Comparison of metal ion dissolutions from lithium ion battery cathodes
Comparison of metal ion dissolutions from lithium ion battery cathodes
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DOI：
10.1149/1.2219710
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发表时间：
2006-01-01
影响因子：
3.9
通讯作者：
Manthiram, A.
中科院分区：
文献类型：
--
作者：
Choi, W.;Manthiram, A.
为了更好地了解锰尖晶石氧化物阴极的容量衰减机制，比较了不同锂离子电池阴极（层状、正交LiMnO2、4 V尖晶石、5 V尖晶石和橄榄石）的金属离子溶解量。与含Mn4+阴极（如层状LiNi1/3Mn1/3Co1/3O2和5 V尖晶石LiMn1.5Ni0.5O4）或层状LiCoO2和橄榄石LiFePO4)相比，正交LiMnO2、层状LiMn0.8Cr0.2O2和含Mn3+尖晶石LiMn2O4的锰溶解总量要高得多，与结构无关。然而，通过适当的阳离子和阴离子（氟）取代，从含Mn3+的尖晶石氧化物中锰的溶解可以显著降低到LiCoO2， LiFePO4和LiMn1.5Ni0.5O4的水平，从而在高温下保持良好的容量。例如，LiMn1.85Li0.075Ni0.075O4和LiMn1.85Li0.075Ni0.075O3.94F0.06的锰溶出率分别为1.5%和1.1%，而LiMn2O4的锰溶出率为3.2%。此外，锰的溶解与充放电过程中形成的两立方相之间的晶格参数差δ a有明显的关系；Mn溶解随δ a的减小而减小。
With an aim to develop a better understanding of the capacity fade mechanisms of manganese spinel oxide cathodes, the amount of metal ion dissolution from various lithium ion battery cathodes (layered, orthorhombic LiMnO2, 4 V spinel, 5 V spinel, and olivine) is compared. Orthorhombic LiMnO2, layered LiMn0.8Cr0.2O2, and spinel LiMn2O4 containing Mn3+ exhibit much higher amounts of manganese dissolution irrespective of the structure compared to the total transition metal ion dissolution found from cathodes containing Mn4+, such as layered LiNi1/3Mn1/3Co1/3O2 and 5 V spinel LiMn1.5Ni0.5O4 or from layered LiCoO2 and olivine LiFePO4. However, the manganese dissolution from the Mn3+-containing spinel oxides could be lowered significantly to the levels found from LiCoO2, LiFePO4, and LiMn1.5Ni0.5O4 by appropriate cationic and anionic (fluorine) substitutions, which leads to excellent capacity retention at elevated temperatures. For example, LiMn1.85Li0.075Ni0.075O4 and LiMn1.85Li0.075Ni0.075O3.94F0.06 exhibit manganese dissolutions of 1.5 and 1.1%, respectively, compared to 3.2% for LiMn2O4. Furthermore, manganese dissolution is found to bear a clear relationship to the lattice parameter difference Delta a between the two cubic phases formed during the charge-discharge process; Mn dissolution decreases with decreasing Delta a.