Promoting the Electrocatalytic Activity of Ti₃C₂T_x MXene by Modulating CO₂ Adsorption through Oxygen Vacancies for High‐Performance Lithium‐Carbon Dioxide Batteries

Abstract

Lithium‐carbon dioxide (Li‐CO2) batteries are considered as a most auspicious energy storage systems owing to their high capacity and the ability of capturing CO2. However, there are still some critical issues needed to be addressed before their practical application, such as high charge potential and poor cyclability. Herein, oxygen vacancy‐enriched TiO2 nanoparticles grown in situ on Ti3C2Tx MXene (OV‐TiO2/MXene) are synthesized as catalysts for Li‐CO2 batteries by facile one‐step ethanol heat treatment of the MXene nanosheets. The thermodynamically metastable Ti atom on the surface of MXenes serves as nucleating sites, which play a critical role in generating the relatively stable vacancy‐rich TiO2 nanoparticles. The spontaneously generated oxygen vacancies can enhance CO2 adsorption, which is beneficial to CO2 involved electrode reactions. The Li‐CO2 batteries with OV‐TiO2/MXene electrodes deliver noteworthily reduced charge voltage of 3.37 V at 100 mA g−1, and a superb cycling performance of 158 cycles. This work highlights the significant role of oxygen vacancies in activating CO2 in Li‐CO2 batteries, instrumental to the development of high‐performance electrocatalysts for Li‐CO2 batteries and beyond.

A High‐Rate Li–CO2 Battery Enabled by 2D Medium‐Entropy Catalyst

“…Both the gravimetric current density and the capacity were improved significantly with an achieved current density of 5–50 times and a capacity of 5–100 times compared to other works. [ 20,25,27,28,40–62 ] The areal current density and the capacity were also enhanced compared to literature, [ 23,26,63,64 ] as shown in Figure S15 (Supporting Information).…”

Recent progress of transition metal-based catalysts as cathodes in O2/H2O-involved and pure Li–CO2batteries

“…12d). 142 The SEM image (Fig. 12e) revealed that the Ov-TiO 2 nanoparticles were uniformly distributed on the potato chip-like MXene with a large amount of space, which facilitated the sufficient contact among CO 2 , the electrolyte and the material, and thus accelerated the CO 2 RR and CO 2 ER kinetics.…”

Challenges for large scale applications of rechargeable Zn–air batteries

“…134 A lot of research about MXene-based cathodes has been done. [150][151][152] Zhang et al 153 prepared a two-dimensional MXene (Fe/Co-Fig. 11 Schematic diagram of the preparation and structure of "woody carbon nanolayers".…”

“…134 A lot of research about MXene-based cathodes has been done. 150–152 Zhang et al 153 prepared a two-dimensional MXene (Fe/Co-CNT@MXene-T) anchored CoFe nano-alloy modified carbon nanotube (CNT) 3D structure dual-function catalyst. Using the active site of CoFe nanoparticles, the strong sheath and fast charge transfer provided by carbon nanotubes and MXene, the Zn–air battery with this air electrode shows a capacity density of 759 mA h g −1 at 10 mA cm −2 , and a power density of 138 mW cm −2 at 250 mA cm −2 .…”