富鋰錳基材料研究進(jìn)展課件

1、富鋰錳基層狀材料研究進(jìn)展指導(dǎo)老師： 報(bào)告人： 1、研究意義2、材料的結(jié)構(gòu)3、充放電機(jī)理4、合成方法5、改性6、課題開展思路目錄1、研究意義Haijun Yu, Haoshen Zhou. J. Phys. Chem. Lett.2013, 4, 1268.充電電壓：2.0-4.8v首次充電比容量：300mAh/g首次放電比容量：200mAh/gPotential next generation cathode of specific capacity with 300 wh/g層狀富鋰錳基材料有待解決的問題充放電機(jī)理結(jié)構(gòu)電化學(xué)缺陷結(jié)構(gòu)高度相似性Li2MnO3和LiMO2(M=Mn,Ni ,Co

2、)的XRD對(duì)比圖M.M. Thackeray,et al. J. Mater. Chem., 2007, 17: 3112.TEM image of a 0.3Li2MnO3.0.7LiMn0.5Ni0.5O2 electrode結(jié)構(gòu)復(fù)雜性DEBATE?六方R-3m固溶體？Koga, H.et al.J. Phys. Chem. C 2012, 116, 13497.Ohzuku, T. et al. J. Mater. Chem.2011, 21, 10179.superlatticeVegard s law兩相結(jié)構(gòu)？Haoshen Zhou,et al. Phys. Chem. Chem.

3、 Phys. 2012,14 ,6548.0.5Li2MnO30.5LiMn0.42Ni0.42Co0.16O2的SXRD圖譜和計(jì)算圖譜富鋰材料結(jié)構(gòu)依條件而變化？3、充放電機(jī)理Li2MnO3“Inactive”LiMO2“active”MO2 (M=Ni,Co,Mn) LiMnO2xLi2MnO3.(1-x)LiMO212344.4 v-Li2O+Li+-Li+xLi2MnO3.(1-x)MO2（X-n）Li2MnO3MnO3. nMnO2 .(1-x)MO2（X-n）Li2MnO3MnO3 - nLiMnO2 .(1-x)LiMO2First cycleThe 2nd to the 51st

4、 cycleH. S. Zhou, et al, Phys. Chem. Chem. Phys. 2012,14, 6548.高溫下高容量基理更加復(fù)雜5585高溫下陽(yáng)離子發(fā)生Mn4+/Mn5+,Mn5+/Mn6+氧化還原，或陰離子發(fā)生O2/O22氧化還原？Ohzuku, T.et al.J. Mater. Chem.2011, 21, 10179.理論放電容量：252mAh/g4、合成方法0.3Li2MnO30.7LiMn0.5Ni0.5O20.3Li2MnO3.0.7LiNi0.5Mn0.5O20.5Li2MnO3.0.5LiNi0.5Co0.2Mn0.3O2Li1.2Mn0.54Ni0.1

5、3Co0.13O2Li1.2Ni0.2Mn0.6O2Li1.2Ni0.2Mn0.6O2合成方法共沉淀溶膠凝膠法固相法固相法燃燒法水熱法充電電壓（V）4.7 2.04.8 2.54.8 2.04.7 2.04.8 2.04.8 2.0電流密度（mA/g）5 510C/25 20C/10首次充電比容量(mAh/g)290.4357340.7280320310首次放電比容量(mAh/g)262.1239197.6250288230Jason R. Croy, et al. Journal of The Electrochemical Society, 2014,16,A318.Jifi Shojan

6、, et al. Materials Letters 2013,104 ,57.Kyung Yoon Chung, et al.Journal of Power Sources 2012,220,422.W.C. West, et al. Journal of Power Sources.2012,204,200.Young-Sik Hong, et al. J.Mater.Chem., 2004,14,1424.Chongmin Wang, et al. Nano Lett.2014, 12, 5186.5、改性1、鎳摻雜可以提高比容量2、造成表面選擇性積聚，阻塞鋰離子擴(kuò)散通道，可能會(huì)降低倍

7、率性能3、水熱合成法可以在原子尺度提高鎳分布的均一度，降低電壓降，提高循環(huán)壽命 Chongmin Wang, et al. Nano Lett.2012, 12, 5186.Ji-Guang Zhang, et al. Nano Lett.,2014,14, 2628.摻雜1、百分之三的鈉摻雜提高了材料的倍率性能2、提高了材料的導(dǎo)電性3、抑制了材料在循環(huán)中向尖晶石相轉(zhuǎn)變K. M. Abraham, et. Journal of The Electrochemical Society, 2014,161, A290.表面包覆Suface coating with Al2O3, CeO2, ZrO

8、2, SiO2, ZnO, AlPO4,LiNiPO4 and grapheneCan enhance the cycling stability and rate capacity and lower the irreversible capacity lossBut cannt adequately overcome the voltage decayBy keeping the cathode from contacting with the organic electrolyte and increasing the electron or ion conductivity , acting as an electron or ion conductor such as LiNiPO4形貌納米化(010)晶面暴露納米片狀Li1.15Ni0.25Mn0.6O2 非(010)晶面暴露納米片狀Li1.15Ni0.25Mn0.6O2 普通共沉淀法制備的Li1.15Ni0.25Mn0.6O2Guo-Zhen Wei ,et al.Adv. Mater. 2010, 22, 4364.1、納米化降低了Li+嵌入距離2、暴露了更多的Li+快速嵌入晶面（010）酸處理S.-H. Kang. Journal of