LiMn2O4尖晶石氧化物的低指数表面结构优化及表面能的第一性原理研究

doi:10.6023/A21050213

摘要/Abstract

采用第一性原理密度泛函方法优化了LiMn₂O₄尖晶石结构, 构建并计算了其低指数表面性质. 结果表明, 广义梯度近似(GGA)和自旋极化广义梯度近似(GGA+U)计算的LiMn₂O₄晶体体相结构中, Mn的d轨道选取有效U值时晶格参数会变大. 但两种计算结果都没有显示出电荷有序和Jahn-Teller畸变的情况. LiMn₂O₄尖晶石结构缺Li条件下, (001)、(010)和(100)表面Li终端与其他终端相比表面能更低; (110)表面Mn/O终端表面能较Li/Mn/O终端更低. 在所涉及的低指数表面中(111)表面能最低, 表面重构后(111)表面能低至0.270 J/m², 是尖晶石结构中最稳定的切面. 关于反铁磁研究, (110)表面Mn/O终端表面能较Li/Mn/O终端更低. [↑↑↓↓]自旋排列下Mn/O终端表面能为1.050 J/m², [↑↓↑↓]自旋排列下Mn/O终端表面能为1.061 J/m², 即(110)-反铁磁型表面在[↑↑↓↓]自旋组态比[↑↓↑↓]的磁性顺序下更加稳定. 通过对(111)表面重构的研究, 发现该表面欠配位的锰离子会与完全配位的锂离子通过位置交换, 从而更加稳定. 重构表面的平均锰氧化态降低, 会减少Jahn-Teller效应的产生. 除(111)表面外, 其它低指数表面在铁磁和反铁磁下的表面能相似. 其中, (001)T3, (100)T1, (110)T1和(111)T2的表面结构在各自不同表面终端中具有最小的表面能. 本研究为理解LiMn₂O₄材料容量衰减问题和实验提供理论计算参考, 有助于推动高性能锂电池材料的研究.

关键词: LiMn₂O₄尖晶石氧化物, 第一性原理计算, Jahn-Teller效应, 低指数表面, 表面重构

The first principles density functional calculation method was used to calculate the index of low surface properties of LiMn₂O₄ spinel. Comparing with the bulk phase structures of LiMn₂O₄ crystals calculated by generalized gradient approximation (GGA) and generalized gradient approximation+on-site coulombic (GGA+U), it is found that the lattice parameters are obviously larger when the effective U value for the d orbital of Mn. However, the structural parameters of charge order and Jahn-Teller distortion are not found in own calculation. The results show that the Li terminal surface energy is lower when the (001), (010) and (100) surfaces of LiMn₂O₄ spinel in the state of lacking Li. The surface energy of (110) Mn/O terminal is lower than that of Li/Mn/O terminal in the state of lacking Li. The surface energy of (111) is the lowest in the low index surfaces. The surface energy of (111) after surface reconstruction is as low as 0.270 J/m², which is the most stable section of spinel structure in this work. Considering antiferromagnetism, the surface energies of Mn/O terminal on (110) surface are lower than those of Li/Mn/O terminal, which Mn/O terminal surface energies are 1.050 J/m² in the [↑↑↓↓] magnetic order and 1.061 J/m² in [↑↓↑↓] magnetic order, respectively. The antiferromagnetic (110) surface is more stable in the spin configuration than in the magnetic order. We found that the structure of undercoordinated manganese ions on the surface are more stable by position exchange with the fully coordinated lithium ions by the observation of the surface reconstruction of (111). The Jahn-Teller effect is reduced when the average manganese oxidation state of the reconstructed surface is reduced. Except for (111) surface, the surface energies of other surfaces in the ferromagnetic state are similar to those in the antiferromagnetic state. Among them, the surface structures of (001)T3, (100)T1, (110)T1 and (111)T2 have the least surface energy among their own different surface terminals. This study provides theoretical calculation reference for understanding the capacity attenuation problem of LiMn₂O₄ materials and related experiments. It is also helpful to promote the research of high-performance lithium battery materials.

