Lithium battery and manufacturing method thereof

Abstract

The invention relates to a lithium battery and a manufacturing method thereof. The lithium battery comprises an anode, a cathode, a diaphragm and an electrolyte solution, wherein the cathode is opposite to the anode; the diaphragm is positioned between the anode and the cathode, and the anode, the cathode and the diaphragm limit an accommodation area together; and the electrolyte solution comprises an organic solvent, a lithium salt and an additive, the additive comprises a maleimide base compound and a hydroxy group-containing substance, the molecular weight of the hydroxy group-containing substance is less than 1000, and the content of the hydroxy group-containing substance in the electrolyte solution is 0.05-5wt%. According to the lithium battery and the manufacturing method of the invention, a problem that water exists in the battery can be solved, and process steps can be carried out without a high-dryness fraction and low water content environment, so it is helpful for reducing the making cost and improving performances of the battery.

Description

technical field [0001] The invention relates to a lithium battery, in particular to an electrolyte solution for a lithium battery. Background technique [0002] Since primary batteries do not meet environmental requirements, rechargeable secondary battery systems have gradually attracted attention in recent years. Now portable electronic products such as digital cameras, mobile phones, and notebook computers all require lightweight batteries, and with the rapid development and popularization of portable electronic products, this lithium battery that can be recharged and discharged is light in weight, high in voltage and High energy density and other characteristics make its market demand increasing day by day. Compared with traditional lead-acid batteries, nickel-metal hydride batteries, nickel-zinc batteries, and nickel-cadmium batteries, lithium batteries have the advantages of high working voltage, high energy density, light weight, long life and good environmental prote...

AI Technical Summary

Problems solved by technology

[0003] However, in the currently known technology, the manufacturing process of lithium batteries must be carried out in an environment with high dryness and low water content. The main reason is that water will be electrolyzed into oxygen and hydrogen during the electrochemical reaction of the battery, which will easily cause battery expansion. with performance degradation

In addition, the high content of water in the battery will also undergo side reactions with lithium salts to form hydrofluoric acid. This product will cause problems such as the dissolution of transition metal ions in the electrode material and the corrosion of the current collector, which will easily cause the battery to be dangerous.

Since lithium batteries must be manufactured in an environment with high dryness and low water content (such as relative humidity <5%), most manufacturers need to build dry rooms and dry workshops for production and assembly to meet the process requirements, thus causing lithium batteries High costs for manufacturers to pay for electricity

On the other hand, there are also problems in using the air chamber (air chamber) method for secondary packaging processing procedures to improve the high water content in the battery

The above secondary packaging means that the high content of water in the battery is electrolyzed to generate gas in the first electrochemical reaction, and the battery first reserves space so that the gas can flow to the gas chamber, and then remove the gas chamber and perform secondary packaging , so the process steps are complex and time-consuming

However, no matter what kind of manufacturing process is carried out, it is extremely inconvenient and additionally increases the manufacturing cost

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