Method for manufacturing lithium-ion batteries

A technology of lithium-ion batteries and manufacturing methods, which is applied in the field of battery manufacturing, can solve problems such as reduced utilization of active materials, inability to use high-current pre-charging, and affecting battery safety performance, so as to improve capacity, shorten pre-charging time, and eliminate Or reduce the effect of lithium analysis

Inactive Publication Date: 2010-03-17
SHENZHEN BAK BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This pre-charging process has the following disadvantages: 1) due to the existence of insulating regions, the utilization rate of active materials will be reduced, and the electrochemical performance will be reduced
2) Due to the existence of an insulating area, the subsequent capacity separation and cycle process will inevitably cause lithium analysis in some areas, which will affect the safety performance of the battery
3) The gas production reaction is not complete during pre-charging, and gas may still be produced during aging, capacity separation, cycling, etc., making the battery size easily exceed the standard. The larger the battery model, the more obvious the size exceeds the standard; , the gas production speed will be much greater than the exhaust speed, and the above disadvantages will be more obvious, so it is not possible to use a large current precharge, which makes the precharge time very long

Method used

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  • Method for manufacturing lithium-ion batteries
  • Method for manufacturing lithium-ion batteries
  • Method for manufacturing lithium-ion batteries

Examples

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Effect test

Embodiment 1

[0023] Assemble a set of 423450A batteries from Shenzhen BAK Battery Co., Ltd. Thickness × width × height = 4.5mm × 34mm × 50mm. The positive electrode material is lithium cobalt oxide. Charge at 0.5C constant current for 30 minutes, the entire pre-charge time is 60 minutes, and the pre-charge capacity is 30% of the nominal capacity. During the whole pre-charging process, the pipeline pumping pressure of the vacuum device is constant at 0.07MPa. After testing, the specific capacity of lithium cobalt oxide is 147.8mAh / g at 0.2C constant current discharge and 146.1mAh / g at 1C constant current discharge for the battery using the above precharging method. After 300 cycles, the capacity retention reached 87.4%.

[0024] Use the conventional method for the above-mentioned other batteries in the same group, that is, do not evacuate during pre-charging, and pre-charge at 0.1C for 390 minutes. After testing, the specific capacity of lithium cobaltate is only 146.3mAh / g at 0.2C consta...

Embodiment 2

[0027] Assemble a set of batteries of Shenzhen BAK Battery Co., Ltd. model 423048A, thickness × width × height = 4.5mm × 30mm × 48mm, the positive electrode material of the battery is a mixed system of lithium cobalt oxide and lithium nickel cobalt manganese oxide, first with 0.1C Constant current charging for 60 minutes, then 0.3C constant current charging for 30 minutes, and then 0.5C current pre-charging for 12 minutes, the entire pre-charging time is 102 minutes, and the pre-charging capacity is 35% of the nominal capacity. During the first 90 minutes of pre-charging, the pipeline pumping pressure is constant at 0.05 MPa, and during the last 12 minutes of pre-charging, the pumping pressure is constant at 0.08 MPa. After testing, the specific capacity of the positive electrode active material is 150.6mAh / g at 0.2C constant current discharge and 146.3mAh / g at 1C constant current discharge for the battery using the above precharging method. After 300 cycles at 1C, the capacit...

Embodiment 3

[0031] Assemble a set of batteries of Shenzhen BAK Battery Co., Ltd. model 053048A, thickness × width × height = 5.3mm × 30mm × 48mm, the positive electrode material of the battery is a mixed system of lithium manganese oxide and nickel cobalt lithium manganese oxide, first with 0.1C Constant current charging for 30 minutes, then 0.3C constant current charging for 30 minutes, then 0.6C current pre-charging for 30 minutes, the entire pre-charging time is 90 minutes, and the pre-charging capacity is 50% of the nominal capacity. During the first 70 minutes of pre-charging, the pipeline pumping pressure is constant at 0.05MPa, and during the last 20 minutes of pre-charging, the pumping pressure is constant at 0.08 MPa. After testing, the specific capacity of the positive electrode active material is 129.8mAh / g at 0.2C constant current discharge and 126.9mAh / g at 1C constant current discharge for the battery using the above precharging method. After 300 cycles at 1C, the capacity r...

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Abstract

The invention discloses a method for manufacturing lithium-ion batteries, which comprises a battery-precharging process. The method is characterized in that the battery-precharging process is realizedin the following way: using a precharging device to precharge a battery and using a vacuumizing device to vacuumize the inside of the battery at the same time, wherein the pressure in the vacuumizingprocess is set to be between 0.03 and 0.08 MPa; the precharging capacity is set to be 0.15 to 1 times of nominal capacity; and the precharging current is set to be between 0.05 and 1 C. The method adopting vacuum precharging can quickly and thoroughly discharge gas produced in the precharging process inside the battery and eliminate insulation region produced by the gas, thereby improving the capacity exerting-cycling performance of the battery, effectively eliminating or reducing lithium-separation situation of pole pieces, guaranteeing the qualified size of the battery and shortening precharging time. In addition, relative to the prior method, the method can leave out the processes of plugging cotton and covering rubber plugs.

Description

technical field [0001] The invention relates to the field of battery manufacturing, in particular to a manufacturing method of a lithium ion battery. Background technique [0002] The pre-charging process of the battery is included in the manufacturing process of the lithium-ion battery, and its function is to form an SEI film on the surface of the negative electrode of the battery by constant current charging to a certain voltage. Gas is generated during the formation of the SEI film and is discharged through the exhaust port. The SEI film acts as a protective layer to prevent the electrolyte from reacting with the negative electrode, and can provide a good ion migration channel. In order to effectively form the SEI film, the battery precharging process is an important step in battery manufacturing. [0003] In the current manufacturing of lithium-ion batteries, except for steel shell cylindrical batteries, the method of pre-charging with liquid injection hole openings is ...

Claims

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Application Information

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IPC IPC(8): H01M10/38
CPCY02E60/12Y02E60/10Y02P70/50
Inventor 唐红辉周冬王驰伟唐联兴罗朝晖王弗刚袁德勇
Owner SHENZHEN BAK BATTERY CO LTD
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