鋰離子二次電池商用正極材料缺陷鑑定

• Main Author: 劉泓杰
• Language: Chinese; English
• Published: 2013
• Subjects: 鋰鎳鈷錳氧; 鋰錳氧; 電池電化學表現; 鑑定技術; 老化影響; lithium nickel manganese cobalt oxide (LiNi1/3Co; lithium manganese oxide (LiMn2O4); the electrochemical performance of the battery; identification technology; aged effects.; Carbonic acid
• Online Access: http://ir.lib.ntust.edu.tw/handle/987654321/37774; http://ir.lib.ntust.edu.tw/bitstream/987654321/37774/-1/index.html

國立臺灣科技大學化學工程系 學位：碩士 指導教授：黃炳照 本研究利用諸多材料鑑定技術，針對電池正極材料之缺陷結構進行分析，並建立缺陷結構與電化學表現之關聯性。鑑定之樣品分為三個部分，主要包含：(1)不同廠牌之商業化層狀材料LiNi1/3Co1/3Mn1/3O2(NMC)；(2)於高溼高溫環境下，不同老化時間之LiNi1/3Co1/3Mn1/3O2(NMC)樣品； (3) 於高濕高溫環境下，不同老化時間之LiMn2O4(LMO)樣品。 第(1)部分：由不同廠商所提供三元系層狀材料分別為NMC 1、NMC2、NMC 3、NMC 4得知同步輻射高解析度X光繞射(NSRRC-XRD)鑑定技術，顯示其它樣品具不純相產生，而NMC 3無不純相；表面散射拉曼光譜鑑定技術，顯示NMC 3 具最小A1g半高寬；掃描式電子顯微鏡鑑定技術，顯示NMC 3較NMC 1、NMC 2、NMC 4具較光滑表面；交流阻抗分析鑑定技術顯示NMC 3具有較低之電荷轉移阻抗(201.4 Ω)，導致0.2 C充放電100圈下，NMC 3具最小電容量衰退率。但於不同速率充放電下，NMC 3隨充放電C-rate增加電容量保持率卻不如其它樣品，主要是因陽離子錯位鑑定技術量測出NMC 3陽離子錯位程度較高(I 003/I 104=1.36)；且由循環伏安法得知，NMC 3具較高之極化電位差且較低之鋰離子擴散係數(3.99×10-13cm2 s-1)。 第(2)部分：對於LiNi1/3Co1/3Mn1/3O2老化材料之電池，於55℃充放電表現，顯示NMC 16W電容量衰退率最大(99.2%)，主要是因隨儲放於高溫高濕環境越久，陽離子錯位鑑定技術量測出NMC 16W陽離錯位程度較高(I 003/I 104=1.40); 表面散射拉曼光譜鑑定技術，顯示材料之表面結構排序降低; 循環伏安法得知NMC 16W具較高之極化電位差且較低之鋰離子擴散係數(4.64×10-14cm2 s-1); 交流阻抗分析鑑定技術，顯示NMC 16W電荷轉移阻抗最大(300.15 Ω) 第(3)部分：對於LiMn2O4老化材料電池之充放電表現，顯示LMO 16W電容量衰退率最大(30.8%)，主要是因隨儲放於高溫高濕環境越久，由同步輻射高解析度X光繞射光譜鑑定技術量，測出錳氧化物及碳酸鋰繞射鋒產生; 表面散射拉曼光譜鑑定技術顯示A1g產生紅位移; X-ray射線光電子能譜表面分析鑑定技術，顯示材料表面形成碳酸鋰(5.3% → 33.4%)，錳溶解導致Mn4+增加(28.1% → 37.2%)，降低反應活性物質量; 循環伏安法得知，LMO 16W具較高之極化電位差且較低之鋰離子擴散係數(1.34×10-14cm2 s-1); 交流阻抗分析鑑定技術，顯示NMC 16W電荷轉移阻抗最大(438.52 Ω)，為了去除雜相影響電化學表現，因此將老化材料經再鍛燒。由結果顯示Re LMO 16W可去除部分碳酸鋰及不純相且極化電位及電荷轉移阻力皆降低，而使電池電容量回復且具0.97%之低衰退率。 本研究建立之材料分析與電化學關聯性指標，可以應用在電池材料之品質管理，使得管理人員能以較快速的方法對電池材料進行篩選，得到準確可靠之結果，有助於電池品質之提昇以及成本之降低。 本研究建立之材料分析與電化學關聯性指標，可以應用在電池材料之品質管理，使得管理人員能以較快速的方法對電池材料進行篩選，得到準確可靠之結果，有助於電池品質之提昇以及成本之降低。 This study aims to establishes several techniques to identify the structure defect and electrochemical performance in cathode materials for lithium ion battery. The work is divided into three parts, (1) the performance of different brands of commercial layered materials LiNi1/3Co1/3Mn1/3O2 (NMC) (2) The aging effect on (NMC) in high humidity environments (3) The aging effect on LiMn2O4 (LMO) in high humidity environments. Section (1) Part : the result reports that after 100th cycle, NMC3 shows the minimum capacity fading at 0.2 C. No impurity peak appeared on the NMC3 shown by synchrotron X-Ray diffraction spectroscopy (NSRRC-XRD). The scanning electron microscope (SEM) image shows that NMC3 surface is the smoothest. AC impedance analysis and identification technique shows NMC3 has a lower charge