液流電池碳電極優化方法Flow battery carbon electrode optimization method
本發明係有關於一種液流電池碳電極優化方法，尤指涉及一種以較安全之氮氣、氦氣等惰性氣體工作環境對碳電極進行電漿活化，特別係指可在碳電極活化產生之缺陷表面與空氣或親水性單體反應生成含氧官能基團，藉以得到穩定、親水且高效能之液流電池用改質電極之方法者。The invention relates to a method for optimizing a carbon electrode of a liquid flow battery, in particular to a plasma activation of a carbon electrode in a working environment of an inert gas such as nitrogen gas or helium gas, in particular, a defect which can be activated at a carbon electrode. A method in which a surface is reacted with air or a hydrophilic monomer to form an oxygen-containing functional group, thereby obtaining a stable, hydrophilic, and highly efficient modified electrode for a liquid flow battery.
電化學液流電池（Electrochemical Flow Cell），亦稱為氧化還原液流電池（Redox Flow Battery），係一種電化學儲能裝置。其中，正、負極都使用釩鹽溶液者亦稱為全釩氧化還原液流電池（Vanadium Redox Flow Battery）。由於全釩氧化還原液流電池具有充放電性能優異、循環使用壽命長及成本低等特性，且其製造、使用與廢棄過程均不產生有害物質，而成為理想之綠色環保儲能裝置。 前述氧化還原液流電池在儲能領域素有高安全性、長期使用性及深充放等優秀特性，其關鍵材料碳電極對電池之各項關鍵指標如效率、電容量及使用壽命等具有顯著影響，其組成長期以來多以有機物燒結之無序碳纖維組成之碳氈為主；亦有使用編織之有序碳纖維構成物如碳紙、碳布等組成，於性質、效能及電池模組組合等液流電池主要課題上各有優劣。 近期因液流電池技術蓬勃發展，碳電極作為前開氧化還原液流電池中關鍵之部件，自然受到極大之重視。為增進碳電極與另一關鍵材料電解液之反應速率、活性與降低其接觸電阻以提升電池效能，做為一個可以大幅影響電池效能、耐用性、電容量衰退率及壽命之關鍵因子，碳電極之改質不僅勢在必行，更要符合當今產業潮流，做到低成本、簡單、安全、環保及量產等優點。 至今已有諸多改質方法被文獻揭露，其主要目的皆在提升碳電極之表面缺陷數量以增加活性表面積或活性中心，並在表面添加含氧、氮等官能基團（帶負電荷）增加電解液中活性離子（多帶正電荷）之接觸性，藉此達到提升整體電池之電子轉移效率。不過這些文獻方法多著重於目的性，其應用性仍舊堪慮，在安全性、環保等方面仍待改進。 一般來說，現有改質液流電池用碳電極之方法有很多，最常見於文獻中之方法係將未改質碳電極以高溫爐或高溫微波烘烤，使其中之碳纖維與空氣反應生成缺陷提高表面積，同時於表面添加含氧官能基團以提高在電池中之反應性。其主要缺點有需高溫400度反應約1小時以上 ，耗能耗時及爐體大小限制改質量體，導致規模化改質有困難。 其次也有諸多文獻與專利係以氧化性酸浸泡反應進行碳電極改質，原理為使用強酸如硝酸、硫酸等氧化性酸加熱反應，使碳電極氧化生成不規則缺陷提高表面積，以提高在電池中之反應性。惟其主要缺點係使用具危害之酸性物質、後處理去除液體等步驟繁瑣，耗時亦久且產生二次廢溶液等問題。 文獻方法亦嚐試於碳電極之表面生成金屬顆粒、高分子、氮氧有機物等結構，藉由類似催化之方式使活性物質於生成之反應中心進行反應 ，以提高原碳電極之效能，然而其主要問題在於與酸反應一樣，因浸泡於改質液中反應，需要繁瑣的後處理步驟或需均勻塗布之方法，且生成之反應中心耐久性較前述生成缺陷之方法為差，優化效果平均亦較前法為差，目前仍僅止於學術研究使用，大規模應用性仍有難處。 以低溫常壓電漿改質液流電池用之碳材電極如石墨氈等，曾於2013年之歐洲專利（EP 2626936 A1）及2014年於中國專利（CN 103825033 A）揭露，惟其方式皆係以含氧，甚至以純氧之常壓氣體為工作環境，在電漿之電離作用下，將產生大量臭氧等有害氣體，如操作不當亦可能有燃燒、爆炸之虞，因此在製程工安、環保等考量下，預期將需更為繁瑣之程序及設備，應用有其限制。以中國專利CN 103825033 A而言，其主張以低溫常壓電漿改質液流電池電極材料，惟本發明之大氣電漿不使用純氧工作氣體，而改用較低成本且更安全之壓縮氮氣、惰性氣體進行活化步驟，可大幅減輕純氧與電漿反應產生之危害性臭氧，後以無成本之空氣接觸或與較高效之親水性單體反應皆可達到液流電池用碳電極之優化效果。 而在文獻報導部分，2011年文獻上曾有以真空氧電漿改質液流電池關鍵材料碳氈的方式，惟其非屬本發明提及之低溫電漿改質方法；而2014年文獻上亦有發表以氮、空氣之介電質電漿放電法（dielectric barrier plasma discharge）改質全釩液流電池用碳氈之方法，除與本發明提及之大氣電漿（air plasma）有本質上之不同外，其並無進行電池實測，僅就其他可間接證實其效果之實驗數據（如循環伏安法資料、交流電阻等）論之；另於2015年亦有文獻提及以氫電漿活化清潔全釩液流電池用碳氈再沉積奈米碳管之方法，亦與本發明有本質上之不同。 故，ㄧ般習用者係無法符合使用者於實際使用時以低溫電漿改質液流電池用碳電極之所需。Electrochemical Flow Cell, also known as Redox Flow Battery, is an electrochemical energy storage device. Among them, the vanadium salt solution used for both positive and negative electrodes is also called Vanadium Redox Flow Battery. Since the all-vanadium redox flow battery has the characteristics of excellent charge and discharge performance, long cycle life and low cost, and no harmful substances are produced in the process of manufacture, use and disposal, it is an ideal green energy storage device. The above-mentioned redox flow battery has excellent characteristics such as high safety, long-term use and deep charge and discharge in the field of energy storage, and its key material carbon electrode has significant effects on various key indexes of the battery such as efficiency, capacity and service life. Influence, its composition has long been dominated by carbon felt composed of disordered carbon fiber sintered by organic matter; it is also composed of woven ordered carbon fiber components such as carbon paper and carbon cloth, in terms of properties, performance