Toward an Understanding of the Reversible Li-CO₂ Batteries over Metal–N₄-Functionalized Graphene Electrocatalysts

Abstract

The lack of low-cost catalysts with high activity leads to the unsatisfactory electrochemical performance of Li-CO2 batteries. Single-atom catalysts (SACs) with metal–N x moieties have great potential to improve battery reaction kinetics and cycling ability. However, how to rationally select and develop highly efficient electrocatalysts remains unclear. Herein, we used density functional theory (DFT) calculations to screen SACs on N-doped graphene (SAMe@NG, Me = Cr, Mn, Fe, Co, Ni, Cu) for CO2 reduction and evolution reaction. Among them, SACr@NG shows the promising potential as an effective electrocatalyst for the reversible Li-CO2 batteries. To verify the validity of the DFT calculations, a two-step method has been developed to fabricate SAMe@NG on a porous carbon foam (SAMe@NG/PCF) with similar loading of ∼8 wt %. Consistent with the theoretical calculations, batteries with the SACr@NG/PCF cathodes exhibit a superior rate performance and cycling ability, with a long cycle life and a narrow voltage gap of 1.39 V over 350 cycles at a rate of 100 μA cm–2. This work not only demonstrates a principle for catalysts selection for the reversible Li-CO2 batteries but also a controllable synthesis method for single atom catalysts.

Atomically miniaturized bi-phase IrOx/Ir catalysts loaded on N-doped carbon nanotubes for high-performance Li–CO2 batteries

“…[18][19][20][21][22][23][24][25]37,38 While metallic substances such as Fe, Cr, Mn, Co, Ni, and Cu for SACs have been recently applied to Li-CO 2 battery research and showed improved cell performance, further detailed studies regarding catalyst size effects are needed. 39,40 In this study, we attempted to atomically miniaturize Ir, which is known to be an effective CO 2 evolving catalyst, on highly conductive N-doped carbon nanotubes (NCNTs) to create efficient cathode catalysts for Li-CO 2 cells (Fig. 1).…”

“…18–25,37,38 While metallic substances such as Fe, Cr, Mn, Co, Ni, and Cu for SACs have been recently applied to Li–CO 2 battery research and showed improved cell performance, further detailed studies regarding catalyst size effects are needed. 39,40…”

Carbon Tube-Based Cathode for Li-CO2 Batteries: A Review

“…Transition metals are widely used in various catalytic fields due to their rich con-tent, low cost, and good catalytic activity. Copper was demonstrated effective in the adsorption and activation of CO 2 molecules [52][53][54]. Xu et al prepared copper polyphthalocyaninecarbon nanotubes composites (CuPPc-CNTs) by solvothermal in-situ polymerization method.…”

All-Solid-State Photo-Assisted Li-CO2 Battery Working at an Ultra-Wide Operation Temperature

“…As is well-known, fast kinetics for CO 2 reduction and evolution reactions (CDRR/CDER) at the cathodes is necessary for the Li-CO 2 batteries . Therefore, various efforts have been directed to developing various efficient catalysts ( e.g ., carbon materials, , metal-based materials, , metal/covalent-organic frameworks, , and redox mediators) . However, despite the great progress that has been made in this regard, Li-CO 2 batteries are still facing severe challenges owing to the large polarization caused by the limited effect of the catalysts.…”