Cylindrical single-piece lithium-ion battery of 400Ah and its preparation method

Patent metadata

Field	Value
Publication number	US-10367190-B2
Application number	US-201615278039-A
Country	US
Kind code	B2
Filing date	Sep 28, 2016
Priority date	Feb 7, 2013
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

A cylindrical single-piece lithium-ion battery of 400 Ah includes: a cylindrical battery enclosure ( 1 ), a battery mandrel ( 3 ), a plurality of tabs ( 4 ), a wiring terminal ( 6 ), a positive and negative electrode cover ( 11 ); a positive electrode sheet, said battery positive electrode is composed of LiFePO 4 , conductive carbon-black, graphite, adhesive such as PVDF, and solvent such as NMP; a negative electrode sheet, the battery negative electrode is composed of lithium titanate, conductive carbon-black, graphite, adhesive such as PVDF, and solvent such as NMP. The cylindrical lithium-ion battery made by the invention has a capacity of 400 Ah which is the one reportedly having the largest capacity in the world presently.

First claim

What is claimed is:

1. A method of making a cylindrical single-piece lithium-ion battery, comprising steps as follows:
(1) mixing evenly LiFePO 4 , conductive carbon black, graphite, polyvinylidene fluoride as adhesive, and N-methylpyrrolidone as solvent in a weight percentage ratio of 42.0-43.0:1.3-1.7:0.8-1.2:2.5-3.5:51.0-53.0 to form a first slurry and mixing evenly lithium titanate, conductive carbon black, graphite, polyvinylidene fluoride as adhesive and N-methylpyrrolidone as solvent in a weight percentage of 49.0-50.0:0.8-1.2:0.8-1.2:3.0-4.0:44.0-46.0 to form a second slurry;
(2) coating and rolling the first slurry and the second slurry to form a positive electrode sheet and a negative electrode sheet, respectively, wherein each of the positive and negative electrode sheets is of a length of 33.81m, has an aluminum foil as current-collector and exposes a foil edge, and the aluminum foil has a thickness between 28 μm and 32 μm and a width between 319 mm and 321 mm;
(3) baking the positive electrode sheet and the negative electrode sheet for 48 hours at 100° C.;
(4) aligning and stacking up the positive electrode sheet and the negative electrode sheet with a separating membrane in-between, which are then mounted to an automatic winding machine to form a cylindrical shape;
(5) welding a plurality of aluminium tabs onto the foil edge of the positive electrode sheet and a plurality of aluminium tabs onto the foil edge of the negative electrode sheet, wherein each of the aluminium tabs has a length between 69 mm and 71 mm, a width between 9.9 mm and 10.1 mm and thickness between 0.135 mm and 0.165 mm;
(6) securing each of the aluminium tabs in a space defined by wiring terminal 6 and sliding ring 7 using tab clamping nut 8 to form a cell pack;
(7) inserting the cell pack into an enclosure with two ends each being wrapped by a supporting bracket;
(8) connecting sequentially wiring terminal 6 , O-ring 10 , insulation cushion 9 and cover 11 together, which are then fixed with clamping nut 12 and locating screw 13 ; and
(9) sealing cover 11 to the enclosure using a laser welder.

Assignees

• Univ Tianjin

Inventors

• Tang Zhiyuan
• Sun Lei
• Wang Qi
• Ling Guowei

Classifications

• H01M50/159

  Metals · CPC title

• H01M50/133

  Thickness · CPC title

• H01M50/119

  Metals · CPC title

• H01M50/534

  characterised by the material of the leads or tabs · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title