Lithium batteries are highly energy-intensive products. The energy released when a fault occurs is also very large. There are often reports of explosions in mobile phones and notebooks. But everyone is still using, do not panic, after all, those are only in the event of a breakdown, if you want to buy a regular brand, there is security, choose Sungzu! In order to avoid accidents such as explosion of lithium batteries, manufacturers must do the following:
1. Improve the safety of electrode materials
Lithium iron phosphate and ternary composites are considered to be low cost “safe” cathode materials and can be widely used in the electric vehicle industry. For the positive electrode material, a common method for improving safety is coating modification. For example, surface coating of the positive electrode material with a metal oxide can prevent direct contact between the positive electrode material and the electrolyte, inhibit phase transition of the positive electrode material, and improve structural stability, thereby reducing cation disorder in the crystal lattice. Reduce the heat generation of side reactions.
For the negative electrode material, since the surface is usually the most susceptible to thermal chemical decomposition and heat release in a lithium ion battery, improving the thermal stability of the SEI film is a key method for improving the safety of the negative electrode material. The polymer or carbon coating can improve the thermal stability of the negative electrode material by weak oxidation, metal and metal oxide deposition.
2. Improve battery safety protection design
In addition to improving the safety of battery materials, commercial lithium-ion batteries also have many safety protection measures, such as setting battery safety valves, thermal fuses, series positive temperature coefficient connecting components, using heat sealing diaphragms, special load protection circuits and special Battery management systems, etc. are also a means of enhancing security.
3. Improve electrolyte safety
There is high reactivity between the electrolyte and the positive and negative electrodes. Especially at high temperatures, in order to improve the safety of the battery, it is one of the more effective ways to improve the safety of the electrolyte. The addition of functional additives, the use of new lithium salts and the use of new solvents can effectively address the safety hazards of electrolytes.
According to the different functions of additives, it can be divided into the following categories: safety protection additives, film forming additives, positive electrode additive protection, stable lithium salt additives, lithium precipitation additives, current-carrying anti-corrosion additives, and infiltration additives.
In order to improve the performance of commercial lithium salts, researchers have atomically substituted them and obtained many derivatives. Among them, a compound obtained by using a perfluoroalkyl-substituted atom has many advantages such as a high flash point, approximate conductivity, and enhanced water resistance. , is a promising lithium salt compound. Further, an anionic lithium salt obtained by isolating an oxygen ligand with a boron atom as a central atom has high thermal stability.
Only in this way can we ensure the safety of the battery and thus the safety of the users!