Enhanced Nucleation of LiCl during Lithium Battery Discharging with Carbon Nanotubes Supported Nitrogen-Rich Manganese Phthalocyanine Catalysts

Large-size LiCl particles deposited on the carbon cathode of lithium thionyl chloride battery during discharge are mainly limited by the sluggish kinetics, decreasing the voltage platform and service life. In this work, the carbon nanotubes supported nano-sized nitrogen-rich manganese phthalocyanine composites (MnTAP/CNTs) were prepared by in situ solid phase synthesis as catalysts. The effect of reaction kinetics of the battery with/without catalysts on nucleation process of LiCl particles is investigated. After discharge, the surface of the carbon cathode with MnTAP/CNTs displays LiCl particles approximately 200 nm, which is only a fifth of the size without catalysts. Moreover, a large number of nano LiCl particles appear inside compared to the catalyst free. The fast reaction kinetics of SOCl2 with MnTAP/CNTs is favorable for the nucleation of LiCl particles. Meanwhile, the electrolyte resistance, the surface film resistance and the charge transfer resistance of the battery are reduced to approximately 57%, and the discharge time and voltage platform are 15.6 min and 0.2 V higher than that without catalysts. (C) 2020 The Electrochemical Society (ECS). Published on behalf of ECS by IOP Publishing Limited.