Key words: LiMn₂O₄ spinel oxide, first principle, Jahn-Teller effect, low exponent surface, surface reconstruction

引用此文

陆远, 王继芬, 谢华清. LiMn₂O₄尖晶石氧化物的低指数表面结构优化及表面能的第一性原理研究[J]. 化学学报, 2021, 79(8): 1058-1064.

Yuan Lu, Jifen Wang, Huaqing Xie. First-principles Study on Low Index Surface Structure Optimization and Surface Energy of LiMn₂O₄ Spinel Oxides[J]. Acta Chimica Sinica, 2021, 79(8): 1058-1064.

导出引用 EndNote|Reference Manager|ProCite|BibTeX|RefWorks

分享此文

图/表 15

图1. LiMn2O4立方尖晶石晶胞结构, 指示Li(绿色)、Mn(紫红)和O(红色)原子的位置

Figure1. LiMn2O4 cubic spinel structure, indicating the positions of atoms Li (green), Mn (magenta), and O (red)

图2. 三元相图表明稳定的化合物结合体Li-Mn-O

Figure 2. Ternary phase diagram, indicating stable compound complex Li-Mn-O

化学式	平板混合物组分	锂锰氧化物基态能量∆G_f
Slab: Li₁₊_xMn₂O₄
Li₁₀Mn₁₆O₃₂	4.67LiMn₂O₄+2.67Li₂MnO₃+1.33Mn₃O₄	E_LiMn2O4= –47.17 eV
Li₁₈Mn₃₂O₆₄	12.67LiMn₂O₄+2.67Li₂MnO₃+1.33Mn₃O₄	E_Li2MnO3= –36.65 eV
Li₂₆Mn₄₈O₉₆	20.67LiMn₂O₄+2.67Li₂MnO₃+1.33Mn₃O₄	E_Mn3O4=–52.30 eV
Slab: LiMn₂₊_xO₄
Li₈Mn₂₀O₃₂	8LiMnO₂+4Mn₃O₄	E_Li10Mn16O32= –387.71 eV
Li₁₆Mn₃₆O₆₄	5.33LiMn₂O₄+5.33Li₂MnO₃+6.67Mn₃O₄	E_Li16Mn36O64= –795.80 eV
Li₂₄Mn₅₂O₉₆	13.33LiMn₂O₄+5.33Li₂MnO₃+6.67Mn₃O₄	E_Li24Mn52O96= –1172.98 eV

表1. 由三相图整理的非化学计量平板组分情况

Table 1. Non-stoichiometric plate composition as summarized by three-phase diagram

LiMn₂O₄	实验值(nm)	GGA (nm)	GGA+U (nm)	GGA (nm)	GGA+U (nm)
a	0.8238^[27]	0.8146	0.8419	0.809^[12]	0.843^[12]
b	0.8238^[27]	0.8146	0.8419	0.809^[12]	0.843^[12]
c	0.8238^[27]	0.8146	0.8419	0.809^[12]	0.843^[12]

表2. LiMn2O4尖晶石的晶格参数a、b和c

Table 2. Experimental and computational lattice parameters a, b and c values of LiMn2O4 spinel

图3. (001)和(010)表面结构图, 尖晶石LiMn2O4(001)表面的原子结构: T1: 非对称Li-和Mn/O-终端的Li8Mn16O32表面 (八层); T2: 对称Li终端的Li8Mn16O32 表面(九层); T3: 对称Li终端, 非化学计量Li10Mn16O32表面(九层). Li(绿色)、Mn(紫红)和O(红色)

Figure 3. (001) Surface and (010) surface structure, atomic structure of spinel LiMn2O4(001) surface: T1: Asymmetric Li- and Mn/O-terminal Li8Mn16O32 surface (eight layers); T2: Li8Mn16O32 surface (nine layers) of symmetrical Li terminal; T3: symmetrical Li terminal, non-stoichiometric Li10Mn16O32 surface (nine layers). Li (green), Mn (magenta) and O (red)

