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1、吉首大学硕士学位论文基于固体电解质烧结片的全固态锂离子薄膜电池的研究姓名：李润秀申请学位级别：硕士专业：应用化学指导教师：吴显明20100401摘 要 第 i 页 摘 要 随着科技的进步，小型化、轻量化的设备越来越多，人们对电池行业也提出了更高的要求。近几年来，锂离子二次电池由于高能量、长寿命、安全、环保等优点而成为人们关注的焦点。然而，锂离子电池的电解质材料大多为有机液体或聚合物，这使电池在一定程度上存在着安全隐患。为了缓解这种现状，本文对锂离子固体电解质材料 Li1+xAlxTi2- x(PO4)3进行了一系列的研究，并研制了全固态锂离子薄膜电池。 采用溶胶- 凝胶法制备了 Al3+掺杂的
2、 Li1+xAlxTi2- x(PO4)3（x=00.4）锂离子固体电解质。通过 X- 衍射、扫描电镜、电化学工作站等测试手段分析了Li1+xAlxTi2- x(PO4)3体系的物相、表面形貌、离子电导率及活化能，探讨了 Al3+的最佳掺杂量。结果表明：采用溶胶- 凝胶法合成的 Li1+xAlxTi2- x(PO4)3体系具有较好的结晶性，烧结片具有较高的离子电导率和较小的活化能，合成的粉末与烧结片之间的结晶性与结构差异不大。当 Al3+掺杂量从 0 增加到 0.3 时，离子电导率逐渐增大，且到 0.3 时其值达到最大，但当掺杂量进一步增加时，离子电导率迅速下降。活化能的变化趋势则与离子电导率
3、相反。 通过改变 Li1.3Al0.3Ti1.7(PO4)3粉末和烧结片的烧结温度和时间，探讨了固体电解质烧结片的最佳热处理条件。结果表明：实验条件下制备的固体电解质Li1.3Al0.3Ti1.7(PO4)3粉末和烧结片都具有较好的结晶性。Li1.3Al0.3Ti1.7(PO4)3烧结片的离子电导率和活化能随着烧结条件的改变而呈现有规律的变化，其中，将 900热处理2h的粉末压片， 再经900煅烧2h制得的烧结片， 其离子电导率最高 （3.46 10- 4 S cm- 1）、活化能最低（0.2821 eV），同时烧结片的表面也相对致密。 向 900热处理 2h 的 Li1.3Al0.3Ti1.
4、7(PO4)3粉末中添加不同百分比的助溶剂Li3PO4。通过 X- 射线衍射、扫描电镜对产物的物相和表面形貌进行分析，并采用交流阻抗分析了产物的离子电导率和活化能。结果显示，在实验条件下，合成的粉末和烧结片都具有良好的结晶性。 所有烧结片的表面都有一些孔洞。 然而， 900热处理 2h，添加量为 1wt.%的烧结片相对比较致密。经电化学分析得知，添加量为 1wt.%的烧结片在 900热处理 2h后有较高的离子电导率（5.3510- 4 S cm- 1）和较低的活化能（0.2700eV）。 采用一种新的工艺方法：喷雾热解法，成功研制了全固态锂离子薄膜电池LiMn2O4/Lil.3Al0.3Ti1
5、.7(PO4)3/LiMn2O4、LiMn2O4/Lil.3Al0.3Ti1.7(PO4)3/Li4Ti5O12，并经过恒电流充放电的性能测试。同时，通过 X- 衍射探讨了合成 LiMn2O4、Li4Ti5O12薄膜的化学计量比、热处理温度和时间。结果表明：合成正极薄膜、负极薄膜的热处理条件分别为：600- 10min、700- 10min，且实验条件下 LiMn2O4正极薄摘 要 第 ii 页 膜和 Li4Ti5O12负极薄膜的前驱体配比分别为 1.052 （乙酸锂乙酸锰） 和 85 （乙酸锂酞酸丁酯）。全固态锂离子薄膜电池 LiMn2O4/Lil.3Al0.3Ti1.7(PO4)3/LiM
6、n2O4和 LiMn2O4/Lil.3Al0.3Ti1.7(PO4)3/Li4Ti5O12的常温恒电流充放电的电压平台分别在1.2V、2.4V左右。 主题词：锂离子电池，固体电解质，Li1.3Al0.3Ti1.7(PO4)3，LiMn2O4薄膜，Li4Ti5O12薄膜 ABSTRACT 第 iii 页 ABSTRACT Along with the technological development, lithium- ion secondary batteries, boasting such merits as high capacity, long cycle life, environ
7、mental- friendliness and high safety, have been widely applied to portable electronic devices. However, It is dangerous that many solid electrolyte materials are organic liquid and polymer. So a series of lithium- ion solid electrolyte Li1+xAlxTi2- x(PO4)3 are synthesized. Solid electrolyte Li1+xAlx
8、Ti2- x(PO4)3 (x=00.4) doped with Al3+ was prepared by sol- gel technique. Phase identification, surface morphology, ionic conductivity and activation energy were studied by X- ray diffraction, scanning electron microscope and A .C. impedance. The results show that Li1+xAlxTi2- x(PO4)3(x=0- 0.4) prep
