- 學位論文
以微波法製備鋰離子電池LiCo1/3Ni1/3Mn1/3O2正極材料
The Preparation of Cathode Materials LiCo1/3Ni1/3Mn1/3O2 for Lithium Ion Batteries by Microwave Method
摘要
LiCo1/3Ni1/3Mn1/3O2此材料所含的Co元素比LiCoO2少，加上具有成本低、優越的電化學性能及結構較穩固的優點，使其具有優勢能取代LiCoO2正極材料。本實驗是採用微波法。利用其製備過程上能使材料反應速率快省時、較高的化學純度、反應條件溫和、使用較低的能量，取代常見的高溫固相法及共沉澱法製備LiCo1/3Ni1/3Mn1/3O2。 利用硝酸鎳、硝酸錳及硝酸鈷作為起始原料，依照固定的比例在微波消化系統中進行合成反應，製備LiCo1/3Ni1/3Mn1/3O2之前驅物，再進行高溫煅燒，得其成品。本實驗探討了不同微波方式、微波功率、微波反應時間的改變對合成LiCo1/3Ni1/3Mn1/3O2的影響。並利用X光繞射分析、SEM/EDX、DLS和恆電位電流儀，觀察合成物的結晶、表面形態、粒徑大小及電化學性能的測試。 經由實驗結果可以得知，利用氫氧化鋰、硝酸鎳、硝酸錳、硝酸鈷為原料進行合成，並使用不同微波條件250 W、300 W、350 W、400 W、微波溫度200 ℃、壓力39 bar、微波時間2小時進行連續微波，之後進行二次煅燒，第一次煅燒溫度為500 ℃煅燒6小時，第二次煅燒溫度為900 ℃煅燒10小時。以功率350 W所合成出的LiCo1/3Ni1/3Mn1/3O2材料為最好。
並列摘要
This material LiCo1/3Ni1/3Mn1/3O2 contains less Cobalt than LiCoO2 and has some advantages: low cost, superior electrochemical characteristics and more stable structure, from above advantages it might replace LiCoO2 cathode material. This experiment is used mcrowave method. The preparation process can make reaction time faster, saving more time, high chemical purity, safty condition of reaction and lower energy used. So this method can replace the conditional methods, like: solid-phase method and co-precipitation method to prepared LiCo1/3Ni1/3Mn1/3O2. Using nickel nitrate, manganese nitrate and cobalt nitrate as a starting materials to make the precursor of LiCo1/3Ni1/3Mn1/3O2 in this reaction by microwave method, and get the LiCo1/3Ni1/3Mn1/3O2 powder after high temperature calcined. This experimental study, we have some variables: different microwave way, microwave power and the time of reaction. We observe the crystallization of the composition, surface morphology, particle size, and electrochemical characteristics by using X-ray diffraction analysis, SEM / EDX, DLS and Autolab Potentiostat. According to the experiment, we could use lithium hydroxide, nickel nitrate, manganese nitrate and cobalt nitrate as a starting materials to synthesize LiCo1/3Ni1/3Mn1/3O2 cathode. And then used different microwave power: 250 W, 300 W, 350 W, 400 W, microwave temperature 200 ℃, pressure 39 bar, continuous microwave reaction time 2 hours and two step calcinations : first calcined temperature at 500 ℃for 6 hours, second calcined temperature at 900℃for 10 hours to synthesis LiCo1/3Ni1/3Mn1/3O2 cathode material.The result shows that 350 W is the best synthesis way.