Dispersed Nickel Phthalocyanine Molecules on Carbon Nanotubes as Cathode Catalysts for Li‐CO₂ Batteries

Abstract

The Li‐CO2 battery has great potential for both CO2 utilization and energy storage, but its practical application is limited by low energy efficiency and short cycle life. Efficient cathode catalysts are needed to address this issue. Herein, this work reports on molecularly dispersed electrocatalysts (MDEs) of nickel phthalocyanine (NiPc) anchored on carbon nanotubes (CNTs) as the cathode catalyst for Li‐CO2 batteries. The dispersed NiPc molecules efficiently catalyze CO2 reduction, while the conductive and porous CNTs networks facilitate CO2 evolution reaction, leading to enhanced discharging and charging performance compared to the NiPc and CNTs mixture. Octa‐cyano substitution on NiPc (NiPc‐CN) further enhances the interaction between the molecule and CNTs, resulting in better cycling stability. The Li‐CO2 battery with the NiPc‐CN MDE cathode shows a high discharge voltage of 2.72 V and a small discharging–charging potential gap of 1.4 V, and can work stably for over 120 cycles. The reversibility of the cathode is confirmed by experimental characterizations. This work lays a foundation for the development of molecular catalysts for Li‐CO2 battery cathodes.

A Li–O2/CO2 battery based on bio-inspired engineering of the Bi2S3/PVP cathode

“…The development of low-cost, high-energy, long-lived energy storage systems holds promise for the widespread use of renewable energy in power grids and cheap electric vehicles. 11–15 As the next generation of high specific energy electrochemical energy storage systems, lithium–air batteries have been widely studied in recent decades.…”

Molecular Catalysis Enables Fast Polyiodide Conversion for Exceptionally Long-Life Zinc–Iodine Batteries

“…14 However, these catalysts still face issues such as insufficient catalytic activity, instability, and complex and costly preparation processes, hindering their application in long-life Zn−I 2 batteries. Recently, molecular catalysts have become popular for electrochemical catalysis such as electrochemical carbon dioxide (CO 2 ) reduction and oxygen redox reactions, exhibiting high activity, adjustability, and specificity, 15−18 batteries and other conversion-type batteries, such as lithium− sulfur batteries, 19−21 seawater batteries, 22 Li−CO 2 batteries, 23 and Zn−air batteries. 24 Here, we for the first time employ a molecular catalyst, chloro(protoporphyrinato)iron(III) (namely, Hemin), to catalyze the iodine redox reaction and suppress polyiodide shuttling for the iodine cathode.…”

“…However, these catalysts still face issues such as insufficient catalytic activity, instability, and complex and costly preparation processes, hindering their application in long-life Zn–I 2 batteries. Recently, molecular catalysts have become popular for electrochemical catalysis such as electrochemical carbon dioxide (CO 2 ) reduction and oxygen redox reactions, exhibiting high activity, adjustability, and specificity, − implying a great catalytic potential for iodine/polyiodide conversion in Zn–I 2 batteries and other conversion-type batteries, such as lithium–sulfur batteries, − seawater batteries, Li–CO 2 batteries, and Zn–air batteries …”