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內(nèi)蒙古科技大學 本科生畢業(yè)論文 題 目:不同沉淀劑水熱合成 Ni(OH)2及其表征 學生姓名: 學 號: 202166115322 專 業(yè):化學工程與工藝 班 級:化工 103 班 指導教師: 教授 內(nèi)蒙古科技大學本科生畢業(yè)論文 I 摘 要 鎳氫電池作為一種高比能量的二次電池得到了廣泛的應用。 氫氧化鎳作為鎳氫電池的主要正極材料,其制備的研究對提高鎳氫電池整體性能具有重要意義。 本實驗以硝酸鎳為鎳源,以尿素為沉淀劑,用氫氧化鈉調(diào)節(jié) pH,以水熱法合成 Ni(OH)2 花瓣狀微球,反應溫度 170℃ ,反應時間 18h,干燥溫度 80℃,干燥時間 24h。過程簡單、易于操作。通過改變鎳和尿素的配比,觀察在不同配比的情況下, Ni(OH)2 花瓣狀微球的晶型結構、顆粒形貌的變化。并以硝酸鎳為鎳源,以氨水為沉淀劑,進行對比觀察在以不同沉淀劑所合成的 Ni(OH)2 晶型結構、顆粒形貌的不同。 利用 X 射線衍射( XRD)和掃描電子顯微鏡 (SEM)分別對合成試樣進行物相和形貌分析,結果表明,隨著鎳尿素摩爾比的增加, Ni(OH)2 粒徑先減小然后增加,花瓣結構變得逐漸清晰,花瓣厚度逐漸減小,花瓣變得松散。其中最佳鎳和尿素的配比為 1:5。增加鎳尿素摩爾比有利于 βNi(OH)2 的形成。增大硝酸鎳溶液的濃度有利于球形氫氧化鎳的形成。以尿素做沉淀劑優(yōu)于氨水。 關鍵詞: 納米 材料 ; 氫氧化鎳 ; 水熱法 ; 尿素 ; 氨水 內(nèi)蒙古科技大學本科生畢業(yè)論文 II Abstract Nickel hydrogen battery as a high energy density secondary batteries have been widely hydroxide as the main NiMH battery cathode materials, preparation of research to improve the overall performance of batteries is important. Nickel nitrate as nickel source,urea as the source of nickel,and in order to regulate the pH of the solution,added the sodium hydroxide. Hydrothermal synthesis of reaction temperature is 170 ℃ ,reaction time is 18h,drying temperature is 80 ℃ ,drying time is 24h. By changing the ratio of nickel and urea was observed in the case of different proportions,Ni(OH) 2 microspheres petal crystal structure,changes in particle nitrate and nickel source,ammonia as the precipitating agent,conduct crystal structure,parison of different particle morphologies observed in different precipitant synthesized Ni(OH)2. Xray diffraction (XRD) and scanning electron microscopy (SEM) were carried out on the synthesis phase and morphology of the sample analysis results show that with the increase of urea molar ratio of nickel,Ni(OH) 2 particle size decreases first and then increased petal structure bees gradually clear,decreases the thickness of the petals,petals bee loose. One of the best nickel and urea ratio of 1:5. Increasing Ni molar ratio in favor of the formation of urea,βNi(OH)2 in. Increasing the concentration of the nickel nitrate solution conducive to the formation of spherical nickel hydroxide. Urea precipitant than ammonia. Key words: Nanomaterials 。 nickel hydroxide。 hydrothermal method。 urea。 ammonia 內(nèi)蒙古科技大學本科生畢業(yè)論文 III 目 錄 摘 要 ......................................................................................................................................... I Abstract ...................................................................................................................................... II 目 錄 .......................................................................................................................................III 第一章 引 言 ......................................................................................................................... 1 鎳氫電池的發(fā)展 ....................................................................................................... 1 納米材料及納米氫氧化鎳簡介 ............................................................................. 3 納米材料簡介 ............................................................................................... 3 納米氫氧化鎳簡介 ....................................................................................... 4 MHNi 電池充放電原理 .......................................................................................... 6 氫氧化鎳制備簡介 ................................................................................................. 10 配位均勻沉淀法 ......................................................................................... 10 均相沉淀法 ................................................................................................. 11 沉淀轉(zhuǎn)換法 ................................................................................................. 12 水熱法 .......................................................................................................... 12 無水乙醇法 ................................................................................................. 13 反相膠束法(微乳液法) ........................................................................ 14 溶膠 — 凝膠法 ............................................................................................. 14 物理法 — 高能球磨法 ................................................................................ 15 離子交換樹脂法 ......................................................................................... 16 低溫固相反應法 ....................................................................................... 16 醇鹽電解法 ............................................................................................... 16 內(nèi)蒙古科技大學本科生畢業(yè)論文 IV 花瓣狀 Ni(OH)2 的形成機制 ............................................................................... 17 氫氧化鎳結晶過程的影響因素 ........................................................................... 18 反應物料的影響 ......................................................................................... 18 加料方式的影響 ......................................................................................... 19 pH 值的影響 ................................................................................................ 19 國內(nèi)外研究現(xiàn)狀 ..................................................................................................... 20 文獻總結 ................................................................................................................. 21 本文工作和實驗方案 ............................................................................................ 22 研究目的及意義 ................................................................................................... 23 第二章 納米 Ni(OH)2 的制備 .........................................................................................