Electrochemical stability of thin film LiMn2O4 cathode in organic electrolyte solutions with different compositions at 55 °C
Electrochemical stability of thin film LiMn2O4 cathode in organic electrolyte solutions with different compositions at 55 °C
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DOI：
10.1016/s0013-4686(02)00285-2
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发表时间：
2002-08
影响因子：
6.6
通讯作者：
M. Mohamedi;Daisuke Takahashi;T. Itoh;I. Uchida
中科院分区：
文献类型：
--
作者：
M. Mohamedi;Daisuke Takahashi;T. Itoh;I. Uchida
在55°C下，研究了LiMn 2 O 4薄膜在LiClO 4-EC-PC、LiBF 4-EC-PC和LiPF 6-EC-PC溶液中的电化学稳定性。溶液电阻，表面膜电阻，和电荷转移电阻都被发现取决于电解质组合物。在所研究的LiX盐中，在LiBF_4-EC-PC溶液中获得最低的电荷转移电阻和表面层电阻。在55°C下，电解质溶液的组成对LiMn 2 O 4中锂离子的迁移没有明显影响。锂在三种溶液中的固相扩散系数在10 - 10-10 - 8 cm 2 s-1范围内变化。总的来说，在LiBF 4溶液中，表面化学性质在所检查的三种溶液中最稳定，因此LiBF 4溶液中的电极阻抗最低。在LiPF 6溶液中，HF似乎起着重要的作用，因此，由于表面LiF的沉淀，电极阻抗相对较高。
A survey of the electrochemical stability of electrostatic spray deposited thin film of LiMn2O4was performed in LiClO4–EC–PC, LiBF4–EC–PC, and LiPF6–EC–PC solutions at 55°C. The solution resistance, the surface film resistance, and the charge-transfer resistance were all found to depend on the electrolyte composition. Among the LiX-salts studied, the lowest charge transfer-resistance, and surface layer resistance were obtained in LiBF4–EC–PC solution. There is no major influence of the electrolyte solution compositions upon lithium ion transport in the LiMn2O4bulk at 55°C. The diffusion coefficient of lithium in the solid phase varied within 10−10–10−8cm2s−1in the three solutions. In general, it seems that in LiBF4solutions, the surface chemistry is the most stable in the three solutions examined, and hence the electrode impedance in LiBF4solutions was the lowest. In LiPF6solutions, HF seems to play an important role, and thus, the electrode impedance is relatively high due to the precipitation of surface LiF.