Quick-charging type lithium ion battery

Abstract

The invention provides a quick-charging type lithium ion battery. The battery comprises a positive electrode, a negative electrode, diaphragms and electrolyte. The positive electrode, the negative electrode and the diaphragm are installed in a battery shell; the electrolyte is injected into the battery shell; the battery shell is sealed; and therefore, the quick-charging type lithium ion battery can be formed. The positive electrode is prepared from the following components in percentage by mass: 97.3 percent of lithium cobalt oxide; 1.5 percent of acetylene black; and 1.2 percent of polyvinylidene fluoride. The negative electrode is prepared from the following components in percentage by mass: 95 percent of secondary carbon beads; 2 percent of acetylene black; 1.3 percent of carboxymethylcellulose; and 1.7 percent of butadiene styrene rubber. The diaphragm is a ceramic diaphragm. The electrolyte is non-aqueous electrolyte. According to the lithium ion battery, the quick charging performance of the battery is improved, and the rate cycle performance, especially the high-current rate (10C) cycle performance of the battery is effectively improved.

Description

technical field [0001] The invention relates to a fast charging lithium ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, and good safety performance. It is widely used in consumer fields such as mobile phones and tablet computers, and power fields such as electric vehicles and energy storage base stations. However, as the degree of intelligence of devices increases, improving the battery life of electronic devices is an urgent problem to be solved. If the electronic device can achieve fast charging, it can guarantee the continuous battery life of the device. The fast charge and discharge capacity and performance of lithium-ion batteries depend to a large extent on the structure and performance of the anode material. The current commercial anode materials are almost all carbon materials, which can be summarized as modified graphite, soft carbon and hard carbon materials. . The structure of graphi...

AI Technical Summary

Problems solved by technology

However, the compatibility with the electrolyte is poor, and the graphite layer is prone to exfoliation during the charging and discharging process, resulting in poor cycle performance, which is not conducive to high-rate charging and discharging.

Especially at high rates, the deterioration of the graphite negative electrode is more serious, so the negative electrode is the main factor limiting the fast charging performance

On the other hand, the lithium intercalation potential of the graphite negative electrode is close to the metal lithium potential. When charging with a high current, the polarization in the battery increases, resulting in lithium deposition on the surface of the negative electrode; high-rate charging will also increase the internal resistance of the battery and cause the battery to heat up. Serious, leading to a series of side reactions, such as intensified electrode / electrolyte interface reactions, gas production, etc., seriously deteriorating battery performance, and even bringing safety problems

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