Ningbo material in new ion conductor coated diaphragm progress
in recent years, lithium ion batteries as new energy electric vehicles at the present stage market occupies the absolute dominance of power battery, the development speed. As the market is more and more high to the requirement of lithium battery energy density, the safety of lithium-ion batteries is increasingly prominent. Continuous electric car explosion due to fire accident shows that the safety of the lithium battery itself is very important for the car. Can say, the safety performance of lithium-ion batteries is an important bottleneck restricting the further development of electric car.
the diaphragm as one of the key materials for lithium-ion batteries, its thermal stability is closely related with the thermal safety performance of lithium-ion batteries. High security diaphragm has good thermal stability, and no obvious deformation under certain environment of high temperature, has good properties of closed-cell and can keep good mechanical strength in order to avoid the battery internal short circuit, thereby inhibiting cell burning explosion. In all kinds of diaphragm, the ceramic membrane has excellent heat-resistant be the first choice of the power lithium batteries in recent years. The introduction of the ceramic coating can effectively improve the thermal shrinkage temperature of diaphragm, cut off the battery internal thermal diffusion, restrain some thermal runaway point to expand to form the overall thermal runaway, thus improve the safety performance of the battery. The diaphragm preparation is relatively simple, easy to mass production and use.
the traditional ceramic membrane used in ceramic materials as inert inorganic nanoparticles, such as Al2O3, AlOOH, BaSO4, etc. Though previous studies have found that ceramic coating can effectively improve the thermal stability of the membrane, improve the safety of the battery, but less contribution to the electrochemical performance of lithium battery. Based on this, the zhao-ping liu, a researcher at the power lithium battery research team led by innovative put forward with lithium ion activity of ceramic materials to replace traditional inert ceramic coating ceramic materials preparation, and with polyolefins diaphragm compound preparation with ontology lithium ionic conduction ability of new ion conductor coating membrane. The study found that in addition to being able to effectively guarantee the thermal stability of the diaphragm, the diaphragm can further realize lithium compensation in the lithium battery, and based on the solid-liquid dual electrolyte give lithium batteries of the conductive effect of more excellent performance ratio ( As shown in figure 1) 。 The technology applied to the Chinese invention patent, 201410284617. 0, 201510042214. X, 201510042292。 X, research is published in the Journal of Power Sources, 2015, 273, 389 - 395. In order to speed up the process of application of the technology innovation, the team for the technology to the study of pilot magnification. Through continuous optimization formula, adjusting process parameters to achieve a new type of ion conductor continuous preparation of coating on the diaphragm. The preparation process is shown in figure 2.
the above research work to get the key deployment project of Chinese Academy of Sciences ( 批准号 KGZD - 电子战- 202 - 4) , ningbo science and technology innovation team ( 批准号 2012 b82001) , the national natural science foundation of China ( 批准号 51403227). And China postdoctoral science foundation of China ( 批准号 2014 m551781) Such as project support. Figure 1new diaphragm principle and wettability and electrochemical properties of ion conductor coating figure 2 new ion conductor coated membrane preparation process