Targeted Synergy between Adjacent Co Atoms on Graphene Oxide as an Efficient New Electrocatalyst for Li–CO₂ Batteries

Abstract

Li-CO 2 batteries are an attractive technology for converting CO 2 into energy. However, the decomposition of insulating Li 2 CO 3 on the cathode during discharge is a barrier to practical application. Here, it is demonstrated that a high loading of single Co atoms (≈5.3%) anchored on graphene oxide (adjacent Co/GO) acts as an efficient and durable electrocatalyst for Li-CO 2 batteries. This targeted dispersion of atomic Co provides catalytically adjacent active sites to decompose Li 2 CO 3 . The adjacent Co/GO exhibits a highly significant sustained discharge capacity of 17 358 mA h g −1 at 100 mA g −1 for >100 cycles. Density functional theory simulations confirm that the adjacent Co electrocatalyst possesses the best performance toward the decomposition of Li 2 CO 3 and maintains metallic-like nature after the adsorption of Li 2 CO 3 . material, however, offer a renewable new means to capture and convert CO 2 into energy. [4] Typically, in Li-CO 2 batteries the electrochemical reaction is: 3CO 2 + 4Li ↔ Li 2 CO 3 + C. [5] Notably, Li 2 CO 3 is an insoluble, wide bandgap insulator in the aprotic system. A major drawback is that it therefore deposits and accumulates on the cathode during discharge. [6] This results in sluggish kinetics of CO 2 evolution during charging. The result is poor reversibility and low energy efficiency. [7] The rational design therefore of cathode materials to decompose Li 2 CO 3 could boost round-trip efficiency in Li-CO 2 batteries.Recently, research has aimed at electrochemical performance of Li-CO 2 batteries through the design of novel cathode materials, including those that are graphene-based materials, [8] Mo 2 C, [7a] Ru, [9] and Ir nanomaterials. [10] For example, because of its large surface area and excellent electrical conductivity, graphene has been used as a cathode material to provide space to store Li 2 CO 3 , together with active sites for its simultaneous decomposition. [8] Zhou and co-workers demonstrated that Ru nanoparticles on Super P carbon decreases the charge potential and improves cycling performance of Li-CO 2 batteries. [9] Ru nanoparticles provide highly active reaction sites for Li 2 CO 3 decomposition during charging and result in boosted cycling performance. However, the significant cost and scarcity of noble metals (Ru and Ir) limit application to Li-CO 2 battery technology.Single metal atom catalysts have attracted significant attention because of unique electronic structure and a low coordination environment. [11] However, because the loading of single metal atoms is usually kept as low as <2%, [11c] these singleatom active sites are far apart, and any interaction has therefore generally been neglected. However, the interaction between a pair of single active-sites has a significant impact on catalytic performance. [12] It was reckoned therefore that synthesis of single metal atoms with high metal loading could narrow the separation between single active-sites and result in formation of adjacent single atoms with potential synergetic interaction ...

Microenvironment modulation of single-atom catalysts and their roles in electrochemical energy conversion

“…Co-based SACs have also been recognized as promising catalysts for CO 2 RR (4,(157)(158)(159). As shown in Fig.…”

The multiscale enhancement of mechanical properties of 3D MWK composites via poly(oxypropylene) diamines and GO nanoparticles

“…RGO was deposited on a screen-printed gold electrode by electrochemical method with subsequent modification of carbon-gold nanocomposites to prepare gas sensor which possessed good sensitivity and linearity [18]. Single Co atoms (≈ 5.3%) were anchored on graphene oxide to solve the problem of the decomposition of insulating Li 2 CO 3 on the cathode, and it exhibited high sustained discharge capability [19]. GO was also been demonstrated to be effective additives in asphalt as construction and building materials [20].…”

Curtailing the Overpotential of Li–CO2 Batteries with Shape‐Controlled Cu2O as Cathode: Effect of Illuminating the Cathode

“…AD FT study on single Co atoms anchored on graphene oxide (GO) showedt hat the binding ability of the dischargep roducts is highly influencedb yt he adsorption energies. [32] The illumination-driven lowering of charge-overpotential in LABs has attracted growingi nterestb ecause it helps in the photo-assisted decomposition of discharge products. [33] The criteria for the photodecomposition of discharge products by the catalyst depend on the positioning of the electron energy levels.…”