- 期刊
以電化學活化調適軟碳微結構在高電壓超高電容器之應用
Tailoring the microstructure of soft carbons using electrochemical activation for high-voltage supercapacitor applications
摘要
軟碳負極材料為中油煉研所自行研發之技術，從2010年實驗室等級1公斤逐步放大至小量產等級10公斤，並於2017年9月取得專利（中華民國專利，發明I603528）。目前可以穩定產出軟碳規格為電容量大於260mAh／g；不可逆百分比小於14%之產品規格。此技術於2015年6月導入試量產階段，已逐步放大至百公斤等級，年產約10噸，目前已規劃建置年產5000噸軟碳，預計於2024年底完成。軟碳除了作為鋰離子電池用之快充與長壽命材料外，透過本研究開發亦可導入高電壓超電容材料使用，提供軟碳產品在前瞻儲能元件之多元發展，同時增加中油公司在未來之營收。電雙層電容器可以提供高功率密度，但其能量密度遠低於普通可充電電池的能量密度。為了解決這個問題，本研究內容針對不同微結構（碳層在晶面（002）尺度的差異，即結晶性不同）軟碳進行電化學測試及鹼活化之化學修飾與電化學活化對軟碳進行處理，再利用從循環伏安法得到電容量與電容量增加之比率，進而了解微結構特性與電容關係，在搭配基本的結構分析儀器包含X光繞射光譜、高解析電子顯微鏡、微孔／中孔分析與比表面積量測等，深入探討軟碳微結構如何改變而能夠得到最高的操作電壓與電容量。最後，我們展示了一個非對稱式的4.0V超級電容器，該電容器由改質軟碳作為正極與活性碳作為負極之電極組成，其能量密度為電雙層超級電容器2倍以上。
並列摘要
The anode material of soft carbon is a self-developed technology by Refining & Manufacturing Research Institute (RMRI), Chinese Petroleum Corporation (CPC). It has been gradually scaled up from a laboratory level of 1 kg in 2010 to a small-scale production level of 10 kg. The patent was obtained in September 2017 (Republic of China patent, invention I603528). At present, the specification of soft carbon that can be stably produced is a specification of product with a capacity greater than 260 mAh/g and an irreversible percentage less than 14 %. The manufacture technology of soft carbon was introduced into the pilot production stage in June2015, and has been gradually scaled up to the 100 kg level, with an annual output of about 10 tons. Currently, it is planned to build an annual output of 5,000 tons of soft carbon and is expected to be completed by the end of 2024. In addition to being served as fast charging and long-life materials for lithium-ion batteries, soft carbon can also be used as high-voltage supercapacitor materials through this study, which will be providing a diverse development of soft carbon products in the advanced energy storage devices, and increasing the CPC's revenue in the future. Electric double layer capacitors (EDLCs) can provide a high power density, but their energy density is much lower than that of ordinary rechargeable batteries. In order to solve this problem, the content of this study focuses on the electrochemical test of soft carbon with different microstructures (the difference of the carbon layer in the crystal plane (002) scale is the difference in crystallinity), the chemical modification with alkali and electrochemical activation of the soft carbon. The capacitance obtained from cyclic voltammetry and the increased capacitance ratio from electrochemical measurements can be used to understand the relationship between microstructure characteristics and capacitance. With basic structural analysis of equipment including X-ray diffraction spectroscopy, high-resolution electron microscope, analysis of micro-pore/ meso-pore and measurements of specific surface area, etc., this study deeply discuss how the microstructure of soft carbon can be changed to obtain the highest operating voltage and capacitance. Finally, we demonstrate an asymmetric 4.0 V supercapacitor. The capacitor is composed of modified soft carbon as the positive electrode and activated carbon as the negative electrode. Its energy density is more than twice that of an electric double-layer supercapacitor.