함침공정을 이용한 고 에너지밀도 리튬 전고체전지용 후막 양극 및 액상공정을 통한 고체 전해질 연구

Abstract

As the use of batteries varies from small electronic devices such as mobile phone to large storage devices, there is a growing interest in the reliability of batteries. Conventional lithium-ion batteries(LIBs) use flammable liquid electrolytes. Liquid electrolytes have a risk of fire. If anode and cathode are encountered and vaporized according to temperature changes, which present a risk of battery expansion and explosion. As an alternative to this plan, an All-solid-state battery(ASSB) is drawing attention as a next-generation battery. Because the battery does not have a risk of bursting, there is no need for leakage and explosion-proof components, such as protective circuits. Therefore, increased energy density can also be expected as a result of reduced battery weight and volume, as well as simplification of the manufacturing process. As above, the electrolyte has superior stability, but the solid electrolyte(SE) has lower ionic conductivity compared to the liquid electrolyte(LE) and the resistance of the interface between the electrode and SE is higher than that of the LE, so both capacity and life characteristics are not as good as that of the LIBs. In this study, two studies were conducted to ensure that the ASSB had enough performance to be commercialized. The first is a process for the manufacture of ASSB cathodes that have similar levels of LIB cathode. we did not use ASSBs electrodes but used conventional LIB electrodes. when making slurry, ASSBs electrodes add solid electrolytes together but LIBs do not add SEs. Instead, we made a SE solution and used a process that infiltrated it with conventional LIB electrodes. SEs in the ion state can easily penetrate into the electrodes. When electrodes have a larger amount of solid electrolyte, the contact area between the electrode and the solid electrolyte can be widened, which can have better performance. Therefore, the temperature of the infiltration process was adjusted to high temperature to increase the content of SEs. When the solvents of SEs increase to the boiling points, solid electrolytes become better infiltrate into the electrodes because molecular motion of the solution becomes active. LIB electrodes are also made using active materials of different sizes. Mixing active materials of various sizes increases the density of the electrodes, and when the electrodes are immersed in the SE solution, they absorb more SE through capillary action.