Improvement of thermal stability of lithium ion battery
Update：9/27/2022 2:59:08 PM View : 1952
At present, the main measures to improve the safety of lithium-ion batteries and prevent battery explosion are to improve the thermal stability of batteries, improve the overcharge protection ability and improve the ability to prevent battery short circuit. In this paper, the relationship between thermal stability and materials of lithium ion batteries will be summarized.
Improve the relationship between battery thermal stability and materials:
① The thermal stability of lithium ion batteries is closely related to the type, structure and surface morphology of cathode materials. Materials with good thermal stability can be synthesized by optimizing synthesis conditions and improving synthesis methods; Or use composite technology (such as doping technology) and surface coating technology (such as coating technology) to improve the thermal stability of cathode materials.
② The thermal stability of the negative electrode material, the type of the negative electrode material, the size of the material particles, and the
The stability of SEI membrane. The quality of SEI film formation directly affects the charge discharge performance and safety of lithium ion batteries
Completeness. It is reported that weakly oxidizing the surface of carbon materials, or reducing, doping, surface modified carbon materials and using spherical or fibrous carbon materials will help to improve the quality of SEI films.
③ The stability of electrolyte is related to the type of lithium salt and solvent. Lithium salt with good thermal stability and solvent with wide potential stability window can improve the thermal stability of the battery. The use of additives to improve the thermal stability of electrolyte has also aroused interest. Adding some high boiling point, high flash point and nonflammable solvents to the electrolyte can improve the safety of the battery.
④ The type and quantity of conductive agent and binder also affect the thermal stability of the battery. It is found that the replacement of acetylene black with nano stainless steel fiber can reduce the resistance of the electrode, improve the conductivity, and reduce the heat release in the non discharge process.
⑤ The binder reacts with lithium at high temperature to generate a lot of heat. The heat value of different binders is different. The heat value of PVDF is almost twice that of fluorine free binder. Replacing PVDF with fluorine free binder can improve the thermal stability of the battery.
Improve the relationship between battery thermal stability and materials:
① The thermal stability of lithium ion batteries is closely related to the type, structure and surface morphology of cathode materials. Materials with good thermal stability can be synthesized by optimizing synthesis conditions and improving synthesis methods; Or use composite technology (such as doping technology) and surface coating technology (such as coating technology) to improve the thermal stability of cathode materials.
② The thermal stability of the negative electrode material, the type of the negative electrode material, the size of the material particles, and the
The stability of SEI membrane. The quality of SEI film formation directly affects the charge discharge performance and safety of lithium ion batteries
Completeness. It is reported that weakly oxidizing the surface of carbon materials, or reducing, doping, surface modified carbon materials and using spherical or fibrous carbon materials will help to improve the quality of SEI films.
③ The stability of electrolyte is related to the type of lithium salt and solvent. Lithium salt with good thermal stability and solvent with wide potential stability window can improve the thermal stability of the battery. The use of additives to improve the thermal stability of electrolyte has also aroused interest. Adding some high boiling point, high flash point and nonflammable solvents to the electrolyte can improve the safety of the battery.
④ The type and quantity of conductive agent and binder also affect the thermal stability of the battery. It is found that the replacement of acetylene black with nano stainless steel fiber can reduce the resistance of the electrode, improve the conductivity, and reduce the heat release in the non discharge process.
⑤ The binder reacts with lithium at high temperature to generate a lot of heat. The heat value of different binders is different. The heat value of PVDF is almost twice that of fluorine free binder. Replacing PVDF with fluorine free binder can improve the thermal stability of the battery.