How does the high viscosity of polyvinylidene fluoride improve its performance in power battery applications?
Publish Time: 2025-04-10
As a high-performance polymer material, polyvinylidene fluoride (PVDF) has shown a wide range of application prospects in the field of power batteries. In particular, the high-viscosity polyvinylidene fluoride resin prepared by the suspension method and copolymerized has brought significant advantages to the performance improvement of power batteries with its unique physical and chemical properties. This article will focus on how the high viscosity of polyvinylidene fluoride helps it to perform better in power battery applications.Source of high viscosity characteristicsThe high viscosity characteristics of polyvinylidene fluoride are mainly due to the length and entanglement of its molecular chain. In the suspension preparation process, by precisely controlling the reaction conditions, the PVDF molecular chain can be fully grown during the polymerization process to form a long chain structure. At the same time, other monomers introduced during the copolymerization modification process copolymerize with the PVDF main chain, further increasing the complexity and entanglement of the molecular chain, thereby giving PVDF the characteristics of high viscosity.Improve bonding performanceIn power batteries, the role of binders is crucial. It requires that the active material (such as positive electrode material, negative electrode material) be firmly bonded to the metal electrode to ensure the stability of the electrode structure during the charge and discharge process. The high viscosity of polyvinylidene fluoride enables its molecular chain to be in closer contact with the active material and the metal electrode surface, forming a stronger bonding force. This enhanced bonding performance helps to reduce the shedding of electrode materials during the charge and discharge process, thereby reducing the internal resistance of the battery and improving the cycle life and capacity retention rate of the battery.Improving electrode structureHigh-viscosity polyvinylidene fluoride can also improve the structure of the electrode. During the electrode preparation process, PVDF as a binder can be evenly distributed between the active material particles to form a stable network structure. This structure can not only improve the mechanical strength of the electrode, but also promote the penetration of the electrolyte and the transmission of lithium ions. During the charge and discharge process, the stable electrode structure can reduce the expansion and contraction of the electrode material, thereby reducing the polarization of the battery and improving the battery's rate performance and energy density.Reduce the amount of formulaDue to the high viscosity of polyvinylidene fluoride, its bonding performance is significantly improved. Therefore, the amount of PVDF can be reduced accordingly in the power battery formula. This not only helps to reduce the cost of the battery, but also reduces the adverse effects of the binder on the battery performance. For example, too much binder may increase the internal resistance of the battery and reduce the rate performance of the battery. The use of high-viscosity PVDF as a binder can reduce the amount of binder while ensuring the bonding performance, thereby optimizing the performance of the battery.Improve the safety of the batteryThe high viscosity of polyvinylidene fluoride also helps to improve the safety of the battery. In power batteries, the shedding of electrode materials and the decomposition of electrolytes are one of the main causes of battery short circuits and thermal runaway. The high-viscosity PVDF can firmly bond active materials and metal electrodes, reducing the shedding of electrode materials. At the same time, PVDF itself has good chemical and thermal stability, and can maintain stable performance at high temperatures, thereby reducing the risk of thermal runaway of the battery.In summary, the high viscosity of polyvinylidene fluoride shows significant advantages in power battery applications. It not only improves the bonding performance and electrode structure, but also reduces the dosage of the formula and improves the safety of the battery. These advantages make polyvinylidene fluoride an indispensable and important material in the field of power batteries.