and battery module combination. There are advantages and disadvantages in the main topics of the flow battery. Recently, due to the vigorous development of liquid flow battery technology, carbon electrode is a key component in the front-opening redox flow battery, and it has naturally received great attention. In order to improve the reaction rate and activity of the carbon electrode and another key material electrolyte and reduce the contact resistance to improve the battery performance, as a key factor that can greatly affect the battery performance, durability, capacity decline rate and life, carbon electrode The reform is not only imperative, but also in line with today's industrial trends, to achieve low cost, simple, safe, environmentally friendly and mass production. So far, many modification methods have been exposed in the literature. The main purpose is to increase the number of surface defects of carbon electrodes to increase the active surface area or active center, and add functional groups (negatively charged) containing oxygen and nitrogen to the surface to increase electrolysis. The contact of active ions (multiple positive charges) in the liquid, thereby improving the electron transfer efficiency of the overall battery. However, these literature methods focus on the purpose, and their applicability is still a concern, and still needs to be improved in terms of safety and environmental protection. In general, there are many methods for modifying the carbon electrode for a liquid flow battery. The most common method in the literature is to bake the unmodified carbon electrode in a high temperature furnace or a high temperature microwave to cause the carbon fiber to react with air to form a defect. The surface area is increased while oxygen-containing functional groups are added to the surface to increase reactivity in the battery. The main disadvantage is that it requires a high temperature of 400 degrees for about 1 hour, and the energy consumption and the size of the furnace are limited to the mass, which makes it difficult to scale up. Secondly, there are many literatures and patents that use oxidizing acid soaking reaction to modify the carbon electrode. The principle is to use a strong acid such as nitric acid, sulfuric acid and other oxidizing acids to heat the reaction, so that the carbon electrode is oxidized to form irregular defects to improve the surface area, so as to improve the battery. Reactivity. However, its main disadvantages are the use of hazardous acid substances, post-treatment and removal of liquids, etc., which are cumbersome, time-consuming and cause secondary waste solutions. The literature method also attempts to form metal particles, polymers, nitrogen oxides and other structures on the surface of the carbon electrode, and the active material is reacted at the reaction center formed by a similar catalytic method to improve the performance of the original carbon electrode. The problem is that, like the acid reaction, the immersion in the reforming solution requires a complicated post-treatment step or a method of uniform coating, and the resulting reaction center durability is inferior to the aforementioned method for generating defects, and the optimization effect is also average. The former method is poor, and it is still only used in academic research. It is still difficult to apply on a large scale. A carbon material electrode such as a graphite felt for a low-temperature constant-current slurry-modified liquid flow battery has been disclosed in European Patent (EP 2626936 A1) in 2013 