锂浆液电池正极集流体表面改性研究（英文）

来源：电工电能新技术杂志2019年第9期北京时间：

作者：TIAN Xueqin, FENG Caimei, JIANG Han, MA Shiyi, CHEN Yongchong, LIU Dandan, ZHAO Teng

单位：1. State Grid Economic and Technological Research Institute Co., Ltd., Beijing 102209, China；
\r\n2. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China；
\r\n3. Global Energy Interconnection Group Co., Ltd., Beijing 100031, China

摘要：Lithium slurry battery (LSB) is a new energy storage technology suitable for the application in lowspeed electric vehicles, base stations, household cases and power grid. Contact resistance between the current collector and the electrode slurry is critical for the electrochemical performance of this technique. In the present work, Al matrixes were decorated with different ratios of carbon black (CB) and polyvinylidene fluoride (PVDF) to investigate the influence of current collector surface treatment on LiFePO4 half slurry cells. Results showed that the ratio of CB and PVDF affected the homogeneity, the microcrack formation, the surface area, the porosity and the adhesion of the coating layer, leading to different electronic and ionic resistances. When the content of CB is too high, the insufficient adhesion agent was not able to accommodate the high surface tension of the CB nanoparticles during drying process, forming cracks and increasing contact resistance. The specific surface area and pore volume of the coating layer was found to first increase and then decrease as the ratio of CB∶PVDF increased from 1∶1 to 5∶1, with a maximum around 3∶1. This phenomenon was consistent with the measured ohmic resistance and charge/discharge profiles. Larger porosity and surface area of the coating layer were beneficial for the transfer of lithium ions in the electrolyte and the electrochemical reactions. Finally, a specific capacity of 1492(mA·h)/g at 02mA/cm2 was obtained for LiFePO4 half slurry cell using the optimized Al mesh current collector with a coating ratio of 3∶1 (CB∶PVDF).

关键词：lithium slurry battery, current collector, surface modification, interface, electrochemical performance