Why do electric vehicles catch fire and explode with lithium batteries but not many lead-acid batteries?

As an important source of power for electric vehicles, lithium batteries have the characteristics of high energy density, light weight, and excellent anti-attenuation performance. At the same time, lithium ion, as an important chemical component of the battery, is highly active. Once a short circuit occurs, it releases a lot of heat, burns or even explodes. The safety protection part of the lithium battery lies in the separator between the positive and negative electrodes. When charging, lithium ions run from the positive electrode to the negative electrode through the electrolyte, and combine with the externally charged electrons. When discharging, on the contrary, the lithium ions run from the negative electrode through the electrolyte. To the negative electrode, the external electrons pass through another path (electronic conductor) to the positive electrode, thus forming a discharge process. During normal charging and discharging, electrons and lithium ions reach the same electrode through two different paths. These two paths are separated by a battery separator to guard against the risk of short circuits. The charging explosion occurred at the corridor of the electric car. More than 90% of the lithium batteries lacked power-off protection when overcharged, which caused the lithium ion crystals inside the battery to pierce the diaphragm, and the lithium electrons and the electrons met in a large area, forming a short circuit, and the electrolyte atomization encountered An open flame occurs at high temperature, causing a violent explosion and releasing a large amount of deadly poisonous gas. In addition, the lithium battery is squeezed, extremely high temperature, and violent falls will also cause the diaphragm to break and cause a short circuit, resulting in a violent explosion. However, qualified lithium batteries and charging equipment have intelligent power-off or high-strength protection devices, and generally do not deflagrate. Inferior lithium batteries and charging equipment do not have these, and the risk of lithium batteries exploding will be greatly increased! Although the energy density of lead-acid batteries is not high, because the chemical composition is not as active as lithium batteries, and the technology of lead-acid batteries is quite mature, the probability of short-circuits is small, and the inside is made of lead-based metal grid material, which is resistant to extrusion , The advantages of high temperature resistance are incomparable to lithium batteries. Disclaimer: Some pictures and content of articles published on this site are from the Internet, please contact to delete if there is any infringement.