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題 名 | 鋅金屬燃料電池鋅電極及隔離膜研製=Development of Metallic Zinc Electrode and Separator Preparation for Zn-Fuel Cells |
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作 者 | 楊純誠; 王景立; 吳成有; | 書刊名 | 台電工程月刊 |
卷 期 | 692 民95.04 |
頁 次 | 頁62-73 |
分類號 | 468.1 |
關鍵詞 | 鋅空氣電池; 電極變形; 針狀鋅; 循環壽命; Zn-air battery; Electrode shape change; Dendrite; Cycle-life; |
語 文 | 中文(Chinese) |
中文摘要 | 鋅金屬燃料電池具有能量密度高、沒有環保污染問題及電極材料便宜等優點,且鋅金屬燃料電池更具有可以用"機械式法"充電(大約5~10分鐘可完成)和"定電流"充電法(一般電池的正常充電需8~10小時來充電,快速充電也要3~4小時)來進行充電的性能。因此,鋅金屬電池也可以用來做為電力儲存的設備,其所儲存的電力即可供應尖峰時段所需求的電力。鋅金屬燃料電池目前約可以重複使用50次,因鋅電極在氧化後成為易溶於KOH電解質中的氧化鋅,以致於造成鋅電極變形,也使鋅空氣電池的電容量會急速下降。因此,如何減少鋅電極在氫氧化鉀電解質中的溶解度及確保電池容量,即成為提昇鋅電極循環壽命的重要課題。藉著抑制氧化鋅溶解的方法以及在鋅電極中加入某些金屬元素或氧化物的對策可減緩電極的變形情況。 本研究計畫的之目的在於開發具有循環壽命長、形狀安定的鋅電極配方。在本研究中透過了線性極化法、循環伏安分析法、交流阻抗法以及定電流充放電法等電化學技術,輔以掃描式電子顯微鏡觀察及薄膜孔徑分析來進行鋅電極化學組成配方及添加劑的深入探討。為了減緩電極的變形以及避免充電過程針狀鋅的形成,使鋅電極循環壽命提昇,在本研究中採取了二項對策(1)化學方法-以添加各種合適的金屬或金屬氧化物的抑制劑或安定劑,此可以加入鋅電極或KOH電解質中;(2)物理方法-在鋅電極外面覆上多層結構的高分子電解質隔離膜,此可以抑制鋅電極的變形或體積膨脹,防止鋅活性物質剝落,且可緩衝鋅電極的針狀問題產生及維持鋅電極溼潤效果的狀態,避免鋅電極發生高阻抗的雙層效果。且所製備完成的鋅電極,組成單電池測試達到了鋅金屬利用率70%,循環壽命可達50次以上。 |
英文摘要 | The advantages of Zn-metallic fuel cells are its high energy density, very low cost of electrode materials, and environmental friendliness (no pollution problem). The Zn-metallic fuel cells can be mechanically recharged (only take 5~10 min) or electrically recharged (normally 8~10 h, rapid recharge about 3~4 h), and can be used as a tool for energy storage. Energy can be stored in the cells to meet need for power in the daytime, and the cells can be reused for several cycles (it can achieve about 50 cycles at the present time). During electrochemical reactions, the anode electrode is oxidized from Zn to ZnO. ZnO is very soluble in KOH electrolyte. It causes anode shape change and lead to a rapid decay in capacity. Hence, it becomes a key issue for improvement of Zn electrode cycleability. It can be improved by reducing ZnO solubility in KOH solution. In fact, by adding some metallic elements and oxides in the anode electrode can eliminate the shape change problems. The main purpose of the study was focused to develop a good recipe for Zn anode electrode with good cycleability and to reduce the shape change (expansion problem) of Zn electrode. The recipe for the chemical composition with additives were evaluated by various electrochemical methods, such as: linear polarization, cyclic voltammetry, AC impendance, and galvanostatic charge/discharge methods. Other auxiliary analyses were also used in the project, like SEM, PMI, etc. The main approach for increasing Zn anode electrode cycleability (i.e. reduce electrode shape change and avoid dendrite formation during the charge period) is as follows: (1) chemical approach by adding metal elements and oxides which increase the overpotential of H₂ evolution and less ZnO dissolving in KOH electrolyte; (2) physical method by wrapping the Zn electrode with alkaline multi-layers polymer electrolyte membrane, which reduced shedding of zinc active materials and KOH electrolyte drying out problem. It can be clearly seen that the polymer electrolyte acted as a buffer and wetting agent when Zn was oxided to ZnO. After being assembled as a single cell, the Zn electrode developed from this study and achieved the target of cycle-life over 50 cycles with percentage of Zn utilization over 70%. |
本系統中英文摘要資訊取自各篇刊載內容。