功能化PVDF粘结剂的制备及在锂电池正极中的应用OA

Lithium N-trifluoromethanesulfonyl p-styrenesulfonimide(LiSTSI)was used as a grafting monomer,and an anionic polymer with good lithium ion conductivity was introduced by UV graft-functionalized modification of poly(vinylidene difluoride-co-hexafluoropropylene)(PVDF)as a polyelectrolyte-type binder STSI,and was applied in a ternary cathode LiNi0.8Co0.1Mn0.1O2(NCM811)system.The structure of the STSI binder was characterized using nuclear magnetic resonance hydrogen spectroscopy(1H-NMR)and fluorine spectroscopy(7F-NMR),the physical properties of the STSI binder were tested using 180° stripping experiment and contact angle experiment,and the electrochemical properties of the SISI binder were evaluated using multiplicity test and long cycle test.The results show that the introduction of this functional anionic branched chain can effectively improve the bond strength of the PVDF binder and form a lithium-ion conduction path in the cathode to improve the cathode electrochemical reaction,and after 100 cycles at a multiplicity of 0.2 C,the battery based on the STSI binder still maintains a specific capacity of 177.2 mAh/g,and maintains an average of 99.1%during the cycling process.