Flexible-package lithium ion battery and method for improving electric capacity of battery

Abstract

The invention relates to the technical field of lithium ion batteries and particularly relates to a flexible-package lithium ion battery and a method for improving electric capacity of the battery. The flexible-package lithium ion battery comprises a composite-membrane battery case made from a hot-melt macromolecule membrane and metal foil, and two sealed spaces are formed in the composite-membrane battery case through heat sealing, wherein a battery cell is placed in one sealed space, the other sealed space is positioned on the upper side surface of the battery cell and forms an air bag positioned upwards, and electrolyte is injected into the air bag which is communicated with the sealed space in which the battery cell is placed. According to the flexible-package lithium ion battery with the structure, under the conditions of not changing the overall dimension of the battery and the interior of the battery cell, the electric capacity can be maximized, the capacity attenuation is slower, and the cycle performance is better.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a soft-pack lithium-ion battery and a method for increasing its electric capacity. Background technique [0002] Soft-pack lithium-ion batteries have the advantages of high voltage, large capacity, long cycle life, no memory effect, light weight, and wide operating range. At present, the market has higher and higher requirements on the performance and capacity of lithium-ion batteries. Not only does it require the battery to have a high initial capacity, but it also requires the battery to have a good capacity retention rate during repeated charging and discharging, showing good performance. Has a long service life. The capacity of the soft-pack lithium-ion battery depends on the selection of raw materials and the utilization rate of the internal space of the battery body. If a battery with a higher capacity density needs to be manufactured, the thickness space is ...

AI Technical Summary

Problems solved by technology

The capacity of soft-pack lithium-ion batteries depends on the selection of raw materials and the utilization rate of the internal space of the battery body. If a battery with a higher capacity density needs to be manufactured, the thickness space is relatively small when the battery size remains unchanged. In the design, the thickness of the battery core must be controlled in a smaller range, which affects and makes the internal space volume of the entire battery smaller, and the liquid injection volume is lower, resulting in a lower capacity of the soft-pack lithium-ion battery, rapid capacity decay, and poor cycle performance. Difference

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