Terminated	Atomic structure	Top view
Li terminated
	T1
Mn/O terminated
	T2

表3. LiMn2O4(100)的表面结构和顶部视角

Table 3. Surface structure and top view of LiMn2O4(100)

图4. (110)表面原子结构图: (a) Mn/O终端的Li8Mn16O32表面(五层); (b) Li/Mn/O终端的Li8Mn16O32表面(五层). Li(绿色)、Mn(紫红)和O(红色)

Figure 4. (110) Surface structure diagram: (a) Mn/O terminal Li8Mn16O32 surface (five layers); (b) Li/Mn/O terminal Li8Mn16O32 surface (five layers). Li (green), Mn (magenta), and O (red)

图5. 尖晶石LiMn2O4(111)表面的原子结构: (a) 不对称Li/Mn/O和Li/O端的Li24Mn48O96表面; (b) 对称等效Li/Mn/O端的Li24Mn48O96; (c) 在底层增加4个Mn原子的非化学计量板层Li24Mn52O96. 表面Li(绿色)、Mn(紫红)和O(红色)

Figure 5. Atomic structure of spinel LiMn2O4(111) surface: (a) asymmetric Li/Mn/O and Li/O terminal Li24Mn48O96 surface; (b) Li24Mn48O96 with symmetrical equivalent Li/Mn/O terminal; (c) Non-stoichiometric laminae Li24Mn52O96 with 4Mn atoms added in the bottom layer. Surface Li (green), Mn (magenta) and O (red)

图6. 重构的(111) LiMn2O4 T1表面的原子结构图: (a) 顶面重构的Li8Mn16O32表面(T1-1); (b) Li16Mn32O64表面(T1-2); (c) Li24Mn48O96表面(T1-3)

Figure 6. Atomic structure diagram of reconstructed (111) surface of LiMn2O4 T1: (a) surface of Li8Mn16O32 reconstructed at the top surface (T1-1); (b) Li16Mn32O64 surface (T1-2); (c) Li24Mn48O96 surface (T1-3)

图7. 上下表面重构的(111) LiMn2O4 T2和T3表面的原子结构图: (a) Li16Mn32O64表面(T2-1); (b) Li24Mn48O96表面(T2-2); (c) Li16Mn36O64表面(T3-1.) (d) Li24Mn52O96表面(T3-2)

Figure 7. Atomic structure diagram of (111) LiMn2O4 T2 and T3 surfaces reconstructed from upper and lower surfaces: (a) Li16Mn32O64 surface (T2-1); (b) Li24Mn48O96 surface (T2-2); (c) Li16Mn36O64 surface (T3-1); (d) Li24Mn52O96 Surface (T3-2)

Surface structure		Surface energy (FM)	Surface energy (AFM)	Literature reference
(001)	T1	0.598	0.628	0.860^[36]
	T2	0.600	0.626	0.840^[36]
	T3	0.597	0.615	0.720^[36]
(100)	T1	0.606	0.654	0.870^[12]
(100)	T2	1.127	1.195	1.280^[12]
(110)	T1	1.026	1.050	1.410^[12]
(110)	T2	1.971	1.969	1.760^[12]
(010)	T1	0.599	0.668	1.300^[12]
	T2	0.603	0.667	0.960^[12]
	T3	0.651	0.644	N/A
(111)	T1	1.005	1.299	1.290^[11]
	T2	0.812	0.896	0.850^[11]
	T3	1.458	1.588	N/A

表4. 使用GGA+U计算(100), (010), (001), (110)和(111)低指数方向的LiMn2O4表面能(单位: J/m2)

Table 4. The surface energies of LiMn2O4 in the low index directions of (100), (010), (001), (110) and (111) are calculated using GGA+U (unit: J/m2)

图8. LiMn2O4(001)和LiMn2O4(010)的表面能图

Figure 8. Surface energy diagrams of LiMn2O4(001) and LiMn2O4(010)

Terminated	Surface energy	Fu^[39]	Benedek^[11]
Li terminated	0.654	0.40	0.58
Mn/O terminated	1.195	0.90	0.98

