Power battery protection structure of new energy automobile

Abstract

The invention relates to a power battery protection structure of a new energy automobile. The structure comprises a voltage regulating mechanism and a fireproof mechanism which are arranged on a battery bin; the pressure regulating mechanism and the fireproof mechanism are both connected to a central controller; the pressure regulating mechanism comprises a standard part, a differential pressure sensor, a pressure release valve and a filter; the fireproof mechanism comprises a fire extinguisher connected with the battery bin and at least one composite detection unit arranged in the battery bin; each composite detection unit comprises a microprocessor as well as a temperature sensor, a smoke sensor and a CO sensor which are in communication connection with the microprocessor. The inventionaims to solve the problems in the prior art. The power battery protection structure of the new energy automobile performs multi-directional monitoring and real-time monitoring on air tightness and fire in the battery bin, timely gives an early warning and an alarm when a fire occurs, avoids missed alarms, reduces false alarms, timely and automatically extinguishes the fire, effectively controls the fire, and maintains the stability of the air pressure in the battery bin.

Description

technical field [0001] The invention belongs to the technical field of new energy battery safety, and in particular relates to a protective structure for a power battery of a new energy vehicle. Background technique [0002] Due to the large specific energy of the battery, no memory effect, good discharge performance, low manufacturing cost, long cycle life, green environmental protection, and high safety performance, lithium batteries have a wide range of applications, and the types of batteries are also diversified. The main markets are 3C digital, storage Energy batteries, power batteries and other fields. In terms of structure, lithium-ion batteries mainly include casing, positive electrode, negative electrode, electrode lead, electrolyte, diaphragm, etc., in which the positive electrode material is generally made of transition metal oxide, and the diaphragm plays the role of isolating the positive and negative electrodes. The negative electrode material is generally var...

AI Technical Summary

Problems solved by technology

The formation process of the disaster is reflected in: causing internal short circuit: Lithium ions will gather at the negative electrode of the battery to form dendrites during overcharging and thermal impact, causing the diaphragm to rupture, and a short circuit occurs inside the lithium battery; large current is generated: internal short circuit forms a large current, which will cause The temperature rises, the diaphragm melts, and the degree of short circuit expands, forming a vicious circle; electrical failure or high-speed impact causes external short circuit, at this time, the external load of the battery is too low, and the instantaneous high current discharge causes huge heat; high temperature and high pressure appear: under the action of large current The electrolyte is electrolyzed to generate gas, which increases the air pressure in the battery, which may cause the battery shell to rupture; cause combustion or explosion: at high temperature and high pressure, the positive electrode undergoes an oxidation reaction to precipitate metal lithium. If the shell is broken, the metal lithium contacts with air and causes combustion. The electrolyte is ignited, and the thermal runaway of the single battery causes the thermal runaway of the battery pack, resulting in fire or explosion

[0003] Lithium-ion power battery is composed of multiple single lithium-ion batteries. When a small battery in one of them is thermally out of control, it can cause a chain reaction of the battery pack. Due to the heat preservation effect and sealing performance of the battery box, if the A fire in the box will cause a sharp increase in the temperature in the box for today's large-capacity lithium-ion power batteries, and the consequences will be unimaginable. If an abnormal state is found, the operator needs to take timely measures to cut off the power supply and stop the temperature rise. In case of flames, use a hand-held fire extinguishing device to extinguish the fire. Due to manual negligence or improper operation, it is easy to cause accidents.

[0004] In addition, the battery system is mainly composed of two parts, the battery pack and the electrical circuit, so the battery pack is absolutely not allowed to enter water. Once water enters, it will cause a short circuit in the battery pack or the electrical circuit and cause a fire, and at least the entire battery pack will be scrapped. , causing economic losses, and even causing the entire vehicle to be burned, and even endangering the personal safety of passengers, the loss is immeasurable

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