Why is lithium ion battery explosion?

Source: 2020 - 03 - 23 clicks desire: why lithium ion battery will explode? Lithium ion batteries are in fashion now. You can be in notebook computer, PDA, mobile phones and ipod find them. They are so common, because they are one of the most powerful rechargeable batteries. Lithium ion battery is very popular, because compared with other competitive skills, they have many important advantages: 1. They usually is lighter than the same size of other rechargeable batteries. Lithium ion battery electrodes are made of lightweight lithium and carbon. Lithium is a highly reactive element, this means that a lot of energy can be stored in its atomic bonds. This means that the lithium ion battery has high energy density. A typical lithium ion battery can be stored in one kilogram of battery 150 watts of electricity. Nickel metal hydride batteries can store 100 watts per kilogram, lead-acid batteries can only be stored 25 watts per kilogram. Use lead-acid technology, it needs 6 kg to store the energy for the 1 kg of lithium ion battery. Lithium ion battery power loss is only 5% per month, and nickel metal hydride battery power loss of 20%. 4. They did not recall effect, that is to say, you don't have to be like other battery chemicals, discharge completely before charging. Lithium ion battery can handle hundreds of times of charge/discharge cycle. This is not to say that the lithium ion battery is perfect. They also have some disadvantages: 1. Whether you use, from the date of production, they can only use two to three years. 2. They have a strong ability to respond to the high temperature, high temperature to cause a decline in lithium ion battery faster than normal. If you put your lithium-ion battery fully discharge, it will spoil. 3. Lithium ion battery pack must have an onboard computer to manage the battery. This makes them very expensive. Assumes that the lithium ion battery failure, it will catch fire. By studying the chemical composition of lithium ion battery, we can learn many of these features. Let's take a look at this: built-in lithium ion battery and battery lithium ion battery pack with various shapes and sizes, but their internal looks are the same. Suppose you open a laptop battery pack ( It is not recommended, because it will short-circuit the battery and cause fire) 。 You will find: lithium ion battery can be cylindrical, and AA batteries look the same; Can also be a prismatic shape, which means they are square or rectangle computer, including: 1. One or more of the temperature sensor to monitor the battery temperature. 2. Voltage converter and voltage regulator circuit, is used to maintain the voltage and current security level 3. A shield notebook connector to the power and information in and out of the battery pack is 4. Used to monitor the battery voltage of single battery energy capacity in switch 5. The battery status monitor is a small computer, responsible for the entire process, to ensure that the battery charge as quickly and efficiently as possible. If the battery become too hot, in the process of charging or using computer will cut off the power supply and trying to cool it. If you put your laptop on a very hot car, and try to use it, it may prevent you from charging, work until cool. If the battery totally discharge, battery pack will be shut down due to cell damage. It also can record the number of charge/discharge, and to send information, so that the laptop battery meter can tell you how much battery left. This is a fairly sophisticated small computer, its energy from the battery. This energy is the lack of lithium ion battery in the idle state one of the reasons for the loss of 5% of electricity each month. Like most batteries, lithium-ion batteries has a metal shell. The use of metal is especially important here, because the battery is pressurized. Metal shell has a pressure outlet. If the battery is too hot, it might explode, due to the large pressure, and exhaust release extra pressure. Battery may become useless, so to avoid this situation. This is the positive temperature coefficient ( PTC(列车自动控制系统) The situation of the switch, this is a device to prevent the battery overheat.