表5. LiMn2O4(100)的表面能量表(单位: J/m2)

Table 5. surface energy scale for LiMn2O4(100) (unit: J/m2)

Terminated	Total energy	Surface energy [↑↑↓↓]	Surface energy [↑↓↑↓]
Mn/O terminated	–364.243 eV	1.050	1.061
Li/Mn/O terminated	–352.375 eV	1.969	1.998

表6. LiMn2O4(110)的表面能量表(单位: J/m2)

Table 6. Surface energy scale for LiMn2O4(110) (unit: J/m2)

图9. 计算随着平板厚度增加的DFT表面能: (a) T1、T2和T3的未构建(111)表面能和(b)重构后表面能(T1R、T2R和T3R)

Figure 9. The surface energy of the DFT with the increase of plate thickness was calculated: (a) unconstructed (111) surface energy of T1, T2 and T3; (b) reconstructed surface energy (T1R, T2R and T3R)

参考文献 40

[1]	Cai, Z. F.; Ma, Y. Z.; Huang, X. N.; Yan, X. H.; Yu, Z. X.; Zhang, S. H.; Song, G. S.; Xu, Y. L.; Wen, C. E.; Yang, W. D. J. Energy Storage. 2020, 27, 101036. doi: 10.1016/j.est.2019.101036
[2]	Lee, A.; Vrs, M.; Dose, W. M.; Niklas, J.; Johnson, C. S. Nat. Commun. 2019, 10, 977. doi: 10.1038/s41467-019-08941-4
[3]	Xu, G. J.; Liu, Z. H.; Zhang, C. J.; Cui, G. L.; Chen, L. Q. J. Mater. Chem. A 2015, 3, 4092. doi: 10.1039/C4TA06264G
[4]	Liu, J. -D.; Zhang, Y. -D.; Liu, J. -X.; Li, J. -H.; Qiu, X. -G.; Cheng, F. -Y. Acta Chim. Sinica 2020, 78, 1426 (in Chinese.) doi: 10.6023/A20070330
	( 刘九鼎, 张宇栋, 刘俊祥, 李金翰, 邱晓光, 程方益, 化学学报, 2020, 78, 1426.) doi: 10.6023/A20070330
[5]	Kozawa, T.; Harata, T.; Naito, M. J. Asian Ceram. Soc. 2020, 8, 309. doi: 10.1080/21870764.2020.1743413
[6]	Yu, Y.; Guo, J.; Xiang, M.; Su, C.; Duan, K. Sci. Rep. 2019, 1, 16864.
[7]	Wei, T.; Zhuang, Q. -C.; Wu, C.; Cui, Y. -L.; Fang, L.; Sun, S. -G. Acta Chim. Sinica 2010, 68, 1481(in Chinese.)
	( 魏涛, 庄全超, 吴超, 崔永丽, 方亮, 孙世刚, 化学学报, 2010, 68, 1481.)
[8]	Yu, F.; Zhang, J. -J.; Wang, C. -Y.; Yuan, J.; Yang, Y. -F.; Song, G. -Z. Prog. Chem. 2010, 22, 9 (in Chinese.)
	( 于锋, 张敬杰, 王昌胤, 袁静, 杨岩峰, 宋广智, 化学进展, 2010, 22, 9.)
[9]	Liu, Y. J.; Li, X. H.; Guo, H. J.; Wang, Z. X.; Hu, Q. Y.; Peng, W. J.; Yang, Y. Rare Metals 2009, 4, 322.
[10]	Lin, C.; Robert, E. W.; Kan, S. C.; Joseph, A. L.; Christopher, J.; Zhen, Z. Y.; Mark, C.; Hersam, ; Jeffrey, P.; Greeley, ; Jeffrey, W. E. Chem 2018, 4, 2418. doi: 10.1016/j.chempr.2018.08.006
[11]	Benedek, R.; Thackeray, M. M. Phys. Rev. B 2011, 83, 173. doi: 10.1103/PhysRev.83.173
[12]	Karim, A.; Fosse, S.; Persson, K. A. Phys. Rev. B 2013, 87, 178.
[13]	Ouyang, C. Y.; Zeng, X. M.; Šljivancanin, Z.; Baldereschi, A. J. Phys. Chem. C 2010, 114, 4756. doi: 10.1021/jp911746g
[14]	Wang, T.; Wang, W.; Zhu, D.; Duan, X. -B.; Wei, Z. -Q.; Chen, Y. -G. Chin. J. Inorg. Chem. 2014, 30, 2461 (in Chinese.) doi: 10.1002/cjoc.201200581
	( 王婷, 王弯, 朱丁, 段晓波, 魏治乾, 陈云贵, 无机化学学报, 2014, 30, 2461.)
[15]	Bi, Z.; Zhao, N.; Ma, L.; Shi, C.; Guo, X. J. Mater. Chem. A 2020, 8, 4252. doi: 10.1039/C9TA11203K
[16]	Kresse, G.; Furthmüller, J. Comput. Mater. Sci. 1996, 6, 15. doi: 10.1016/0927-0256(96)00008-0
[17]	Kresse, G.; Furthmüller, J. Phys. Rev. B 1996, 54, 11169. pmid: 9984901
