Abstract
Redox-active organic electrode materials have emerged as a promising alternative to inorganic counter-parts in view of their low cost and easily tunable chemical/electrical/mechanical properties.However,practical issues of using these materials remain as a consequence of their electrically insulating character,limited specific capacity and cyclability.Porphyrin,a highly conjugated macrocyclic organic compound,is an appealing candidate due to its multi-electron transfer mechanism and its small energy barrier for rapid electron transfer.Here,a new class of copper(Ⅱ)meso-tetra(4-pyridyl)porphyrin(CuTPyP)was ob-tained by introducing copper ions into free-base H2TPyP for regulation of redox activity and prevention of material dissolution,and was further hosted on conducting reduced graphene oxide(rGO)to enhance the redox activity.The resultant CuTPyP/rGO composites hence demonstrated a high reversible discharge capacity of 152 mAh g-1 after 200 cycles,with a capacity retention rate of 84.5％at 0.5 C,vastly superior to the bare CuTPyP(113 mAh g-1)and free-base H2TPyP(62 mAh g-1).A deep insight into the chemical states showed that electron-donating N atoms in the tetrapyridyl subunits behaved as the main charge storage sites during the charge and discharge state along with part contribution from the Cu(Ⅱ)/Cu(Ⅰ)conversion center.The high and stable electrochemical performance makes porphyrins a potential choice for real-use cathodes for long-term organic alkali metal batteries.
基金项目
National Natural Science Foundation of China(52371248)
National Key R&D Program of China(2021YFB3802200)
Guangdong Basic and Applied Basic Research Foundation(2023A1515010905)
Scientific and Technological Innovation Foundation of Shunde Graduate School,USTB(BK22BE012)
NETL
NSTL
万方数据