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Square lithium ion battery with prestress structure

A pre-stressed structure, lithium-ion battery technology, applied in secondary batteries, structural parts, battery pack parts, etc., can solve the problems of low battery shell strength, reduced shell strength, battery shell deformation, etc., to reduce the phenomenon of bulging shells , improve safety and reliability, improve the effect of strength

Inactive Publication Date: 2012-11-28
ZHEJIANG GODSEND POWER TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If a thin-walled metal case with the same thickness as the small battery is used, the strength of the battery case is low, and it cannot bear force. The size of the battery changes greatly during the discharge process, and the battery is easy to bulge, reducing safety.
In fact, the shell structure of large-capacity power batteries in China is not much different from that of small batteries. Generally, the size of the battery shell is only enlarged and the wall thickness is uniform, and the thickness of the square shell is generally small, and the length and width directions are larger, further reducing If the battery produces a small amount of gas during operation or the expansion of the battery pole piece during charging and discharging, it will easily lead to deformation of the battery shell, bulging and other phenomena.
In order to reduce adverse effects, it is necessary to reserve battery expansion space when designing the battery, reduce the specific energy density of the battery or cause loosening of the battery cell, which will have an adverse impact on the application and development of the power battery

Method used

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  • Square lithium ion battery with prestress structure
  • Square lithium ion battery with prestress structure
  • Square lithium ion battery with prestress structure

Examples

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Effect test

preparation example Construction

[0039] The prismatic lithium-ion battery structure of the described prestressed structure can refer to figure 1 , its preparation method comprises the following steps:

[0040] 1) Use the square winding method to wind the small winding core 17, and when winding, the positive pole tab 19 and the negative pole tab 29 each face one side;

[0041] 2) The positive pole tab 19 and the negative pole tab 29 are welded to the drain strips 12 and 22 respectively;

[0042] 3) The positive drain strip 12 and the negative drain strip 22 are welded to the battery positive cap 11 and the negative cap 21 respectively;

[0043] 4) The positive electrode cap 11 and the negative electrode cap 21 are sealed by laser welding with the square casing of unequal thickness.

[0044] 5) If the plastic shell is used, it shall be sealed by heat welding

[0045] 6) After vacuum drying, liquid injection and aging, chemical formation and volumetric screening are carried out to obtain qualified battery pro...

Embodiment 1

[0048] A square lithium-ion battery with a prestressed structure, the lithium-ion battery structure can refer to figure 1 , The designed battery capacity is 50Ah. The shell size is 102mm×52mm×130mm, the wall thickness of the battery’s long side shell is 1mm, and the short side shell’s wall thickness is 2mm. Each large battery is designed to be composed of 10 square winding cells connected in parallel. The size of the square winding cells is 9.9mm×49mm×114mm. The design capacity of each square winding cell is 5Ah and the thickness is 9.9mm.

[0049] The performance indicators of the assembled battery are shown in Table 1:

[0050] Table 1

[0051]

[0052] The performance index of the designed 50Ah prestressed square lithium-ion battery has obvious advantages compared with conventional square batteries in terms of internal resistance, discharge platform voltage, specific energy density, cycle life, high-rate discharge characteristics, and low-temperature performance. , it...

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Abstract

The invention discloses a square lithium ion battery with a prestress structure. The square lithium ion battery comprises a battery cell, a battery shell used for packaging the battery cell, and an electrolyte, wherein the cross section of the battery shell is rectangular, the thicknesses on the battery shell are different, the thickness of the short edge of the battery shell is larger than that of the long edge of the battery shell; and the battery cell comprises a plurality of square coiling battery cells which are compressed in parallel, is installed in the battery shell and is matched with the battery shell tightly, and the distribution direction of the square coiling battery cell is parallel to the direction of the short edge of the battery shell. According to the square lithium ion battery with the prestress structure provided by the invention, the compression strength of the whole battery is improved, and the shell expansion in the charging and discharging processes of the battery is prevented.

Description

technical field [0001] The invention relates to the field of square lithium ion batteries, in particular to a square lithium ion battery with a prestressed structure. Background technique [0002] Lithium-ion battery is a new type of high-energy secondary chemical battery successfully developed at the end of the 20th century. Compared with other secondary batteries, lithium-ion battery has many outstanding advantages: [0003] 1) High voltage: The working voltage of a single battery is as high as 3.7-3.8V (3.2V for lithium iron phosphate), which is three times that of Ni-Cd and Ni-H batteries. 2) Large specific energy: The actual specific energy that can be achieved at present is about 555Wh / kg, that is, the specific capacity of the material can reach more than 150mAh / g (3~4 times that of Ni-Cd, 2~3 times that of Ni-MH), It is close to about 88% of its theoretical value. 3) Long cycle life: Generally, it can reach more than 500 times, or even more than 1000 times, and the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/0587H01M2/02H01M2/12
CPCY02E60/12Y02E60/10Y02P70/50
Inventor 孙建平周晓政胡益兰倪九江缪东栋陶新永甘永平
Owner ZHEJIANG GODSEND POWER TECH
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