transfer resistance (201.4 Ω) Moreover, The Raman scattering spectroscopy observes the lowest FWHM of A1g peak on the NMC3. However, at the different C-rate the capacity of NMC3 is significantly decrease by the increasing of C-rate, this is due to the amount of cation mixing of NMC 3 is high (I 003 / I 104 = 1.36) and also due to the higher polarization and lower lithium ion diffusion coefficient (3.99 × 10-13 cm2 s-1) of NMC depicted in the Cyclic Voltammetry (CV) curve . Section (2) parts: The result report that after 16 weeks aging at 55℃ the NMC shows the maximum capacity fading rate (99.2%), this is due to high temperatures, high humidity, and the long time for storage . cationic dislocation identification techniques shows that after 16 weeks aging the cation mixing of the martial is the highest (I 003 / I 104 = 1.40) compared to the other cells using different aged time. the Raman scattering spectroscopy observes the lowest FWHM of A1g peak on the NMC after 16 weeks aging. After 16 weeks aging , the NMC shows higher polarization potential and lower lithium ion diffusion coefficient (4.64 × 10-14 cm2 s-1) after 16 W aging; AC impedance analysis shows that after 16W NMC has maximum charge transfer resistance (300.15 Ω) . Section (3) Part: The result report that after 16 W aging the LiMn2O4 shows the maximum capacity fading rate (30.8%), this is due to high temperatures, high humidity, and the long time for storage. NSRRC-XRD result shows the manganese oxide and lithium carbonate. The Raman spectra depict the red shift of A1g. X-ray photoelectron spectroscopy (XPS) surface analysis shows the material surface form carbonic acid to lithium (5.3% → 33.4%), manganese dissolved increase the amount of Mn4+ (28.1% → 37.2%). the LMO shows higher polarization potential and lower lithium ion diffusion coefficient (4.64 × 10-14 cm2 s-1) after 16 W aging; AC impedance analysis shows that after 16W , LMO has maximum charge transfer resistance (300.15 Ω). In order to remove the impurity phase influence on the electrochemical performance re-annealing material is done by calcinations. The results show Re-annealing of LMO after 16W aging can remove the portion of lithium carbonate and impure phase, the polarization potentials and electron charge transfer resistance significantly decrease, it enhance the capacity of battery with the decline rate 0.97%. This study establishes the association and electrochemical indicators which can be applied to make the quality control in the lithium ion battery, proposes the management personnel to more rapid method of screening of the battery, obtains accurate and reliable results, and helps to improve the quality of the battery and cost reduction.