Time-delay protective system for external short circuit positioned inside lithium ion cell

Abstract

The invention provides an external short circuit time-delay protecting system which is arranged inside a lithium ion battery, which relates to the field of the internal structure of the lithium ion battery. The system includes: metal material arranged between a pole ear and a pole column of the lithium ion battery, and the metal material can delay destroy to the electrical connection between the pole ear and the pole column when an external short circuit current passes through; and an easy melting insulated sealing washer used for sealing the pole column and a battery shell together. The system can destroy the connection between the pole ear and the pole column of the battery after short circuit occurs 2s, thus achieving the aim of further improving the safety of the lithium ion battery.

Description

technical field [0001] The invention relates to the field of internal structures of lithium-ion batteries, in particular to an external short-circuit protection system for poles and lugs of lithium-ion power batteries. Background technique [0002] Since its invention, lithium-ion secondary batteries have attracted widespread attention due to their outstanding energy density and power density, and they have been placed high hopes in many application fields. On the other hand, their safety has been criticized by the market. , making it difficult to enter applications such as electric vehicles that have high requirements for capacity, power, and safety. In recent years, with the emergence of safer cathode materials, electrolytes, separators and more reliable protection circuits, lithium-ion secondary batteries have gradually entered the field of electric bicycles and hybrid vehicles. [0003] At present, one of the most important safety requirements for lithium-ion power batt...

AI Technical Summary

Problems solved by technology

For example, installing thermistor elements on the tabs inside the battery for over-current protection, this method will increase the cost of the battery significantly and affect the internal space of the battery, especially for high-power lithium-ion power batteries with multiple tabs. It is obvious; another method is to install a thermal fuse outside the battery for overcurrent protection, which will also increase the cost significantly, and occupy the external space and affect the layout and energy density of the battery pack

In addition, the method of adding additional components will also have the potential danger of component failure