本研究製備鋰離子混合式電容器，結合高比表面積的活性碳做為正極材料，搭配奈米碳管/錫/銅複合材料，及1M LiPF6/EC:DMC= 1:1(w/w)有機電解液，得到高能量密度的電容器。電極改良重點在於負極，多孔負極製程採用一維導電的奈米碳管先進行表面氧化，再以無電電鍍的方式成功將錫與銅鍍於奈米碳管上形成碳管/錫/銅複合材料(CNT/Sn/Cu)。
奈米碳管表面若未做氧化處理，無電電鍍錫難以附著，若高度氧化，則將損傷奈米碳管導電能力甚至結構，利用XPS做量測，建立表面氧化處理的指標，根據C1s圖譜分峰處理後的結果，可以觀察到π-π*電子躍遷訊號，說明經過表面氧化及無電電鍍後的奈米碳管仍具有一定的導電能力。輕微氧化過的奈米碳管，電鍍高比例均勻分布的錫/銅金屬，碳管:錫:銅重量比約為36:50:14。二次電子影像顯示錫銅顆粒狀包覆碳管，但也有局部區域形成錫銅金屬片狀。碳管/錫/銅電極預鋰化時消耗大量的電量，第一圈鋰化電量1045 mAh g-1，第二圈電量500 mAh g-1，第三圈電量435 mAh g-1。顯示並非所有鋰合金參與充放電，只有部分鋰合金釋放出鋰離子。
充放電結果顯示: CNT/Sn/Cu : AC=1 : 1混合式電容器的能量密度很高，當電流密度0.3A g-1時，電位窗口為 3.5 V及3.8 V的電容值分別高達42.7 F g-1及58.8 F g-1。由Ragone plot圖可知，0.3A g-1在電位窗口為3.5 V時，能量密度為61.6 Wh kg-1，功率密度為0.45 kW kg-1，而在電位窗口為3.8 V能量密度高達93.6 Wh kg-1，此時的功率密度為0.45 kW kg-1，能量密度是普通電雙層電容器的十倍或二十倍。鋰化去鋰化反應速率較慢，是充放電的速率決定步驟，因此，CNT/Sn/Cu負極的鋰離子混合式電容器適用於低電流密度充放電，此外，負極材料與鋰離子結合造成體積嚴重膨脹也將是充放壽命的隱憂。

We prepare a lithium hybrid ion capacitor, consisting of a negative electrode of CNT/Sn/Cu composite, activated carbon positive electrode, LiPF6/EC:DMC electrolyte, and measure its capacity. The research efforts are focused on modification of the negative electrode, in which one-dimensional CNT has been oxidized and electroless plating tin and copper.
The CNT surface is essentially hydrophobic, coating of tin cannot be done homogeneously over the entire CNT assembly without oxidizing the CNT surface. On the other hand, if the CNT surface is oxidized excessively, the electrical conductivity of CNT shall be degraded. Guided through the C1s spectrum, we oxidize CNT properly such that tin coating can be done properly while the π-π* transition of C1s remains observable. And the weight distribution of carbon:tin:copper= 36:50:14 on the CNT/Sn/Cu composite. SEM images indicate the metallic tin and copper wrap the nanotube up and also suspend among the nanotube crosses. The so-prepared electrode exhibits huge capacity, 1045 mAh g-1 in the first discharge cycle, 500 mAh g-1 in the second cycle, and 435 mAh g-1 in the third cycle. The high irreversible capacity indicates that not all lithium tin alloy involves in the charge process.
The energy and power densities of the lithium hybrid ion capacitor are measured with a mass ratio of 1:1 for positive and negative electrodes. At current density 0.3 A g-1, the capacitor demonstrates 61.6 Wh kg-1 and 0.45 kW kg-1 in the 3.5 V window, the energy density increases to 93.6 Wh kg-1 and the power remains 0.45 kW kg-1 in the 3.8 V window. Lithiation and delithiation is an intrinsically slow process, determining the charge/discharge rate of capacitor. Hence the capacitor equipped with CNT/Sn/Cu negative is righteously operated at low current densities. But its performance degradation is fast, because irreversible capacity and large stresses associated with cycling.

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