and Chinese Patent (CN 103825033 A) in 2014, except that the method is In the working environment with oxygen or even atmospheric oxygen gas, under the ionization of plasma, a large amount of harmful gases such as ozone will be generated. If the operation is improper, there may be combustion and explosion. Therefore, the process is safe and environmentally friendly. Under the consideration of the above, it is expected that more cumbersome procedures and equipment will be required, and the application has its limitations. In the case of Chinese patent CN 103825033 A, it claims to use a low-temperature normal piezoelectric slurry to modify the flow battery electrode material, but the atmospheric plasma of the present invention does not use pure oxygen working gas, but uses a lower cost and safer compression. The activation step of nitrogen and inert gas can greatly reduce the harmful ozone generated by the reaction between pure oxygen and plasma, and then can reach the carbon electrode for liquid flow battery by contacting with no cost air or reacting with more efficient hydrophilic monomer. Optimize the effect. In the literature report, in 2011, there was a way to modify the key material carbon felt of vacuum oxygen plasma in the literature, but it is not the low temperature plasma modification method mentioned in the present invention; There is a method for modifying a carbon felt for a vanadium redox flow battery by a dielectric barrier plasma discharge, which is essentially the same as the air plasma mentioned in the present invention. In addition, there is no actual battery measurement, only other experimental data that can indirectly confirm its effect (such as cyclic voltammetry data, AC resistance, etc.); in 2015, there are also references to hydrogen plasma The method of re-depositing a carbon nanotube for a carbon monoxide for a cleaned all-vanadium flow battery is also substantially different from the present invention. Therefore, it is not possible for the user to conform to the user's need to use a low temperature plasma to modify the flow of the carbon electrode for the battery in actual use.
本發明之主要目的係在於，克服習知技藝所遭遇之上述問題並提供一種在低溫、開放環境條件下，以改良之前案低溫常壓電漿方法將液流電池用碳電極以較安全之氮氣、氦氣等惰性氣體工作環境進行電漿活化後，靜置於低溫空氣環境中一段時間，使原本碳電極表面性質轉化，除增加電極反應表面積外，可在碳電極活化產生之缺陷表面與空氣或親水性單體反應生成含氧官能基團，使受改質之液流電池碳電極具備與前案類似或更優化之穩定、親水且高效能之液流電池用改質電極，令整體方法較前案大幅減輕危害臭氧之生成，更加安全、環保之液流電池碳電極優化方法。 本發明之次要目的係在於，提供一種可提升液流電池之充放電效率表現，相對於傳統方法諸如加熱、酸蝕等改質方法，具有提高相同體積電解液下之電容量、減輕充放電進行時離子穿膜自放電之缺點的優點 ，也具有快速、操作簡單、安全、量產性、及環保等優勢之液流電池碳電極優化方法。 為達以上之目的，本發明係一種液流電池碳電極優化方法，其至少包含下列步驟：活化處理步驟：在低溫常壓下，於大氣電漿機台之反應區固定碳電極，設定平移台位移區域，通入氮氣或惰性氣體，製造電漿產生環境，產生電漿後，並使該平移台依設定之參數進行均勻之活化反應，以大氣電漿活化該碳電極表面；以及改質處理步驟：從該大氣電漿機台之反應區將活化處理完成之碳電極快速取出，並置於常溫空氣中或浸入親水性單體中使之反應、改質，使原本碳電極表面性質轉化，除增加電極反應表面積外，可在該碳電極活化產生之缺陷表面與空氣接觸反應或與親水性單體反應生成含氧官能基團，經水滴接觸角測試分析該碳電極之親水性，確保優化後之液流電池碳電極與水滴之接觸角呈0度（親水化），藉以得到穩定、親水且高效能之液流電池用改質電極。 於本發明上述實施例中，該碳電極係為碳氈或石墨氈。 於本發明上述實施例中，該惰性氣體係為氦氣。 於本發明上述實施例中，該活化處理步驟係可配合量產或實驗需求而設定反應區域，調整參數以控制改質面積、速度。 於本發明上述實施例中，該親水性單體係為甲基丙烯酸羥乙酯（Hydroxyethyl methacrylate）、或苯乙烯磺酸鈉（4-styrenesulfonic acid）。 於本發明上述實施例中，該改質處理步驟中，該碳電極活化產生之缺陷表面與該親水性單體反應，其反應時間為1～24小時，反應溫度介於65～95°C。