Nature Plant Polyphenol Coating Silicon Sub-microparticle Conjugated with Polyacrylic Acid for Achieving...




Meng Tian, and Peiyi Wu*. Nature Plant Polyphenol Coating Silicon Sub-Microparticle Conjugated with Polyacrylic Acid for Achieving a High-Performance Anode of Lithium-Ion Battery. ACS Appl. Energy Mater. 2019, 2, 5066-5073.




Silicon as an anode material of lithium ion battery has received widespread attention for high capacity and proper lithium intercalation potential. However Si-based anode possesses so poor cycle life that it cannot be commercialized due to the drastic volume change of Si particles during charging-discharging process. Herein, we report a facile and low-cost method to improve cycle performance of Si-based anode by modifying active materials (more inexpensive and fragile Si sub-microparticles (SiSMPs) than silicon nanoparticles) using tannic acid(TA) (a biocompatible nature plant polyphenol) and then interacting it with poly(acrylic acid) (PAA) binder. Tannic acid conformal coating can protect SiSMPs from side reactions with electrolyte and can conjugate with PAA binder and conductive materials, which keeps the electrode structure integrity during cycling. Furthermore, TA coating makes PAA binder form 3D crosslinked network, which can enhance binding strength compared with linear PAA chains, and the wet adhesion of TA inspired mussel can ensure good adhesion between SiSMPs and other components in electrolytes. Therefore, the combination between moderate amounts of TA coating and PAA can improve cycle performance and rate performance of low-cost sub-microsized Si particle-based Li-ion battery anodes.