Over-temperature fuse protection technology for power battery high in current passing ability

Abstract

The invention discloses over-temperature fuse protection technology for a power battery high in current passing ability. A cover plate electrode of battery cells is connected with a current collection plate through a low-resistance low-melting-point metal block; when temperature of a certain battery cell exceeds own protection temperature, the low-resistance low-melting-point metal block connected with the battery cell is fused to disconnect current between the current collection plate and the battery cell to prevent thermal runaway. The low-resistance low-melting-point metal block is added between the cover plate electrode of a battery module and the current collection plate, so that the low-resistance low-melting-point metal block connected with the current collection plate is automatically fused and plays a role in protecting the battery to avoid electrothermal runaway during module short-out, cell short-out, overcharging and overloading.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and in particular relates to a power battery over-temperature fusing protection technology with strong over-current capability. Background technique [0002] In recent years, lithium batteries have been widely used in various occasions such as electric vehicles, energy storage power stations, and electric tools due to their advantages such as high energy density, high average voltage, high output power, and long service life. Multiple battery cells are connected in series and parallel through the bus bar, and the current of multiple battery cells is collected to form a large-capacity battery pack, so as to meet the power supply requirements. With the gradual expansion of the application range, the safety of lithium batteries has received widespread attention. [0003] During the charging and discharging process of the lithium battery, the battery itself and the components on the high c...

AI Technical Summary

Problems solved by technology

[0003] During the charging and discharging process of the lithium battery, the battery itself and the components on the high current path will generate heat. Although the management system circuit of the battery pack can control the charging and discharging of the lithium battery within a certain temperature range, in some extreme cases For example, if the battery pack is squeezed in a collision or an internal short circuit occurs in a single cell, one or more batteries of the battery will have a violent internal reaction and generate a lot of heat, which will cause the temperature in the battery pack to continue to rise , and pass each other, so that each battery cell in the entire battery pack produces a chain reaction

[0004] On the other hand, if a lithium battery has an internal or external short circuit or overcharge, the lithium battery will generate high heat, causing part of the electrolyte to vaporize, breaking the lithium battery shell and exploding, especially for lithium batteries used as automotive power sources. Once a certain lithium battery explodes, the lithium batteries connected to it will explode one after another due to the diffusion of heat. s damage

When the charging voltage of a single battery cell is higher than 4.2V or the discharge voltage is lower than 2.4V, the battery capacity will be permanently reduced, and the positive and negative electrodes will be short-circuited, causing the lithium battery to explode.

In addition, when the current of the lithium battery is too large, the lithium ions will not have time to enter the storage cell, and will gather on the surface of the material, which will also cause the lithium battery to explode.