The main object of the present invention is to overcome the above problems encountered in the prior art and to provide a method for improving the carbon electrode for a liquid flow battery with a safe nitrogen gas under a low temperature and open environment condition. After inert gas working environment such as helium gas is activated by plasma, it is left in a low temperature air environment for a period of time, so that the surface properties of the original carbon electrode are transformed. In addition to increasing the reaction surface area of the electrode, the defect surface and air generated by the activation of the carbon electrode can be Or the hydrophilic monomer reacts to form an oxygen-containing functional group, so that the modified liquid flow battery carbon electrode has a modified, hydrophilic and high-efficiency liquid flow battery modified electrode similar to or better than the previous case, so that the overall method Compared with the previous case, the carbon electrode optimization method for liquid flow battery which is more safe and environmentally friendly is greatly reduced. The secondary object of the present invention is to provide a performance improvement method for improving the charge and discharge efficiency of a liquid flow battery, and to improve the electric capacity under the same volume of electrolyte and to reduce charge and discharge compared with the conventional methods such as heating, acid etching and the like. The advantages of the shortcomings of ion-transmission self-discharge during the process, and the optimization of the carbon electrode of the liquid flow battery with the advantages of quickness, simple operation, safety, mass production, and environmental protection. For the purpose of the above, the present invention is a method for optimizing a carbon electrode of a flow battery, comprising at least the following steps: an activation treatment step: fixing a carbon electrode in a reaction zone of an atmospheric plasma machine under a low temperature and normal pressure, and setting a translation stage Displacement area, nitrogen or inert gas is introduced to create a plasma generating environment, and plasma is generated, and the translation stage is uniformly activated according to the set parameters, and the surface of the carbon electrode is activated by atmospheric plasma; and the modification process is performed. Step: quickly remove the activated carbon electrode from the reaction zone of the atmospheric plasma machine, and place it in a room temperature air or immersed in a hydrophilic monomer to react and modify the surface of the original carbon electrode. In addition to increasing the surface area of the electrode reaction, the surface of the defect generated by activation of the carbon electrode may be reacted with air or reacted with a hydrophilic monomer to form an oxygen-containing functional group, and the hydrophilicity of the carbon electrode is analyzed by a contact angle test of water droplets to ensure optimization. The contact angle between the carbon electrode and the water droplet of the flow battery is 0 degree (hydrophilic), thereby obtaining a stable, hydrophilic and high-efficiency liquid flow battery modification. electrode. In the above embodiment of the invention, the carbon electrode is a carbon felt or a graphite felt. In the above embodiment of the invention, the inert gas system is helium. In the above embodiment of the present invention, the activation treatment step can set the reaction area in accordance with mass production or experimental requirements, and adjust parameters to control the reformed area and speed. In the above embodiment of the invention, the hydrophilic single system is Hydroxyethyl methacrylate or 4-styrenesulfonic acid. In the above embodiment of the present invention, in the upgrading treatment step, the defect surface generated by the activation of the carbon electrode reacts with the hydrophilic monomer, and the reaction time is 1 to 24 hours, and the reaction temperature is 65 to 95 °C.
