近年來，鋁金屬是電化學存儲裝置的理想材料。由於在電化學氧化還原反應期間涉及三個電子的氧化還原能力(Al3++3e-↔Al)，且其密度(2.7 g/cm3)遠大於鋰(0.53 g/cm3)，因此鋁金屬的體積能量密度(8.06 Ah/cm3)遠高於鋰(2.04 Ah/cm3)。此外，鋁是地殼中最豐富的金屬元素，且在空氣中穩定，為電池應用帶來巨大的優勢，從而大大地提高了電化學存儲系統的安全水平。而本篇研究利用臨場X射線繞射分析和臨場拉曼光譜分析探討不同石墨材料作為鋁離子電池之陰極的電化學表現，藉由此兩種方法證明了材料結晶性的強弱會影響其與氯鋁酸根陰離子AlCl4-的作用機制。此外，經過簡單的酸處理和高溫鍛燒後得到的膨脹性石墨，結合了插層及吸附兩種機制以達到電容量提升的效果，並透過臨場電化學實驗去探討吸附機制所發生的電位。 In recent years, aluminum has been considered as suitable candidate for electrochemical storage devices due to its high volumetric and gravimetric capacities besides its high abudance. The high capacity of aluminum ion battery is attributed to trivalent electrochemical redox reaction (Al3++3e-↔Al). Moreover, it is supported by its density which is around four times the lithium and it can be handled under the air leading to enormous advantages for the battery application, thus extremely improves the safety level of electrochemical storage system.We investigated the electrochemical performance of different graphite materials as cathode for aluminum-ion battery by using in-situ X-ray diffraction and in-situ Raman techniques. The two analytical methods demonstrated that crystallinity of the graphite materials will influence the storage mechanism of AlCl4-.Furthermore, we synthesized expanded graphite (EG) by simple acid treatment and followed by high temperature annealing.The high capacity displayed by EG can be attributed to integreated intercalation and adsorption mechanisms. In-situ XRD and in-situ Raman techaniques were used to speculate the different mechanisms adopted by EG during cycling.
