Study on flexible anode using electrochemically exfoliated graphene-glass fiber integrated electrode for Li-ion batteries

초록

The lithium-ion batteries (LIBs) have been widely used in portable electronic devices due to their advantages including long cycle life, high energy density, wide operating temperature range, and low self-discharge. With the increasing interests for wearable devices, artificial skins, and roll-up displays, the development of flexible and light-weight electrodes is indispensable to achieve the outstanding performances in flexible electronics. Since the components of current LIBs electrodes, such as active materials and metal foil current collectors, have some limitations for flexible electronic devices due to their inherent stiffness properties, the electrode materials easily separate from the rigid current collectors during mechanical deformation, resulting in capacity loss and inferior electrochemical performances. In this regards, carbonaceous materials have been attracting great attention as self-supporting flexible electrodes to eliminate the need for metal current collectors. In this study, we investigated the electrochemical exfoliation approach to obtain high-quality graphene in inexpensive and straightforward manner. By appliying a constant voltage of 10 V in a two-electrode system composed of graphite sheet and Pt wire working as anode and cathode electrode, respectively, graphene was efficiently exfoliated through the interlayer intercalation of ions and gasification reactions. Then, the obtained graphene was directly filtered to a glass fiber used as a separator in LIBs to synthesize a separator-integrated electrode wigh a high flexibility. This study proposes a facile stragety to producing a separator?integrated flexible electrode with a high potential application as a anode for flexible LIBs. It is expected to attributed to flexible energy storage device applications with high capacity and excellent electrochemical performances.