請參閱『第１圖～第３圖』所示，係分別為本發明液流電池碳電極優化方法之操作流程示意圖、本發明優化之液流電池碳電極在其他條件均固定之全釩液流電池單電池中之充放電曲線示意圖、及本發明之親水性單體改質示意圖。如圖所示：本發明係一種液流電池碳電極優化方法，其至少包含下列活化及改質處理步驟： 活化處理步驟s11：在低溫常壓下，因大氣電漿需通入高流量氣體，需於大氣電漿機台之反應區固定碳電極，設定平移台位移區域，應以適中移動量防止活化不均勻。設定完成後，通入氮氣或惰性氣體（如氦氣），製造電漿產生環境，產生電漿後，並使該平移台依設定之參數進行均勻之活化反應，以大氣電漿活化該碳電極表面；其中該碳電極係為碳氈或石墨氈。 改質處理步驟s12：活化處理完成後，從該大氣電漿機台之反應區將該碳電極快速取出，並置於常溫空氣中或浸入親水性單體中使之反應 、改質，使原本碳電極表面性質轉化，除增加電極反應表面積外，可在該碳電極活化產生之缺陷表面與空氣接觸反應或與親水性單體反應生成含氧官能基團，經水滴接觸角測試分析該碳電極之親水性，確保優化後之液流電池碳電極與水滴之接觸角呈0度（親水化），藉以得到穩定、親水且高效能之液流電池用改質電極。如是，藉由上述揭露之流程構成一全新之液流電池碳電極優化方法。 上述活化處理步驟係可配合量產或實驗需求而設定反應區域，調整參數以控制改質面積、速度。 於一具體實施例中，以空氣反應優化後之液流電池碳電極，經水滴接觸角測試，可由原疏水之100度變為親水之0度。另於組裝在本所全釩液流電池模組中，在電池模組（反應面積）、電解液、隔離膜、及組裝方法等條件固定不變下，於120mA/cm
2電流密度下，進行1.6V～0.7V範圍內之充放電測試。如第２圖所示，能量效率（放電能量Wh/充電能量Wh）可由處理前之76%提升至82～84%，減少了電池在充放電轉換中能量之損失，進而達成優化電池效能之目的。 於另一具體實施例中，前述改質處理若以親水性單體反應者，係以帶有OH或SO
3-官能基之親水單體為主，如甲基丙烯酸羥乙酯（Hydroxyethyl methacrylate）、或苯乙烯磺酸鈉（4-styrenesulfonic acid），反應時間為1～24小時而反應溫度介於65～95度可達最適改質效果。 如第３圖所示，以親水性單體反應者，可利用帶親水官能基（OH、SO
3-、COOH、R
4N
+等）之單體以共聚合（copolymerization）方式進行反應，使不同親水基團生長於碳電極１表面，達到不同改質效果之優點。若以OH或SO
3-親水官能基之單體反應優化後之液流電池碳電極，經水滴接觸角測試，亦可由原疏水之100度變為親水之0度。另於組裝在本所全釩液流電池模組中，其他條件不變下，進行電流密度120mA/cm
2之測試，能量效率（放電能量Wh/充電能量Wh）亦可由處理前之76%提升至82～84%，代表著親水官能基可以改善電極之親水性，有助於電解液在電極表面流動，電壓效率可與能量效率皆可提升，減少了電池在充放電轉換中能量之損失，達成優化電池效能之目的。 本方法以改良之已知低溫常壓電漿方法，配合平移台移動經固定之碳電極進行活化處理後，再以無成本之空氣接觸進行簡單、快速、清潔、環保、大面積之改質，其特色如下： 1. 低溫常壓電漿產生環境僅需便宜且容易取得之壓縮氮氣或惰性氣體。 2. 機台操作方法簡單，操作環境亦為低溫常壓之惰性氣體空間，無需一般電漿所需之真空環境。 3. 本方法使用惰性氣體及空氣，不使用危險、易燃之化學物質，亦無廢棄物、副產品之產生，符合現代環保、安全、清潔生產之原則。 4. 以改良之已知電漿方法處理後之改質處理步驟亦很簡單，僅需將反應面靜置於開放環境中與空氣或親水性單體反應即可達到優化功能。 5. 反應時間快速，可客製化對特定面積之碳電極進行反應，彈性、可控且節約能源，其活化面積亦較一般雙極介質放電方法為佳。 本方法之主要功效係在於生成一種高效能液流電池碳電極，以低溫電漿轟擊碳電極使其組成纖維表面產生不規則但均勻分布之缺陷，提高了碳電極之活性表面積及活性中心數量，並經空氣或親水性單體優化處理增加了氧官能基及親水性，提升了電池活性物質之反應性及穩定性，達到提高液流電池之充放電效率、相同體積電解液下之電容量及減輕充放電進行時離子穿膜自放電之缺點等功效，也具有快速、安全、量產性等之優勢。 商業應用性：低溫電漿處理程序在業界已被廣泛使用於表面清潔、活化、蝕刻、沉積、氧化還原等領域，主要應用於許多產業如半導體製造、醫療儀器、生技、傳感器、塑料、複合材料及航太科技等。本方法主要將低溫常壓電漿應用於液流電池碳電極活化，再經空氣改質，安全無毒又環保，只要有低溫常壓電漿機台之工廠均有能力配合產製 ，技術門檻不高，容易量產及應用。 進步性：本方法不同於前案在表面處理時使用氧氣等活性物質，大幅減輕在活化過程中產生有毒物質臭氧外，不會有燃燒及爆炸之虞，亦不生成廢棄物。除具有相對於傳統及其他改質方法非常清潔及環保、操作簡單易學、低溫常壓下操作安全且管理容易、改質速度快、可配合量產或實驗需要而調整改質面積、速度，具有彈性及控制性等前案特性外，因可使用比含氧氣體更便宜之氮氣，整體來說比前案方法更加低成本、更符合工安、環保原則，足見本方法之進步性。 創新性：經檢索國內目前尚未有以低溫電漿改質液流電池用碳電極之方法及應用，屬於跨領域應用。 由上述可知，本發明所提優化方法係改良前案（低溫常壓等離子技術改質液流電池用石墨氈及電極）之已知缺點，不同於前案以較危險及較高成本之氧氣工作環境，改以較安全之氮氣、氦氣等惰性氣體工作環境進行，並在電漿活化後，與空氣接觸反應或與浸入親水性單體反應一段時間，使受改質之液流電池碳電極具備與前案類似或更優化之效能，整體方法較前案大幅減輕危害臭氧之生成，更加安全、環保。 綜上所述，本發明係一種液流電池碳電極優化方法，可有效改善習用之種種缺點，藉由在低溫、開放環境條件下，以改良之前案低溫常壓電漿方法將液流電池用碳電極進行活化後，靜置於低溫空氣環境中一段時間，使原本碳電極表面性質轉化，除增加電極反應表面積外，可在碳電極活化產生之缺陷表面與空氣或親水性單體反應生成含氧官能基團，藉以得到穩定、親水且高效能之液流電池用改質電極；藉此，可提升液流電池之充放電效率表現，相對於傳統方法諸如加熱、酸蝕等改質方法，具有提高相同體積電解液下之電容量、減輕充放電進行時離子穿膜自放電之缺點的優點，也具有快速、操作簡單、安全、量產性、及環保等優勢，進而使本發明之□生能更進步、更實用、更符合使用者之所須，確已符合發明專利申請之要件，爰依法提出專利申請。 惟以上所述者，僅為本發明之較佳實施例而已，當不能以此限定本發明實施之範圍；故，凡依本發明申請專利範圍及發明說明書內容所作之簡單的等效變化與修飾，皆應仍屬本發明專利涵蓋之範圍內。
Please refer to FIG. 1 to FIG. 3, which are schematic diagrams showing the operation flow of the carbon electrode optimization method for the flow battery of the present invention, and the optimized vanadium flow of the liquid battery of the flow battery which is fixed under other conditions. A schematic diagram of a charge and discharge curve in a battery cell, and a schematic diagram of the modification of the hydrophilic monomer of the present invention. As shown in the figure, the present invention is a method for optimizing a carbon electrode of a flow battery, which comprises at least the following activation and upgrading treatment steps: an activation treatment step s11: at a low temperature and a normal pressure, a high flow gas is required to be introduced into the atmospheric plasma. It is necessary to fix the carbon electrode in the reaction zone of the atmospheric plasma machine and set the displacement zone of the translation stage. The