Application of a separator-integrated graphene/graphite anode to lithium metal batteries

초록

Flexible lithium-ion batteries have been actively studied over the past few decades due to the continuous increase in demand for roll-up displays, wearable electronic devices, and smart electronic devices. However, graphite anode which are commonly used in most of lithium secondary batteries, are limited in use due to their low energy density. For this reason, lithium metal has been spotlighted as a next-generation battery anode material. Lithium metal has the lowest electrochemical reaction potential (-3.04 V vs SHE.) and a high theoretical capacity of 3860 m Ah/g, which is superior to existing graphite anode. However, internal short circuits caused by dendrite structures growing on the surface of lithium metal during charging and discharging, as well as mechanical stability due to volume expansion during the deposition process of lithium metal are pointed out as problems. In this research, reduced graphene oxide was synthesized through electrochemical exfoliation to address the performance degradation and mechanical stability problems caused by dendrite formation of lithium metal anode, and a flexible separator integrated electrode mixed with graphene and graphite was synthesized through a simple filtration process. The structure of the synthesized electrode was observed through a scanning electron microscope (SEM), and qualitative analysis was performed through Raman spectroscopy and X-ray diffraction analysis (XRD). The synthesized electrode was used as a anode of a lithium metal battery to evaluate battery performance through CE test and Symmetric cell test.