[18]	Shi, S. Q.; Gao, J.; Liu, Y.; Zhao, Y.; Wu, Q.; Ju, W. W.; Ouyang, C.; Xiao, R. J. Chinese Phys. B 2016, 25, 018212. doi: 10.1088/1674-1056/25/1/018212
[19]	Wang, J.; Zhang, Z.; Zhang, Y. N.; Han, D.; Jin, L. L.; Sheng, L. Y.; Chartrand, P.; Medraj, M. Mater. Lett. 2019, 256, 126628. doi: 10.1016/j.matlet.2019.126628
[20]	Saal, J. E.; Kirklin, S.; Aykol, M.; Meredig, B.; Wolverton, C. JOM 2013, 65, 1501. doi: 10.1007/s11837-013-0755-4
[21]	Kirklin, S.; Meredig, B.; Wolverton, C. Adv. Energy Mater. 2013, 3, 252. doi: 10.1002/aenm.v3.2
[22]	Vallverdu, G.; Minvielle, M.; Andreu, N.; Gonbeau, D.; Baraille, I. Surf. Sci. 2016, 649, 46. doi: 10.1016/j.susc.2016.01.004
[23]	Shukla, A.; Gaur, N. K.; Ghosh, P. Appl. Surf. Sci. 2020, 527, 146703. doi: 10.1016/j.apsusc.2020.146703
[24]	Ouyang, C. Y.; Shi, S. Q.; Lei, M. S. J. Alloys Compd. 2009, 474, 370. doi: 10.1016/j.jallcom.2008.06.123
[25]	Tomeno, I.; Kasuya, Y.; Tsunoda, Y. Phys. Rev. B 2001, 64, 115.
[26]	Singh, G.; Gupta, S. L.; Prasad, R.; Auluck, S.; Gupta, R.; Sil, A. J. Phys. Chem. Solids 2009, 70, 1200. doi: 10.1016/j.jpcs.2009.07.001
[27]	Singh, P.; Sil, A.; Nath, M.; Ray, S. J. Electrochem. Soc. 2010, 157, 259. doi: 10.1149/1.3273195
[28]	Lee, Y. K. Ph.D. Dissertation, The University of Michigan, United States, 2015.
[29]	Garcia, J. C.; Bareo, J.; Chen, G.; Croy, J. R.; Iddir, H. Phys. Chem. Chem. Phys. 2020, 22, 24490. doi: 10.1039/D0CP03942J
[30]	Yan, P.; Nie, A.; Zheng, J.; Zhou, Y.; Lu, D.; Zhang, X.; Xu, R.; Belharouak, I.; Zu, X.; Xiao, J. Nano Lett. 2015, 15, 514. doi: 10.1021/nl5038598
[31]	Qian, K.; Tang, L. K.; Wagemaker, M.; He, Y. B.; Liu, D. Q.; Li, H.; Shi, R. Y.; Li, B. H.; Kang, F. Y. Adv. Sci. 2017, 4, 1700205. doi: 10.1002/advs.201700205
[32]	Xu, C.; Märker, K.; Lee, J. H.; Mahadevegowda, A.; Reeves, P. J.; Day, S. J.; Groh, M. F.; Emge, S. P.; Ducati, C.; Layla, M. B.; Tang, C. C.; Grey, C. P. Nat. Mater. 2020, 20, 1. doi: 10.1038/s41563-020-00895-z
[33]	Chen, J.; Wu, X. P.; Hope, M. A.; Qian, K.; Peng, L. Nat. Commun. 2019, 10, 5420. doi: 10.1038/s41467-019-13424-7
[34]	Rasmussen, M. K.; Meinander, K.; Besenbacher, F.; Lauritsen, J. V. Beilstein J. Nanotechnol. 2012, 3, 192. doi: 10.3762/bjnano.3.21
[35]	Yoo, S. H.; Todorova, M.; Neugebauer, J. R. Phys. Rev. Lett. 2018, 120, 066101. doi: 10.1103/PhysRevLett.120.066101
[36]	Kim, S.; Aykol, M.; Wolverton, C. Phys. Rev. B 2015, 92, 115411. doi: 10.1103/PhysRevB.92.115411
[37]	Fu, C. C.; Wang, J. Y.; Wang, J. F.; Meng, L. L.; Zhang, W. M.; Li, X. T.; Li, L. P. J. Mater. Chem. A 2019, 7, 23149. doi: 10.1039/C9TA09327C
[38]	Julien, C. M.; Zaghib, K. Electrochim. Acta 2004, 50, 411. doi: 10.1016/j.electacta.2004.03.052
[39]	Fu, K. M.S. Thesis, University of Pittsburgh, United States. 2014.
[40]	Yu, F. D.; Wang, Z. B.; Chen, F.; Jin, W.; Zhang, X. G.; Gu, D. M. J. Power Sources 2014, 262, 104. doi: 10.1016/j.jpowsour.2014.03.120