activation should be prevented by the moderate movement amount. After the setting is completed, nitrogen or an inert gas (such as helium gas) is introduced to create a plasma generating environment, and after the plasma is generated, the translation stage is uniformly activated according to the set parameters, and the carbon electrode is activated by atmospheric plasma. a surface; wherein the carbon electrode is a carbon felt or a graphite felt. Reforming step s12: After the activation treatment is completed, the carbon electrode is quickly taken out from the reaction zone of the atmospheric plasma machine, and placed in a room temperature air or immersed in a hydrophilic monomer to react and reform, so that the original carbon The surface property of the electrode is transformed. In addition to increasing the reaction surface area of the electrode, the surface of the defect generated by activation of the carbon electrode may react with air or react with a hydrophilic monomer to form an oxygen-containing functional group, and the carbon electrode is analyzed by a contact angle test of water droplets. The hydrophilicity ensures that the contact angle between the carbon electrode and the water droplet of the optimized flow battery is 0 degree (hydrophilization), thereby obtaining a stable, hydrophilic and high-efficiency modified electrode for a liquid flow battery. If so, a new flow battery carbon electrode optimization method is constructed by the above disclosed process. The above activation treatment step can set the reaction area in combination with mass production or experimental requirements, and adjust parameters to control the reformed area and speed. In a specific embodiment, the carbon electrode of the flow battery optimized by the air reaction can be changed from 100 degrees of the original hydrophobicity to 0 degree of the hydrophilic state by the contact angle test of the water drop. In addition, it is assembled in our all-vanadium redox flow battery module, and the battery module (reaction area), electrolyte, separator, and assembly method are fixed at a current density of 120 mA/cm 2 . Charge and discharge test in the range of 1.6V to 0.7V. As shown in Fig. 2, the energy efficiency (discharge energy Wh/charge energy Wh) can be increased from 76% before processing to 82-84%, which reduces the energy loss of the battery during charge-discharge conversion, thereby achieving the purpose of optimizing battery performance. . In another embodiment, the aforementioned modification treatment is performed by a hydrophilic monomer, and is mainly a hydrophilic monomer having an OH or SO 3- functional group, such as Hydroxyethyl methacrylate. Or 4-styrenesulfonic acid, the reaction time is 1 to 24 hours and the reaction temperature is between 65 and 95 degrees to achieve the optimum quality modification effect. As shown in Fig. 3, a monomer having a hydrophilic functional group (OH, SO 3 - , COOH, R 4 N + or the like) can be reacted by a copolymerization method as a hydrophilic monomer. Different hydrophilic groups are grown on the surface of the carbon electrode 1 to achieve the advantages of different modification effects. If the cell electrode of the flow battery optimized by the reaction of the monomer of OH or SO 3- hydrophilic functional group is tested, the contact angle of the water droplet can be changed from 100 degrees of the original hydrophobicity to 0 degree of the hydrophilicity. In addition, it is assembled in the whole vanadium redox flow battery module of the Institute, and the current density is 120mA/cm 2 under other conditions. The energy efficiency (discharge energy Wh/charge energy Wh) can also be improved by 76% before processing. Up to 82-84%, representing a hydrophilic functional group can improve the hydrophilicity