Morphological Structure Characterizations in Lithium-Ion Battery (LIB) Slurry under Shear Rotational Conditions by On-Line Dynamic Electrochemical Impedance Spectroscopy (EIS) Method
Morphological Structure Characterizations in Lithium-Ion Battery (LIB) Slurry under Shear Rotational Conditions by On-Line Dynamic Electrochemical Impedance Spectroscopy (EIS) Method
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DOI：
10.1149/2.0391712jes
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发表时间：
2017
影响因子：
3.9
通讯作者：
Zhilong Wang;Tong Zhao;M. Takei
中科院分区：
文献类型：
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作者：
Zhilong Wang;Tong Zhao;M. Takei
用在线动态阻抗谱(EIS)方法研究了锂离子电池(LiB)浆料在剪切转速n和旋转时间t条件下的形态结构。用10参数电等效电路(10P-EEC)对EIS、Nyquist和Bode曲线进行了拟合，明确了LiB浆料的电阻、电抗和峰值频率等电化学特性。然后，得到了导电路径的在线动态电阻Rp、PVDF-CB双层Cdl和PVDF-NMP溶液Cso的时间平均电容，从而得到了LiB浆料的形态结构表征。在低转速(n=50rpm和n=150rpm)下，LiB浆料的网络结构恶化；在高转速(n=300rpm和n=720rpm)下，LiB浆料网络结构良好。此外，随着n的增加，PVDF-CB形成了良好的双层结构，在低转速(n=50rpm和n=150rpm)下，随着t的增加，包覆有CB的LiCoO2的粒径变化不大，而在高转速(n=300rpm和n=720rpm)下，包覆有CB的LiCoO2的粒径增大。上述形态结构特征与LiB浆料的形态图像相一致。
The morphological structure characterizations of Lithium-ion battery (LIB) slurry have been clarified under shear rotational conditions of rotation speed n and rotation time t by on-line dynamic electrical impedance spectroscopy (EIS) method. The EIS Nyquist and Bode plots are fitted by 10-parameter electrical equivalent circuit (10p-EEC) to clarify electrochemical characteristics which are resistance, reactance and peak frequency of LIB slurry. Then, the on-line dynamic resistance of conductive path R p, the time-averaged capacitances of PVDF-CB double layer C dl and PVDF-NMP solution C SO are obtained, which results in the following morphological structure characterizations of LIB slurry. The network structure of LIB slurry is deteriorated in the low rotation speeds of n= 50 rpm and n= 150 rpm and is well constructed in the high rotation speeds of n= 300 rpm and n= 720 rpm. Moreover, PVDF-CB double layer is well formed with the increase of n. Furthermore, with the increase of t, the particle size of LiCoO 2 coated by CB is slightly changed in the low rotation speeds of n= 50 rpm and of n= 150 rpm; however, the particle size of LiCoO 2 coated by CB is increased in the high rotation speeds of n= 300 rpm and n= 720 rpm. The above-mentioned morphological structure characterizations are in agreement with those observed from morphological images of LIB slurry.