- 學位論文
兩種動態陽極研製對鋅顆粒液流電池性能改善之研究
Study of Performance Improvement on Two Type Dynamic Anode Develop of Zinc Particle Flow Cell
摘要
本研究延續學長的基礎架構，改善電池漏液現象與燃料在電池內的電化學反應與流動的順暢性，為使鋅顆粒能在電池內達到充分利用，提出一套動態陽極流道系統，達到電池性能提升之目的。針對影響電池性能之因子如集電材料、電解液流速、鋅粉造粒等進行分析與測試，找出單電池各個最佳參數，藉由I-V極化曲線及交流阻抗分析法，以作為判斷單電池性能好壞之依據，最後進行鋅顆粒燃料電池陽極流道與無流道兩種形式的性能比較。本研究使用之鋅顆粒概念與傳統使用鋅板之設計有所不同。空氣電極為冠炬綠能科技所製作，鋅顆粒使用20g鋅粉及86%氫氧化鉀依據不同電解液濃度所調配而成，隔離膜材質採用不織布，並透過動態陽極流道設計與流動式電解液兩大優點將反應後所產生的水、碳酸鹽、生成物氧化鋅等物質一併帶離電池外。流動式電解液可降低鋅電極極化，使電池可在較高電流密度下穩定的工作，放電時所產生之熱能隨電解液帶出至電池外部。 由實驗結果顯示，電解液流速固定在0.11m/s，電池內部OH-濃度更新速率較佳，集電材料選用鎳網與鎳板，鎳網與不鏽鋼網相比，有較高導電性；鎳板比鎳片在大電流下有較佳的集電效果。目前單電池最大功率達20W，能量密度約為528Wh/kg，電流密度為519mA/cm2與功率密度為418mW/cm2，對應之電壓為0.8V。
並列摘要
Based on the former researcher’s framework, this study intends to improve the phenomenon of cell weeping and the electrochemical reaction of zinc particles in the cell. In order to make zinc particles elaborate in the cell completely, we address a system of dynamic anode channel. We analyze and examine the factors affecting the cell performance, such as current collector materials, velocity of electrolyte and zinc powder granulation, to find out the best parameter of single cells; we use I-V polarization curves and AC impedance analysis as the criteria to determine if the performance of the single cells is good or bad. Finally, we compare and test the performance of zinc particle fuel cells within two forms: anode channel and flow channel. The concept of zinc particles applied in this study is different from the traditional design of zinc plate. The air electrode is manufactured by ALT Green Energy Incorporation. Zinc particles are made from 20g zinc powder and 86% potassium hydroxide depending on different electrolyte concentration, and we use nonwoven fabric as the separator; via the two advantages, the system of dynamic anode channel and flowing electrolyte, the water, carbonate and zinc oxide generated after the reaction can outflow. Flowing electrolyte can reduce zinc electric polarization, so that the cell can work and function steadily under the higher current density; the heat generated from the discharge can outflow together with the electrolyte to the outside of the cell. The results show that the velocity of electrolyte is fixed at 0.11m/s, and the update rate of OH-concentration within the cell is better. We choose nickel meshes and nickel plates as current collector materials: nickel meshes have higher electric conductivity than stainless steel, while nickel plates have better performance on current collecting than nickel sheet under the bulk current. Currently, the maximum power of single cell is 20w; the energy density is about 528Wh/kg; the current density is 519mA/cm2; the power density is 418mW/cm2; the corresponding voltage is 0.8V.