of the electrode, help the electrolyte to flow on the surface of the electrode, and the voltage efficiency can be improved with energy efficiency, thereby reducing the energy loss of the battery during charge-discharge conversion. Achieve the goal of optimizing battery performance. The method is improved, simple, rapid, clean, environmentally friendly, and large-area modified by a modified low-temperature normal piezoelectric slurry method, which is combined with a moving carbon electrode to be activated by a translation stage, and then subjected to air contact without cost. Its characteristics are as follows: 1. Low temperature normal piezoelectric slurry production environment requires only cheap and easy to obtain compressed nitrogen or inert gas. 2. The operation method of the machine is simple, and the operating environment is also an inert gas space with low temperature and normal pressure, which does not require the vacuum environment required for general plasma. 3. This method uses inert gas and air, does not use dangerous, flammable chemicals, and does not produce waste or by-products. It conforms to the principles of modern environmental protection, safety and clean production. 4. The upgrading process after the modified known plasma method is also very simple, and it is only necessary to statically place the reaction surface in an open environment to react with air or a hydrophilic monomer to achieve an optimized function. 5. The reaction time is fast, and it can be customized to react to the carbon electrode of a specific area. It is elastic, controllable and energy-saving. The activation area is better than that of the general bipolar medium discharge method. The main function of the method is to generate a high-performance liquid battery carbon electrode, which bombards the carbon electrode with a low-temperature plasma to form an irregular but uniform distribution defect on the surface of the fiber, thereby improving the active surface area of the carbon electrode and the number of active centers. Optimized by air or hydrophilic monomer, the oxygen functional group and hydrophilicity are increased, the reactivity and stability of the battery active material are improved, and the charge and discharge efficiency of the liquid flow battery and the electric capacity under the same volume of electrolyte are improved. It can reduce the shortcomings of ion-transmissive self-discharge when charging and discharging, and it also has the advantages of fast, safe and mass production. Commercial applicability: Low-temperature plasma processing procedures have been widely used in the fields of surface cleaning, activation, etching, deposition, redox, etc., and are mainly used in many industries such as semiconductor manufacturing, medical instruments, biotechnology, sensors, plastics, composites. Materials and aerospace technology. The method mainly applies low-temperature normal piezoelectric slurry to the activation of the carbon electrode of the liquid flow battery, and then is modified by air, safe, non-toxic and environmentally friendly. As long as the factory of the low-temperature normal piezoelectric pulp machine has the ability to cooperate with the production system, the technical threshold is not High, easy to mass produce and application. Progressive: This method is different from the previous case in the use of active substances such as oxygen in the surface treatment, which greatly reduces the generation of toxic substances in the activation process, there is no burning or explosion, and no waste is generated. In addition to being relatively clean and environmentally friendly, easy to learn, easy to operate, low temperature and pressure, safe and easy to manage, fast to change, and can be adjusted to the mass production or