Toward an Understanding of Bimetallic MXene Solid‐Solution in Binder‐Free Electrocatalyst Cathode for Advanced Li–CO₂ Batteries

Abstract

Li–CO2 batteries have received extensive attention due to their high energy storage capacity and utilization of CO2 resources. Herein, bimetallic MXene solid‐solution TiVC is prepared and combined with highly conductive graphene for the construction of binder‐free electrocatalyst cathodes for Li–CO2 batteries. Considering the electronic structure, the unique synergy effect between Ti and V in TiVC enhances the interfacial chemical bonding ability, facilitates sufficient exposure of active sites and promotes catalytic interfacial structural reformation, thereby promoting the reversible formation and decomposition of the chemically inert discharge product Li2CO3. Meanwhile, the abundant pores and excellent electron transfer ability of graphene aerogel are conducive to the gas diffusion and ion transport, thus reducing the mass and charge transfer resistance. As a result, the assembled Li–CO2 battery presents an excellent discharge capacity of 27 880 mAh g−1 with a stable discharge plateau of 2.77 V and low overpotential of 1.5 V based on the TiVC‐graphene aerogel electrocatalytic cathode. The density functional theory calculations are further performed to deeply reveal the unique electronic structure information between Ti and V in the solid‐solution TiVC. This study provides inspiration for exploring more bimetallic MXene solid solutions and developing advanced cathode catalysts for flexible Li–CO2 batteries.

Confinement of SnCuxO2+x Nanoclusters in Zeolites for High‐Efficient Electrochemical Carbon Dioxide Reduction

“…The relatively high nucleation overpotential are mainly correlated with the low loading of SnCu 1.5 O 3.5 clusters and inferior conductivity of the MFI zeolites support. [ 45–48 ] In this study, the actual contents of Sn and Cu in the SnCu 1.5 O 3.5 @MFI composites were estimated to be 0.225 and 0.198 wt% with ICP‐MS method, respectively (Table S1, Supporting Information). Nevertheless, the SnCu 1.5 O 3.5 @MFI catalyst presents an impressive bifunctional catalytic activity for the formation and decomposition of Li 2 CO 3 /C for Li‐CO 2 batteries in a wide current density range.…”

Minireview on Achieving Low Charge Overpotential in Li–CO2 Batteries with Advancing Cathode Materials and Electrolytes

“…Liu and co-workers have anchored ultrafine Ru/RuO 2 nanoparticles onto a hierarchial porous carbon shell (Ru/RuO 2 –HPC) as an efficient cathode catalyst for Li–CO 2 batteries. The anchored Ru/RuO 2 nanoparticles act as a catalytic site that not only accelerates carbon dioxide reduction reaction (CDRR) and carbon dioxide evolution reaction (CDER) kinetics but also tailors the reaction process of Li–CO 2 batteries, making discharge products more susceptible to become sheet-like by a surface adsorption pathway, which is easier to decompose in the charge process . It comes into a consensus that the smaller catalyst perticle size will make higher active and more electron transfer sites for the cathode.…”

“…In conventional Li–CO 2 batteries, electrocatalysts in the cathode decrease energy barriers and mediate electrochemical reaction pathways. , In light-assisted Li–CO 2 batteries, most reactions start with the generation of photoelectrons and holes. Then, participation of photoelectrons/holes in the CO 2 RR and CO 2 ER can achieve a high round-trip efficiency, as presented in Figure .…”

Recent Progress in Hot Spot Regulated Strategies for Catalysts Applied in Li–CO2 Batteries

“…Moreover, the interaction between metals changes the internal electronic structure, improves the conductivity, and enhances the catalytic activity. In view of these properties, Zhao and coworkers [ 88 ] construct an ultralight porous TiVC/graphene aerogel by mixing TiVC nanosheets obtained by one‐step chemical etching with GO through a facile hydrothermal reaction. The unique synergy effect between Ti and V enhances the interfacial chemical bonding ability, facilitates sufficient exposure of active sites, and promotes the reformation of the catalytic interface structure; thus promoting the reversible formation and decomposition of the chemically inert discharge product Li 2 CO 3 .…”