| 摘要: | 摘要
隨著化石燃料儲量日益減少，尋求永續的能源解決方案已成為全球優先事項，其中儲能與電化學能源轉換裝置被視為最有潛力的方法，這些方法有效率、環保、無輻射危害，並且能夠提供高效能。關鍵的創新包括利用燃料電池進行電化學能量轉換以及將電能儲存在電池或超電容裝置，電化學電池中作為電子傳導的電極結構是這些裝置效能的核心技術。過去十數年中研究人員在電化學催化劑與電化學電極的高度多孔結構取得重大進展，這些具有高表面積、高穩定性、改善電子傳輸路徑的設計有效地提升了電化學電池的性能。
在儲能方面，我們先前的研究重點是利用氧化鎳(NiO)作為商用發泡鎳中的集電器來提升3D全固態微型超電容的性能，這項研究提出一種創新而直接的方法來製作具有大比表面積的電極藉以優化活性材料的應用。製作的方法首先將商用發泡鎳利用雷射切割成指叉狀結構並利用浸鍍法將鎳粉填充於發泡鎳中，並利用各種化學方法將奈米活性二氧化錳(MnO2)塗覆在發泡鎳上，所製作創新集電電極NF-V2的孔隙大小在200-600奈米，此結構相較於商用發泡鎳(NF)提供了30倍以上的比表面積，有效將活性材料負載量由1 mg/cm2提升至20 mg/cm2以上，實驗結果顯示這些高度多孔的3D電極結構具有顯著的效果，能量密度達到671 µW h/cm2，面積容量達到19.34 F/cm2，電容維持率在達到95%@5 mA/cm2。進一步將此高度多孔電極應用在微型超電容，可達到7.22 F/cm2面積容量和263.9 µWh/cm2能量密度性能。
在能量轉換方面，本研究並將高度多孔鎳電極結合氧化鐵(Fe3O4)以應用在提升水電解的氧析出反應(Oxygen Evolution Reaction, OER)，透過調控電極孔隙度以及活性觸媒結合的參數調控嘗試提升效率，本研究製作了基於自製多孔鎳(NF-V3)的電極並以商用發泡鎳(NF)電極作為對照，首先利用浸鍍法將二價與三價鐵氧化物裝填在多孔鎳結構上，接著利用雷射進行鍛燒製作為Fe3O4/NF-V3電極，電化學測試結果揭示Fe3O4在增強反應動力學的關鍵作用，1 M KOH 溶液中在電流密度10 mA下Fe3O4/NF-V3電極的過電位為217.3 mV，低於NF-V3的361.4 mV。計時電流法量測結果顯示在155 mV過電位下經過5小時後電極仍展示優異穩定性與持久性能。
;Abstract
As fossil fuel reserves dwindle, the quest for sustainable energy solutions has become a global priority. Among the most promising approaches are energy storage technologies and electrochemical-based energy conversion devices. These methods are efficient, environmentally friendly, free from radiation hazards, and capable of delivering high performance. Key innovations include converting electrochemical energy into usable forms through electrochemical cells like fuel cells and storing it in batteries or electrochemical supercapacitors. Central to the efficiency of these technologies is the architecture of the electrodes within electrochemical cells, which conduct electrons from one half-cell to another which is produced by chemical reactions in the system. Over the past decade, researchers have made significant strides in developing highly porous architectures for electrocatalyst and electrochemical electrodes. These designs boast large surface areas, enhanced stability, and improved charge transport pathways, significantly boosting the performance of electrochemical cells.
In energy storage, our previous study focused on enhancing the performance of 3D all-solid-state micro-supercapacitors by utilizing nickel oxide (NiO) as a current collector within commercial nickel foam. This study introduces an innovative and straightforward method for producing electrodes with a large specific surface area, optimizing the application of active materials. The process exploits the commercial nickel foam, which is laser-cut into an interdigitated structure and then filled with Ni-based powder using dip coating techniques. Various chemical reactions were employed to coat the nickel foam with the nano-active material MnO2. This resulted in a novel current collector, NF-V2, with a 200-600 nm porosity range. Compared to commercial nickel foam (NF), this new structure offers a 30-fold increase in specific surface area and a substantial rise in active material loading (> 20 mg/cm2, up from less than 1 mg/cm2). Experiments on these highly porous 3D architectural electrodes demonstrate remarkable results, including an energy density of 671 µW h/cm2, which is 25 times higher than electrodes without filler, an area capacity of 19.34 F/cm2, and capacitance retention exceeding 95% at 5 mA/cm2. Furthermore, in the field of solid-state applications for micro-supercapacitors (MSCs), the highly porous electrode achieves a commendable areal capacity of 7.22 F/cm2 and an energy density of 263.9 µW h/cm2, making it appropriate for MSCs applications.
In energy conversion, our recent endeavor has yielded a breakthrough: creating a highly porous Ni electrode adorned with Fe3O4 for the Oxygen Evolution Reaction (OER). This undertaking is driven by the ambition to bolster the efficiency of water electrolysis through meticulous adjustments to the electrode′s porosity and the integration of active catalyst materials. Two distinct types of electrodes were meticulously crafted for the electrolysis process: self-manufactured nickel foam (NF-V3) and commercial nickel foam (NF), serving as a benchmark for comparison. Employing a dip coating process, the Ni porous structures were embellished with iron (II, III) oxide (Fe3O4), followed by a meticulous calcination process utilizing laser technology, culminating in the creation of Fe3O4/NF-V3 electrodes. Electrochemical tests unveiled the pivotal role of Fe3O4 in enhancing reaction kinetics. In a 1 M KOH solution at a current density of 10 mA, the Fe3O4/NF-V3 electrode exhibited an overpotential of 217.3 mV, significantly lower than its counterpart lacking Fe3O4, which registered an overpotential of 361.4 mV under identical conditions. Moreover, despite minor disparities in mass loading—less than 5 mg—the variances in porosity exhibited negligible effects on the electrode′s functionality. Notably, chronoamperometry tests conducted for 5 hours at a 155 mV overpotential underscored the stability and enduring performance of Fe3O4/NF-V3 electrodes. |