LiMn₂O₄尖晶石氧化物的低指数表面结构优化及表面能的第一性原理研究

First-principles Study on Low Index Surface Structure Optimization and Surface Energy of LiMn₂O₄ Spinel Oxides

RichHTML

PDF

可视化

摘要/Abstract

引用此文

分享此文

图/表 15

参考文献 40

相关文章 6

编辑推荐

相关统计

本文评价

[1]	郭瑞, 魏星, 曹末云, 张研, 杨云, 樊继斌, 刘剑, 田野, 赵泽坤, 段理. AlAs/InSe范德华异质结构的光学和可调谐电子特性[J]. 化学学报, 2022, 80(4): 526-534.
[2]	邱凯, 严铭霞, 赵守旺, 安胜利, 王玮, 贾桂霄. Al掺杂的锂离子电池层状正极材料Li(Li_0.17Ni_0.17Al_0.04Fe_0.13Mn_0.49)O₂结构稳定性及氧离子氧化的理论研究[J]. 化学学报, 2021, 79(9): 1146-1153.
[3]	梁其梅, 郭昱娇, 郭俊明, 向明武, 刘晓芳, 白玮, 宁平. 亚微米去顶角八面体LiNi_0.08Mn_1.92O₄正极材料制备及高温电化学性能[J]. 化学学报, 2021, 79(12): 1526-1533.
[4]	万洋, 郑荞佶, 赁敦敏. 锂离子电池正极材料磷酸锰锂研究进展[J]. 化学学报, 2014, 72(5): 537-551.
[5]	吴其胜, 王子路, 王金兰. 单轴应变对石墨烯掺杂硼、氮、铝、硅、磷的影响与调控[J]. 化学学报, 2014, 72(12): 1233-1237.
[6]	刘媛媛. 新型光催化材料石墨炔-TiO₂的第一性原理研究[J]. 化学学报, 2013, 71(02): 260-264.