本文選題：鋰氧氣電池 + 鈣鈦礦型氧化物��； 參考：《天津大學(xué)》2014年碩士論文

【摘要】：鋰氧氣電池是特殊的鋰空氣電池，兩者的反應(yīng)機(jī)理是相同的，只是在結(jié)構(gòu)和工作環(huán)境上有差異。本文簡要概述了鋰空氣電池的研究進(jìn)展，及空氣電池正極所用催化劑的種類，特別是鈣鈦礦型復(fù)合氧化物的研究現(xiàn)狀及進(jìn)展，并對幾種常用制備鈣鈦礦型氧化物的方法做了簡要介紹。通過查閱文獻(xiàn)并結(jié)合本實(shí)驗(yàn)室的情況，最終選用溶膠-凝膠法制備鈣鈦礦型氧化物作為鋰氧氣電池的正極材料。 首先，研究傳統(tǒng)溶膠-凝膠法合成鈣鈦礦型LaNi0.8Co0.2O3的最佳條件，并研究了用其作為鋰氧氣電池正極催化劑的電化學(xué)性能。本實(shí)驗(yàn)以金屬硝酸鹽為原料，研究制備過程中絡(luò)合劑檸檬酸和分散劑乙二醇的含量、pH、反應(yīng)溫度、煅燒溫度及時間對制備鈣鈦礦型LaNi0.8Co0.2O3結(jié)構(gòu)、形貌和電化學(xué)性能的影響，并對其進(jìn)行物相分析和電化學(xué)性能測試。結(jié)果表明：用膠-凝膠法，以檸檬酸為絡(luò)合劑，乙二醇為分散劑，pH為8，n乙二醇:n酸:n總金屬=2:2:1，90℃水浴加熱5h，空氣中700℃煅燒3h時制備出的LaNi0.8Co0.2O3結(jié)晶度好，顆粒粒徑小，分散均勻，電化學(xué)性能好。以Super為碳材料，0.1C和截止放電電壓為2V時，鋰氧氣電池首次放電比容量為2152mAh g-1；限制充放電時間為4h時，保持電壓在2V以上可循環(huán)30圈；當(dāng)電流增大到0.2C，設(shè)置充放電時間為2h時，保持電壓在2V以上可循環(huán)25圈。 其次，研究了氣體擴(kuò)散電極的制備工藝。以LaNi0.8Co0.2O3為鋰氧氣電池的正極催化劑，通過Super P、乙炔黑和石墨烯三種碳材料對其電化學(xué)性能影響的對比，發(fā)現(xiàn)石墨烯的電化學(xué)性能最好。進(jìn)而又對氣體擴(kuò)散電極的催化劑和聚偏氟乙烯用量進(jìn)行優(yōu)化，得出當(dāng)石墨烯：催化劑：聚偏氟乙烯=8:1:1時，0.1C和截止放電電壓為2V，首次放電比容量達(dá)到2223mAh g-1。 最后，用AgNO3做為銀源，用抗壞血酸還原劑，制備出LaNi0.8Co0.2O3/Ag樣品，研究了LaNi0.8Co0.2O3/Ag形貌和電化學(xué)性能。結(jié)果表明：把Ag包覆到LaNi0.8Co0.2O3上，，樣品的顆粒稍變小，結(jié)晶度不變；以LaNi0.8Co0.2O3/Ag為氣體擴(kuò)散電極的催化劑，石墨烯：催化劑：聚偏氟乙烯=8:1:1時，在0.1C和截止放電電壓為2V下，其首次放電比容量為2854mAh g-1；當(dāng)0.4C時，首次放電比容量急劇減少到910mAh g-1。當(dāng)設(shè)置其充放電時間為4h，0.1C時，放電電壓保持在2V以上可循環(huán)60圈。
[Abstract]:Lithium-oxygen battery is a special lithium air battery. The reaction mechanism is the same, but the structure and working environment are different. In this paper, the research progress of lithium-air batteries and the types of catalysts used in the cathode of air batteries, especially perovskite-type composite oxides, are briefly reviewed. Several methods of preparing perovskite oxides are briefly introduced. Perovskite oxides were prepared by sol-gel method as cathode materials for lithium-oxygen batteries. Firstly, the optimal conditions for the synthesis of perovskite-type LaNi0.8Co0.2O3 by traditional sol-gel method were studied, and the electrochemical performance of perovskite LaNi0.8Co0.2O3 as cathode catalyst for lithium-oxygen battery was studied. The effects of the content of citric acid and dispersant ethylene glycol, pH, reaction temperature, calcination temperature and time on the structure, morphology and electrochemical properties of perovskite-type LaNi0.8Co0.2O3 were studied. Phase analysis and electrochemical performance tests were carried out. The results showed that the LaNi0.8Co0.2O3 prepared by gelatin-gel method, citric acid as complexing agent, ethylene glycol as dispersant, pH = 8% ethylene glycol: n: n total metal was heated in water bath at 2: 2: 1 ~ 90 鈩

本文編號：1866033