anode plate and the lower side of a cathode plate along the direction of winding. The anode and the cathode plates are staggered in some distance along the width, and then wound to be an electrical core. The blank current collectors exposing the two ends of the electrical core are closed down to be a plane, and then current collecting discs or lugs are welded on the end faces thereof respectively. Or, the reserved bland current collectors on the anode and the cathode plates are flanged and then staggered along the width to expose the flanging blank to be wound into an electrical core, and current collecting discs or lugs are welded on the end faces of the electrical core. The end face current collecting structure in the invention not only increases the contact area between the current collecting discs and the electrode plates, but also ensures the welding strength, effectively reducing inner resistance of batteries, allowing a uniform distribution of current density in the process of big current charging and discharging, generating a small quantity of heat and good radiating performance, facilitating to enhance security and cycle life of batteries, and being suitable for the field of power battery, such at electric tools, electric bicycles, electric vehicles and so on.

Description

technical field [0001] The invention relates to a lithium-ion battery and a manufacturing method thereof, in particular to a wound-type lithium-ion battery with high-power charging and discharging characteristics and a manufacturing method thereof, belonging to the field of lithium-ion batteries. Background technique [0002] In recent years, with the rapid rise of electric tools, electric toys, model airplanes and electric vehicles, higher requirements have been put forward for the high rate charge and discharge performance of secondary batteries. Lithium-ion batteries have been widely used due to their outstanding characteristics such as high operating voltage, high energy density, low pollution, long cycle life, and low self-discharge rate. At present, most of the traditional winding lithium-ion batteries use single or multiple tabs as the current collection method. During the discharge process, the current distribution is uneven, and it is difficult to realize high-curr...

Claims

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Application Information

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IPC IPC(8): H01M10/38
CPCY02E60/12Y02E60/10Y02P70/50
Inventor 夏保佳张建张熙贵娄豫皖
Owner SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CHINESE ACAD OF SCI