| 摘要: | 本研究使用發泡鎳網作為鋅二次電池負極集電網，搭配不同轉速之流場電解質，抑制鋅在充電沉積過程中產生樹枝狀晶的問題，並提升單位面積鋅負載量與循環充放電之效率。實驗採用三極式電化學裝置，參考電極為飽和甘汞電極，電解液為含有飽和氧化鋅(ZnO)的6M氫氧化鉀(KOH)溶液，分別在無轉速、300、450與900 rpm轉速下進行電化學測試。
Nickel foam在不同電流密度下鍍鋅30分鐘，並使用掃描式電子顯微鏡(SEM)來觀測鋅沉積的樣貌，顯示在高轉速下Nickel foam可以承受更高的電流密度鍍鋅而不產生樹枝狀晶；以循環伏安法測試負極在流場下有較高的氧化峰值，表示搭配流場電解質會有較好的放電表現；以100 mA/cm2電流密度做充放電循環測試，可以發現負極在流場下有較好的循環穩定性，且有較高的庫倫放電效率。
不同表面積之Nickel foam可藉由電化學沉積法製備，固定電流180mA/cm2，調整電鍍時間15、30、45分鐘與一小時，搭配不同轉速之流場電解液，經由循環伏安法與充放電循環測試後，可以提升鋅的氧化電流值與庫倫效率，也有較好的循環穩定性，其中鍍鎳30分鐘的實驗組有最高的氧化電流與穩定性，有最好電化學表現。
Nickel foam因為其多孔性結構，具有相當高的比表面積，並搭配流場電解質，可有效利用內部的面積，提升Nickel foam的使用率，進而分散單位面積的電流密度，可以使Nickel foam有更多的空間讓鋅沉積，並且承受更大的鍍鋅電流密度，故Nickel foam作為鋅二次電池負極集電網搭配流場電解質可有利於儲能裝置發展前景。
;Using Ni foam as the current collector with different flow field electrolyte for Zn-based secondary batteries could inhibit dendrite formation and enhance electrochemical performance. In this work, electrochemical analysis was conducted in an alkaline electrolyte composed of 6 M KOH with saturated ZnO and under different flow field, 0 rpm, 300rpm, 450 rpm, 900 rpm respectively. Zn was electrodeposited on Ni foam at different current density for 30 minutes, the SEM images showed that with the flow field electrolyte Ni foam could be applied for higher current density without dendrite formation. According to the results of cyclic voltammetry, the anodic peak with high revolutions per minute, especially for 450 rpm, was larger than without flow field electrolyte. It indicated that Ni foam with flow field electrolyte had a better discharge performance. Constant current density, 100 mA/cm2, was applied for the charge/discharge cyclic test. Ni foam with flow field electrolyte exhibited a better discharge efficiency and superior cycle stability. Ni foam of different surface area has been prepared by an electrodeposition technique. We used a constant current density, 180mA/cm2, and set different parameters of time, 15, 30, 45 minutes and 1 hour for the electrodeposition. Under different flow field, Ni foam of different surface area was determined by cyclic voltammetry and charge/discharge cycle test. The anodic current and cycle stability of Ni foam of different surface area was higher than that of the commercial Ni foam. Because of the high porosity and large specific surface area, the inner area of Ni foam could be fully used with the flow field electrolyte. This effect caused the applied current density was being separated, so the real current density per unit area decreased and the space of Ni foam for Zn deposition increased. Owing to these results, Ni foam used as the current collector with the flow field electrolyte is a good choice for energy storage. |
