Lithium ion battery

Abstract

The invention discloses a lithium ion battery which comprises a housing as well as a positive electrode piece and a negative electrode piece located in the housing, wherein a diaphragm is arranged between the positive electrode piece and the negative electrode piece; the negative electrode piece comprises a plurality of side action active sites; the side action active sites are formed by volatilizing volatile substancs having boiling points lower than a preset boiling point in a negative electrode slurry in a process of forming the negative electrode piece; an overcharge gas-generating substance is arranged in the positive electrode piece; and the overcharge gas-generating substance generates gas when a charging voltage of the lithium ion battery reaches a preset charging voltage. According to a technical solution provided by the invention, the lithium ion battery can generate a large amount of gas during overcharging by forming the side action active sites in the negative electrode piece and arranging the overcharge gas-generating substance in the positive electrode piece; the generated gas is timely discharged from a loosened roll core so as to ensure that a current cut-off device in the lithium ion battery can be turned on in time to break the lithium ion battery and improve safety performance of high-rate lithium ion batteries.

Description

technical field [0001] Embodiments of the present invention relate to battery technology, and in particular to a lithium ion battery. Background technique [0002] Cylindrical lithium-ion batteries have high energy density and are environmentally friendly, and have been widely used in the power tool and garden tool industries. According to market analysis, the global demand in 2017 was 500 million, and maintained a growth rate of 15% to 20%. [0003] With the widespread application of lithium-ion batteries in daily life, the requirements for their safety performance are more stringent. In practical applications, the demand for the discharge rate of lithium-ion batteries is gradually increasing. In order to increase the discharge rate of the battery, the number of active particles on the electrode sheet per unit area is generally reduced, and the small number of active particles will lead to a decrease in the safety performance of the lithium-ion battery. In general, lithiu...

AI Technical Summary

Problems solved by technology

In order to increase the discharge rate of the battery, the number of active particles on the electrode sheet per unit area is generally reduced, and the small number of active particles will reduce the safety performance of lithium-ion batteries.

In general, lithium-ion batteries mainly have the following deficiencies in terms of safety performance: the battery explodes the aluminum mesh during the overcharge fire and burning splash test

However, under normal circumstances, large-rate lithium-ion batteries may catch fire or explode during the overcharge test and combustion injection test, and their safety performance is low.

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