Department of Chemical and Biological Engineering, Hanbat National University , 125 Dongseo-daero, Yuseong-gu, Daejeon 34158, Republic of Korea.
Department of Energy Systems Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST) , Daegu 42988, Republic of Korea.
ACS Appl Mater Interfaces. 2017 May 31;9(21):17814-17821. doi: 10.1021/acsami.7b00044. Epub 2017 May 19.
To improve the rate capability and safety of lithium-ion batteries (LIBs), we developed an integrated separator/electrode by gluing polyethylene (PE) separators and electrodes using a polymeric adhesive (poly(vinylidene fluoride), PVdF). To fabricate thin and uniform polymer coating layers on the substrate, we applied the polymer solution using a spray-coating technique. PVdF was chosen because of its superior mechanical properties and stable electrochemical properties within the voltage range of commercial LIBs. The integrated separator/electrode showed superior thermal stability compared to that of the control PE separators. Although PVdF coating layers partially blocked the porous structures of the PE separators, resulting in reduced ionic conductivity (control PE = 0.666 mS cm, PVdF-coated PE = 0.617 mS cm), improved interfacial properties between the separators and the electrodes were obtained due to the intimate contact, and the rate capabilities of the LIBs based on integrated separators/electrodes showed 176.6% improvement at the 7 C rate (LIBs based on PVdF-coated and control PE maintained 48.4 and 27.4% of the initial discharge capacity, respectively).
为提高锂离子电池 (LIBs) 的倍率性能和安全性，我们使用聚合物胶（聚偏氟乙烯，PVdF）将聚乙烯 (PE) 隔离膜和电极粘合成一个集成的隔离膜/电极。为了在基底上涂覆薄且均匀的聚合物涂层，我们使用喷涂技术涂覆聚合物溶液。选择 PVdF 是因为它具有优异的机械性能和在商业 LIBs 电压范围内稳定的电化学性能。与对照的 PE 隔离膜相比，集成的隔离膜/电极显示出更好的热稳定性。尽管 PVdF 涂层部分阻塞了 PE 隔离膜的多孔结构，导致离子电导率降低（对照 PE = 0.666 mS cm，PVdF 涂层 PE = 0.617 mS cm），但由于紧密接触，隔离膜和电极之间的界面性能得到了改善，基于集成隔离膜/电极的 LIBs 在 7 C 倍率下的倍率性能提高了 176.6%（基于 PVdF 涂层和对照 PE 的 LIBs 分别保持了初始放电容量的 48.4%和 27.4%）。