experimental needs, the modified area and speed are adjusted. In addition to the characteristics of flexibility and control, the use of nitrogen, which is cheaper than oxygen-containing gas, is generally lower cost than the previous method, and is more in line with the safety and environmental protection principles. This shows the progress of this method. Innovative: The method and application of carbon electrode for low-temperature plasma-modified liquid flow battery have not been searched in China, and it is a cross-domain application. It can be seen from the above that the optimization method proposed by the present invention is a known shortcoming of the improved case (low temperature atmospheric plasma technology and graphite felt and electrode for upgrading liquid flow battery), and is different from the previous case to work with more dangerous and higher cost oxygen. The environment is changed to a safe working environment such as nitrogen and helium, and after the plasma is activated, it is reacted with air or reacted with a hydrophilic monomer for a certain period of time to make the modified carbon battery electrode With the similar or more optimized performance as the previous case, the overall method is much safer and more environmentally friendly than the previous case. In summary, the present invention is a method for optimizing a carbon electrode of a flow battery, which can effectively improve various disadvantages of the conventional use, and can improve the flow of the battery by using the low-temperature normal piezoelectric slurry method under low temperature and open environment conditions. After activation of the carbon electrode, it is statically placed in a low-temperature air environment for a period of time to convert the surface properties of the original carbon electrode. In addition to increasing the reaction surface area of the electrode, the surface of the defect generated by activation of the carbon electrode may react with air or a hydrophilic monomer to form a content. An oxygen-functional group for obtaining a stable, hydrophilic and high-efficiency reforming electrode for a liquid flow battery; thereby, the performance of the charge and discharge efficiency of the flow battery can be improved, compared with a conventional method such as heating, acid etching, etc. The utility model has the advantages of improving the electric capacity under the same volume of the electrolyte and reducing the shortcomings of the ion-transmissive self-discharge during the charging and discharging, and has the advantages of quickness, simple operation, safety, mass production, environmental protection, etc., and further the invention. Health is more progressive, more practical, and more in line with the needs of users. It has indeed met the requirements of the invention patent application, and has filed a patent application according to law. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto; therefore, the simple equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the invention are modified. All should remain within the scope of the invention patent.
s11‧‧‧活化處理步驟S11‧‧‧activation treatment steps
s12‧‧‧改質處理步驟S12‧‧‧Modification process steps
1‧‧‧碳電極1‧‧‧ carbon electrode
第１圖，係本發明液流電池碳電極優化方法之操作流程示意圖。 第２圖，係本發明優化之液流電池碳電極在其他條件均固定之全釩 液流電池單電池中之充放電曲線示意圖。 第３圖，係本發明之親水性單體改質示意圖。Fig. 1 is a schematic view showing the operation flow of the carbon electrode optimization method of the flow battery of the present invention. Fig. 2 is a schematic diagram showing the charge and discharge curves of the carbon electrode of the optimized flow battery of the present invention in an all-vanadium flow battery cell fixed in other conditions. Fig. 3 is a schematic diagram showing the modification of the hydrophilic monomer of the present invention.