표면 처리를 통한 LNCA의 특성 변화?

초록

Li2CO3 or LiOH on the surface of lithium nickel cobalt aluminum oxide (LNCA), which remains as the residue of synthetic reaction or are formed from adsorption of moisture, deteriorate the performance of the cathode material. Converting the free lithium compounds to a stable layer is necessary to restore the charge/discharge capacity and prevent their side-reactions with the electrolyte. In this study, a stable pseudo-solid electrolyte interphase (SEI) layer was introduced on the surface of LNCA by a simple one-step solution process: LNCA powder which had been exposed to ambient air for a long time was mixed with a solution of lithium hydroxide, dimethyl carbonate, water and ethyl-alcohol, and the slurry was stirred at 60℃ for 2h. The structure of the surface-treated LNCA was characterized by scanning electron microscopy (SEM) and the electrochemical properties were analyzed using a battery testing system. The surface-treated LNCA showed increased charge/discharge capacity and less amount of gas generation during high-temperature storage test, while maintaining the same level of cyclability as the pristine LNCA.