Disc-shaped and cylindrical safety devices for lithium ion battery

Abstract

The invention discloses disc-shaped and cylindrical safety devices for a lithium ion battery. The disc-shaped safety device comprises a first annular electric conductor, a second annular electric conductor, a fuse, an annular insulating base material and an electric conduction hole, wherein the first annular electric conductor is electrically connected to a first electrode of the lithium ion battery; the second annular electric conductor comprises a first metal ring and a second metal ring; the first metal ring and the second metal ring are isolated with each other; the first metal ring is electrically connected to a second electrode of the lithium ion battery; the fuse is electrically connected to the first metal ring and the second metal ring; the annular insulating base material is filled between the first annular electric conductor and the second annular electric conductor; and the electric conduction hole is formed on the first annular electric conductor, passes through the annular insulating base material and the second metal ring, and conducts the first annular electric conductor and the second metal ring. According to the disc-shaped and cylindrical safety devices for the lithium ion battery disclosed by the invention, the two electrodes are communicated through an electroplated inner ring surface or a through hole; two metal areas are etched on a top electrode; the two metal areas are respectively connected with positive and negative electrodes of the lithium ion electrode; furthermore, the fuse is formed between the two metal areas; and thus, ignition and explosion can be prevented by cutting off current passing through the battery when over-current occurs.

Description

technical field [0001] The invention relates to the field of electronic fuses, in particular to a disc-shaped and cylindrical safety device for a lithium-ion battery, which protects the battery in an overcurrent state to prevent explosion and fire. Background technique [0002] Cylindrical lithium-ion batteries were used in consumer mobile devices 30 years ago. Rechargeable lithium-ion batteries are prone to fire or explosion during overcharge or short circuit conditions. In order to protect the battery in the case of overcurrent, a disc-shaped thermistor (Positive Temperature Coefficient, referred to as PTC) material fuse is used. The PTC disc fuse structure is as follows figure 1 with figure 2 shown. The resistance of this PTC material increases dramatically under overcurrent conditions, thereby reducing the current flow to a safe level. Limited by the characteristics of the material itself, such as the high electrical conductivity of the material, the performance of ...

AI Technical Summary

Problems solved by technology

With the growth of cylindrical lithium-ion battery applications in electric vehicles and energy storage systems (for example: general-purpose 18650 and 26650 batteries), PTC disc fuses are no longer suitable for applications that exceed their operating voltage and current. Even though there are many sensors and controllers in the battery management system (BMS) of electric vehicles and energy storage systems to mitigate the risk of battery failure, there is still a potential risk of explosion under some unsafe conditions, such as inside the battery. short circuit, which is still the major damage to human life and property

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