9、ared by sol- gel has better cystallintiy. Crystallinity and structure have little difference between the powder and sintered pellet. The ionic conductivity increases first and then decreases with the increase of Al3+ content. When doping amount is 0.3 ,the ionic conductivity is higher. The change of
10、 activation energy is contrary to that of the ionic conductivity. Electrochemical Performance of Li1.3Al0.3Ti1.7(PO4)3 pellets were studied by a change of heat treatment conditions. The results show that the sol- gel derived Li1.3Al0.3Ti1.7(PO4)3 pellet has the better crystallinity. All the sintered
11、 pellets show a lot of holes. However, the pellet sintered at 900 for 2h is much denser than the pellets sintered at other conditions. The ionic conductivity and activation energy for Li1.3Al0.3Ti1.7(PO3)4 sintered pellets vary with the sintering conditions. The pellet sintered at 900 for 2h shows t
12、he highest ionic conductivity of 3.4610- 4 S cm- 1 and the lowest activation energy of 0.2821eV. Solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 adding lithium salt Li3PO4 was prepared. The X- ray diffraction and scanning electron microscopy were used to analyse the phase and the morphology of the surface o
13、f the product. A.C. impedance spectrum was used to determine the ionic conductivity and activation energy. The result shows that the sintered pellets with different mass fractions have little difference on structure.All of the sintered pellets have holes, however, Li1.3Al0.3Ti1.7(PO4)3 pellets mixed
14、 Li3PO4 (1%) is denser than other pellets.The pellet mixed 1% Li3PO4 has higher ionic conductivity (5.3510- 4S cm- 1) and lower activation energy (0.2700 eV). All solid- state lithium thin- film batteries, LiMn2O4/ Lil.3Al0.3Ti1.7(PO4)3/LiMn2O4、 LiMn2O4/ Lil.3Al0.3Ti1.7(PO4)3/Li4Ti5O12,were synthesi
15、zed by spray pyrolysis. The batteries were tested by constant current charge- discharge. LiMn2O4 and Li4Ti5O12 thin- film were studied by X- ray diffraction. The molar ratio of Li- Mn, Li- Ti and synthesis conditions of thin- film were discussed.The results indicate that the optimal synthesis proces
16、s for LiMn2O4 and Li4Ti5O12 thin- film was as following: n(CH3COOLi 2H2O):n(Mn(CH3COO)2 4H2O)=1.05:2,n(CH3COOLi 2H2O):n(Ti(OC4HABSTRACT 第 iv 页 9)4)=8:5 and the synthesis conditions was 600- 10min,700- 10min,separately. All solid- state thin- film lithium- ion batteries were studied. The charge- discharge flat of LiMn2O4 /Lil.3Al0.3Ti1.7(PO4)3 /LiMn2O4 and LiMn2O4/Lil.3Al0.3Ti1.7(PO4)3/Li4Ti5O12 was about 1.2V and 2.4V, separately. K
