Fast decomposition of Li2CO3/C actuated by single-atom catalysts for Li-CO2 batteries

Abstract

Lithium carbon dioxide (Li-CO 2 ) batteries deliver a theoretical energy density of 1876 W h kg −1 in terms of effective utilization of greenhouse gases. This battery system is considered to be an encouraging electrochemical energy storage device and a promising alternative to Li-ion batteries. However, the main drawback of Li-CO 2 batteries is their accumulative discharge product of Li 2 CO 3 /C, which leads to large overpotential and poor cycling performance. Thus, specific and efficient catalysts must be explored to enhance the decomposition of Li 2 CO 3 /C. Single-atom catalysts (SACs) are regarded as promising heterogeneous catalysts owing to their maximized utilization of metal atoms and strong interfacial electronic interactions. Herein, single-metal atoms of Fe, Co, and Ni uniformly anchored on N-doped reduced graphene oxide (rGO), designated as Fe 1 /N-rGO, Co 1 /N-rGO, and Ni 1 / N-rGO, respectively, are designed and fabricated to investigate their catalytic activity toward the decomposition of Li 2 CO 3 /C. Among them, Fe 1 /N-rGO delivers a high discharge capacity of 16,835 mA h g −1 at 100 mA g −1 and maintains stability for more than 170 cycles with a discharge voltage of 2.30 V at 400 mA g −1 . Therefore, this catalysts are overwhelmingly superior to other types. This work reveals the advances of SACs in Li-CO 2 batteries and offers an effective method for realizing high-performance Li-CO 2 batteries.

Designing Electrophilic and Nucleophilic Dual Centers in the ReS2 Plane toward Efficient Bifunctional Catalysts for Li-CO2 Batteries

“…For the CO 2 ER, the decomposition of Li 2 CO 3 was regarded as the rate-determining step. − During the decomposition process, the rupture of the Li–O bond is critical due to its large binding energy. As shown in Figures S7, all planes adsorb Li 2 CO 3 molecules through Li–S bonds that weaken the strength of the Li–O bond, which is beneficial to the Li 2 CO 3 decomposition.…”

Homogenizing Li2CO3 Nucleation and Growth through High-Density Single-Atomic Ru Loading toward Reversible Li-CO2 Reaction

“…Such a high density of single-atomic metal loading was rarely seen in the literature. 28,32 The spectra of X-ray absorption near edge structure (XANES) in Figure 2c show that both the absorption edges of Ru h -NC@rGO and Ru l -NC@rGO lie between those of Ru foil and RuO 2 , indicative of positively charged Ru oxidation states between 0 and +4 as a result of the local charge polarization in Ru−N coordination. Correspondingly, no Ru−Ru bonding was observed in the Fourier-transformed extended X-ray absorption fine structure (FT-EXAFS) of Ru h -NC@rGO and Ru l -NC@rGO (Figure 2d), confirming their single-atomic Ru states.…”

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

“…, Ru, Ir) have been widely used as highly effective catalysts in lowering charge plateau in Li-CO 2 batteries. ,,, Unfortunately, the high cost and the low natural abundance of noble metals limit their widespread use. Single atom catalysts (SACs), especially nonprecious 3d transition metals stabilized by nitrogen atoms (metal–N x moieties), with tunable electronic structures, high atom utilization, and catalytic activity, have attracted considerable interest. − Although they have shown promising catalytic activity in Li-CO 2 batteries, the lack of reasonable guidance remains a problem for Li-CO 2 batteries. − In this case, developing a universal method to synthesize SACs with high mass loading and catalytic activity for systematic study is urgently needed.…”