Lithium battery explosion is too terrible, it is very necessary to master these safety knowledge!

In recent years, there are frequent explosion accidents caused by the quality, improper use of lithium batteries and other reasons.According to statistics from the Shanghai Fire and Rescue Corps, there were 786 electric bicycle fires in 2021, causing 11 people in the city and injuring 41 others.Analysis of the causes of these fires is mostly related to the batteries used in electric bicycles."In lithium batteries, in particular, because of their own characteristics, indoor deflagration is easy to cause casualties.”

The investigation of fire accident found that overcharging, battery failure and electrical line short circuit are the root causes of electric bicycle electric fire.Some industry insiders point out that about 80% of the fires caused by electric bicycles and their battery failures on the market come from informal enterprises, as well as private assembly, disassembly, modification and other circulation channels.

01

Classification of lithium batteries

According to the video, we learned that most of the lithium batteries used in the original electric vehicles are mainly divided into ternary lithium batteries, lithium manganese acid battery and lithium iron phosphate battery. Because different types of batteries use different cathode materials, the existence of differentiation exists.

Therefore, ternary lithium battery uses lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminate as ternary cathode material, lithium manganese oxide battery and lithium iron phosphate battery are the same.

In terms of application scenarios, ternary lithium battery and lithium manganese oxide battery are widely used in two-wheeled (three-wheeled) electric vehicles.Although the lithium iron phosphate battery is cheap, it occupies a large amount of space, so it is more widely used in electric buses.

02

Which lithium battery is better

At present, our common electric vehicles use lithium battery is more three lithium, lithium manganese oxide and lithium iron phosphate battery, so these three kinds of batteries, which one is better?

From a safety point of view, professionals conduct acupuncture and compression experiments on three types of lithium batteries.The safety performance of the three types of lithium batteries is judged by the test results of the three types of lithium batteries.

First of all, the three types of qualified lithium battery products on the market for acupuncture experiment.Through this experiment, can simulate the lithium battery internal short circuit.

Through the above experiment, we can see that the ternary lithium battery in the needle penetration of the moment of the fire everywhere, and lithium manganese oxide battery and lithium iron phosphate battery although white smoke rising, but there is no open fire burning phenomenon.

Next, let's squeeze test the three types of batteries and see what happens when they get squeezed?

Through gravity extrusion tests on three types of lithium batteries, the result is that ternary lithium batteries still caught fire, while lithium manganese oxide batteries and lithium iron phosphate batteries did not catch fire.

So, ternary lithium battery is necessarily inferior to lithium manganate battery and lithium iron phosphate battery?

Experts said that although lithium batteries have certain fire risks, but as far as the material itself, lithium manganese oxide battery and lithium iron phosphate battery stability is strong, the probability of fire will be much lower than three lithium battery.

So, from a safety point of view, lithium manganese oxide batteries and lithium iron phosphate batteries will be more stable.

03

How to use lithium batteries safely

So, when our electric vehicles use lithium battery, how should we avoid electric vehicle fire, to ensure their own safety?In this regard, He Xiangming, director of lithium ion battery Laboratory and doctoral supervisor of Tsinghua University, gave the following suggestions:

1. Do not replace the lithium batteries without authorization

In life, there are a lot of people clearly buy an electric car equipped with lead-acid battery, but without authorization to replace it with lithium battery, so not only easy to cause the charger, battery, line mismatch, resulting in internal failure, but also a great safety risks, many fire electric car fire accidents are caused by this.

So, you must remember, do not replace the battery without authorization.

2. Prevent excessive charging, and try to use manganese acid and lithium iron phosphate batteries

Because of the current electric car battery charging time is longer, generally in about 8 hours.After charging the electric car after work, it is difficult to recharge when they sleep, so many people will choose to disconnect the charger the next day.

Overcharging not only has great damage to the battery itself, accelerates the loss of the battery, but also has a certain safety risk.

It is recommended that you avoid overcharging the battery. You can choose to disconnect the charger in advance or use a socket with regular power off function, so as to avoid overcharging while ensuring full charge.

In addition, try to buy and use manganese acid and lithium iron phosphate batteries, safety is more guaranteed.

3. In addition, try to buy and use manganese acid and lithium iron phosphate batteries, safety is more guaranteed.

Whether it is a high temperature environment or a low temperature environment, in the charging process, the battery and the charger will cause a certain impact, resulting in the charger or battery failure.In addition to the use of the standard, in the purchase of batteries and electric vehicles, do not blindly pursue the endurance and covet cheap, must choose the regular manufacturers of products.