전기 영동 증착을 통한 첨가제 없는 MAX(Ti3AlC2) 리튬 이온 배터리 음극의 사이클 안정성

초록

We fabricated an additive-free MAX(Ti3AlC2) phase Li-ion battery (LIB) electrode using theelectrophoretic deposition (EPD) method. In this study, MAX, a precursor of MXene, which has recently beenreceiving great attention as a negative electrode material for LIBs, was manufactured as a coin cell throughEPD rather than the conventional slurry system. We excluded the effect of additives on the electrochemicalperformance, enabling evaluation of the intrinsic electrochemical properties related to battery charging anddischarging. As a result, the battery using MAX as an anode material showed a large specific capacity of 148.2mAh/g in the first discharge and superior cycle stability. Enhanced cycle stability and reversibleelectrochemical reactions were attributed to activation of faradaic and non-faradaic behavior, i.e., pseudocapacitivebehavior, caused by delamination of the MAX(Ti3AlC2) into MXene (Ti3C2). This was confirmed bythe decrease in the charge transfer resistance and the increase in total capacitance at the interface, usingelectrochemical impedance spectroscopy and cyclic voltammetry measurements. In addition, the activation ofpseudocapacitive behavior was confirmed by the change in kinetic mechanism, as evidenced from a significantincrease in the Li ion diffusivity with cycles. These results demonstrate that MAX(Ti3AlC2) is promising asan anode material for LIBs and at the same time shows potential for tuning electrochemical propertiesthrough the electrochemical delamination process.

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